The Dragon's Tales

What Happened Prior to the Carbon Prior to the Marinoan Glaciations (Snowball Earth)

2012-01-27T07:15:00.000-08:00

In a study published in the journal Geology, scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science suggest that the large changes in the carbon isotopic composition of carbonates which occurred prior to the major climatic event more than 500 million years ago, known as 'Snowball Earth,' are unrelated to worldwide glacial events.

"Our study suggests that the geochemical record documented in rocks prior to the Marinoan glaciation or 'Snowball Earth' are unrelated to the glaciation itself," said UM Rosenstiel professor Peter Swart, a co-author of the study. "Instead the changes in the carbon isotopic ratio are related to alteration by freshwater as sea level fell."

In order to better understand the environmental conditions prior to 'Snowball Earth', the research team analyzed geochemical signatures preserved in carbonate rock cores from similar climactic events that happened more recently — two million years ago — during the Pliocene-Pleistocene period.

The team analyzed the ratio of the rare isotope of carbon (13C) to the more abundant carbon isotope (12C) from cores drilled in the Bahamas and the Enewetak Atoll in the Pacific Ocean. The geochemical patterns that were observed in these cores were nearly identical to the pattern seen prior to the Marinoan glaciation, which suggests that the alteration of rocks by water, a process known as diagenesis, is the source of the changes seen during that time period.

Prior to this study, scientists theorized that large changes in the cycling of carbon between the organic and inorganic reservoirs occurred in the atmosphere and oceans, setting the stage for the global glacial event known as 'Snowball Earth'.

"It is widely accepted that changes in the carbon isotopic ratio during the Pliocene-Pleistocene time are the result of alteration of rocks by freshwater," said Swart. "We believe this is also what occurred during the Neoproterozoic. Instead of being related to massive and complicated changes in the carbon cycle, the variations seen in the Neoproterozoic can be explained by simple process which we understand very well."

Scientists acknowledge that multiple sea level fluctuations occurred during the Pliocene-Pleistocene glaciations resulting from water being locked up in glaciers. Similar sea-level changes during the Neoproterozoic caused the variations in the global carbon isotopic signal preserved in the older rocks, not a change in the distribution of carbon as had been widely postulated.

I don't see the paper online as yet...

All These Worlds...

2012-01-27T04:42:00.000-08:00

Purty Bird: X-47 From Above

2012-01-25T12:40:00.000-08:00

Archetype: Robocop Nouveau

2012-01-24T00:57:00.000-08:00

Greenhouse Gases Postpone (Cancel?) Next Glacial Cycle

2012-01-18T07:28:00.000-08:00

Unprecedented levels of greenhouse gases in the Earth's atmosphere are disrupting normal patterns of glaciation, according to a study co-authored by a University of Florida researcher and published online Jan. 8 in Nature Geoscience.

The Earth's current warm period that began about 11,000 years ago should give way to another ice age within about 1,500 years, according to accepted astronomical models. However, current levels of carbon dioxide are trapping too much heat in the atmosphere to allow the Earth to cool as it has in its prehistoric past in response to changes in Earth's orbital pattern. The research team, a collaboration among University College London, University of Cambridge and UF, said their data indicate that the next ice age will likely be delayed by tens of thousands of years.

That may sound like good news, but it probably isn't, said Jim Channell, distinguished professor of geology at UF and co-author.

"Ice sheets like those in western Antarctica are already destabilized by global warming," said Channell. "When they eventually slough off and become a part of the ocean's volume, it will have a dramatic effect on sea level." Ice sheets will continue to melt until the next phase of cooling begins in earnest.

The study looks at the prehistoric climate-change drivers of the past to project the onset of the next ice age. Using astronomical models that show Earth's orbital pattern with all of its fluctuations and wobbles over the last several million years, astronomers can calculate the amount of solar heat that has reached the Earth's atmosphere during past glacial and interglacial periods.

"We know from past records that Earth's orbital characteristics during our present interglacial period are a dead ringer for orbital characteristics in an interglacial period 780,000 years ago," said Channell. The pattern suggests that our current period of warmth should be ending within about 1,500 years.

However, there is a much higher concentration of greenhouse gases trapping the sun's heat in the Earth's atmosphere now than there was in at least the last several million years, he said. So the cooling that would naturally occur due to changes in the Earth's orbital characteristics are unable to turn the temperature tide.

Over the past million years, the Earth's carbon dioxide levels, as recorded in ice core samples, have never reached more than 280 parts per million in the atmosphere. "We are now at 390 parts per million," Channell said. The sudden spike has occurred in the last 150 years.

For millions of years, carbon dioxide levels have ebbed and flowed between ice ages. Orbital patterns initiate periods of warming that cause ocean circulation to change. The changes cause carbon dioxide-rich water in the deep ocean to well up toward the surface where the carbon dioxide is released as a gas back into the atmosphere. The increase in atmospheric carbon dioxide then drives further warming and eventually the orbital pattern shifts again and decreases the amount of solar heat that reaches the Earth.

"The problem is that now we have added to the total amount of CO2 cycling through the system by burning fossil fuels," said Channell. "The cooling forces can't keep up."

1. Duh.

2. This may well be a permanent off ramp for Ice Age we have been in.

3. There might have been interglacial ending on-ramps we missed before and are missing right now.

4. Keep in mind it took over 50k years for the last time there was a huge build up in CO2 like the modern one took over 50k years for the environment to recover...and it didn't go back to what it was before.

5. The main question is whether or not we are going to have a Neo-Eocene (hot, wet) or Neo-Oligocene (hot dry).

NorAm Mammalian Fauna Diversity Shifts with Climate

2012-01-18T01:13:00.000-08:00

(original artist here)

History often seems to happen in waves – fashion and musical tastes turn over every decade and empires give way to new ones over centuries. A similar pattern characterizes the last 65 million years of natural history in North America, where a novel quantitative analysis has identified six distinct, consecutive waves of mammal species diversity, or "evolutionary faunas." What force of history determined the destiny of these groupings? The numbers say it was typically climate change.

"Although we've always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion," said Brown University evolutionary biology Professor Christine Janis. "We show that the rise and fall of these faunas is indeed correlated with climatic change – the rise or fall of global paleotemperatures – and also influenced by other more local perturbations such as immigration events."

Specifically, of the six waves of species diversity that Janis and her Spanish collaborators describe online this week in the Proceedings of the National Academy of Sciences, four show statistically significant correlations with major changes in temperature. The two transitions that show a weaker but still apparent correlation with the pattern correspond to periods when mammals from other continents happened to invade in large numbers, said Janis, who is the paper's senior and second author.

Previous studies of the potential connection between climate change and mammal species evolution have counted total species diversity in the fossil record over similar time periods. But in this analysis, led by postdoctoral scholar Borja Figueirido, the scientists asked whether there were any patterns within the species diversity that might be significant. They were guided by a similar methodology pioneered in a study of "evolutionary faunas" in marine invertebrates by Janis' late husband Jack Sepkoski, who was a paleontologist at the University of Chicago.

What the authors found is six distinct and consecutive groupings of mammal species that shared a common rise, peak and decline in their numbers. For example, the "Paleocene fauna" had largely given way to the "early-middle Eocene fauna" by about 50 million years ago. Moreover, the authors found that these transfers of dominance correlated with temperature shifts, as reflected in data on past levels of atmospheric oxygen (determined from the isotopes in the fossilized remains of deep sea microorganisms).

By the numbers, the research showed correlations between species diversity and temperature change, but qualitatively, it also provided a narrative of how the traits of typical species within each wave made sense given the changes in vegetation that followed changes in climate. For example, after a warming episode about 20 million years in the early Miocene epoch, the dominant vegetation transitioned from woodland to a savannah-like grassland. It is no surprise, therefore, that many of the herbivores that comprised the accompanying "Miocene fauna" had high-crowned teeth that allowed them to eat the foods from those savannah sources.

Original paper here.

Tasmanian Triassic Dicynodont Found

2012-01-11T01:00:00.000-08:00

A Tasmanian couple on a quiet walk down to the beach a few years ago discovered a fossil that scientists say is 250 million years old.

Bob and Penny Tyson found the fossilised remains of a dicynodont, a tusked plant-eating animal that's believed to be a distant ancestor of modern mammals.

Roughly the size of a cow, it had two tusks and a horny beak.

Queensland Museum palaeontologist Andrew Rozefelds says the dicynodont lived on every continent, including Antarctica.

The ABC reports that until now, the only specimen previously found in Australia was in Queensland almost 30 years ago.

He describes the dicynodont as a ''strange-looking beast''.

''They had tusks at the front of their skull, which makes you think maybe they were a carnivore, but in fact they were a plant eater.

''They had slightly splayed legs, so their posture was quite different to say some of the modern mammals you see and they're very, very distantly related to modern mammals.''

I don't see a paper at the JVP. However, considering the journal is a little outdated from the last time they updated what's online, I'm not surprised. Previously, in Tasmania the predominant fossils were temnospondyls. And not much else.

Even Nastier Siberian Traps

2012-01-10T00:02:00.000-08:00

Around 250 million years ago, at the end of the Permian geologic period, there was a mass extinction so severe that it remains the most traumatic known species die-off in Earth's history. Although the cause of this event is a mystery, it has been speculated that the eruption of a large swath of volcanic rock in Russia called the Siberian Traps was a trigger for the extinction. New research from Carnegie's Linda Elkins-Tanton and her co-authors offers insight into how this volcanism could have contributed to drastic deterioration in the global environment of the period. Their work is published January 9 in Earth and Planetary Science Letters.

The end-Permian mass extinction saw the sudden loss of more than 90 percent of marine species and more than 70 percent of terrestrial species. The fossil record suggests that ecological diversity did not fully recover until several million years after the main pulse of the extinction. This suggests that environmental conditions remained inhospitable for an extended period of time.

Volcanic activity in the Siberian Traps has been proposed as one of the mechanisms that may have triggered the mass extinction. Gases released as a result of Siberian magmatism could have caused environmental damage. For example, perhaps sulfur particles in the atmosphere reflected the sun's heat back into space, cooling the planet; or maybe chlorine and other chemically similar nonmetal elements called halogens significantly damaged the ozone layer in the stratosphere.

The team designed experiments to examine these possibilities.

Led by Benjamin Black of the Massachusetts Institute of Technology, the group included Elkins-Tanton, formerly of MIT and now director of Carnegie's Department of Terrestrial Magnetism, Michael C. Rowe of Washington State University, and Ingrid Ukstins Peate of the University of Iowa.

The geology of the Siberian Traps is comprised of flood basalts, which form when giant lava eruptions coat large swaths of land or ocean floor with basaltic lava. This lava hardens into rock formations. The team investigated concentrations of sulfur, chlorine and fluorine (another halogen) that were dissolved in tiny samples of ancient magma found within basalt samples from the Siberian Traps. These small frozen droplets, which preserve a record of volcanic gases from the time of the eruption 250 million years ago, are called melt inclusions.

Sulfur, chlorine, and fluorine gasses could have been released into the atmosphere from eruptions spewing out of large fissures, which is common in basalt flood formation. Plumes escaping from these cracks could have reached the stratosphere. If sulfur, chlorine, and fluorine made it to the upper atmosphere, these gasses could have cause a wide array of adverse climate events, including temperature change and acid rain.

Based on their findings, the team estimated that between 6,300 and 7,800 gigatonnes of sulfur, between 3,400 and 8,700 gigatonnes of chlorine, and between 7,100 and 13,700 gigatonnes of fluorine were released from magma in the Siberian Traps during the end of the Permian period.

Anyone have the paper itself? I've not been able to find it on the server.

Siberian Traps Were Meaner Than We Knew

2012-01-06T22:08:00.000-08:00

Explosive eruption of coal and basalt and the end-Permian mass extinction

1. Darcy E. Ogden (a)
2. Norman H. Sleep (b,*)

a. Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, 1156 Gilman Drive, La Jolla, CA 92093-0225; and

b. Department of Geophysics, Mitchell Building, 397 Panama Mall, Stanford University, Stanford CA 94305

* To whom correspondence should be addressed. E-mail: norm@stanford.edu.

Abstract:

The end-Permian extinction decimated up to 95% of carbonate shell-bearing marine species and 80% of land animals. Isotopic excursions, dissolution of shallow marine carbonates, and the demise of carbonate shell-bearing organisms suggest global warming and ocean acidification. The temporal association of the extinction with the Siberia flood basalts at approximately 250 Ma is well known, and recent evidence suggests these flood basalts may have mobilized carbon in thick deposits of organic-rich sediments. Large isotopic excursions recorded in this period are potentially explained by rapid venting of coal-derived methane, which has primarily been attributed to metamorphism of coal by basaltic intrusion. However, recently discovered contemporaneous deposits of fly ash in northern Canada suggest large-scale combustion of coal as an additional mechanism for rapid release of carbon. This massive coal combustion may have resulted from explosive interaction with basalt sills of the Siberian Traps. Here we present physical analysis of explosive eruption of coal and basalt, demonstrating that it is a viable mechanism for global extinction. We describe and constrain the physics of this process including necessary magnitudes of basaltic intrusion, mixing and mobilization of coal and basalt, ascent to the surface, explosive combustion, and the atmospheric rise necessary for global distribution.

Explosive coal eruptions and mass mercury poisoning. Halogen emitting lakes and ozone layer depletion. Its definitely time for a rewrite of my PT Extinction post.

...in my copious amounts of spare time.

On Titan the Rain Mainly Falls on the Plains in Spring and Fall

2012-01-06T21:50:00.000-08:00

Saturn's largest moon, Titan, is an intriguing, alien world that's covered in a thick atmosphere with abundant methane. With an average surface temperature of a brisk -297 degrees Fahrenheit (about 90 kelvins) and a diameter just less than half of Earth's, Titan boasts methane clouds and fog, as well as rainstorms and plentiful lakes of liquid methane. It's the only place in the solar system, other than Earth, that has large bodies of liquid on its surface.

The origins of many of these features, however, remain puzzling to scientists. Now, researchers at the California Institute of Technology (Caltech) have developed a computer model of Titan's atmosphere and methane cycle that, for the first time, explains many of these phenomena in a relatively simple and coherent way.

In particular, the new model explains three baffling observations of Titan. One oddity was discovered in 2009, when researchers led by Caltech professor of planetary science Oded Aharonson found that Titan's methane lakes tend to cluster around its poles—and noted that there are more lakes in the northern hemisphere than in the south.

Secondly, the areas at low latitudes, near Titan's equator, are known to be dry, lacking lakes and regular precipitation. But when the Huygens probe landed on Titan in 2005, it saw channels carved out by flowing liquid—possibly runoff from rain. And in 2009, Caltech researchers discovered raging storms that may have brought rain to this supposedly dry region.

Finally, scientists uncovered a third mystery when they noticed that clouds observed over the past decade—during summer in Titan's southern hemisphere—cluster around southern middle and high latitudes.

Scientists have proposed various ideas to explain these features, but their models either can't account for all of the observations, or do so by requiring exotic processes, such as cryogenic volcanoes that spew methane vapor to form clouds. The Caltech researchers say their new computer model, on the other hand, can explain all these observations—and does so using relatively straightforward and fundamental principles of atmospheric circulation.

"We have a unified explanation for many of the observed features," says Tapio Schneider, the Frank J. Gilloon Professor of Environmental Science and Engineering. "It doesn't require cryovolcanoes or anything esoteric." Schneider, along with Caltech graduate student Sonja Graves, former Caltech graduate student Emily Schaller (PhD '08), and Mike Brown, the Richard and Barbara Rosenberg Professor and professor of planetary astronomy, have published their findings in the January 5 issue of the journal Nature.

Schneider says the team's simulations were able to reproduce the distribution of clouds that's been observed—which was not the case with previous models. The new model also produces the right distribution of lakes. Methane tends to collect in lakes around the poles because the sunlight there is weaker on average, he explains. Energy from the sun normally evaporates liquid methane on the surface, but since there's generally less sunlight at the poles, it's easier for liquid methane there to accumulate into lakes.

But then why are there more lakes in the northern hemisphere? Schneider points out that Saturn's slightly elongated orbit means that Titan is farther from the sun when it's summer in the northern hemisphere. Kepler's second law says that a planet orbits more slowly the farther it is from the sun, which means that Titan spends more time at the far end of its elliptical orbit, when it's summer in the north. As a result, the northern summer is longer than the southern summer. And since summer is the rainy season in Titan's polar regions, the rainy season is longer in the north. Even though the summer rains in the southern hemisphere are more intense—triggered by stronger sunlight, since Titan is closer to the sun during southern summer—there's more rain over the course of a year in the north, filling more lakes.

In general, however, Titan's weather is bland, and the regions near the equator are particularly dull, the researchers say. Years can go by without a drop of rain, leaving the lower latitudes of Titan parched. It was a surprise, then, when the Huygens probe saw evidence of rain runoff in the terrain. That surprise only increased in 2009 when Schaller, Brown, Schneider, and then–postdoctoral scholar Henry Roe discovered storms in this same, supposedly rainless, area.

No one really understood how those storms arose, and previous models failed to generate anything more than a drizzle. But the new model was able to produce intense downpours during Titan's vernal and autumnal equinoxes—enough liquid to carve out the type of channels that Huygens found. With the model, the researchers can now explain the storms. "It rains very rarely at low latitudes," Schneider says. "But when it rains, it pours."

The new model differs from previous ones in that it's three-dimensional and simulates Titan's atmosphere for 135 Titan years—equivalent to 3,000 years on Earth—so that it reaches a steady state. The model also couples the atmosphere to a methane reservoir on the surface, simulating how methane is transported throughout the moon.

The model successfully reproduces what scientists have already seen on Titan, but perhaps what's most exciting, Schneider says, is that it also can predict what scientists will see in the next few years. For instance, based on the simulations, the researchers predict that the changing seasons will cause the lake levels in the north to rise over the next 15 years. They also predict that clouds will form around the north pole in the next two years. Making testable predictions is "a rare and beautiful opportunity in the planetary sciences," Schneider says. "In a few years, we'll know how right or wrong they are.

Its a frozen Tanith!

A Few Xmas Pix

2012-01-06T12:01:00.000-08:00

Its been a while since I put up some family pix. Here's my daughter, Avrora, now age 6, and my son, Orest, now 2.

Another PT Extinction Factor: Mercury Poisoning

2012-01-06T01:31:00.000-08:00

Scientists have uncovered a lot about the Earth's greatest extinction event that took place 250 million years ago when rapid climate change wiped out nearly all marine species and a majority of those on land. Now, they have discovered a new culprit likely involved in the annihilation: an influx of mercury into the eco-system.

"No one had ever looked to see if mercury was a potential culprit. This was a time of the greatest volcanic activity in Earth's history and we know today that the largest source of mercury comes from volcanic eruptions," says Dr. Steve Grasby, co-author of a paper published this month in the journal Geology. "We estimate that the mercury released then could have been up to 30 times greater than today's volcanic activity, making the event truly catastrophic." Grasby is a research scientist at Natural Resources Canada and an adjunct professor at the University of Calgary.

[...]

During the late Permian, the natural buffering system in the ocean became overloaded with mercury contributing to the loss of 95 per cent of life in the sea.

"Typically, algae acts like a scavenger and buries the mercury in the sediment, mitigating the effect in the oceans," says lead-author Dr. Hamed Sanei, research scientist at Natural Resources Canada and adjunct professor at the University of Calgary. "But in this case, the load was just so huge that it could not stop the damage."

[...]

The mercury deposition rates could have been significantly higher in the late Permian when compared with today's human-caused emissions. In some cases, levels of mercury in the late Permian ocean was similar to what is found near highly contaminated ponds near smelters, where the aquatic system is severely damaged, say researchers

Looking more and more like my PT Extinction post needs an update. It has been almost 6 years. (wow) And I have STILL not finished my other paleo posts. :(

6th Generation US Fighter Concepts

2012-01-05T01:45:00.000-08:00

Lockheed Martin(snark: Hey! look! Its am YF-23!)

Northrop Grumman

Boeing

Varanopids Coexisted with More Advanced Synapsids

2011-12-06T12:58:00.000-08:00

(Heleosaurus, a varanopid)

A species of ancient predator with saw-like teeth, sleek bodies and a voracious appetite for meat survived a major extinction at a time when the distant relatives of mammals ruled the earth.

A detailed description of a fossil that scientists identify as a varanopid "pelycosaur" is published in the December issue of Naturwissenschaften – The Science of Nature. Professors Sean Modesto from Cape Breton University, and Robert Reisz from University of Toronto Mississauga provide evidence that a group of ancient, agile predators called varanopids survived for more than 35 million years, and co-existed with more advanced animals.

Modesto and the team performed a detailed examination of the partial skull and jaw of the youngest known primitive mammal-like animal, which they believe lived over 260 million years ago in the Permian Period. The fossils are from rocks forming the Pristerognathus Assemblage Zone of the Beaufort Group in South Africa.

"These animals were the most agile predators of their time, sleek-looking when compared to their contemporaries," says Reisz. "They seem to have survived a major change in the terrestrial fauna that occurred during the Middle Permian, a poorly understood extinction event in the history of life on land."

According to Modesto, who was once a student at U of T Mississauga, "these ancient animals really looked like modern goannas or monitor lizards, but are actually more closely related to mammals."

The fossil revealed teeth that are strongly flattened, curved towards the throat and with finely serrated cutting edges typical of hypercarnivores--animals with a diet that consists of more than 70 per cent meat.

Modesto and his colleagues concluded that these varanopids had a longer co-existence with animals that eventually evolved into mammals than previously believed. They suggest that the dental and skeletal design of varanopids, reminiscent of the Komodo dragon of today, may have contributed to their long survival and their success.

no time. But VERY interesting.

Spinops sternbergorum: ANOTHER New Ceratopsian

2011-12-06T12:36:00.000-08:00

Sheesh. Ceratopsians were the freakin NorAm bunnies of the Late Cretaceous.

(very nice Andy)

PrePhanerozoic Prone to Snowball Events?

2011-12-06T12:08:00.000-08:00

Two University of Colorado Boulder researchers who have adapted a three-dimensional, general circulation model of Earth's climate to a time some 2.8 billion years ago when the sun was significantly fainter than present think the planet may have been more prone to catastrophic glaciation than previously believed.

The new 3-D model of the Archean Eon on Earth that lasted from about 3.8 billion years to 2.5 billion years ago, incorporates interactions between the atmosphere, ocean, land, ice and hydrological cycles, said CU-Boulder doctoral student Eric Wolf of the atmospheric and oceanic sciences department. Wolf has been using the new climate model -- which is based on the Community Earth System Model maintained by the National Center for Atmospheric Research in Boulder -- in part to solve the "faint young sun paradox" that occurred several billion years ago when the sun's output was only 70 to 80 percent of that today but when geologic evidence shows the climate was as warm or warmer than now.

In the past, scientists have used several types of one-dimensional climate models -- none of which included clouds or dynamic sea ice -- in an attempt to understand the conditions on early Earth that kept it warm and hospitable for primitive life forms. But the 1-D model most commonly used by scientists fixes Earth's sea ice extent at one specific level through time despite periodic temperature fluctuations on the planet, said Wolf.

"The inclusion of dynamic sea ice makes it harder to keep the early Earth warm in our 3-D model," Wolf said. "Stable, global mean temperatures below 55 degrees Fahrenheit are not possible, as the system will slowly succumb to expanding sea ice and cooling temperatures. As sea ice expands, the planet surface becomes highly reflective and less solar energy is absorbed, temperatures cool, and sea ice continues to expand."

This is interesting since it seems to be rather contrary to the general consensus that the earth was actually a lot warmer based on isotopic geological data.

Came in Email: Tenure Track Professorship at UIUC

2011-12-06T10:26:00.000-08:00

UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN
Department of Atmospheric Sciences
School of Earth, Society, and Environment

—Tenure Track Assistant or Tenure Track/Tenured Associate Professor Search—

The Department of Atmospheric Sciences within the School of Earth, Society, and Environment at the University of Illinois at Urbana-Champaign invites applications for a full-time, tenure-track/tenured faculty position at the rank of Assistant or Associate Professor in climate science. The position is a nine-month academic appointment with a target start date of August 16, 2012.

The area of research, within the context of climate science, is open. Possible areas of emphasis include, but are not limited to, causes of past and future climate change; studies of climate and climate change at regional to global scales using numerical modeling, data analysis, and/or remote sensing techniques; climate change impacts and the mitigation of, and adaptation to future impacts of a changing climate. Candidates with exceptional strengths in other related research areas are also welcome to apply.

The successful candidate must have a Ph.D. degree by the date of appointment. The candidate must show the potential to establish a quality research and teaching program and collaborate effectively with other faculty. For consideration at the Associate level, the candidate must also demonstrate a strong external funding and publication record. A tenured Associate Professor appointment is possible for a candidate with the appropriate research credentials who has demonstrated excellence in teaching at either or both the graduate and undergraduate levels, commensurate with tenure guidelines at the University of Illinois at Urbana-Champaign.

The Department currently comprises 10 faculty, 5 emeritus faculty, 8 affiliated and adjunct faculty, 1 lecturer, 1 instructor, 9 research scientists, 51 graduate students, and 80 undergraduates. The members of the Department work in a broad range of research areas. Opportunities are available for collaborations with departments across the university, with linkages already existing with the Departments of Geography and Geology within the School of Earth, Society, and Environment, the Illinois State Water Survey, the National Center for Supercomputing Applications (NCSA), the Electrical and Civil Engineering Departments and many others. More information about the department can be found at www.atmos.illinois.edu, and about the School of Earth, Society and Environment at www.earth.illinois.edu.

A competitive salary, commensurate with qualifications and experience, and benefits package will be offered. To ensure full consideration applications must be submitted online by December 15, 2011. Create your U of I application through http://jobs.illinois.edu and upload your application materials: cover letter, vita, list of publications, record of research funding, teaching record, description of research and teaching interests, and names and email addresses of at least 3 references. Applicants may be interviewed before the closing date; however, no hiring decision will be made until after that date.

Questions can be addressed to Prof. Atul Jain, Chair of the Search Committee, at Email: jain1@illinois.edu or Phone: 217-333-2128.

The University of Illinois is an Affirmative Action /Equal Opportunity Employer and welcomes individuals with diverse backgrounds, experiences, and ideas who embrace and value diversity and inclusivity. (www.inclusiveillinois.illinois.edu)

Kepler 22B: A Potentially Habitable Planet

2011-12-06T08:53:00.000-08:00

Also check out the Habitable Exoplanet Catalog. Nifty press release about the latter here.

New Pix of the Japanese Stealth Fighter (aka Shinshin)

2011-11-30T08:28:00.000-08:00

Via flight global.

Duration of the Permian Extinction

2011-11-17T17:21:00.000-08:00

"This is the first paper to provide rates of such massive extinction," says Dr. Charles Henderson, professor in the Department of Geoscience at the University of Calgary and co-author of the paper: Calibrating the end-Permian mass extinction. "Our information narrows down the possibilities of what triggered the massive extinction and any potential kill mechanism must coincide with this time."

About 95 percent of marine life and 70 percent of terrestrial life became extinct during what is known as the end-Permian, a time when continents were all one land mass called Pangea. The environment ranged from desert to lush forest. Four-limbed vertebrates were becoming diverse and among them were primitive amphibians, reptiles and a group that would, one day, include mammals.

Through the analysis of various types of dating techniques on well-preserved sedimentary sections from South China to Tibet, researchers determined that the mass extinction peaked about 252.28 million years ago and lasted less than 200,000 years, with most of the extinction lasting about 20,000 years.

"These dates are important as it will allow us to understand the physical and biological changes that took place," says Henderson. "We do not discuss modern climate change, but obviously global warming is a biodiversity concern today. The geologic record tells us that 'change' happens all the time, and from this great extinction life did recover."

That's far and away the shortest time period that I've heard for the PT. I'd be interested in what other contrasting sources have to show.

Protoceratops Nest Full of Babies

2011-11-17T16:59:00.000-08:00

A 70-million-year-old nest of the dinosaur Protoceratops andrewsi has been found with evidence that 15 juveniles were once inside it, according to a paper in the latestJournal of Paleontology.

While large numbers of eggs have been associated with other dinosaurs, such as the meat-eating Oviraptor or certain duck-billed hadrosaurs, finding multiple juveniles in the same dino nest is quite rare.

This would be the strongest evidence yet of parental care of ceratopsians. That has been a topic of considerable arguments as of late. In fact, one of the papers in the book, Horns and Beaks, iirc, argued that ceratopsians abandoned their young to form their own pre breeding herds in NorAm. Now Protoceratops is not Triceratops by any means, but being related as closely as they (relatively) are makes it more likely that the NorAm ceratopsians gave as much parental care.

Are There Near Surface Liquid Water Aquifers on Europa?

2011-11-16T16:43:00.000-08:00

Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae)

2011-11-16T16:02:00.000-08:00

Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae)

1. Johan Lindgren (a,*)
2. Michael J. Everhart (b)
3. Michael W. Caldwell(c)

a. Department of Earth and Ecosystem Sciences, Lund University, Lund, Sweden
b. Sternberg Museum of Natural History, Fort Hays State University, Hays, Kansas, United States of America
c. Department of Earth and Atmospheric Sciences, and Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada

* E-mail: johan.lindgren@geol.lu.se

Abstract:

The physical properties of water and the environment it presents to its inhabitants provide stringent constraints and selection pressures affecting aquatic adaptation and evolution. Mosasaurs (a group of secondarily aquatic reptiles that occupied a broad array of predatory niches in the Cretaceous marine ecosystems about 98–65 million years ago) have traditionally been considered as anguilliform locomotors capable only of generating short bursts of speed during brief ambush pursuits. Here we report on an exceptionally preserved, long-snouted mosasaur (Ectenosaurus clidastoides) from the Santonian (Upper Cretaceous) part of the Smoky Hill Chalk Member of the Niobrara Formation in western Kansas, USA, that contains phosphatized remains of the integument displaying both depth and structure. The small, ovoid neck and/or anterior trunk scales exhibit a longitudinal central keel, and are obliquely arrayed into an alternating pattern where neighboring scales overlap one another. Supportive sculpturing in the form of two parallel, longitudinal ridges on the inner scale surface and a complex system of multiple, superimposed layers of straight, cross-woven helical fiber bundles in the underlying dermis, may have served to minimize surface deformation and frictional drag during locomotion. Additional parallel fiber bundles oriented at acute angles to the long axis of the animal presumably provided stiffness in the lateral plane. These features suggest that the anterior torso of Ectenosaurus was held somewhat rigid during swimming, thereby limiting propulsive movements to the posterior body and tail.

Return to the XenoPermian

2011-11-08T10:30:00.000-08:00

A Quick Intro:

The XenoPermian Period is a fictitious, alternate geological period that takes place because we hand wave away the Permian Extinction. The assumed point of departure is that the Permian Extinction never takes place. The reason for this is that the Siberian Traps are defused and their eruptions happen over a much longer period of time. This has knock-on effects. One of them being that the world's geography is different and another being that evolution has gone in rather different directions, too.

Scott, Raven, Zach and I have been working on this for some time. We'd hoped to be further along than we are, but there have been multiple setbacks and everyone has been dealing with other projects and life in general. I either had the choice of waiting until the project was further along - which would mean probably another year - or going ahead and unveiling what we have so far.

With that in mind, I have decided to start showing off what we have. I will be putting up one XenoPermian post every other week. This will space out the posts enough that maybe we might be able to get something else done prior to the last post and reduce the lag getting new artwork done.

Geography and Areas of Interest

A world is a big place. Covering the whole world is rather difficult even in a fantasy world like the XenoPermian. This is doubly difficult because we want to give a "real" sampling of the ecologies. One of the criticisms we have for Dougal Dixon is that he does such a tepid sampling that the world feels incredibly unfinished. We realized part way through we can do better, but not even get as close as we wanted to get this done right. Even then, when we considered a better than tepid attempt, but less than boiling, we realized the world was simply too big. To that end, we settled on six places to cover, with a seventh possible if we had time (ha!). The six places are Arctica, Ural Sea, Megavongo, Transpangean Mountains, Karoo and Conan Doyle's Relica.

Let's run through the five and exhibit some of the high level characteristics of each environ and the biota there.

Arctica:

Arctica is as close to a tundra as can exist under the conditions of the XenoPermian. It has very seasonal weather. This is no surprise given that the whole environment is above the Arctic Circle. While there are some shrub like vegetation, in the form of various conifers, the vast majority of the plants present are ferns. They sprout during the start of spring as the sun moves above the horizon and then die as the sunsets for winter. Life in the north polar region is tough, albeit not as tough as Arctic of our Holocene. Temperatures hover around freezing in the winter and get quite warm in the summer. Snow dusts and covers, but no more than what can happen in, say, the Midwestern states of the US in relative spring. That's nontrivial, but not what happens in the depths of winter of our Holocene. Since vegetation is sparse in winter, most herds of animals out migrate to the more southern reaches.

Animal life is dominated thoroughly by the therapsids. While archosaurs are present, the parareptiles and nonarchosaurian diapsids are largely not. The waters are filled with temnospondyls and lepospondyls, though there are no known reptilomorphs. Despite the presence of the macrofauna, the biggest presence is actually insect and a huge number of archaic invertebrate detrivores that are active even in winter munching up the dead ferns and fertilizing for the next spring.

Megavongo:

The Megavongo is a vast outletless river delta that covers a huge area in what would have been North America. This is similar to the Okavango Delta in modern Africa, but on a far, far grander scale. Life during the dry season is much like living in a desert, even one you would fine in modern Arizona or southern New Mexico, but when the megamonsoon rains hit the Transpangean Mountains, a fraction, albeit a still vast inundation, runs down the far side of the mountains and into the dry desert. The model is much like what happens in the Ethiopian Highlands for the Okavango Delta and Nile River.

Life here is harsh and dry for most of the year. Seasonal ferns mixed with specialized horsetails and lots of seed plants, especially cycads and conifers. The most inland fringes of the delta, furthest away from the seasonal water source nearly salt flats.

The fauna here is dominated by migrants. Animals conduct impressive migrations from the foothills of the Transpangaean Mountains and the coasts of the Panthalassa and Tethys consume and breed. All clades, parareptilian, diapsid & archosarian, and therapsid participate. Of those that stay between the wet seasons, active or aestivating, there is surprising diversity amongst the clades, though shockingly low on the species level.

Transpangean Mountains:

These are the mountains that straddle and divide the vast Pangaea supercontinent. Due to the fact that the world has a lower than lower oxygen level than in our time (18% instead of 21 %), the mountains make for an interesting, but rather different biota than elsewhere. The upper altitudes are filled with archosaurs and archaic amphibians in cloud forests that get megamonsoons. The lower reaches in the rift that will eventually become the Newark supergroup, is a tropical rain forest with extremely unique mix of the clades.

Karoo:

The Karoo of what is modern South Africa also joins the mix as a temperate environment. A mix of plains, forests and everything between can be found here. Despite its name, this environment stretches all the way from one side of the Therapsids dominate southern hemisphere's terrestrial environment to the other, producing a swath of life filling the analogous role of Eurasia in our own biota.

Here, too, therapsids dominate, but the neoparieasaurs and the archosaurs have truly important additions. Vast herds migrating from along the latitudes are common here. Some that reach even from one end to the other in circular migratory paths.

Conan Doyle's Relica:

Lost worlds are a common theme. The Xenopermian is an extrapolation of the lost biota of the end Permian. Here, though, too a large single island has allowed populations of archaic forms to survive...and evolve in different directions than the mainland populations. Relica separated from the mainland during the early Permian allowing for pelycosaur grade synapsids and early parareptiles to evolve into strange, but plausible forms independent of the therapsids and more derived mainland clades. What happens when a sphenodont evolves for 60 million years independently of the therapsids and differently?

Life here is harsh and very similar in flora to Arctica, at least in analogous forms. Yet still very, very unique.

Ural Sea:

We jump back to the northern hemisphere for an environment that is like someone took the Red Sea, Tropical Forests, the coast of California and coast of Crimea and mixed them up in a massive way. Flanked in the east by the AnteUral Mountains and the West by the ProtoUral Mountains, the Ural Sea formed when the two mountain ranges that would form the future Ural Mountains caused the crust between them to buckle under rather than rise. Due to the weathering from the two mountain ranges, the sea is a very fertile and the lands, although narrow in the east-west direction, are very fertile as well, sporting a terrestrial fauna as diverse and teeming as the marine.

The reason that the Ural Sea was held to last, out of the north to south order, is that this is our first land to visit and the first

The XenoPermian Pareiasaurs, the pseudochelonids and their phylogeny, are our first graphic examples of the Xenopermian. They are excellent examples of one side of a megafaunal arms race!

Check back on 11/22!

Another Awesome Video

2011-10-10T01:05:00.000-07:00

Landscapes: Volume Two from Dustin Farrell on Vimeo.

Aurora from Space Pic

2011-09-29T01:16:00.000-07:00

The Kepler Orrery

2011-09-27T01:40:00.000-07:00

Kewl Picture

2011-09-22T01:52:00.000-07:00

New-ish J-20 Flight Stop Motion Pix

2011-09-21T01:01:00.000-07:00

This is actually pretty important...at least for us

2011-09-19T22:58:00.000-07:00

A bit of a preface...

My family, as I have stated here before, has a very long tradition of being soldiers. My great grandfather, grandfather, father and brother all served. We served as a "family battalion" in the Civil War (Tennesseans fighting for the north). We were even exiled from Scotland for being Covenanters back in 1683 when we rose up against the then Dual Scottish/English crown (and like almost all glorious celtic rebellions rose heroically, fought like lions and were crushed thoroughly).

I've pondered that heritage more than a few times: why do we make such good soldiers? Why do we gravitate to the profession whether or not irregardless of our person wealth.

My wife and I are very different people. We often discuss it. One of the thing that came out is that I described that I truly enjoy being around other people...but I don't need to interact with others for me to be fine, even happy. My father was a true loner, but I don't see myself that way.

Then, a few days ago, a friend pointed this out:

IDK if I ought to be very, very worried or not. I'm conflicted whether or not to take a look under the hood as another friend put it. However, the only real benefit from doing so would be to see what I can do to raise my son better. (The fringe benefit is that I get my curiosity satisfied) That alone may be worth it.

IDK when regular postings will continue. I'd like to, but...Too Damned Busy.

Another Terrestrial Fish

2011-08-30T16:29:00.000-07:00

One of the world's strangest animals – a unique fish that lives on land and can leap large distances despite having no legs – has a rich and complex social life, a new study has found.
The odd lifestyle of the Pacific leaping blenny (Alticus arnoldorum) has been detailed for the first time in research findings that throw new light on how animal life first evolved to colonise the land.
The Pacific leaping blenny is a marine fish yet is terrestrial in all aspects of its daily adult life, eking out a precarious existence in the intertidal zone of rocky shores in Micronesia, according to the study published in the journal Ethology , led by Dr Terry Ord, of the UNSW Evolution and Ecology Research Centre.
"This remarkable little fish seems to have made a highly successful transition across the water–land interface, although it is still needs to stay moist to enable it to breathe through its gills and skin," says Dr Ord, who is an evolutionary ecologist with a special interest in animal behaviour.
"Our study showed that life on land for a marine fish is heavily dependent on tide and temperature fluctuations, so much so that almost all activity is restricted to a brief period at mid-tide, the timing of which changes daily. During our field study on Guam we never saw one voluntary return to water. Indeed, they spend much of their time actively avoiding submersion by incoming waves, even when we tried to capture them for study.
"I can tell you they are very hard to catch and are extremely agile on land. They move quickly over complex rocky surfaces using a unique tail-twisting behaviour combined with expanded pectoral and tail fins that let them cling to almost any firm surface. To reach higher ground in a hurry, they can also twist their bodies and flick their tails to leap many times their own body length."
Working with Toni Hsieh, of Temple University in the US, Dr Ord found that adult blennies shelter in rock crevices at high and low tide, emerging at mid-tide to feed, breed and socialise in surprisingly complex ways – given their brief window of opportunity.
The researchers discovered that males are territorial and use complex visual displays to warn off rivals and attract mates. Females were seen aggressively defending feeding territory at the start of their breeding season, while males displayed a red-coloured fin and nodded their heads vigorously to attract females to their closely defended rock holes. The team filmed females inspecting these holes before entering with a chosen mate.
Little is known of their breeding and development of the young, but it seems that females lay their eggs in a chosen rock hole then play no further role in parenting, leaving the male to guard the eggs.

There's a good video here. The thing is damned agile. I was only aware of the mudskipper.

I Hate the Name Anthropocene

2011-08-30T12:03:00.000-07:00

Anthropocene Mapping from Globaïa on Vimeo.

The Holocene is the same thing, really, and predates the goofy name. This is a nifty video though.

Nicked from James,

Juramaia sinensis: Earliest Known Eutherian Mammal?

2011-08-24T10:31:00.000-07:00

A remarkably well-preserved fossil discovered in northeast China provides new information about the earliest ancestors of most of today's mammal species—the placental mammals. According to a paper published August 25 in the prestigious journal Nature, this fossil represents a new milestone in mammal evolution that was reached 35 million years earlier than previously thought, filling an important gap in the fossil record and helping to calibrate modern, DNA-based methods of dating the evolution.

The paper by a team of scientists led by Carnegie Museum of Natural History paleontologist Zhe-Xi Luo describes Juramaia sinensis, a small shrew-like mammal that lived in China 160 million years ago during the Jurassic period. Juramaia is the earliest known fossil of eutherians—the group that evolved to include all placental mammals, which provide nourishment to unborn young via a placenta. As the earliest known fossil ancestral to placental mammals, Juramaia provides fossil evidence of the date when eutherian mammals diverged from other mammals: metatherians (whose descendants include marsupials such as kangaroos) and monotremes (such as the platypus). As Luo explains, "Juramaia, from 160 million years ago, is either a great-grand-aunt, or a 'great-grandmother' of all placental mammals that are thriving today."

[...]

The fossil of Juramaia sinensis was discovered in the Liaoning Province in northeast China and examined in Beijing by Zhe-Xi Luo and his collaborators: Chong-Xi Yuan and Qiang Ji from the Chinese Academy of Geological Sciences, and Qing-Jin Meng from the Beijing Museum of Natural History, where the fossil is stored. The name Juramaia sinensis means "Jurassic mother from China." The fossil has an incomplete skull, part of the skeleton, and, remarkably, impressions of residual soft tissues such as hair. Most importantly, Juramaia's complete teeth and forepaw bones enable paleontologists to pin-point that it is closer to living placentals on the mammalian family tree than to the pouched marsupials, such as kangaroos.

less than no time...but could not resist.

Cool Video

2011-08-24T10:09:00.000-07:00

Tempest Milky Way from Randy Halverson on Vimeo.

Brain cruncher is nearly done with me.

Awesome Pic

2011-08-22T17:02:00.001-07:00

Its not mine though.

Expressing Some Frustrations

2011-08-17T23:51:00.000-07:00

From the GLXP Summit

2011-08-03T00:05:00.000-07:00

ARCA posted that from the team summit last july: we were at the Google's headquarters.

Team Puli posted this one.

Yes, I am at work. :(

Wow

2011-07-28T12:15:00.000-07:00

This blog has been rather neglected.

I am hoping about the middle of next month, I can get past what has been eating my brain, time and life to post once more. I may get something out tomorrow though.

The Computer Game (and Interface) I Want

2011-07-13T19:29:00.000-07:00

Yeah, stick late at the dayjob...waiting for my turn again.

Blood Vessels in Dinosaur Bones Suggest Endothermy

2011-07-08T09:00:00.001-07:00

(caption:The y-axis is an index of the amount of blood flow through the foramen in relation to the body size of mammals (red), reptiles (blue) and dinosaurs (orange-red).)

New research from the University of Adelaide has added to the debate about whether dinosaurs were cold-blooded and sluggish or warm-blooded and active.

Professor Roger Seymour from the University's School of Earth & Environmental Sciences has applied the latest theories of human and animal anatomy and physiology to provide insight into the lives of dinosaurs. The results will be published this month in Proceedings B, the Proceedings of the Royal Society B (Biological Sciences), and can now be found online at: http://dx.doi.org/10.1098/rspb.2011.0968

Human thigh bones have tiny holes – known as the 'nutrient foramen' – on the shaft that supply blood to living bone cells inside. New research has shown that the size of those holes is related to the maximum rate that a person can be active during aerobic exercise. Professor Seymour has used this principle to evaluate the activity levels of dinosaurs.

"Far from being lifeless, bone cells have a relatively high metabolic rate and they therefore require a large blood supply to deliver oxygen. On the inside of the bone, the blood supply comes usually from a single artery and vein that pass through a hole on the shaft – the nutrient foramen," he says.

Professor Seymour wondered whether the size of the nutrient foramen might indicate how much blood was necessary to keep the bones in good repair. For example, highly active animals might cause more bone 'microfractures', requiring more frequent repairs by the bone cells and therefore a greater blood supply.

"My aim was to see whether we could use fossil bones of dinosaurs to indicate the level of bone metabolic rate and possibly extend it to the whole body's metabolic rate," he says. "One of the big controversies among paleobiologists is whether dinosaurs were cold-blooded and sluggish or warm-blooded and active. Could the size of the foramen be a possible gauge for dinosaur metabolic rate?"

Comparisons were made with the sizes of the holes in living mammals and reptiles, and their metabolic rates. Measuring mammals ranging from mice to elephants, and reptiles from lizards to crocodiles, one of Professor Seymour's Honours students, Sarah Smith, combed the collections of Australian museums, photographing and measuring hundreds of tiny holes in thigh bones.

"The results were unequivocal. The sizes of the holes were related closely to the maximum metabolic rates during peak movement in mammals and reptiles," Professor Seymour says. "The holes found in mammals were about 10 times larger than those in reptiles."

These holes were compared to those of fossil dinosaurs. Dr Don Henderson, Curator of Dinosaurs from the Royal Tyrrell Museum in Alberta, Canada, and Daniela Schwarz-Wings from the Museum für Naturkunde and Humboldt University Berlin, Germany, measured the holes in 10 species of dinosaur from five different groups, including bipedal and quadrupedal carnivores and herbivores, weighing 50kg to 20,000kg.

"On a relative comparison to eliminate the differences in body size, all of the dinosaurs had holes in their thigh bones larger than those of mammals," Professor Seymour says.

"The dinosaurs appeared to be even more active than the mammals. We certainly didn't expect to see that. These results provide additional weight to theories that dinosaurs were warm-blooded and highly active creatures, rather than cold-blooded and sluggish."

I don't have time to read the paper, but did they do modern birds?

Some original content coming soon, promise.

We both lovez and hatez the Beast Heads!

Wife Picture

2011-07-01T15:28:00.000-07:00

Antarctica's Glacier Expansion Rate

2011-07-01T14:54:00.000-07:00

A painstaking examination of the first direct and detailed climate record from the continental shelves surrounding Antarctica reveals that the last remnant of Antarctic vegetation existed in a tundra landscape on the continent's northern peninsula about 12 million years ago. The research, which was led by researchers at Rice University and Louisiana State University, appears online this week and will be featured on the cover of the July 12 issue of the Proceedings of the National Academy of Sciences.

The new study contains the most detailed reconstruction to date of the climatic history of the Antarctic Peninsula, which has warmed significantly in recent decades. The rapid decline of glaciers along the peninsula has led to widespread speculation about how the rest of the continent's ice sheets will react to rising global temperatures.

"The best way to predict future changes in the behavior of Antarctic ice sheets and their influence on climate is to understand their past," said Rice University marine geologist John Anderson, the study's lead author. The study paints the most detailed picture to date of how the Antarctic Peninsula first succumbed to ice during a prolonged period of global cooling.

In the warmest period in Earth's past 55 million years, Antarctica was ice-free and forested. The continent's vast ice sheets, which today contain more than two-thirds of Earth's freshwater, began forming about 38 million years ago. The Antarctic Peninsula, which juts farther north than the rest of the continent, was the last part of Antarctica to succumb to ice. It's also the part that has experienced the most dramatic warming in recent decades; its mean annual temperatures rose as much as six times faster than mean annual temperatures worldwide.

"There's a longstanding debate about how rapidly glaciation progressed in Antarctica," said Sophie Warny, a Louisiana State University geologist who specializes in palynology (the study of fossilized pollen and spores) and led the palynological reconstruction. "We found that the fossil record was unambiguous; glacial expansion in the Antarctic Peninsula was a long, gradual process that was influenced by atmospheric, tectonic and oceanographic changes."

Warny, her students and colleague Rosemary Askin were able to ascertain the exact species of plants that existed on the peninsula over the past 36 million years after a painstaking, three-year examination of thousands of individual grains of pollen that were preserved in muddy sediments beneath the sea floor just off the coast.

"The pollen record in the sedimentary layers was beautiful, both in its richness and depth," Warny said. "It allowed us to construct a detailed picture of the rapid decline of the forests during the late Eocene -- about 35 million years ago -- and the widespread glaciation that took place in the middle Miocene -- about 13 million years ago."

Paper here.

Solar Sand Sintering

2011-07-01T14:22:00.001-07:00

Markus Kayser - Solar Sinter Project from Markus Kayser on Vimeo.

Dude! Little White Hunter

2011-06-24T16:11:00.001-07:00

Or is this the ultimate in the therapsid v. archosaur wars?

He's closing in on two years old.

A Cretaceous Gomphodont?

2011-06-20T14:17:00.000-07:00

This is not a new paper, but rather me digging through old papers looking for info for both the XenoPermian and the therocephalian post. Theoretically, there might have been dicynodonts and gomphodonts in the Australian Cretaceous. Ponder that!

AN ENIGMATIC (SYNAPSID?) TOOTH FROM THE EARLY CRETACEOUS OF NEW SOUTH WALES, AUSTRALIA

1. WILLIAM A. CLEMENS (a)
2. GREGORY P. WILSON (a)
3. RALPH E. MOLNAR (b)

a. Museum of Paleontology and Department of Integrative Biology, University of California Berkeley, California 94720-4785, bclemens@uclink4.berkeley.edu

b. Queensland Museum, P.O. Box 3300, South Brisbane QLD 4101, Australia, and Museum of Northern Arizona, Flagstaff, Arizona 86011

Abstract:

Largely fragmentary fossils from sites in New South Wales, Victoria, and Queensland, Australia document terrestrial and marine vertebrate faunas of Aptian–Albian age. The natural cast of a large tooth from the Griman Creek Formation, Lightning Ridge, New South Wales, records the presence of a hitherto unknown member of the fauna. Although reference to one of the groups of crocodyliforms that evolved complex, mammal-like postcanine teeth cannot be excluded, the fossil more likely represents a species of synapsid. In some respects it is similar to lower postcanines of traversodontids. Greater morphological similarities to upper molars of dryolestids make reference of this tooth to this group more likely. Current Mesozoic Laurasian and Gondwanan fossil records include mammals with cheek teeth of similar large size.

Link to paper in title.

Why Animals Don't Have IR Vision

2011-06-20T13:55:00.000-07:00

On rare occasion, the light-sensing photoreceptor cells in the eye misfire and signal to the brain as if they have captured photons, when in reality they haven't. For years this phenomenon remained a mystery. Reporting in the June 10 issue of Science, neuroscientists at the Johns Hopkins University School of Medicine have discovered that a light-capturing pigment molecule in photoreceptors can be triggered by heat, as well, giving rise to these false alarms.
"A photon, the unit of light, is just energy, which, when captured by the pigment rhodopsin, most of the time causes the molecule to change shape, then triggering the cell to send an electrical signal to the brain to inform about light absorption," explains King-Wai Yau, Ph.D., professor of neuroscience at Johns Hopkins and member of its Center for Sensory Biology. "If rhodopsin can be triggered by light energy," says Yau, "it may also be occasionally triggered by other types of energy, such as heat, producing false alarms. These fake signals compromise our ability to see objects on a moonless night. So we tried to figure it out; namely, how the pigment is tripped by accident."

"Thermal energy is everywhere, as long as the temperature is above absolute zero," says neuroscience research associate Dong-Gen Luo, Ph.D. "The question is: How much heat energy would it take to trigger rhodopsin and enable it to fire off a signal, even without capturing light?" says Johns Hopkins Biochemistry, Cellular and Molecular Biology graduate student Wendy Yue.

For 30 years, the assumption was that heat could trigger a pigment molecule to send a false signal, but through a mechanism different from that of light, says Yau, because it seemed, based on theoretical calculations: that very little thermal energy was required compared to light energy.

But the theory, according to Yau, was based mainly on the pigment rhodopsin. However, rhodopsin is mainly responsible for seeing in dim light and is not the only pigment in the eye; other pigments are present in red-, green- and blue-sensitive cone photoreceptors that are used for color and bright-light vision. Although researchers are able to measure the false events of rhodopsin from a single rhodopsin-containing cell, a long-standing challenge has been to take measurements of the other pigments. "The electrical signal from a single cone pigment molecule is so small in a cone cell that it is simply not measurable," says Luo. "So we had to figure out a new way to measure these false signals from cone pigments."

By engineering a rod cell to make human red cone pigment, which is usually only found in cone cells, Yau's team was able to measure the electrical output from an individual cell and calculate this pigment's false signals by taking advantage of the large and detectable signals sent out from the cell.

As for blue cone pigment, "Nature did the experiment for us," says Yau. "In many amphibians, one type of rod cells called green rods naturally express a blue cone pigment, as do blue cones." So to determine whether heat can cause pigment cells to misfire, the team, working in the dark, first cooled the cells, and then slowly returned the cells to room temperature, measuring the electrical activity of the cells as they warmed up. They found that red-sensing pigment triggers false alarms most frequently, rhodopsin (bluish-green-sensing pigment) triggers falsely less frequently, and blue-sensing pigment does so even less.

"This validates the 60-year-old Barlow's hypothesis that suggested the longer wavelength the pigment senses—meaning the closer to the red end of the spectrum—the noisier it is," says Yau. And this finding led the team to develop and test a new theory: that heat can trigger pigments to misfire, by the same mechanism as light.

Pivotal to this theory is that visual pigment molecules are large, complex molecules containing many chemical bonds. And since each chemical bond has the potential to contain some small amount of thermal energy, the total amount of energy a pigment molecule could contain can, in theory, be enough to trigger the false alarm.

"For a long time, people assumed that light and heat had to trigger via different mechanisms, but now we think that both types of energy, in fact, trigger identical changes in the pigment molecules," says Yau. Moreover, since longer wavelength pigments have higher rates of false alarms, Yau says this may explain why animals never evolved to have infrared-sensing pigments.

"Apart from putting to rest a long-standing debate, it's a wake-up call for researchers to realize that biomolecules in general have more potential thermal energy than previously thought," says Luo.

Link in title.

The Geography of the XenoPermian

2011-06-15T22:17:00.000-07:00

The XenoPermian Period is a fictitious, alternate geological period that takes place because we hand wave away the Permian Extinction. The assumed point of departure is that the Permian Extinction never takes place. The reason for this is that the Siberian Traps are defused and their eruptions happen over a much longer period of time. This has knock-on effects. One of them being that the world's geography is different...

No, I am not the artist. Scott is.

Just wait until the unveiling of Raven's Walrodont. Wow. Along with the suminid...they're stunning.

Comments?

PAK-FA Flight Video

2011-06-10T21:38:00.000-07:00

Glaciations Influences Biodiversity More Than Climate

2011-06-08T18:09:00.000-07:00

The study, published yesterday in the journal Ecology Letters, analyzed the species richness and the structure of their communities throughout the different regions of the European territory from the Ural Mountains to the Iberian Peninsula. The selection of this family of insects was motivated by their high dispersal ability and because their food sources (mainly cattle and sheep dung) are present throughout the continent.

Research by the Spanish National Research Council reveals that the large impacts occurred during the last ice age maintain their effects on the current distribution of dung beetles of the scarab family. The presence of these beetles in Europe seems to be more influenced by the climate of that glaciation than by the present one.

Scarabs are insects of tropical origin that cannot survive below 0 ° C mean annual temperature, "so it could be expected that their presence gradually decreases as temperatures drop down northwards " says the researcher from the National Museum of Natural Sciences, CSIC, Joaquín Hortal. However, the analysis of the relationship between the magnitude of climate change since the last glaciation and the distribution of scarabs evidences that these insects are not evenly distributed according to this gradient, but rather show two different patterns, one in the north and one in the south. Horton said: "The border defining the two areas is almost similar to the limit of 0 °C of mean annual temperature at the time of the last ice age." (See Figure 1)

Although scarab species richness is actually lower in the north that in the south, another two characteristics can be explained under the hypothesis of the influence of the last ice age.

The first one is based on the species present throughout Europe. Data show that all scarab species living in the northern territory above the border defined by the 0 ° C limit in the last glaciations are also present in the south, and there is no species exclusive to the northernmost area. According to Hortal, "this is an effect of the difficulty of adapting to cold climate that still exists, as the north does not hold unique species adapted to the cold."

This feature is consistent with the second observation, based on the age of the species present in each area. The study results show that the species that have been able to re-colonize the north are also those that have evolved most recently." Although the adaptation to cold climates started before the last glaciation, these species belong to the newer phylogenetic branches of the Scarabaeidae," says the researcher from CSIC.

Must. Read. Paper.

And have no time.

JH-7B? A New Stealth Fighter-Bomber?

2011-06-08T17:08:00.000-07:00

Dewline also noticed it.

Carbon Biomass Maps of Tropical Forests

2011-06-02T15:43:00.000-07:00

Japanese Are Planning an Ikaros Follow-on

2011-06-02T15:24:00.000-07:00

Japanese researchers are working on a solar-sail spacecraft with 10 times the surface area of the Ikaros testbed launched toward Venus last year, after achieving all of their technical objectives with the testbed.

This spacecraft will launch on a five-year mission instead of the six-month span allotted to Ikaros. Lofted as a piggyback payload with the Venus Climate Orbiter Akasuki on May 21, 2010, Ikaros passed Venus on Dec. 8.

Researchers hoped to demonstrate automatic sail deployment, power generation with thin-film solar cells on the sail surface, verification that the pressure of photons from the Sun caused the sail to accelerate, and guidance and navigation with the sail. The sail met its intended acceleration of 100 meters per second and veered off the ballistic trajectory it would have followed without the Sun’s pressure, says Yuichi Tsuda, an assistant professor in the Japan Aerospace Exploration Agency (JAXA) Space Exploration Center, in an English-language report on the experiment’s outcome.

The deployment and power generation were demonstrated early on. To control the 14 x 14-meter (46 x 46-ft.) spin-stabilized sail, the Ikaros team used a non-toxic “gas-liquid equilibrium thruster” for attitude control, and an attitude-detection system that combined a Sun sensor and Doppler measurements from the low-gain antenna.

To tilt the spin axis of the spacecraft, the team powered a liquid-crystal variable-reflectivity element mounted as a thin polyimide film around the edges of the sail off and on to throw the spinning sail off balance and tilt it as it spun. As it happened, the spacecraft required almost no fuel to keep its sail facing the Sun, even though it turned a full 180 deg. over the six months, according to Tsuda.

*sighs* This is actually a pretty important piece of tech going forward.

Another XenoPermian Teaser

2011-06-02T15:17:00.000-07:00

Raven is making progress, too. I can't wait to show the whole piece. She's doing an astounding job.

These are Walrodonts.

Wooly-Columbian Mammoth Hybrid Found?

2011-06-01T14:21:00.000-07:00

Mammoths were a diverse genus that roamed across Eurasia and North America during the Pleistocene era. In continental North America, at least two highly divergent species have long been recognized – woolly mammoths (Mammuthus primigenius) and Columbian mammoths (M. columbi). But new genetic evidence published in BioMed Central's open access journal Genome Biology suggests that these species may have been closely related enough to mate when they had the chance.

Remains of woolly mammoths have been found across the glacial tundra-steppe of Eurasia and northern North America, while the much physically larger Columbian mammoths inhabited the savannah environments of temperate southern and central North America. The differences between the species have long been considered as unique adaptations to the environments where they evolved. But by piecing together trace fragments of DNA from an 11 thousand year-old Columbian mammoth from Fairview, Utah, a team of Canadian, American and French researchers found that surprisingly the mitochondrial genome from this mammoth was nearly indiscernible from that of its northern woolly counterparts.

But the group does not suspect that this requires a re-write of North American mammoth evolution. "We think this individual may have been a woolly-Columbian hybrid," says Jacob Enk of the McMaster Ancient DNA Centre, the group that led the research. "Living African elephant species interbreed where their ranges adjoin, with males of the bigger species out-competing the smaller for mates. This results in mitochondrial genomes from the smaller species showing up in populations of the larger. Since woolly and Columbian ranges periodically overlapped in time and space, it's likely that they engaged in similar behaviour and left a similar genetic signal." The team goes on to suggest that interbreeding may explain some mammoth fossils that have intermediate physical characteristics, between woollies and Columbians, sometimes assigned to the species M. jeffersonii.

They do not rule out other explanations however, and note that the only way to know for sure whether their mammoth was a hybrid is to sequence nuclear DNA from it and other mammoths. For poorly-preserved remains like those of southern-ranging Columbians, this will be a challenge. But they expect that by exploiting new cutting-edge sequencing technologies, the nuclear genomes of these amazing animals are within reach.

...

Quantum Data Deletion May Have Cooling Effect?

2011-06-01T11:01:00.000-07:00

Recent research by a team of physicists reveals a surprise at this fundamental level. ETH-Professor Renato Renner, and Vlatko Vedral of the Centre for Quantum Technologies at the National University of Singapore and the University of Oxford, UK, and their colleagues describe in the scientific journal Nature how the deletion of data, under certain conditions, can create a cooling effect instead of generating heat. The cooling effect appears when the strange quantum phenomenon of entanglement is invoked. Ultimately, it may be possible to harness this effect to cool supercomputers that have their performance held back by heat generation. «Achieving the control at the quantum level that would be required to implement this in supercomputers is a huge technological challenge, but it may not be impossible. We have seen enormous progress is quantum technologies over the past 20 years,» says Vedral. With the technology in quantum physics labs today, it should be possible to do a proof of principle experiment on a few bits of data.

hmmm. This almost sounds like a real world version of a Reynolds cryocomp.

A Crazy Dangerous Precedent: Seismologists Tried for Manslaughter In Italy

2011-05-27T14:51:00.000-07:00

Earthquake prediction can be a grave, and faulty science, and in the case of Italian seismologists who are being tried for the manslaughter of the people who died in the 2009 L'Aquila quake, it can have legal consequences.

The group of seven, including six seismologists and a government official, reportedly didn't alert the public ahead of time of the risk of the L'Aquila earthquake, which occurred on April 6 of that year, killing around 300 people, according to the U.S. Geological Survey.

But most scientists would agree it's not their fault they couldn't predict the wrath of Mother Nature.

"We're not able to predict earthquakes very well at all," John Vidale, a Washington State seismologist and professor at the University of Washington, told LiveScience.

F?!

Strongly suggest if they get convicted that Italy's seismologists ought to...leave.

Younger Dryas Impactor Hypothesis Crashes and Burns

2011-05-26T09:30:00.000-07:00

It seemed like such an elegant answer to an age-old mystery: the disappearance of what are arguably North America’s first people. A speeding comet nearly 13,000 years ago was the culprit, the theory goes, spraying ice and rocks across the continent, killing the Clovis people and the mammoths they fed on, and plunging the region into a deep chill. The idea so captivated the public that three movies describing the catastrophe were produced.

But now, four years after the purportedly supportive evidence was reported, a host of scientific authorities systematically have made the case that the comet theory is “bogus.” Researchers from multiple scientific fields are calling the theory one of the most misguided ideas in the history of modern archaeology, which begs for an independent review so an accurate record is reflected in the literature.

“It is an impossible scenario,” says Mark Boslough, a physicist at Sandia Laboratory in Albuquerque, N.M., where he taps the world’s fastest computers for nuclear bomb experiments to study such impacts. His computations show the debris from such a comet couldn’t cover the proposed impact field. In March, a “requiem” for the theory even was published by a group that included leading specialists from archaeology to botany.

Yet, the scientists who described the alleged impact in a hallowed U.S. scientific journal refuse to consider the critics’ evidence — insisting they are correct, even though no one can replicate their work: the hallmark of credibility in the scientific world.

[...]

A new look at the comet claim suggests all of these phenomena may be in play, apparently creating a peculiar bond of desperation as the theory came under increasing attack. Indeed, the team’s established scientists are so wedded to the theory they have opted to ignore the fact their colleague “Allen West” isn’t exactly who he says he is.
West is Allen Whitt — who, in 2002, was fined by California and convicted for masquerading as a state-licensed geologist when he charged small-town officials fat fees for water studies. After completing probation in 2003 in San Bernardino County, he began work on the comet theory, legally adopting his new name in 2006 as he promoted it in a popular book. Only when questioned by this reporter last year did his co-authors learn his original identity and legal history. Since then, they have not disclosed it to the scientific community.
West’s history — and new concerns about study results he was integrally involved in — raise intriguing questions about the veracity of the comet claim. His background is likely to create more doubts about the theory. And the controversy — because it involves the politically sensitive issue of a climate shift — is potentially more broadly damaging, authorities suggest.

[...]

West has no formal appointment at an academic institution. He has said he obtained a doctorate from a Bible college, but he won’t describe it further. Firestone said West has told him he has no scientific doctorate but is self-taught. West’s Arizona attorney refers to him in writing as: “A retired geophysicist who has had a long and distinguished career.”

In the early 1990s, a new-age business West was involved in Sedona, Ariz., failed, and his well-drilling company went bankrupt. Then he ran afoul of California law in small Mojave Desert towns in a scheme with two other men, with court records saying they collected fees up to $39,500 for questionable groundwater reports.

He originally was charged with two felonies for falsely representing himself as a state-licensed geologist but agreed to a no contest plea to a single misdemeanor of false advertising as part of plea bargain in which state records say he was fined $4,500. Two other men in the scam also were sanctioned.

Acknowledging he made a mistake, West has sought to downplay the 9-year-old conviction. And last September, after his impact theory colleagues learned of it, he went back to court in Victorville, Calif., convincing a judge to void the old plea.

After earlier denying any impropriety with his Younger Dryas work, West declined a recent interview request. Last month, he wrote a letter charging it was “highly prejudicial and distorted” to bring up his legal past in the context of his current studies. He is a member of “a group of two dozen dedicated scientists performing cutting-edge, although controversial, research,” he wrote.

...

ouch.

Homo confisio strikes again? Or ought that be Homo audacia?

OSIRIS-REX Selected as Third New Frontiers Mission

2011-05-25T14:51:00.000-07:00

NASA will launch a spacecraft to an asteroid in 2016 and use a robotic arm to pluck samples that could better explain our solar system's formation and how life began. The mission, called Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, or OSIRIS-REx, will be the first U.S. mission to carry samples from an asteroid back to Earth.

"This is a critical step in meeting the objectives outlined by President Obama to extend our reach beyond low-Earth orbit and explore into deep space," said NASA Administrator Charlie Bolden. "It’s robotic missions like these that will pave the way for future human space missions to an asteroid and other deep space destinations."

The first New Frontiers Mission was New Horizons which is en route to Pluto. The second is Juno which is due to be launched to Jupiter quite soon. NASA press release is here. Future Planetary Exploration has a nice summation of the proposal here.

Looks as Though Spirit Has Died But Not Opportunity

2011-05-25T13:14:00.000-07:00

The MER Spirit seems to have not survived the winter. Opportunity continues to function.

Sadly, in some ways, that isn't a bad description of the space program at times. At least when I am bluest.

New Very Large Ordovician Anomalocaridid Discovered

2011-05-25T10:51:00.000-07:00

aleontologists have discovered that a group of remarkable ancient sea creatures existed for much longer and grew to much larger sizes than previously thought, thanks to extraordinarily well-preserved fossils discovered in Morocco.

The creatures, known as anomalocaridids, were already thought to be the largest animals of the Cambrian period, known for the "Cambrian Explosion" that saw the sudden appearance of all the major animal groups and the establishment of complex ecosystems about 540 to 500 million years ago. Fossils from this period suggested these marine predators grew to be about two feet long. Until now, scientists also thought these strange invertebrates—which had long spiny head limbs presumably used to snag worms and other prey, and a circlet of plates around the mouth—died out at the end of the Cambrian.

Now a team led by former Yale researcher Peter Van Roy (now at Ghent University in Belgium) and Derek Briggs, director of the Yale Peabody Museum of Natural History, has discovered a giant fossilized anomalocaridid that measures one meter (more than three feet) in length. The anomalocaridid fossils reveal a series of blade like filaments in each segment across the animal's back, which scientists think might have functioned as gills.

In addition, the creature dates back to the Ordovician period, a time of intense biodiversification that followed the Cambrian, meaning these animals existed for 30 million years longer than previously realized.

"The anomalocaridids are one of the most iconic groups of Cambrian animals," Briggs said. "These giant invertebrate predators and scavengers have come to symbolize the unfamiliar morphologies displayed by organisms that branched off early from lineages leading to modern marine animals, and then went extinct. Now we know that they died out much more recently than we thought."

Note: There is a Devonian anomalocaridid already, Schinderhannes bartelsi, which already extended the clades' existence furter than the Ordovician already. This one IS the biggest by far though.

Kepler/Spitzer Telescopes Find, Confirm New Multi ExoPlanet System

2011-05-23T15:40:00.000-07:00

A new planetary member of the Kepler-10 solar system was announced today. Using data from NASA's Spitzer Space Telescope, members of the Kepler science team confirmed a new planet, dubbed Kepler-10c.

The Kepler-10 star system is located about 560 light-years away near the Cygnus and Lyra constellations. The Kepler telescope has discovered two planets around this star. Kepler-10b is, to date, the smallest known rocky exoplanet, or planet outside our solar system (dark spot against yellow sun). This planet, which has a radius of 1.4 times that of Earth's, whips around its star every .8 days. Its discovery was announced in Jan. 2011.

Now, in May 2011, the Kepler team is announcing another member of the Kepler-10 family, called Kepler-10c. It's bigger than Kepler-10b with a radius of 2.2 times that of Earth's, and it orbits the star every 45 days. Both planets would be blistering hot worlds.

Kepler-10c was first identified by Kepler, and later validated using a combination of a computer simulation technique called "Blender," and NASA's Spitzer Space Telescope. Both of these methods are powerful ways to validate the Kepler planets that are too small and faraway for ground-based telescopes to confirm using the radial-velocity technique. The Kepler team says that a large fraction of their discoveries will be validated with both of these methods.

In the case of Kepler-10c, scientists can be 99.998 percent sure that the signal they detected is from an orbiting planet. Part of this confidence comes from the fact that Spitzer, an infrared observatory, saw a signal similar to what Kepler detected in visible light. If the signal were coming from something other than an orbiting planet -- for example an indistinguishable background pair of orbiting stars -- then scientists would expect to see different signals in visible and infrared light.

No time...but awesome.

The Most Expensive Part Is Not the First Two Steps

2011-05-20T16:08:00.000-07:00

I'm working on a lunar resources chimera post like what James did for us about He-3.

Mammalian Brain Expansion Due to Increased Sense of Smell?

2011-05-19T13:06:00.000-07:00

Mammals first evolved their characteristic large brains to enable a stronger sense of smell, according to a new study published this week in the journal Science by paleontologists from The University of Texas at Austin, Carnegie Museum of Natural History and St. Mary's University in San Antonio.

This latest study is the first to use CT technology, similar to medical scanners, to reconstruct the brains of two of the earliest known mammal species, both from the Jurassic fossil beds of China. The 3D scans revealed that even these tiny, 190-million-year-old animals had developed brains larger than expected for specimens of their period, particularly in the brain area for smell.

Among living animals, mammals have the largest brains relative to body size. Scientists have proposed many explanations, but because fossil skulls of early mammals are extremely rare, have been reluctant to cut them open for closer study, thus destroying the fossils. Scientists have mostly relied on comparative studies of living mammals.

"We studied the outside features of these fossils for years," said Tim Rowe, professor in the Jackson School of Geosciences and director of the Vertebrate Paleontology Laboratory at The University of Texas at Austin, and lead author of the new study. "But until now, studying the brains meant destroying the fossils. With CT technology, we can have our cake and eat it, too."

According to the study, other factors leading to larger brains in early mammals included greater tactile sensitivity and enhanced motor coordination. Fossils of some of the earliest mammals, such as Hadrocodium, bore full coats of fur, explaining the need for enhanced tactile sensitivity.

Rowe's co-authors are Thomas E. Macrini, assistant professor of biological sciences at St. Mary's University in San Antonio, and Zhe-Xi Luo, curator and associate director for research and collections at the Carnegie Museum of Natural History.

Macrini conducted much of this research for his doctoral dissertation at The University of Texas at Austin, in which he scanned the heads of numerous fossil and living species to visualize the size and shape of their brains.

"This is the most comprehensive study yet undertaken using computed tomography to study the evolution of the mammalian skull," said Macrini. "And it is exciting to see these new insights emerging from years of intense labor."

Luo was involved in the discovery and research on the fossils for this study. When he first described the paper clip-sized mammal Hadrocodium ten years ago, he named it for its relatively large cranium despite its appearance so early in the mammalian lineage ("hadro" means "fullness" in Latin and "codium" means "head").

hm. Do we see a similar trend for gorgons? They had an awesome sense of smell.

Another Xenopermian Teaser

2011-05-18T17:42:00.001-07:00

Zach did it.

Can you guess the lineage?

It LOVES walrodonts.

Cryptolacerta hassiaca: A New Basal Amphisbaenian

2011-05-18T15:21:00.001-07:00

The recent discovery by researchers from the University of Toronto Mississauga and the Museum für Naturkunde Berlin, Germany of a tiny, 47 million-year-old fossil of a lizard called Cryptolacerta hassiaca provides the first anatomical evidence that the body shapes of snakes and limbless lizards evolved independently.

"This fossil refutes the theory that snakes and other burrowing reptiles share a common ancestry and reveals that their body shapes evolved independently," says lead author Professor Johannes Müller of Humboldt-Universität, Berlin.

The fossil reveals that amphisbaenians are not closely related to snakes, but instead are related to lacertids, a group of limbed lizards from Europe, Africa and Asia. "This is the sort of study that shows the unique contributions of fossils in understanding evolutionary relationships," says Professor Robert Reisz from the University of Toronto Mississauga, the senior author of the study. "It is particularly exciting to see that tiny fossil skeletons can answer some really important questions in vertebrate evolution".

The German research team, led by Müller and American graduate student Christy Hipsley, used X-ray computed tomography to reveal the detailed anatomy of the lizard's skull and combined the anatomy of Cryptolacerta and other lizards with DNA from living lizards and snakes to analyze relationships. Their results showed that Cryptolacerta shared a thickened, reinforced skull with worm lizards and that both were most closely related to lacertids, while snakes were related to monitor lizards like the living Komodo dragons.

The press release was badly written, IMNSHO.

Triassic Archosaur Pushes Back Archosaurian Origins

2011-05-18T15:16:00.000-07:00

A fossil unearthed in China in the 1970s of a creature that died about 247 million years ago, originally thought to be a distant relative of both birds and crocodiles, turns out to have come from the crocodile family tree after it had already split from the bird family tree, according to research led by a University of Washington paleontologist.

The only known specimen of Xilousuchus sapingensis has been reexamined and is now classified as an archosaur. Archosaurs, characterized by skulls with long, narrow snouts and teeth set in sockets, include dinosaurs as well as crocodiles and birds.

The new examination dates the X. sapingensis specimen to the early Triassic period, 247 million to 252 million years ago, said Sterling Nesbitt, a UW postdoctoral researcher in biology. That means the creature lived just a short geological time after the largest mass extinction in Earth's history, 252 million years ago at the end of the Permian period, when as much as 95 percent of marine life and 70 percent of land creatures perished. The evidence, he said, places X. sapingensis on the crocodile side of the archosaur family tree.

"We're marching closer and closer to the Permian-Triassic boundary with the origin of archosaurs," Nesbitt said. "And today the archosaurs are still the dominant land vertebrate, when you look at the diversity of birds."

The work could sharpen debate among paleontologists about whether archosaurs existed before the Permian period and survived the extinction event, or if only archosaur precursors were on the scene before the end of the Permian.

"Archosaurs might have survived the extinction or they might have been a product of the recovery from the extinction," Nesbitt said.

The research is published May 17 online in Earth and Environmental Science Transactions of the Royal Society of Edinburgh, a journal of Cambridge University in the United Kingdom.

The paper is here.

16th Annual CESM Workshop: Final Agenda

2011-05-18T15:01:00.000-07:00

16th Annual CESM Workshop

20 - 23 June 2011

The Village, Breckenridge, Colorado

Monday, 20 June 2011
10:00 a.m. Registration
12:00 – 1:00 p.m. Lunch (on your own)
1:00 – 2:00 p.m. “State of the CESM” by Jim Hurrell, NCAR
2:00 – 3:00 p.m. CESM Distinguished Achievement Award
3:00 – 3:30 p.m. Break
3:30 – 5:00 p.m. Poster Session (Forest Room)
5:00 – 6:30 p.m. Reception (light appetizers and cash bar) (Elk Room; Antlers A; Antlers B)

Tuesday, 21 June 2011
7:00 – 8:30 a.m. Registration and Continental Breakfast
8:30 – 12:00p.m. Atmosphere Model Working Group Meeting (Ten Mile Room)
8:30 – 12:00p.m. Paleoclimate Working Group Meeting (Tarn Room)
8:30 – 12:00p.m. Polar Climate Working Group Meeting (Aspen / Blue Spruce Room)
10:30 – 11:00 a.m. Break
12:00 – 1:30 p.m. Lunch (on your own)
1:30 – 5:00 p.m. Ocean Model Working Group Meeting (Ten Mile Room)
1:30 – 5:00 p.m. Chemistry Climate Working Group Meeting (Tarn Room)
1:30 – 5:00 p.m. Land Model Working Group Meeting (Aspen / Blue Spruce Room)
3:00 – 3:30 p.m. Break
6:30 – 8:00 p.m. Interest Group on Uncertainty Quantification in Climate (Ten Mile Room)

Wednesday, 22 June 2011
7:00 – 8:30 a.m. Registration and Continental Breakfast
8:30 – 12:00 a.m. Biogeochemistry Working Group Meeting (Ten Mile Room)
8:30 – 12:00 a.m. Climate Variability Working Group Meeting (Tarn Room)
8:30 – 12:00 a.m. Land Ice Working Group Meeting (Aspen / Blue Spruce Room)
10:30 – 11:00 a.m. Break
12:00 – 2:00 p.m. Lunch (on your own)
2:00 – 3:00 p.m. Plenary Presentation – GFDL's ESM2 Series Simulations of Coupled Carbon, Climate and Ecosystems by John Dunne, NOAA / GFDL
3:00 – 3:30 p.m. Break
3:30 – 4:30 p.m. Plenary Presentation – Communicating the Credibility of Climate Change Science by Jeff Kiehl, NCAR

Thursday, 23 June 2011
7:00 – 8:30 a.m. Registration and Continental Breakfast
8:30 – 12:00 p.m. Software Engineering Working Group Meeting (Aspen / Blue Spruce Room)
8:30 – 12:00 p.m. Climate Change Working Group Meeting (Ten Mile Room)
8:30 – 12:00 p.m. WACCM Working Group Meeting (Tarn Room)
10:30 – 11:00 a.m. Break
12:00 – 1:30 p.m. Discussion and Wrap-up (Ten Mile Room)
1:30 p.m. Adjourn

Anyone Have a Copy?

2011-05-17T17:30:00.000-07:00

H. -D. Sues, J. A. Hopson, and N. H. Shubin. 1992. Affinities of Scalenodontoides plemmyridon Hopson, 1984 (Synapsida: Cynodontia) from the Upper Triassic of Nova Scotia. Journal of Vertebrate Paleontology 12(2):168-171 [R. Butler/R. Butler/R. Butler]

Any other more recent papers on Arctotraversodon would be welcome, too.

Thanx.

Climatically driven biogeographic provinces of Late Triassic tropical Pangea

2011-05-17T14:00:00.000-07:00

Climatically driven biogeographic provinces of Late Triassic tropical Pangea

1. Jessica H. Whiteside (a,*),
2. Danielle S. Grogan (a)
3. Paul E. Olsen (b,*)
4. Dennis V. Kent (b,c)

a. Department of Geological Sciences, Brown University, 324 Brook Street, Box 1846, Providence, RI 02912;

b. Lamont-Doherty Earth Observatory, Columbia University, 61 Route 9W, Palisades, NY 10964

c. Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854

*. To whom correspondence may be addressed. E-mail: Jessica_Whiteside@Brown.edu or polsen@ldeo.columbia.edu.

Abstract:

Although continents were coalesced into the single landmass Pangea, Late Triassic terrestrial tetrapod assemblages are surprisingly provincial. In eastern North America, we show that assemblages dominated by traversodont cynodonts are restricted to a humid 6° equatorial swath that persisted for over 20 million years characterized by “semiprecessional” (approximately 10,000-y) climatic fluctuations reflected in stable carbon isotopes and sedimentary facies in lacustrine strata. More arid regions from 5–20°N preserve procolophonid-dominated faunal assemblages associated with a much stronger expression of approximately 20,000-y climatic cycles. In the absence of geographic barriers, we hypothesize that these variations in the climatic expression of astronomical forcing produced latitudinal climatic zones that sorted terrestrial vertebrate taxa, perhaps by excretory physiology, into distinct biogeographic provinces tracking latitude, not geographic position, as the proto-North American plate translated northward. Although the early Mesozoic is usually assumed to be characterized by globally distributed land animal communities due to of a lack of geographic barriers, strong provinciality was actually the norm, and nearly global communities were present only after times of massive ecological disruptions.

ha! Called it! Over at Chineleana some time ago, I asked if anyone had looked at the difference in climates between the the American SW and the Newark Basin.

Note: SF Authors. If you have a supercontinent, its just as likely to have multiple ecosystems as a world broke up into multiple continents.

Another interesting note is that the procolophonids and the traversodont cynodonts seem to have been ecological equivalents. I don't know of any procs the size of Arctotraversodon though. It had a 40 cm skull, iirc.

Could Leakage from the Agulhas Current System Moderate Europe's Changed Climate?

2011-05-17T13:44:00.000-07:00

Neandertals Had Second Late Survival Locale in Russia?

2011-05-12T11:24:00.000-07:00

Scientists have identified what may be one of the last northern refuges of Neanderthals, a spot near the Arctic Circle in Russia with artifacts dated to 31,000 to 34,000 years ago.

Stone tools and flakes found there look like the work of Neanderthals, the stocky, muscular hunters who lived in Europe and western Asia until they were replaced by modern humans, researchers reported Thursday in the journal Science.

The site lies along the Pechora River west of the Ural Mountains, about 92 miles south of the Arctic Circle. Researchers dated it from animal bones and sand grains. Nobody has found any human bones or DNA that could provide stronger evidence that Neanderthals lived there, report the scientists, from Russia, France and Norway. The artifacts had been collected during various expeditions.

Neanderthals first appeared more than 200,000 years ago. They died out sometime after modern humans arrived in Europe, which occurred some 40,000 to 45,000 years ago.

Richard Klein, a Stanford University professor of anthropology, said the artifacts do look like the work of Neanderthals, but that it's also possible they were made by modern people instead.

Neanderthals were not previously known to be in that area, nor convincingly shown to be present anywhere at such a recent time, he said. Finding another site or human bones would help settle the question, he said.

paper here.

Paleocene Marsupials Demonstrate Social Behavior

2011-05-12T10:41:00.000-07:00

Evidence of lifestyle and social behavior is almost never preserved in the fossil record. Now, a group of researchers from the Muséum national d'Histoire naturelle (Paris), CNRS (Paris) and Museo de Historia naturel Alcide d'Orbigny de Cochabamba (Bolivia) has excavated a remarkable collection of dozens of small mammal skulls and skeletons from the Tiupampa site in the central Andes in Bolivia that provides compelling fossil evidence of social behavior. A study of these remains, published this week in Nature, reveals the oldest example of group-living in mammals.

Today, many mammals live in groups. Others, such as most marsupials (which include the South American opossums and Australian koalas and wombats), are strictly solitary. We know very little about social behavior of fossil mammals, because only rarely is the number of preserved individuals large enough to provide evidence of community life.

Now, the discovery of a population of a mouse-sized ancient relative of marsupials (Pucadelphys andinus) from the early Tertiary (64 million years ago) in Bolivia demonstrates that group-living appeared early in the mammalian history, and may even represent the ancestral condition for mammals as a whole.

Basal synapsids have already been shown to be social, just an fyi.

More on NASA's Discovery Mission Down Select

2011-05-12T10:25:00.000-07:00

Dollo's Law Has Exceptions?

2011-05-11T13:15:00.000-07:00

Ever since Charles Darwin proposed his theory of evolution in 1859, scientists have wondered whether evolutionary adaptations can be reversed.

Answering that question has proved difficult, partly due to conflicting evidence. In 2003, scientists showed that some species of insects have gained, lost and regained wings over millions of years. But a few years later, a different team found that a protein that helps control cells' stress responses could not evolve back to its original form.

Jeff Gore, assistant professor of physics at MIT, says the critical question to ask is not whether evolution is reversible, but under what circumstances it could be. "It's known that evolution can be irreversible. And we know that it's possible to reverse evolution in some cases. So what you really want to know is: What fraction of the time is evolution reversible?" he says.

By combining a computational model with experiments on the evolution of drug resistance in bacteria, Gore and his students have, for the first time, calculated the likelihood of a particular evolutionary adaptation reversing itself.

They found that a very small percentage of evolutionary adaptations in a drug-resistance gene can be reversed, but only if the adaptations involve fewer than four discrete genetic mutations. The findings will appear in the May 13 issue of the journal Physical Review Letters. Lead authors of the paper are two MIT juniors, Longzhi Tan and Stephen Serene.

Gore and his students used an experimental model system developed by researchers at Harvard University to study the evolution of a gene conferring resistance to the antibiotic cefotaxime in bacteria.

The Harvard team identified five mutations that are crucial to gaining resistance to the drug. Bacteria that have all five mutations are the most resistant, while bacteria with none are very susceptible to the drug. Susceptible bacteria can evolve toward resistance by gaining each of the five mutations, but they can't be acquired in any old order. That's because evolution can only proceed along a given path if each mutation along the way offers a survival advantage.

Scientists study these paths by creating a "fitness landscape": a diagram of possible genetic states for a particular gene, and each state's relative fitness in a given environment. There are 120 possible paths through which bacteria with zero mutations could accumulate all five, but the Harvard team found that only 18 could ever actually occur.

The MIT team built on that study by asking whether bacteria could evolve resistance to cefotaxime but then lose it if they were placed in a new environment in which resistance to the original drug hindered their ability to survive.

Genetic states that differ by only one mutation are always reversible if one state is more fit in one environment and the other is more fit in the other. The MIT researchers were able to study how the possibility of reversal decreases as the number of mutations between the two states increased.

"This is the first case where anyone's been able to say anything about how reversibility behaves as a function of distance," Gore says. "What we see in our system is that once the system gets four mutations, it's unable to get back to where it started."

Daniel Weinreich, assistant professor of biology at Brown University, says the study's most important contribution is its analysis of the reversibility between every possible intermediate state in the fitness landscape.

"What Jeff has done is show that there's another layer of mathematical complexity that enters when you ask questions about reversing environmental pressure," says Weinreich, who was not involved in this research.

In the late 19th century, paleontologist Louis Dollo argued that evolution could not retrace its steps to reverse complex adaptations — a hypothesis known as Dollo's law of irreversibility. Gore says his team's results offer support for Dollo's law, but with some qualifications.

"It's not that complex adaptations can never be reversed," he says. "It's that complex adaptations are harder to reverse, but in a sense that you can quantify."

The study also helps explain why organs no longer needed, such as the human appendix, do not readily disappear. "You can only ever really think about evolution reversing itself if there is a cost associated with the adaptation," Gore says. "For example, with the appendix, it may just be that the cost is very small, in which case there's no selective pressure to get rid of it."

hmmm.

Phantom Ray Takes Flight

2011-05-11T10:01:00.000-07:00

While China works on its J-20 - an interesting, if questionable analysis of the J-20 here and the F-22 fleet has oxygen generator problems - the US is rapidly working on its UCAVs. The Phantom Ray is the one above and conducted its first flight last month.

Also being worked on are the X-47B and Avenger.

Note the F-35 in the background above. The F-35 program delivered its first production aircraft this week as well. Still a ways from IOC though.

NASA Selects Next Discovery Missions

2011-05-10T15:52:00.000-07:00

ASA has selected three science investigations from which it will pick one potential 2016 mission to look at Mars' interior for the first time; study an extraterrestrial sea on one of Saturn's moons; or study in unprecedented detail the surface of a comet's nucleus.

Each investigation team will receive $3 million to conduct its mission's concept phase or preliminary design studies and analyses. After another detailed review in 2012 of the concept studies, NASA will select one to continue development efforts leading up to launch. The selected mission will be cost-capped at $425 million, not including launch vehicle funding.

NASA's Discovery Program requested proposals for spaceflight investigations in June 2010. A panel of NASA and other scientists and engineers reviewed 28 submissions. The selected investigations could reveal much about the formation of our solar system and its dynamic processes. Three technology developments for possible future planetary missions also were selected.

"NASA continues to do extraordinary science that is re-writing textbooks," said NASA Administrator Charles Bolden. "Missions like these hold great promise to vastly increase our knowledge, extend our reach into the solar system and inspire future generations of explorers."
The planetary missions selected to pursue preliminary design studies are:

* Geophysical Monitoring Station (GEMS) would study the structure and composition of the interior of Mars and advance understanding of the formation and evolution of terrestrial planets. Bruce Banerdt of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., is principal investigator. JPL would manage the project. [Editorial note: This previous post describes a two station Mars geophysical network, while the short description for this candidate proposal suggests it may be for a single station.]
* Titan Mare Explorer (TiME) would provide the first direct exploration of an ocean environment beyond Earth by landing in, and floating on, a large methane-ethane sea on Saturn's moon Titan. Ellen Stofan of Proxemy Research Inc. in Gaithersburg, Md., is principal investigator. Johns Hopkins University's Applied Physics Laboratory in Laurel, Md., would manage the project.
* Comet Hopper would study cometary evolution by landing on a comet multiple times and observing its changes as it interacts with the sun. Jessica Sunshine of the University of Maryland in College Park is principal investigator. NASA's Goddard Space Flight Center in Greenbelt, Md., would manage the project.

"This is high science return at a price that’s right," said Jim Green, director of NASA’s Planetary Science Division in Washington. "The selected studies clearly demonstrate a new era with missions that all touch their targets to perform unique and exciting science."

Torn between Titan and Mars here...

Parareptiles Not Hit as Badly by Permian Extinction?

2011-05-10T15:43:00.000-07:00

The end-Permian extinction, by far the most dramatic biological crisis to affect life on Earth, may not have been as catastrophic for some creatures as previously thought, according to a new study led by the University of Bristol.

An international team of researchers studied the parareptiles, a diverse group of bizarre-looking terrestrial vertebrates which varied in shape and size. Some were small, slender, agile and lizard-like creatures, while others attained the size of rhinos; many had knobbly ornaments, fringes, and bony spikes on their skulls.

The researchers found that, surprisingly, parareptiles were not hit much harder by the end-Permian extinction than at any other point in their 90 million-year history. Furthermore, the group as a whole declined and diversified time and time again throughout its history, and it was not until about 50 million years after the end-Permian crisis that the parareptiles finally disappeared.

During the end-Permian extinction, some 250 million years ago, entire groups of animals and plants either vanished altogether or decreased significantly in numbers, and the recovery of the survivors was at times slow and prolonged before new radiations took place.

By studying the fossil record, palaeontologists can examine how individual groups of organisms responded to the end-Permian event and assess just how dramatic it was. However, as the quality and completeness of the fossil record varies considerably, both geographically and stratigraphically, palaeontologists need to find a way to ‘join the dots’ and piece together the fragments of a complex mosaic to give a more satisfactory and better picture of ancient life’s diversity.

Paper here.

CAM Plants Spread During Miocene When Habitat Expanded

2011-05-05T12:35:00.000-07:00

n a paper published in the early edition of the Proceedings of the National Academy of Sciences, Brown University biologists and colleagues have discovered that the rapid speciation of cacti occurred between 5 and 10 million years ago and coincided with species explosions by other succulent plant groups around the world. The researchers propose that a prolonged dry spell and possibly lower levels of atmospheric carbon dioxide during that time, known as the late Miocene, opened habitat that contributed to the rise of these plants and a broad vegetative makeover on Earth.

"The cacti, as a group, have been around for a while, but most of the species diversity that we see today was generated really recently," said Monica Arakaki, a postdoctoral researcher at Brown and the paper's lead author.

The Brown team and colleagues from Oberlin College and the University of Zurich, Switzerland, were interested primarily in dating the origins of the cacti (scientific name Cactaceae). The team sequenced the chloroplast genomes (the organelles inside plant leaves that engineer photosynthesis) for a dozen cacti and their relatives and combined their new genomic data with existing genomes to build a phylogeny, or evolutionary tree, for angiosperms, the genealogical line of flowering plants that represents roughly 90 percent of all plants worldwide. From there, the scientists deduced that Cactaceae first diverged from its angiosperm relatives roughly 35 million years ago but didn't engage in rapid speciation for at least another 25 million years.

"Cacti were actually present on the landscape for millions of years — looking like cacti and acting like cacti — before they began their major diversification," said Erika Edwards, assistant professor of biology in the Department of Ecology and Evolutionary Biology at Brown and corresponding author on the paper.

The team then sifted through the literature on the timing of diversification in other succulents from regions around the globe. Succulents include aloes, the agaves of North America, the ice plants of South Africa and other lineages. Their comfort zone is in water-limited climates, and they have adapted physical characteristics to cope in those locales, such as shallow root systems, specialized water-storing tissue and exchanging gas at night, when it is cooler and less humid and so less water is lost. What struck the researchers was that all the succulent lineages, across habitats and continents, underwent major speciation between 5 and 10 million years ago, during roughly the same time period as the cacti.

C4 grasses, the tropical grasses that are now up to 20 percent of our planet's vegetative covering, burst onto the scene as well during this same window of time.

This must be more than a coincidence, the researchers thought. "It isn't overly surprising that most of the standing cactus diversity is relatively young. But when you put these species radiations in the context of all the other changes in plant communities that were happening at that very moment, all over the world, it begs some sort of global environmental driver," Edwards said.

The most plausible causes, the scientists thought, were a drying out of the planet and lowering of atmospheric carbon-dioxide levels. A wealth of research involving oxygen isotopes from a deep-sea organism showed the Earth underwent a drop in temperature, which the researchers believe led to reduced rainfall and increased aridity worldwide.

The carbon-dioxide link is more nuanced and controversial. The authors highlight one study that inferred atmospheric CO2 levels spiraled downward beginning roughly 15 million years ago. Combined with global cooling, "a drop in CO2 concentration would therefore immediately expand the ecological space in which drought-adapted succulent plants, with their high photosynthetic water use efficiency, would be competitive," the authors write.

"We suggest that a rapid expansion of available habitat (rather than any particular new 'key' innovation) during the late Miocene was a primary driver of the global diversification of plant lineages already possessing a preadapted succulent syndrome," the researchers write. "Against a backdrop of increasing global aridity, a sharp CO2 decline is a plausible driver of the simultaneous expansion of C4 grasslands, the clustering of new C4 origins, and the diversification of succulent lineages."

New High Quality J-20 Picture

2011-05-05T12:25:00.000-07:00

Rain Forest Correlated Characteristic IDed in Flowering Plants

2011-05-05T12:21:00.000-07:00

A team of scientists, including several from the Smithsonian Institution, discovered that leaves of flowering plants in the world's first rainforests had more veins per unit area than leaves ever had before. They suggest that this increased the amount of water available to the leaves, making it possible for plants to capture more carbon and grow larger. A better plumbing system may also have radically altered water and carbon movement through forests, driving environmental change.

"It's fascinating that a simple leaf feature such as vein density allows one to study plant performance in the past," said Klaus Winter, staff scientist at the Smithsonian Tropical Research Institute in Panama, who was not an author, "Of course, you can't directly measure water flow through fossil leaves. When plants fix carbon, they lose water to the atmosphere. So to become highly productive, as many modern flowering plants are, requires that plants have a highly elaborate plumbing system."

A walk through a tropical forest more than 100 million years ago would have been different than a walk through a modern rainforest. Dinosaurs were shaded by flowerless plants like cycads and ferns. Fast-forward 40 million years. The dinosaurs have disappeared and the first modern rainforests have appeared: a realm of giant trees—with flowers. By examining images of more than 300 hundred kinds of fossil leaves, the team, led by Taylor Feild from the University of Tennessee, Knoxville, counted how many veins there were in a given area of leaf. Flowerless plants then and now have relatively few veins. But their work shows that even after flowering plants evolved, it took some time before they developed the efficient plumbing systems that would allow them to develop into giant life-forms like tropical trees. The density of veins in the leaves of flowering plants increased at least two different times as the transition from ancient to modern rainforests took place, according to this research reported in the journal, Proceedings of the National Academy of Sciences.

The first jump—when the vein density in fossil leaves of flowering plants first exceeded vein density in the leaves of flowerless plants—took place approximately one hundred million years ago. The second and more significant increase in vein density took place 35 million years later. Petrified tree trunks more than a meter in diameter were first found from this period, indicating another landmark—the evolution of flowering trees. Soon the leaves of flowering plants had twice more veins per unit leaf area than the non-flowering plants. By the end of the Cretaceous period about 65 million years ago, the number of leaf veins per unit area was very similar to that of modern rainforest leaves.

Exoplanet 55 Cancri e Has a Density Greater Than Lead

2011-05-05T12:15:00.000-07:00

An international team of astronomers today revealed details of a "super-exotic" exoplanet that would make the planet Pandora in the movie Avatar pale in comparison.

The planet, named 55 Cancri e, is 60 per cent larger in diameter than Earth but eight times as massive. Twice as dense as Earth – almost as dense as lead – it is the densest solid planet known, according to a team led by astronomers from the Massachusetts Institute of Technology (MIT), the University of British Columbia (UBC), the Harvard‑Smithsonian Center for Astrophysics and the University of California at Santa Cruz (UCSC).

The research, based on observations from Canada's MOST (Microvariability & Oscillations of STars) space telescope, was released online today at arXiv.org and has been submitted for publication in The Astrophysical Journal Letters. MOST is a Canadian Space Agency mission.

Approximately 40 light years from Earth, 55 Cancri e orbits a star – called 55 Cancri A – so closely that its year is less than 18 hours long. "You could set dates on this world by your wrist watch, not a calendar," says UBC astronomer Jaymie Matthews.

The temperature on the planet's surface could be as high as 2,700 degrees Celsius. "Because of the infernal heat, it's unlikely that 55 Cancri e has an atmosphere," says lead author Josh Winn of MIT. "So this is not the type of place where exobiologists would look for life."

However, 55 Cancri e is the type of place exoplanetary scientists will be eager to "visit" with their telescopes, says Winn. "The brightness of the host star makes many types of sensitive measurements possible, so 55 Cancri e is the perfect laboratory to test theories of planet formation, evolution and survival."

While the planet isn't visible, even through a telescope, its host star, 55 Cancri A, can be observed with the naked eye for the next two months on a clear dark night.

"On this world – the densest solid planet found anywhere so far, in the Solar System or beyond – you would weigh three times heavier than you do on Earth. By day, the sun would look 60 times bigger and shine 3,600 times brighter in the sky," says Matthews, MOST Mission Scientist and second author on the paper.

That is one weird system.

South African Ocean Currents Could Stabilize Europe's Climate

2011-05-05T11:25:00.000-07:00

One of the ocean currents which particularly interests oceanographers and climatologists is the Gulf Stream. This current, originating in the Gulf of Mexico, transports enormous amounts of warm tropical waters to the North Atlantic and is the cause of Europe's habitable climate. Climate predictions point to the fact that this will change in the future and affect especially the climate in countries of the Mediterranean region, with more dry spells. As global warming progresses, the North Atlantic will receive more precipitation and a greater amount of water from the melting of glaciers in Greenland, thus reducing the salinity of ocean water and weakening the Gulf Stream's effects.

The article published in Nature describes an alternative approach which suggests that flows from the Indian Ocean to the South Atlantic, near the tip of Africa, also are important in relation to future current systems in the North Atlantic.

The Agulhas Current, located in the southwest of the Indian Ocean, transports high density salt water to the southern tip of Africa, where part of it escapes to the South Atlantic, contributing to the strength of the global circulation of this ocean. The study describes how this inflow of salt water from the Indian Ocean can compensate the decrease in salinity in the North Atlantic and therefore stabilise the Gulf Stream and the climate in Europe. These processes have been simulated using computational climate models.

The article reviews information available until now and enumerates the steps which must be taken with the aim of carrying out a better assessment of the processes involved in this current system. To demonstrate the dynamics of the Agulhas Current, its sensitivity to climate change and the way it transmits its signals to the North Atlantic, researchers point out the need to combine long-term studies on temperature variation and salinity of the Agulhas Current, analyses on climate changes in the past and detailed computer simulation models.

Let's hope so our its going to be very uncomfy in Europe soon.

Increasing the Awesome

2011-05-03T21:52:00.000-07:00

Could China's Energy Consumption Stabilize?

2011-04-27T10:47:00.000-07:00

As China's economy continues to soar, its energy use and greenhouse gas emissions will keep on soaring as well—or so goes the conventional wisdom. A new analysis by researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) now is challenging that notion, one widely held in both the United States and China.

Well before mid-century, according to a new study by Berkeley Lab's China Energy Group, that nation's energy use will level off, even as its population edges past 1.4 billion. "I think this is very good news,'' says Mark Levine, co-author of the report, "China's Energy and Carbon Emissions Outlook to 2050" and director of the group. "There's been a perception that China's rising prosperity means runaway growth in energy consumption. Our study shows this won't be the case."

Along with China's rise as a world economic power have come a rapid climb in energy use and a related boost in man-made carbon dioxide emissions. In fact, China overtook the United States in 2007 as the world's leading emitter of greenhouse gases.

Yet according to this new forecast, the steeply rising curve of energy demand in China will begin to moderate between 2030 and 2035 and flatten thereafter. There will come a time—within the next two decades—when the number of people in China acquiring cars, larger homes, and other accouterments of industrialized societies will peak. It's a phenomenon known as saturation. "Once nearly every household owns a refrigerator, a washing machine, air conditioners and other appliances, and once housing area per capita has stabilized, per household electricity growth will slow,'' Levine explains.

Similarly, China will reach saturation in road and rail construction before the 2030-2035 time frame, resulting in very large decreases in iron and steel demand. Additionally, other energy-intensive industries will see demand for their products flatten.

The Berkeley Lab report also anticipates the widespread use of electric cars, a significant drop in reliance on coal for electricity generation, and a big expansion in the use of nuclear power—all helping to drive down China's CO2 emissions. Although China has temporarily suspended approvals of new nuclear power plant construction in the wake of the disaster at Japan's Fukushima Daiichi Nuclear Power Station, the long-range forecast remains unchanged.

Key to the new findings is a deeper look at patterns of energy demand in China: a "bottom-up" modeling system that develops projections of energy use in far greater detail than standard methods and which is much more time- and labor-intensive to undertake. Work on the project has been ongoing for the last four years. "Other studies don't have this kind of detail,'' says Levine. "There's no model outside of China that even comes close to having this kind of information, such as our data on housing stock and appliances."

Not only does the report examine demand for appliances such as refrigerators and fans, it also makes predictions about adoption of improvements in the energy efficiency of such equipment – just as Americans are now buying more efficient washing machines, cars with better gas-mileage, and less power-hungry light bulbs.

Berkeley Lab researchers Nan Zhou, David Fridley, Michael McNeil, Nina Zheng, and Jing Ke co-authored the report with Levine. Their study is a "scenario analysis" that forecasts two possible energy futures for China, one an "accelerated improvement scenario" that assumes success for a very aggressive effort to improve energy efficiency, the other a more conservative "continued improvement scenario" that meets less ambitious targets. Yet both of these scenarios, at a different pace, show similar moderation effects and a flattening of energy consumption well before 2050.

Under the more aggressive scenario, energy consumption begins to flatten in 2025, just 14 years from now. The more conservative scenario sees energy consumption rates beginning to taper in 2030. By the mid-century mark, energy consumption under the "accelerated improvement scenario" will be 20 percent below that of the other.

Scenario analysis is also used in more conventional forecasts, but these are typically based on macroeconomic variables such as gross domestic product and population growth. Such scenarios are developed "without reference to saturation, efficiency, or usage of energy-using devices, e.g., air conditioners,'' says the Berkeley Lab report. "For energy analysts and policymakers, this is a serious omission, in some cases calling into question the very meaning of the scenarios.''

The new Berkeley Lab forecast also uses the two scenarios to examine CO2 emissions anticipated through 2050. Under the more aggressive scenario, China's emissions of the greenhouse gas are predicted to peak in 2027 at 9.7 billion metric tons. From then on, they will fall significantly, to about 7 billion metric tons by 2050. Under the more conservative scenario, CO2 emissions will reach a plateau of 12 billion metric tons by 2033, and then trail down to 11 billion metric tons at mid-century.

Several assumptions about China's efforts to "decarbonize" its energy production and consumption are built into the optimistic forecasts for reductions in the growth of greenhouse gas emissions. They include:

A dramatic reduction in coal's share of energy production, to as low as 30 percent by 2050, compared to 74 percent in 2005

An expansion of nuclear power from 8 gigwatts in 2005 to 86 gigawatts by 2020, followed by a rise to as much as 550 gigawatts in 2050

A switch to electric cars. The assumption is that urban private car ownership will reach 356 million vehicles by 2050. Under the "continued improvement scenario," 30 percent of these will be electric; under the "accelerated improvement scenario," 70 percent will be electric.

hmm. That's all I am gonna say until I can squeeze in a chance to read the report.

Further Examination of the PETM

2011-04-21T12:44:00.000-07:00

The Earth may be able to recover from rising carbon dioxide emissions faster than previously thought, according to evidence from a prehistoric event analyzed by a Purdue University-led team.

When faced with high levels of atmospheric carbon dioxide and rising temperatures 56 million years ago, the Earth increased its ability to pull carbon from the air. This led to a recovery that was quicker than anticipated by many models of the carbon cycle - though still on the order of tens of thousands of years, said Gabriel Bowen, the associate professor of earth and atmospheric sciences who led the study.

"We found that more than half of the added carbon dioxide was pulled from the atmosphere within 30,000 to 40,000 years, which is one-third of the time span previously thought," said Bowen, who also is a member of the Purdue Climate Change Research Center. "We still don't know exactly where this carbon went, but the evidence suggests it was a much more dynamic response than traditional models represent."

Bowen worked with James Zachos, a professor of earth and planetary sciences at the University of California, Santa Cruz, to study the end of the Palaeocene-Eocene Thermal Maximum, an approximately 170,000-year-long period of global warming that has many features in common with the world's current situation, he said.

"During this prehistoric event billions of tons of carbon was released into the ocean, atmosphere and biosphere, causing warming of about 5 degrees Celsius," Bowen said. "This is a good analog for the carbon being released from fossil fuels today."

Scientists have known of this prehistoric event for 20 years, but how the system recovered and returned to normal atmospheric levels has remained a mystery.

Bowen and Zachos examined samples of marine and terrestrial sediments deposited throughout the event. The team measured the levels of two different types of carbon atoms, the isotopes carbon-12 and carbon-13. The ratio of these isotopes changes as carbon dioxide is drawn from or added to the atmosphere during the growth or decay of organic matter.

Plants prefer carbon-12 during photosynthesis, and when they accelerate their uptake of carbon dioxide it shifts the carbon isotope ratio in the atmosphere. This shift is then reflected in the carbon isotopes present in rock minerals formed by reactions involving atmospheric carbon dioxide, Bowen said.

"The rate of the carbon isotope change in rock minerals tells us how rapidly the carbon dioxide was pulled from the atmosphere," he said. "We can see the fluxes of carbon dioxide in to and out of the atmosphere. At the beginning of the event we see a shift indicating that a lot of organic-derived carbon dioxide had been added to the atmosphere, and at the end of the event we see a shift indicating that a lot of carbon dioxide was taken up as organic carbon and thus removed from the atmosphere."

A paper detailing the team's National Science Foundation-funded work was published in Nature Geoscience.

It had been thought that a slow and fairly constant recovery began soon after excess carbon entered the atmosphere and that the weathering of rocks, called silicate weathering, dictated the timing of the response.

Atmospheric carbon dioxide that reacts with silicon-based minerals in rocks is pulled from the air and captured in the end product of the reaction. This mechanism has a fairly direct correlation with the amount of carbon dioxide in the atmosphere and occurs relatively slowly, Bowen said.

The changes Bowen and Zachos found during the Palaeocene-Eocene Thermal Maximum went beyond the effects expected from silicate weathering, he said.

"It seems there was actually a long period of higher levels of atmospheric carbon dioxide followed by a short and rapid recovery to normal levels," he said. "During the recovery, the rate at which carbon was pulled from the atmosphere was an order of magnitude greater than the slow drawdown of carbon expected from silicate weathering alone."

A rapid growth of the biosphere, with a spread of forests, plants and carbon-rich soils to take in the excess carbon dioxide, could explain the quick recovery, Bowen said.

"Expansion of the biosphere is one plausible mechanism for the rapid recovery, but in order to take up this much carbon in forests and soils there must have first been a massive depletion of these carbon stocks," he said. "We don't currently know where all the carbon that caused this event came from, and our results suggest the troubling possibility that widespread decay or burning of large parts of the continental biosphere may have been involved."

Release from a different source, such as volcanoes or sea floor sediments, may have started the event, he said.

Marsupials with Skink Like Dentation

2011-04-21T12:37:00.000-07:00

Hammer-toothed ‘marsupial skinks' from the Australian Cenozoic

1. Derrick A. Arena (A,*)
2. Michael Archer (A)
3. Henk Godthelp (A),
4. Suzanne J. Hand (A)
5. Scott Hocknull (B)

A. School of Biological, Earth and Environmental Sciences, University of New South Wales, New South Wales 2052, Australia
B. Queensland Museum South Bank, Brisbane, Queensland 4101, Australia

*. Author for correspondence (r.arena@unsw.edu.au).

Abstract:

Extinct species of Malleodectes gen. nov. from Middle to Late Miocene deposits of the Riversleigh World Heritage Area, northwestern Queensland, Australia are enigmatic, highly specialized, probably snail-eating marsupials. Dentally, they closely resemble a bizarre group of living heterodont, wet forest scincid lizards from Australia (Cyclodomorphus) that may well have outcompeted them as snail-eaters when the closed forests of central Australia began to decline. Although there are scincids known from the same Miocene deposits at Riversleigh, these are relatively plesiomorphic, generalized feeders. This appears to be the most striking example known of dental convergence and possible competition between a mammal and a lizard, which in the long run worked out better for the lizards.

no time. Link to paper at the top.

Flight Testing the Avenger UCAV

2011-04-20T15:16:00.000-07:00

Draft Agenda for 16th Annual CESM Workshop

2011-04-20T15:01:00.000-07:00

DRAFT AGENDA

16th Annual CESM Workshop

20 - 23 June 2011

The Village, Breckenridge, Colorado

Monday, 20 June 2011

10:00 a.m. Registration

12:00 – 1:00 p.m. Lunch (on your own)

1:00 – 2:00 p.m. “State of the CESM” by Jim Hurrell, NCAR

2:00 – 3:00 p.m. CCSM Distinguished Achievement Award

3:00 – 3:30 p.m. Break

3:30 – 5:00 p.m. Poster Session (Forest Room)

5:00 – 6:30 p.m. Reception (light appetizers and cash bar) (Elk Room; Antlers A; Antlers B)

Tuesday, 21 June 2011

7:00 – 8:30 a.m. Registration and Continental Breakfast

8:30 – 12:00p.m. Atmosphere Model Working Group Meeting (Ten Mile Room)

8:30 – 12:00p.m. Paleoclimate Working Group Meeting (Tarn Room)

8:30 – 12:00p.m. Polar Climate Working Group Meeting (Aspen / Blue Spruce Room)

10:30 – 11:00 a.m. Break

12:00 – 1:30 p.m. Lunch (on your own)

1:30 – 5:00 p.m. Ocean Model Working Group Meeting (Ten Mile Room)

1:30 – 5:00 p.m. Chemistry Climate Working Group Meeting (Tarn Room)

1:30 – 5:00 p.m. Land Model Working Group Meeting (Aspen / Blue Spruce Room)

3:00 – 3:30 p.m. Break

Wednesday, 22 June 2011

7:00 – 8:30 a.m. Registration and Continental Breakfast

8:30 – 12:00 a.m. Biogeochemistry Working Group Meeting (Ten Mile Room)

8:30 – 12:00 a.m. Climate Variability Working Group Meeting (Tarn Room)

8:30 – 12:00 a.m. Land Ice Working Group Meeting (Aspen / Blue Spruce Room)

10:30 – 11:00 a.m. Break

12:00 – 2:00 p.m. Lunch (on your own)

2:00 – 3:00 p.m. Plenary Presentation – GFDL's ESM2 Series Simulations of Coupled Carbon, Climate and Ecosystems by John Dunne, NOAA / GFDL

3:00 – 3:30 p.m. Break

3:30 – 4:30 p.m. Plenary Presentation – by Jeff Kiehl, NCAR

Thursday, 23 June 2011

7:00 – 8:30 a.m. Registration and Continental Breakfast

8:30 – 12:00 p.m. Software Engineering Working Group Meeting (Aspen / Blue Spruce Room)

8:30 – 12:00 p.m. Climate Change Working Group Meeting (Ten Mile Room)

8:30 – 12:00 p.m. WACCM Working Group Meeting (Tarn Room)

10:30 – 11:00 a.m. Break

12:00 – 1:30 p.m. Discussion and Wrap-up (Ten Mile Room)

1:30 p.m. Adjourn

Link to the PDF is at the top.

First Detailed Maps of Canopy Height and Carbon Stock in US

2011-04-20T12:49:00.000-07:00

The Woods Hole Research Center has released the first hectare-scale maps of canopy height, aboveground biomass, and associated carbon stock for the forests and woodlands of the conterminous United States. The multi-year project, referred to as the National Biomass and Carbon Dataset (NBCD), produced maps of these key forest attributes at an unprecedented spatial resolution of 30 m. The digital raster data set is now freely accessible from the WHRC website at www.whrc.org/nbcd.

According to Dr. Josef Kellndorfer, who led the project at WHRC, "We are excited about the completion of this mapping project. The dataset represents a comprehensive assessment of forest structure and carbon stock within the lower 48 States at the beginning of the third millennium, providing an important baseline with which to improve our understanding of the United States forest resources and its link to the terrestrial carbon flux in North America. This dataset will be useful to foresters, wildlife ecologists, resource managers, and scientists alike."

Volker Radeloff, professor at the University of Wisconsin-Madison, Department of Forest and Wildlife Ecology, added, "Vegetation structure data has been the holy grail for biodiversity science: absolutely essential, but unattainable for large areas. The NBCD data set fills this crucial gap and will advance of our understanding of why biodiversity is so much higher in some areas than others, and target biodiversity conservation efforts."

The project was initiated in 2005 with funding from NASA's Terrestrial Ecology Program as well as support from the USGS/LANDFIRE consortium. Collaborators included the U.S. Forest Service Forest Inventory and Analysis (FIA) Program, and the National Land Cover Database (NLCD 2001) and National Elevation Dataset (NED) project teams at the USGS EROS Data Center.

To produce this first-of-its-kind data set, NASA space-borne imagery (SRTM/Landsat-7), land use/land cover information (NLCD 2001), topographic survey data (NED), and extensive forest inventory data (FIA) were combined. Production of the NBCD followed an ecoregional mapping zone approach developed for the NLCD 2001 project. Across 66 individual mapping zones, spatial data, field observations, and statistical models were used to generate the canopy height, aboveground biomass, and carbon stock maps, which were then joined to form national-scale products.

"This effort is an excellent example of FIA partnering to marry ground and remotely-sensed data to provide natural resource information at resolutions much finer than the FIA sampling frame," said Dennis May, Forest Inventory and Analysis program manager with the U.S. Forest Service, Northern Research Station.

Dr. Wayne Walker, a Center scientist who also worked on the project, added, "Maps of key forest attributes like canopy height and carbon stock have not existed for the U.S. at this level of spatial detail and consistency. They will provide ecologists and land managers with new and better information to support biodiversity conservation, wildfire risk assessment, and timber production while helping climate scientists and others to better understand the role that U.S. forests play in the global carbon cycle."

Potential for American Biological Carbon Sequestration Increased

2011-04-20T10:14:00.001-07:00

A research group has concluded that forests and other terrestrial ecosystems in the lower 48 states can sequester up to 40 percent of the nation’s fossil fuel carbon emissions, a larger amount than previously estimated – unless a drought or other major disturbance occurs.

Widespread droughts, such as those that occurred in 2002 and 2006, can cut the amount of carbon sequestered by about 20 percent, the scientists concluded in a recent study that was supported by the National Science Foundation and U.S. Department of Energy.

The research, published by scientists from 35 institutions in the journal Agricultural and Forest Meteorology, was based on satellite measurements and dozens of environmental observation sites in the AmeriFlux network. Not all of this data had previously been incorporated into earlier estimates, and the new study provides one of the most accurate assessments to date of the nation’s carbon balance.

“With this data it appears that our forests and other vegetation can sequester as much as 40 percent of the carbon emissions in the lower 48 states,” said Beverly Law, a co-author of the study, professor in the Department of Forest Ecosystems and Society at Oregon State University, and science team chair of the AmeriFlux network.

“That’s substantially higher than some previous estimates, which indicated these ecosystems could take up the equivalent of only about 30 percent of emissions or less,” Law said. “There’s still some uncertainty in these data, but it does appear that the terrestrial carbon sink is higher than believed in earlier studies.”

However, the scientists cautioned that major disturbances, such as droughts, wildfires and hurricanes, can all affect the amount of carbon sequestered in a given year. Large droughts that happened twice in the U.S. in the past decade reduced the carbon sink about 20 percent, compared to a normal year.

“With climate change, we may get more extreme or frequent weather events in the future than we had before,” Law said. “About half of the United States was affected by the major droughts in 2002 and 2006, which were unusually severe in their spatial extent and severity. And we’re now learning that this can have significant effects on the amount of carbon sequestered in a given year.”

Carbon dioxide, when released by the burning of fossil fuels, forest fires, or other activities, is a major “greenhouse gas” and factor in global warming. But vegetation, mostly in the form of growing evergreen and deciduous forests, can play an important role in absorbing some of the excess carbon dioxide.

Such information is important to understand global climate issues and develop policies, the researchers noted. This study examined the carbon budget in the U.S. from 2001 to 2006. Also playing a key role in the analysis was the PRISM climate database at OSU, a sophisticated system to monitor weather on a very localized and specific basis.

The period from 2001-06, the researchers noted, had some catastrophic and unusual events, not the least of which was Hurricane Katrina and the massive destruction it caused. It also factored in the 2002 Biscuit Fire in southwest Oregon, one of the largest forest fires in modern U.S. history.

The research found that the temperate forests in the eastern U.S. absorbed carbon mainly because of forest regrowth following the abandonment of agricultural lands, while some areas of the Pacific Northwest assimilated carbon during much of the year because of the region’s mild climate.

Crop lands were not considered in determining the annual magnitude of the U.S. terrestrial carbon sink, because the carbon they absorb each year during growth will be soon released when the crops are harvested or their biomass burned.

The study was led by Jingfeng Xiao, a research assistant professor at the Complex Systems Research Center, Institute for the Study of Earth, Oceans, and Space, at the University of New Hampshire.

Given that the climate would shift would probably cause a lot more droughts, the amount of sequestration is iffy given their own results.

Stunning Hubble Pic

2011-04-20T09:37:00.000-07:00

Oak Ridge National Lab Offline

2011-04-19T17:02:00.000-07:00

A highly sophisticated cyber attack -- known as Advanced Persistent Threat or APT -- forced Oak Ridge National Laboratory to shut down all Internet access and email systems over the weekend.

Those restrictions will remain in place until lab officials and others investigating the attack are sure the situation is well controlled and manageable, ORNL Director Thom Mason said today.

Mason said he expects that email functions may be restored Tuesday on a limited basis, with no attachments allowed and restrictions on length. He said he couldn't speculate on when Internet access will be restored fully, even though the shutdown limits many of the lab's functions.

"We made the decision (at about midnight Friday) to close down the connection to the Internet to make sure there was no data exfiltrated from the lab while we got the system cleaned up," he said.

The lab's cyber specialists had been monitoring the attack and recommended further action after it looked like efforts were underway to remove data from ORNL systems, Mason said.

Mason said the APT at ORNL is similar to attacks in recent times on Google, a security company known as RSA and other government institutions and corporations.

"In this case, it was initiated with phishing email, which led to the download of some software that took advantage of a 'zero day exploit,' a vulnerability for which there is no patch yet issued," he said. The vulnerability involved Internet Explorer, he said.

bah.

Reconstructed Enzymes Suggest Hot, Acidic Conditions for Early Life

2011-04-19T14:43:00.000-07:00

A new study reveals that a group of ancient enzymes adapted to substantial changes in ocean temperature and acidity during the last four billion years, providing evidence that life on Early Earth evolved from a much hotter, more acidic environment to the cooler, less acidic global environment that exists today.

The study found that a group of ancient enzymes known as thioredoxin were chemically stable at temperatures up to 32 degrees Celsius (58 degrees Fahrenheit) higher than their modern counterparts. The enzymes, which were several billion years old, also showed increased activity at lower pH levels -- which correspond to greater acidity.

"This study shows that a group of ubiquitous proteins operated in a hot, acidic environment during early life, which supports the view that the environment progressively cooled and became more alkaline between four billion and 500 million years ago," said Eric Gaucher, an associate professor in the School of Biology at the Georgia Institute of Technology.

The study, which was published April 3 in the advance online edition of the journal Nature Structural & Molecular Biology, was conducted by an international team of researchers from Georgia Tech, Columbia University and the Universidad de Granada in Spain.

Major funding for this study was provided by two grants from the National Aeronautics and Space Administration to Georgia Tech, a grant from the National Institutes of Health to Columbia University, and a grant from the Spanish Ministry of Science and Innovation to the Universidad de Granada.

Using a technique called ancestral sequence reconstruction, Gaucher and Georgia Tech biology graduate student Zi-Ming Zhao reconstructed seven ancient thioredoxin enzymes from the three domains of life -- archaea, bacteria and eukaryote -- that date back between one and four billion years.

To resurrect these enzymes, which are found in nearly all known modern organisms and are essential for life in mammals, the researchers first constructed a family tree of the more than 200 thioredoxin sequences available from the three domains of life. Then they reconstructed the sequences of the ancestral thioredoxin enzymes using statistical methods based on maximum likelihood. Finally, they synthesized the genes that encoded these sequences, expressed the ancient proteins in the cells of modern Escherichia coli bacteria and then purified the proteins.

"By resurrecting proteins, we are able to gather valuable information about the adaptation of extinct forms of life to climatic, ecological and physiological alterations that cannot be uncovered through fossil record examinations," said Gaucher.

The reconstructed enzymes from the Precambrian period -- which ended about 542 million years ago -- were used to examine how environmental conditions, including pH and temperature, affected the evolution of the enzymes and their chemical mechanisms.

"Given the ancient origin of the reconstructed thioredoxin enzymes, with some of them predating the buildup of atmospheric oxygen, we thought their catalytic chemistry would be simple, but we found that thioredoxin enzymes use a complex mixture of chemical mechanisms that increases their efficiency over the simpler compounds that were available in early geochemistry," said Julio Fernández, a professor in the Department of Biological Sciences professor at Columbia University.

no time.

She Flew Again (China's J-20 "Black Eagle")

2011-04-19T12:36:00.001-07:00

Phylogenetics Show Green Algae Closest to Ancestors of Plants?

2011-04-18T12:18:00.000-07:00

t was previously thought that land plants evolved from stonewort-like algae. However, new research published in BioMed Central's open access journal BMC Evolutionary Biology shows that the closest relatives to land plants are actually conjugating green algae such as Spirogyra.

Ancestors of green plants began to colonise the land about 500 million years ago and it is generally accepted that they evolved from streptophyte algae (a group of green, fresh water algae). But this group of algae is very diverse and currently ranges from simple, one cell, flagellates to more complex, branching, algae such as stoneworts (Chara).

It was thought that Charales were the closest relatives to land plants because they share (amongst other characteristics) a similar method of fertilisation, oogamy, with a large egg and small swimming sperm. For flowering plants this sperm is contained within pollen grains. In contrast, another type of streptophytes, the Zygnematales, use conjugation, a method of reproduction where the gametes are of equal size, isogamy, and one or both crawl, amoeba-like, into a fertilization tube where they meet and fuse.

Some phylogenetic analysis had been done previously, on a smaller number of genes, which seemed to support the Charales theory. However, a multinational team, involving researchers in Germany and Canada, analysed genetic divergence in 129 genes from 40 different green plant taxa. This data showed that, despite the differences in reproductive strategy, the closest living relatives to land plants are in fact the Zygnematales.

Dr Becker explained, "It seems that Zygnematales have lost oogamy and their ability to produce sperm and egg cells, and instead, possibly due to selection pressure in the absence of free water, use conjugation for reproduction. Investigation of such a large number of genes has shown that, despite their apparent simplicity, Zygnematales have genetic traces of other complex traits also associated with green land plants. Consequently Zygnematales true place as the closest living relative to land plants has been revealed."

no time.

Permian Reptile With a Tooth Ache

2011-04-18T11:59:00.001-07:00

A reptile that lived 275-million years ago in what is now Oklahoma is giving paleontologists a glimpse of the oldest known toothache.

Led by Professor Robert Reisz, the chair of the Department of Biology at the University of Toronto Mississauga, scientists found evidence of bone damage due to oral infection in Paleozoic reptiles as they adapted to living on land. Their findings, published online in the journal Naturwissenschaften – The Nature of Science, predate the previous record for oral and dental disease in a terrestrial vertebrate by nearly 200 million years.

"Not only does this fossil extend our understanding of dental disease, it reveals the advantages and disadvantages that certain creatures faced as their teeth evolved to feed on both meat and plants," says Reisz. "In this case, as with humans, it may have increased their susceptibility to oral infections."

The researchers investigated the jaws of several well-preserved specimens of Labidosaurus hamatus, a 275-million-year-old terrestrial reptile from North America. One specimen stood out because of missing teeth and associated erosion of the jaw bone. With the aid of CT-scanning, Reisz and colleagues found evidence of a massive infection. This resulted in the loss of several teeth, as well as bone destruction in the jaw in the form of an abscess and internal loss of bone tissue.

As the ancestors of advanced reptiles adapted to life on land, many evolved dental and cranial specializations to feed more efficiently on other animals and to incorporate high-fiber plant leaves and stems into their diet. The primitive dental pattern in which teeth were loosely attached to the jaws and continuously replaced, changed in some animals. Teeth became strongly attached to the jaw, with little or no tooth replacement. This was clearly advantageous to some early reptiles, allowing them to chew their food and thus improve nutrient absorption. The abundance and global distribution of Labidosauris and its kin suggest that it was an evolutionary success.

However, Reisz and his colleagues suggest that as this reptile lost the ability to replace teeth, the likelihood of infections of the jaw, resulting from damage to the teeth, increased substantially. This is because prolonged exposure of the dental pulp cavity of heavily worn or damaged teeth to oral bacteria was much greater than in other animals that quickly replaced their teeth.

Is Captorhinidae parareptilia or diapsid these days?

Does Titan Have an Europa-style Interior Ocean?

2011-04-18T11:51:00.000-07:00

In the seven years Cassini has spent orbiting Saturn, the spacecraft has sent back mountains of data that has changed our view of the ringed planet and its moons. Saturn's largest moon, Titan, has been a particular focus of attention because of its dense, complex atmosphere, its weather and its lakes and oceans.

Now it looks as if Titan is even stranger still. The evidence comes from careful observations of Titan's orbit and rotation. This indicates that Titan has an orbit similar to our Moon's: it always presents the same face towards Saturn and its axis of rotation tilts by about 0.3 degrees.

Together, these data allow astronomers to work out Titan's moment of inertia and this throws up something interesting. The numbers indicate that Titan's moment of inertia can only be explained if it is a solid body that is denser near the surface than it is at its centre.

That's just plain weird--unthinkable really, given what we know about how planets and moons form.

But there is another explanation, however: that Titan isn't solid at all.

Today, Rose-Marie Baland and buddies at the Royal Observatory of Belgium in Brussels, crunch some numbers to see whether a liquid model is compatible with the measured moment of inertia. "We assume the presence of a liquid water ocean beneath an ice shell and consider the gravitational and pressure torques arising between the different layers of the satellite," they say.

Their conclusion is that Titan's moment of inertia could well be explained by the presence of liquid ocean beneath an icy shell.

no time, but intriguing. I think it'd need to work for methane rather than water though.

Paper here.

Dinosaurs Were Both Diurnal and Nocturnal

2011-04-14T16:24:00.000-07:00

Velociraptors hunted by night while big plant-eating dinosaurs browsed around the clock, according to a paper on the eyes of fossil animals published on-line this week in Science Express.

That overturns the conventional wisdom that dinosaurs were active by day while early mammals scurried around at night, said Ryosuke Motani, a geologist at the University of California at Davis, and a co-author of the paper.

"It was a surprise, but it makes sense," Motani said.

It's also providing insight into how ecology influences the evolution of animal shape and form over tens of millions of years, according to Motani and collaborator Lars Schmitz, a postdoctoral researcher at UC Davis.

"These authors' conclusion that these dinosaurs were active diurnally and nocturnally challenges a general dogma--that nocturnality in that time was mostly restricted to mammals," says H. Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research.

Motani and Schmitz worked out the dinosaurs' daily habits by studying their eyes.

Dinosaurs, lizards and birds all have a bony ring called the "scleral ring" in their eyes, although this is lacking in mammals and crocodiles.

Schmitz and Motani measured the inner and outer dimensions of this ring, plus the size of the eye socket, in 33 fossils of dinosaurs, ancestral birds and pterosaurs--and in 164 living species.

Day-active, or diurnal animals have a small opening in the middle of the ring while the opening is much larger in nocturnal animals.

Cathemeral animals--active in both day and night--tend to be in between.

But the size of these features is also affected by ancestry.

For example, two closely related animals might have similar eye shape even if one is active by day and the other by night: the shape of the eye is constrained by ancestry, and that could bias the results.

Schmitz and Motani developed a computer program to separate the "ecological signal" from this "phylogenetic signal."

The results of that analysis are in a separate paper published simultaneously in the journal Evolution.

By looking at a 164 living species, they could confirm that the eye measurements were accurate in predicting whether animals were active by day, by night or around the clock.

Then they applied the technique to fossils, including plant-eating and carnivorous dinosaurs, flying reptiles called pterosaurs and ancestral birds.

The big plant-eating dinosaurs were active day and night, probably because they had to eat most of the time, except for the hottest hours of the day when they avoided overheating.

Modern megaherbivores like elephants show the same activity pattern, Motani said.

Velociraptors and other small carnivores were night hunters.

Schmitz and Motani were not able to study big carnivores such as Tyrannosaurus rex, because there are no fossils with sufficiently well-preserved eyes.

Flying creatures, including early birds and pterosaurs, were mostly day-active, although some of the pterosaurs--including a filter-feeding animal that probably lived like a duck, and a fish-eating pterosaur--were apparently night-active.

"This strongly suggests that ecology drives activity," Schmitz said.

no time, but awesome.

A Strong Sense of Smell is a Basal Trait for Theropods

2011-04-13T13:03:00.001-07:00

Birds are known more for their senses of vision and hearing than smell, but new research suggests that millions of years ago, the winged critters also boasted a better sense for scents.

A study published today by scientists at the University of Calgary, the Royal Tyrrell Museum and the Ohio University College of Osteopathic Medicine tested the long-standing view that during the evolution from dinosaurs to birds, the sense of smell declined as birds developed heightened senses of vision, hearing and balance for flight. The team compared the olfactory bulbs in the brains of 157 species of dinosaurs and ancient and modern-day birds.

The findings, published in the journal Proceedings of the Royal Society B, dispute that theory. The scientists discovered that the sense of smell actually increased in early bird evolution, peaking millions of years ago during a time when the ancestors of modern-day birds competed with dinosaurs and more ancient branches of the bird family.

"It was previously believed that birds were so busy developing vision, balance and coordination for flight that their sense of smell was scaled way back," said Darla Zelenitsky, assistant professor of paleontology at the University of Calgary and lead author of the research. "Surprisingly, our research shows that the sense of smell actually improved during dinosaur-bird evolution, like vision and balance."

In an effort to conduct the most detailed study to date on the evolution of sense of smell, the research team made CT scans of dinosaurs and extinct bird skulls to reconstruct their brains. The scientists used the scans to determine the size of the creatures' olfactory bulbs, a part of the brain involved in the sense of smell. Among modern-day birds and mammals, larger bulbs correspond to a heightened sense of smell.

"Of course the actual brain tissue is long gone from the fossil skulls," said study co-author Lawrence Witmer, Chang Professor of Paleontology at the Ohio University College of Osteopathic Medicine, "but we can use CT scanning to visualize the cavity that the brain once occupied and then generate 3D computer renderings of the olfactory bulbs and other brain parts."

The study revealed details of how birds inherited their sense of smell from dinosaurs.

"The oldest known bird, Archaeopteryx, inherited its sense of smell from small meat-eating dinosaurs about 150 million years ago," said François Therrien, curator of dinosaur palaeoecology at the Royal Tyrrell Museum and co-author of the study. "Later, around 95 million years ago, the ancestor of all modern birds evolved even better olfactory capabilities."

How well did dinosaurs smell, especially compared to modern animals? Although scientists haven't been able to make an exhaustive comparison, Witmer noted that the ancient beasts most likely exhibited a range of olfactory abilities. T. rex had large olfactory bulbs, which probably aided the creature in tracking prey, finding carcasses and possibly even territorial behavior, while a sense of smell was probably less important to dinosaurs such as Triceratops, he said.

The team was able to make some direct comparisons between the ancient and modern-day animals under study. Archaeopteryx, for example, had a sense of smell similar to pigeons, which rely on odors for a number of behaviors.

"Turkey vultures and albatrosses are birds well known for their keen sense of smell, which they use to search for food or navigate over large areas," says Zelenitsky. "Our discovery that small Velociraptor-like dinosaurs, like Bambiraptor, had a sense of smell as developed as turkey vultures and albatrosses suggests that smell may have played an important role while these dinosaurs hunted for food."

If early birds had such powerful sniffers, why do birds have a reputation for a poor sense of smell? Witmer explained that the new study confirms that the most common birds that humans encounter today—the backyard perching birds such as crows and finches, as well as pet parrots—indeed have smaller olfactory bulbs and weaker senses of smell. It may be no coincidence that the latter are also the cleverest birds, suggesting that their enhanced smarts may have decreased the need for a strong sniffer, he said.

Fossils of Early Endosymbiotic Life in the Proterozoic Era?

2011-04-13T12:52:00.000-07:00

A team of scientists exploring rocks around Loch Torridon have discovered the remarkably preserved remains of organisms that once lived on the bottom of ancient lake beds as long as a billion (1000 million) years ago.

These fossils illuminate a key moment in the history of evolution when life made the leap from tiny, simple bacterial (prokaryote) cells towards larger, more complex (eukaryotic) cells which would make photosynthesis and sexual reproduction possible.

The team, from Oxford University, the University of Sheffield and Boston College, report their findings in this week's Nature.

"These new fossils show that the move toward complex algal cells living in lakes on land had started over a billion years ago, much earlier than had been thought," said Professor Martin Brasier of Oxford University's Department of Earth Sciences, an author of the paper.

"These new cells differ from their bacterial ancestors in that they have specialized structures including a nucleus, as well as mitochondria and chloroplasts – which are vital for photosynthesis. They also undergo sexual reproduction, leading to much more rapid rates of evolutionary turnover."

Some of these ancient fossils are so finely ornamented, and so large and complex, that they are evidence for a surprisingly early start for the emergence of complex eukaryote cells on land. The researchers believe that it was from complex cells such as these that green algae and green land plants – everything from lettuce to larch trees – were able to evolve and colonise the land.

Dr Charles Wellman, Reader in Palaeobiology in the Department of Animal and Plant Sciences at the University of Sheffield, an author of the paper, said: "It is generally considered that life originated in the ocean and that the important developments in the early evolution of life took place in the marine environment: the origin of prokaryotes, eukaryotes, sex, multicellularity etc. During this time the continents are often considered to have been essentially barren of life - or at the most with an insignificant microbial biota dominated by cyanobacteria.

"We have discovered evidence for complex life on land from 1 billion year old deposits from Scotland. This suggests that life on land at this time was more abundant and complex than anticipated. It also opens the intriguing possibility that some of the major events in the early history of life may have taken place on land and not entirely within the marine realm."

Professor Brasier said: "It may even be that the sort of conditions found in the ancient lakes around Loch Torridon favoured a key step in this transformation, which involved the incorporation of symbiotic bacteria into the cell to form chloroplasts, rather than this occurring in the sea as usually envisaged."

Well, that last may be stretching it a bit: this may be preservation bias. However, it is interesting that life like this was in the lake beds.