Beginning to Think About the Medea Hypothesis

I'm reading The Medea Hypothesis by Dr Peter Ward. The basic premise is that life is toxic to life and will, eventually, kill itself off. I'm about 2/3s done and there have been a number of things that are bugging me. I'll do a post eventually, however, I went looking for some responses to the book...so far, only one major one. There was some criticism by fellow scientists there:

Lynn Margulis, a noted biologist at the University of Massachusetts,Amherst, who helped Lovelock shape and promote the Gaia concept,dismisses Ward's work as misguided, describing it as “pseudo-quantitation, a nice example of the fallacy of misplaced concreteness.”

J. David Archibald, a professor of biology and a vertebrate paleontologist at San Diego State University, said he was “underwhelmed” by the Medea idea. “I don't know that it tells us anything we didn't already know.”

Christopher Wills, a biologist at the University of California San Diego and co-author of “The Spark of Life,” a 2001 book on the origins of life on Earth, said it was too simplistic to say life causes mass extinctions. There are other, perhaps more compelling, factors, too.

“The dramatic changes in the Earth's climate have been accompanied by meteorite impacts and truly mind-boggling massive volcanic eruptions,” said Wills. “The Siberian eruptions that accompanied the great Permo-Triassic extinction 200 million years ago piled up layers of lava 10,000 feet thick over an area of 75,000 square miles. Life
didn't cause that.”

Wills' co-author, Jeffrey Bada, a marine chemist at the Scripps Institution of Oceanography, also found the hypothesis wanting, particularly its eventual doomsday scenario.

“Given the ability for life on Earth to seemingly adopt to slowly changing conditions, I find the hypothesis to be far-fetched. There are certainly bacteria, some of which are photosynthetic, that would survive (increased solar radiation). And there is convincing evidence that some bacteria live far below the surface of the Earth, so they would be survivors as well.

“Animals, including humans, would probably have a rough go, but given the billion-year time scale for this scenario, it is likely that other catastrophes – a large impact event, nuclear war – would do these life-forms in before the heating was severe.”

One of the criticisms I have of the book is that there is a paper by Franck et al (2006) that is heavily cited...yet does not appear anywhere in the bibliography. Given it's absolute importance to the central thesis of the book, it's absence is pretty glaring and embarrassing. Fix it, guys, eh?

I've been googling for the paper and coming up empty handed. It has to do with paleoatmospheric content. Again, Franck et al 2006. I'll dig through and see if I can narrow down the journal. If anyone has it, *grovel*.

Memory Densities About to Go Up?

Researches at the Leibniz Institute for Solid State and Materials Research, in Dresden, Germany headed up by Ruijuan Xiao say they found a way to increase storage capacity of magnetic data drives by a factor of 1,000. While the finding is simply a theory, the answer lies in tying cobalt molecules to a ring of carbon, as cobalt has the highest magnetic anisotropy energy (MAE) of all ferromagnetic elements suitable for storage. The density of data storage depends on the size of magnetic grains, which cannot be shrunk indefinitely.

MAE is related to how easy it is to flip the magnetic field from one direction to the other, with a reliable lifespan of about 10 years for current hard drives. Today's high-end cobalt drives have about 50,000 atoms in a hexagonal close-packed structure, which results in an MAE of 0.06 meV per atom. Without changing this arrangement, which is necessary for reliable, long-term data storage, it is said to be possible to reduce the size of the cobalt grains to 15,000 atoms.

Xiao and his researchers say they have found a way to trick cobalt dimers, or two identical simple molecules, to think they're in a hexagonal close structure by attaching of them to a hexagonal carbon ring such as benzene or graphene.

The magnetic field between the cobalt atoms can then be switched by applying a weak magnetic field along with a strong electric field. Cobalt's MAE is 100 meV, which is reduced when the element is chemically bonded, but Xiao says his method of bonding it to carbon hexagons does not have such an effect.

Apart from longer life, this finding, if proven true with a working prototype, could also result in higher memory density, as current cobalt grains used in magnetic storage are about 8nm in width. Benzene rings, in comparison, are just 0.5nm wide. [via TechnologyReview]

Three hurdles to go. One functional prototype. Then a product unit (scaling and reproducibility issues as well as cost effectiveness). Then getting it adopted. That last is harder than it seems. There was a company during the dotcom days that came up with some CD/DVD replacement tech that was amazing for its time (TB+ sized disks), but...didn't get anywhere due to not being able to get someone to adopt it.

Notional F/A-XX: F/A-18E/F Replacement

On the heels of the Russian designer putting out how he thinks the PAK FA will look like, Boeing has put out what they currently think a 6th Generation Fighter will look like, one intended to replace the F/A-18E/F for the USN. Optionally manned is one of the key words here. I'm pretty convinced that it really ought to be completely unmanned. In fact, what they ought to be doing is having something like the old Vikings flying off the decks to control or coordinate the UCAVs.

One thought I had on the whole fighter concept was to have very fast UAVs that could close much faster than a manned platform for visual ID (possibly even expendable ones) and a manned control plane (E-2, whatever) and a few fat missile carriers that would follow long unmanned as well. UAV IDs target, man in the loop on control plane says yea or nay, missileer fires. Preferably there's a laser on the manned planned to tag obnoxious jerks and incoming missiles. Sounds vaguely FCS though.

Armadillosuchus Rendition

It looks like a cros between a croc, an armadillo and a fscking wolf. Was the fossil even close to that complete?

Is Putin's Russia Proto-Fascist?

Despite the hopes of many in the West for a more progressive approach from Russian President Dmitry Medvedev, the Moscow “tandem” of Medvedev and Prime Minister Vladimir Putin represents a form of “proto-fascism,” one that will only get worse for both its people and the surrounding countries unless Western countries adopt a tough line.

In Kyiv’s “Den’” on July 4, Ukrainian commentator Volodomyr Lesnoy said that the current Russian regime can best be classified as “proto-fascist,” a system he defines as one “in which the characteristics of fascism exist in an incomplete form” but which are sufficiently developed that they recall “the first stage of fascism”.

So is Russia becoming fascist? Or is this an overblown nationalist in Ukraine? I have some pretty strong opinions about Putin and they are, by and large, rather negative. However, calling someone a fascist has a lot of historical baggage in the xUSSR. What do others think?

Sperm From Stem Cells

Human sperm have been created using embryonic stem cells for the first time in a scientific development which will lead researchers to a better understanding of the causes of infertility.

Researchers led by Professor Karim Nayernia at Newcastle University and the NorthEast England Stem Cell Institute (NESCI) have developed a new technique which has made the creation of human sperm possible in the laboratory.

The work is published today (8th July 2009) in the academic journal Stem Cells and Development.

[...]

In the technique developed at Newcastle, stem cells with XY chromosomes (male) were developed into germline stem cells which were then prompted to complete meiosis - cell division with halving of the chromosome set. These were shown to produce fully mature, sperm called scientifically, In Vitro Derived sperm (IVD sperm).

In contrast, stem cells with XX chromosomes (female) were prompted to form early stage sperm, spermatagonia, but did not progress further. This demonstrates to researchers that the genes on a Y chromosome are essential for meiosis and for sperm maturation.

Can't quite do away with us yet ladies.

Notional Sukhoi PAK FA's

Not the real deal, just someone's renderings of their ideas on how the PAK FA will supposedly look. Dewline noted the designer, Alekander Dultsev. The quesiton remains whether or not there will be a PAK FA at all: after all, there was this Mig 1.44 that was supposed to be the Russian answer to the F-22. And then there was the LFI and then...The PAK FA is already 2 years behind schedule. It's rumored to be because of manufacturing issues. Russian aerospace industry age much in how many years since they designed a new fighter?

Armadillosuchus, Brazilian Cretaceous Croc

Fossils found in Brazil are from a crocodile resembling a large armadillo that was a predator in the area around modern-day Sao Paulo state 90 million years ago, researchers said on Tuesday.

The 6.6-foot-long (two-meter-long), 265-lb (120-kg) crocodile, named the "Armadillosuchus," appears to have been unique to that area, the researchers at Rio de Janeiro's Federal University said.

The creature displayed some characteristics of an armadillo, with bony plates on its neck and back.

It had a carapace, a wide skull, a short, narrow snout, and relatively small, specialized teeth that make it distinct from any other crocodile discovered, the university said.

"The Armadillosuchus is only found in the interior of Sao Paulo state and this is a surprise, partly because it challenges the idea that crocodiles are found in hot and humid climates," UFRJ paleontologist Ismar de Souza Carvalho told reporters.

"In this case, they are crocodiles that live in a climate that is quite hot, dry and arid," he added.

The crocodile lived during the Cretaceous period, when temperatures would have reached about 113 degree Fahrenheit (45 degrees Celsius), the researchers said.

Regular blogging will resume soon. Promise.

PS. First tank passed the pressure test.

Reminder: Boneyard in Two Weeks

I had to postpone the BY until the 17th due to Team Phoenicia related stuff. However, I'm imploring the paleoset, please, get your posts in! My email is anzha lyu at gmail dottttted com or if you prefer my work email as wbaird at nersc dottted gov.

Zach and I are trying hard to get this revived. I'd really appreciate the paleoblogs contribution. Thanx, folks.

The Foraminifers Mass Extinction Paper

Surviving mass extinction by bridging the benthic/planktic divide

1. Kate F. Darling (a,1)
2. Ellen Thomas (b,c)
3. Simone A. Kasemann (a,d)
4. Heidi A. Seears (e)
5. Christopher W. Smart (f)
6. Christopher M. Wade (e)


a School of GeoSciences and Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JW, United Kingdom;

b Department of Geology and Geophysics, Yale University, New Haven, CT 06520-8109;

c Department of Earth and Environmental Sciences, Wesleyan University, Middletown, CT 06459;

d Institut für Geologische Wissenschaften, Fachrichtung Geologie, Freie Universität Berlin, Malteserstrasse 74-100, 12249 Berlin, Germany;

e Institute of Genetics, University of Nottingham, Nottingham NG7 2UH, United Kingdom;

f School of Earth, Ocean and Environmental Sciences, University of Plymouth, Plymouth PL4 8AA, United Kingdom

1 To whom correspondence should be addressed. E-mail: kate.darling@ed.ac.uk

Abstract:

Evolution of planktic organisms from benthic ancestors is commonly thought to represent unidirectional expansion into new ecological domains, possibly only once per clade. For foraminifera, this evolutionary expansion occurred in the Early–Middle Jurassic, and all living and extinct planktic foraminifera have been placed within 1 clade, the Suborder Globigerinina. The subsequent radiation of planktic foraminifera in the Jurassic and Cretaceous resulted in highly diverse assemblages, which suffered mass extinction at the end of the Cretaceous, leaving an impoverished assemblage dominated by microperforate triserial and biserial forms. The few survivor species radiated to form diverse assemblages once again in the Cenozoic. There have, however, long been doubts regarding the monophyletic origin of planktic foraminifera. We present surprising but conclusive genetic evidence that the Recent biserial planktic Streptochilus globigerus belongs to the same biological species as the benthic Bolivina variabilis, and geochemical evidence that this ecologically flexible species actively grows within the open-ocean surface waters, thus occupying both planktic and benthic domains. Such a lifestyle (tychopelagic) had not been recognized as adapted by foraminifera. Tychopelagic are endowed with great ecological advantage, enabling rapid recolonization of the extinction-susceptible pelagic domain from the benthos. We argue that the existence of such forms must be considered in resolving foraminiferal phylogeny.

That's a doozie. Here is my original post that Julia shared. Now, the question is...how many dual or multilifestyle foraminifers are there?!

(hey, Julia, boneyard, July 17, writewrite...please?)

New Australian Dinosaurs

Scientists have confirmed for the first time that Australia was once home to a dinosaur that was big, fast and terrifying, and they've named it like something from an Arnold Schwarzenegger movie. Meet the Australovenator.

The beast was a 1,100 pound (500 kilogram) meat-eating predator with three slashing claws on each of its powerful forelimbs that stalked the Outback 98 million years ago, researchers said in a report published Friday.

Fossilized remnants of its limb bones, ribs, jaw and fangs were found — along with bones of two other new species of gigantic, long-necked herbivores weighing up to 22 tons (20 metric tons) — in Queensland state over the past three years.

The discovery, analyzed in a 51-page report published in the peer-reviewed online science journal PLoS ONE, was the first substantial find of large dinosaurs in Australia to be revealed in 28 years.

[...]

The finders nicknamed the 16-foot (5-meter) long carnivore, Australovenator wintonensis (pronounced oss-tra-low-VEN'-ah-tor win-TON'-en-sis), "Banjo," after the poet A.B. "Banjo" Paterson who in 1885 penned Australia's unofficial anthem "Waltzing Matilda" on a sheep ranch near Winton — a cattle town that lies closest to where the dinosaur bones were found. Banjo's Latin name means "Winton's Southern Hunter."

"The cheetah of his time, Banjo was light and agile," the report's lead author, Scott Hocknull, a Queensland Museum paleontologist, said in a statement.

"He's Australia's answer to Velociraptor, but many times bigger and more terrifying," Hocknull added, referring to the turkey-sized prehistoric predators recreated with artistic license in the "Jurassic Park" movies.

The other two finds — 52-foot- (16-meter-) long herbivores — were previously unknown types of titanosaur, the largest dinosaurs that ever lived. The giraffe-like Wintonotitan wattsi (pronounced win-ton-oh-TIE-tan wot-SIGH) and nicknamed Clancy translates from Latin as "Watts' Winton Giant." The Diamantinasaurus matildae (pronounced dye-man-TEEN'-ah-sor-us mah-TIL'-day) resembled a hippopotamus and has been nicknamed Matilda; the Latin name translates as "Matilda's Diamantina River Lizard."

Paper link is here.

New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia

Scott A. Hocknull (a*)
Matt A. White (b)
Travis R. Tischler(b)
Alex G. Cook(a)
Naomi D. Calleja(b)
Trish Sloan(b)
David A. Elliott(b)

a Geosciences, Queensland Museum, Hendra, Queensland, Australia

b Australian Age of Dinosaurs Museum of Natural History, The Jump-up, Winton, Queensland, Australia

Abstract:

Background

Australia's dinosaurian fossil record is exceptionally poor compared to that of other similar-sized continents. Most taxa are known from fragmentary isolated remains with uncertain taxonomic and phylogenetic placement. A better understanding of the Australian dinosaurian record is crucial to understanding the global palaeobiogeography of dinosaurian groups, including groups previously considered to have had Gondwanan origins, such as the titanosaurs and carcharodontosaurids.
Methodology/Principal Findings

We describe three new dinosaurs from the late Early Cretaceous (latest Albian) Winton Formation of eastern Australia, including; Wintonotitan wattsi gen. et sp. nov., a basal titanosauriform; Diamantinasaurus matildae gen. et sp. nov., a derived lithostrotian titanosaur; and Australovenator wintonensis gen. et sp. nov., an allosauroid. We compare an isolated astragalus from the Early Cretaceous of southern Australia; formerly identified as Allosaurus sp., and conclude that it most-likely represents Australovenator sp.
Conclusion/Significance

The occurrence of Australovenator from the Aptian to latest Albian confirms the presence in Australia of allosauroids basal to the Carcharodontosauridae. These new taxa, along with the fragmentary remains of other taxa, indicate a diverse Early Cretaceous sauropod and theropod fauna in Australia, including plesiomorphic forms (e.g. Wintonotitan and Australovenator) and more derived forms (e.g. Diamantinasaurus).

Perhaps Australia wasn't as much of a refugium as people - including me - have thought. Perhaps the difference in fauna - labrynthodonts, possibly dicynodonts, etc - are just a case of a different locale's fauna. huh. Wouldn't be funny if in Laurasia, in a polar region, there ended up being some dicynodonts and uber sized amphibians, too? And the only reason we don't know they are there is just sampling bias...huh. Interesting thought that.

The Late Miocene Pikermian Chronofauna

Distribution history and climatic controls of the Late Miocene Pikermian chronofauna

1. Jussi T. Eronen (a,1)
2. Majid Mirzaie Ataabadi (a)
3. Arne Micheels (b)
4. Aleksis Karme (a)
5. Raymond L. Bernor (c,d)
6. Mikael Fortelius (a, e)

a Department of Geology and

e Institute of Biotechnology, FIN-00014 University of Helsinki, Finland;

b Senckenberg Forschungsinstitut und Naturmuseum, Biodiversität und Klima Forschungszentrum (BiK-F), Senckenberganlage 25, D-60325, Frankfurt am Main, Germany;

c Sedimentary Geology and Paleobiology Program, Geosciences/Earth Sciences, National Science Foundation, 4201 Wilson Boulevard, Arlington, VA 22230; and

d College of Medicine, Department of Anatomy, Laboratory of Evolutionary Biology, Howard University, 520 W Street Northwest, Washington, D.C. 20059

Abstract:

The Late Miocene development of faunas and environments in western Eurasia is well known, but the climatic and environmental processes that controlled its details are incompletely understood. Here we map the rise and fall of the classic Pikermian fossil mammal chronofauna between 12 and 4.2 Ma, using genus-level faunal similarity between localities. To directly relate land mammal community evolution to environmental change, we use the hypsodonty paleoprecipitation proxy and paleoclimate modeling. The geographic distribution of faunal similarity and paleoprecipitation in successive timeslices shows the development of the open biome that favored the evolution and spread of the open-habitat adapted large mammal lineages. In the climate model run, this corresponds to a decrease in precipitation over its core area south of the Paratethys Sea. The process began in the latest Middle Miocene and climaxed in the medial Late Miocene, about 7–8 million years ago. The geographic range of the Pikermian chronofauna contracted in the latest Miocene, a time of increasing summer drought and regional differentiation of habitats in Eastern Europe and Southwestern Asia. Its demise at the Miocene-Pliocene boundary coincides with an environmental reversal toward increased humidity and forestation, changes inevitably detrimental to open-adapted, wide-ranging large mammals.

Likewise. No time.

Water Temperatures Warm Enough For Hurricanes

The first month of the 2009 Atlantic hurricane season drew to a close without so much as a tropical storm, but that isn’t unusual. According to the National Hurricane Center, the 1944-2002 average for named storms in June was only about 0.75, which means they don't occur every year. When they do form, it is usually the Gulf of Mexico that brews them up, and this image of sea surface temperatures on June 30, 2009, shows why.

Based on a blend of observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) on NASA’s Aqua satellite and MODIS on the Terra satellite, the image shows temperatures that are generally warm enough to sustain hurricanes in yellow, orange and red. The waters of the Caribbean Sea (south of Cuba), the Gulf of Mexico, and the Atlantic off the Southeast coast were all warm enough to fuel hurricanes, while most of the tropical Atlantic between the Americas and Africa was still too cool.

No time to comment. Well, ok, very fast. Now imagine that pic with the surface water temps shifted 5 C up.

Using Foraminifers for Tracking Mass Extinctions Just Got A Whole Lot More Complicated

Two separate species of tiny marine organisms, a sea-floor dweller and an ocean surface swimmer, are one and the same despite radical differences in lifestyle.

The surprising discovery suggests that the group survived the Cretaceous mass extinction by abandoning the poisonous oceans for a refuge in the relative safety of the sea-floor.

Foraminifers have lived throughout the oceans for many millions of years. They are microscopic, single-celled organisms with tiny shells and are so abundant in marine sediments that they have been used to trace long-term changes in the ocean's environment. Scientists have recognised two main groups: the benthics live in sea-floor sediments, while the planktics inhabit surface ocean waters as part of the plankton.

Dr Kate Darling, from the University of Edinburgh, and colleagues discovered that a planktic species living 600 nautical miles offshore in the Arabian Sea - the Streptochilus globigerus (pictured) - is genetically identical to a benthic species called Boliviana variabilis, found off the coast of Kenya.

'This was a very surprising discovery,' says Darling. 'It's the same biological species but it is living two separate lives: on the shallow continental shelf and as plankton at the surface of the open ocean.'

[...]

Scientists think that all modern planktic foraminifers descend from a bottom-dwelling species that switched to a planktonic lifestyle sometime during the Mid to Early Jurassic, between 160 and 200 million years ago.

After the jump, the group diversified and new planktic species quickly colonised the oceans. Planktic foraminifers became very abundant, but only a small part survived the late Cretaceous extinction that killed off the dinosaurs. All modern planktic foraminifers are believed to descend from these lucky few.

Darling's findings complicate the story considerably. If some species can switch between free-swimming and bottom-dwelling lifestyles, then it's possible that 'most planktic foraminifers may have survived the KT [late Cretaceous] extinction in the sediment, not in the plankton,' says Darling.

It seems likely that the foraminifer species which had the ability to occupy both habitats survived on the sea-floor, avoiding the meteor impact catastrophe in the oceans above, argue the authors in the report published this week in the Proceedings of the National Academy of Sciences. When the oceans returned to normal, the survivors were able to recolonise the ocean surface once more.

Darling is still working on this idea, but it's very telling that 'two of the three types that survived the KT extinction belong to the same kind of foraminifera' she says, referring to the two species now revealed as one.

oh boy.

The implications are huge. Mama Nature may have just played a nasty prank on paleo types, especially the mass extinction folks. More as I have time.

DARPA's Man Made Hummingbird

Intertropical Convergence Zone Creeping Northward

The rain band near the equator that determines the supply of freshwater to nearly a billion people throughout the tropics and subtropics has been creeping north for more than 300 years, probably because of a warmer world, according to research published in the July issue of Nature Geoscience.

If the band continues to migrate at just less than a mile (1.4 kilometers) a year, which is the average for all the years it has been moving north, then some Pacific islands near the equator – even those that currently enjoy abundant rainfall – may be drier within decades and starved of freshwater by midcentury or sooner. The prospect of additional warming because of greenhouse gases means that situation could happen even sooner.

The findings suggest "that increasing greenhouse gases could potentially shift the primary band of precipitation in the tropics with profound implications for the societies and economies that depend on it," the article says.

"We're talking about the most prominent rainfall feature on the planet, one that many people depend on as the source of their freshwater because there is no groundwater to speak of where they live," says Julian Sachs, associate professor of oceanography at the University of Washington and lead author of the paper. "In addition many other people who live in the tropics but farther afield from the Pacific could be affected because this band of rain shapes atmospheric circulation patterns throughout the world."

The band of rainfall happens at what is called the intertropical convergence zone. There, just north of the equator, trade winds from the northern and southern hemispheres collide at the same time heat pours into the atmosphere from the tropical sun. Rain clouds 30,000 feet thick in places proceed to dump as much as 13 feet (4 meters) of rain a year in some places. The band stretching across the Pacific is generally between 3 degrees and 10 degrees north of the equator depending on the time of year. It has recently been hypothesized that the intertropical convergence zone does not reside in the southern hemisphere for reasons having to do with the distribution of land masses and locations of major mountain ranges in the world, particularly the Andes mountains, that have not changed for millions of years.

The new article presents surprising evidence that the intertropical convergence zone hugged the equator some 3 ½ centuries ago during Earth's little ice age, which lasted from 1400 to 1850.

The authors analyzed the record of rainfall in lake and lagoon sediments from four Pacific islands at or near the equator.

One of the islands they studied, Washington Island, is about 5 degrees north of the equator. Today it is at the southern edge of the intertropical convergence zone and receives nearly 10 feet (2.9 meters) of rain a year. But cores reveal a very different Washington Island in the past: It was arid, especially during the little ice age.

Among other things, the scientists looked for evidence in sediment cores of salt-tolerant microbes. On Washington Island they found that evidence in 400- to 1,000-year-old sediment underlying what is now a freshwater lake. Such organisms could only have thrived if rainfall was much reduced from today's high levels on the island. Additional evidence for changes in rainfall were provided by ratios of hydrogen isotopes of material in the sediments that can only be explained by large changes in precipitation.

Sediment cores from Palau, which lies about 7 degrees north of the equator and in the heart of the modern convergence zone, also revealed arid conditions during the little ice age.

In contrast, the researchers present evidence that the Galapagos Islands, today an arid place on the equator in the Eastern Pacific, had a wet climate during the little ice age.

They write, "The observations of dry climates on Washington Island and Palau and a wet climate in the Galapagos between about 1420-1560/1640 provide strong evidence for an intertropical convergence zone located perennially south of Washington Island (5 degrees north) during that time and perhaps until the end of the eighteenth century."

If the zone at that time experienced seasonal variations of 7 degrees latitude, as it does today, then during some seasons it would have extended southward to at least the equator, Sachs says. This has been inferred previously from studies of the intertropical convergence zone on or near the continents, but the new data from the Pacific Ocean region is clearer because the feature is so easy to identify there.

The remarkable southward shift in the location of the intertropical convergence zone during the little ice age cannot be explained by changes in the distribution of continents and mountain ranges because they were in the same places in the little ice age as they are now. Instead, the co-authors point out that the Earth received less solar radiation during the little ice age, about 0.1 percent less than today, and speculate that may have caused the zone to hover closer to the equator until solar radiation picked back up.

"If the intertropical convergence zone was 550 kilometers, or 5 degrees, south of its present position as recently as 1630, it must have migrated north at an average rate of 1.4 kilometers – just less than a mile – a year," Sachs says. "Were that rate to continue, the intertropical convergence zone will be 126 kilometers – or more than 75 miles – north of its current position by the latter part of this century."

Interesting. Why North? Why not defuse north and south? Perhaps because of the thermal inertia of the oceans and the south has more of it? Or...? This is going to be important!


ObFutureThought: mmm. Sodden Hawaii. albeit several centuries from now...

Another Corrective Feedback Mechanism for Ice Ages

When glaciers advanced over much of the Earth's surface during the last ice age, what kept the planet from freezing over entirely? This has been a puzzle to climate scientists because leading models have indicated that over the past 24 million years geological conditions should have caused carbon dioxide levels in the atmosphere to plummet, possibly leading to runaway "icehouse" conditions. Now researchers writing in the July 2, 2009, Nature report on the missing piece of the puzzle – plants.

"Atmospheric CO2 concentrations have been remarkably stable over the last 20 or 25 million years despite other changes in the environment," says co-author Ken Caldeira of the Carnegie Institution's Department of Global Ecology. "We can look to land plants as the primary buffering agent that's held CO2 in such a narrow range during this time."

The research team, led by Mark Pagani of Yale University, found that the critical role of plants in the chemical breakdown and weathering of rocks and soil gave them a strong influence on carbon dioxide levels. It was a link that earlier studies had missed.

Over geologic time, large volumes of carbon dioxide have been released into the atmosphere by volcanoes. This would cause CO2 to build up in the atmosphere were it not for countervailing geologic processes of sedimentation, which bury carbon-containing minerals in the crust, sequestering it from the atmosphere. The overall rate of sedimentation is controlled by the upthrust of mountains and the erosion and chemical breakdown of their rocks. The rise of the Andes, Himalayas, Tibetan Plateau, and mountain ranges in western North America over the past 25 million years would have been expected to have cause faster weathering and erosion, and therefore a faster burial of carbon drawn from the atmosphere. But the stability of carbon dioxide levels indicate that this didn't happen. Why not?

This is where the plants come in. "The rates of weathering reactions are largely controlled by plants. Their roots secrete acids that dissolve minerals, they hold soils, and they increase the amount of carbon dissolved in groundwater," says Caldeira. "But when levels of carbon dioxide get too low, the plants basically suffocate and the weathering slows down. That means less sediment is eroded from the uplands and less carbon can be buried. It's a negative feedback on the system that has kept carbon dioxide levels from dropping too low."

Extremely low carbon dioxide levels would have reduced the atmosphere's ability to retain heat, putting the planet into a deep freeze. "So you could say that by limiting the drawdown of CO2 by chemical weathering and sedimentation, plants saved the planet from freezing over," says Caldeira.

This is an interesting contrast - a long with the earlier extended biosphere news - in contrast to the other book I am reading, The Medea Hypothesis. There will be posts on Ward's book. I am not so sure that I am agreeing with what he says. However, time will tell. I'm only a 1/3 done reading.

Fern Radiation in Cenozoic Angiosperm Forests

Evidence for a Cenozoic radiation of ferns in an angiosperm-dominated canopy

1. Eric Schuettpelz,1 and
2. Kathleen M. Pryer

Department of Biology, Duke University, Durham, NC 27708

Abstract:

In today's angiosperm-dominated terrestrial ecosystems, leptosporangiate ferns are truly exceptional—accounting for 80% of the ≈11,000 nonflowering vascular plant species. Recent studies have shown that this remarkable diversity is mostly the result of a major leptosporangiate radiation beginning in the Cretaceous, following the rise of angiosperms. This pattern is suggestive of an ecological opportunistic response, with the proliferation of flowering plants across the landscape resulting in the formation of many new niches—both on forest floors and within forest canopies—into which leptosporangiate ferns could diversify. At present, one-third of leptosporangiate species grow as epiphytes in the canopies of angiosperm-dominated tropical rain forests. However, we know too little about the evolutionary history of epiphytic ferns to assess whether or not their diversification was in fact linked to the establishment of these forests, as would be predicted by the ecological opportunistic response hypothesis. Here we provide new insight into leptosporangiate diversification and the evolution of epiphytism by integrating a 400-taxon molecular dataset with an expanded set of fossil age constraints. We find evidence for a burst of fern diversification in the Cenozoic, apparently driven by the evolution of epiphytism. Whether this explosive radiation was triggered simply by the establishment of modern angiosperm-dominated tropical rain forest canopies, or spurred on by some other large-scale extrinsic factor (e.g., climate change) remains to be determined. In either case, it is clear that in both the Cretaceous and Cenozoic, leptosporangiate ferns were adept at exploiting newly created niches in angiosperm-dominated ecosystems.

Dakota Gives Up Hadrosaur Skin Secrets

There's no evidence of goosebumps just yet, but a remarkably preserved dinosaur reveals that the prehistoric reptile had skin like that of birds and crocodiles, a new study says.

"This is the closest you're going to get to patting the animal," said excavation leader Phillip Manning, a paleontologist at Britain's University of Manchester.

Advanced imaging and chemical techniques revealed that the 66-million-year-old "mummified" duckbilled dinosaur had two layers of skin, as do modern vertebrates, including humans.

Such a discovery was possible because the dinosaur's skin fossilized before bacteria had a chance to eat up the tissue.

[...]

With electron microscopes and x-rays, Manning discovered that Dakota had cell-like structures indicative of two-ply skin: a thin surface layer plus an underlying layer of dense connective tissues.

That's just like skin of modern birds and reptiles, which scientists believe are closely related to duckbilled dinosaurs.

Protein-recovery techniques used on the skin and a claw detected amino acids, the building blocks of proteins. Proteins themselves, complex molecules that degrade easily over time, were not found, however.

But Manning did identify molecules that would have broken down proteins in Dakota's body.

That's like finding fragments of a broken vase instead of the intact vase, explained Thomas R. Holtz Jr., a vertebrate paleontologist at the University of Maryland.

Again, no time, but it is really good to see the famed dino mummies producing papers for a change, instead of just news stories.

Moa Colors Extracted from Feather DNA

Australian and New Zealand scientists have used prehistoric feathers to help map the color of giant extinct birds and said Wednesday they believe their method could help reconstruct the appearance of other extinct bird species.

The researchers retrieved ancient DNA from four species of New Zealand's extinct Moa from feathers found in caves and rock shelters and believed to be at least 2,500 years old.

The native Moa — a flightless, powerfully built forager that stood over 8 feet (2.50 meters) tall and weighed 550 pounds (250 kilograms) — ranged widely in southern New Zealand before the arrival of man.

Using DNA analysis, scientists from New Zealand's Landcare Research and Australia's Adelaide University reconstructed the mainly plain brown plumage of the stout legged Moa, heavy-footed Moa, upland Moa and South Island giant Moa.

"Some had white-tipped feathers to create a speckled appearance" that they used as camouflage, said researcher Nicolas Rawlence from the university's Australian Center for Ancient DNA.

The findings were published Wednesday in the Proceedings of the Royal Society of London.

no time to comment.

Canada Ranks Last on G8 Climate Change List

Canada ranks last among the Group of Eight (G8) industrialised nations for tackling climate change while Germany is top, the green group WWF and the German insurance giant Allianz reported on Wednesday.

Their assessment, issued ahead of the annual G8 summit, blasts Canada for greenhouse-gas emissions that are surging "far above" its obligations under under the UN's Kyoto Protocol.

"(Canada's) per capita emissions are among the highest in the world," they said.

"(Its) mid- to long-term greenhouse targets are inadequate. A plan to curb emissions was developed last year but has not been implemented. The Kyoto target will stay completely out of reach."

The United States, which placed last in the 2008 rankings, moves up a notch, thanks to the pro-climate policies launched by President Barack Obama.

haha. Wasn't James just talking about 'superior' being the other possible name of Canada?

Thhhhhbbbbbpppppt! :P

We will now return to our regular levels of maturity.

More on Vertical Farms

Encountered this - and posted on it - a couple years ago.

Ida Challenged by Burmese Primate

According to new research published online in the Proceedings of the Royal Society B (Biological Sciences) on July 1, 2009, a new fossil primate from Myanmar (previously known as Burma) suggests that the common ancestor of humans, monkeys and apes evolved from primates in Asia, not Africa as many researchers believe.

A major focus of recent paleoanthropological research has been to establish the origin of anthropoid primates (monkeys, apes and humans) from earlier and more primitive primates known as prosimians (lemurs, tarsiers and their extinct relatives). Prior to recent discoveries in China, Thailand, and Myanmar, most scientists believed that anthropoids originated in Africa. Earlier this year, the discovery of the fossil primate skeleton known as "Ida" from the Messel oil shale pit in Germany led some scientists to suggest that anthropoid primates evolved from lemur-like ancestors known as adapiforms.

According to Dr. Chris Beard–– a paleontologist at Carnegie Museum of Natural History in Pittsburgh, Pennsylvania and a member of the international team of researchers behind the Myanmar anthropoid findings––the new primate, Ganlea megacanina, shows that early anthropoids originated in Asia rather than Africa. These early Asian anthropoids differed radically from adapiforms like Ida, indicating that Ida is more closely related to modern lemurs than it is to monkeys, apes and humans.

The 38-million-year-old Ganlea megacanina fossils, excavated at multiple sites in central Myanmar, belong to a new genus and species. The name of the new species refers to a small village, Ganle, near the original site where the fossils were found, and the greatly enlarged canine teeth that distinguish the animal from closely related primates. Heavy dental abrasion indicates that Ganlea megacanina used its enlarged canine teeth to pry open the hard exteriors of tough tropical fruits in order to extract the nutritious seeds contained inside.

"This unusual type of feeding adaptation has never been documented among prosimian primates, but is characteristic of modern South American saki monkeys that inhabit the Amazon Basin," says Dr. Beard. "Ganlea shows that early Asian anthropoids had already assumed the modern ecological role of modern monkeys 38 million years ago."

Ganlea and its closest relatives belong to an extinct family of Asian anthropoid primates known as the Amphipithecidae. Two other amphipithecids, Pondaungia and Myanmarpithecus, were previously discovered in Myanmar, while a third, named Siamopithecus, had been found in Thailand. A detailed analysis of their evolutionary relationships shows that amphipithecids are closely related to living anthropoids and that all of the Burmese amphipithecids evolved from a single common ancestor. Some scientists had previously argued that amphipithecids were not anthropoids at all, being more closely related to the lemur-like adapiforms.

The discovery of Ganlea strongly supports the idea that amphipithecids are anthropoids, because adapiforms never evolved the features that are necessary to become specialized seed predators. Indeed, all of the Burmese amphipithecids appear to have been specialized seed predators, filling the same ecological niche occupied by modern pitheciine monkeys in the Amazon Basin of South America. During the Eocene when Ganlea and other amphipithecids were living in Myanmar, they inhabited a tropical floodplain that was very similar to the environment of the modern Amazon Basin.

Ha! Ida didn't change anything! They're still arguing this same argument: whither the origins of anthropoids? The book I'm almost down with, Splendid Isolation - written in the 80s - had the exact same argument and lamenting that it was still going on then.

Update: Oh, Brian has a great post on the subject.

Cali-Texan Hybrid Salamander Super Predator

A and B are the largest of the native california tiger salamanders. Note D is the hybrid. Holy shibbit. Picture from National Geographic.

Invasive hybrid tiger salamander genotypes impact native amphibians

1. Maureen E. Ryan (a,1)
2. Jarrett R. Johnson (a)
3. Benjamin M. Fitzpatrick (b)

a. Center for Population Biology, University of California, Davis, CA 95616; and
b. Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996

Abstract:

Although the ecological consequences of species invasions are well studied, the ecological impacts of genetic introgression through hybridization are less understood. This is particularly true of the impacts of hybridization on “third party” community members not genetically involved in hybridization. We also know little about how direct interactions between hybrid and parental individuals influence fitness. Here, we examined the ecological effects of hybridization between the native, threatened California Tiger Salamander (Ambystoma californiense) and the introduced Barred Tiger Salamander (Ambystoma tigrinum mavortium). Native x introduced hybrids are widespread in California, where they are top predators in seasonal ponds. We examined the impacts of early generation hybrids (first 2 generations of parental crosses) and contemporary hybrids derived from ponds where hybrids have been under selection in the wild for 20 generations. We found that most classes of hybrid tiger salamander larvae dramatically reduced survival of 2 native community members, the Pacific Chorus Frog (Pseudacris regilla) and the California Newt (Taricha torosa). We also found that native A. californiense larvae were negatively impacted by the presence of hybrid larvae: Native survival and size at metamorphosis were reduced and time to metamorphosis was extended. We also observed a large influence of Mendelian dominance on size, metamorphic timing and predation rate of hybrid tiger salamanders. These results suggest that both genetic and ecological factors are likely to influence the dynamics of admixture, and that tiger salamander hybridization might constitute a threat to additional pond-breeding species of concern in the region.

1. To whom correspondence should be addressed. E-mail: meryan@ucdavis.edu

I think this goes beyond introgression. That there is such a huge difference in phenotype is just amazing.

Uranium Found On the Moon

Hey James! A whole new reason to go to the moon that's not Helium-3!

So what's the going rate for Uranium ore?

Hadrosaur Tooth Wear Patterns Reveal Chewing Methodology

Microscopic analysis of scratches on dinosaur teeth has helped scientists unravel an ancient riddle of what a major group of dinosaurs ate- and exactly how they did it!

Now for the first time, a study led by the University of Leicester, has found evidence that the duck-billed dinosaurs- the Hadrosaurs- in fact had a unique way of eating, unlike any living creature today.

Working with researchers from the Natural History Museum, the study uses a new approach to analyse the feeding mechanisms of dinosaurs and understand their place in the ecosystems of tens of millions of years ago. The results are published today in the Proceedings of the National Academy of Sciences.

Palaeontologist Mark Purnell of the University of Leicester Department of Geology, who led the research, said: "For millions of years, until their extinction at the end of the Cretaceous, duck-billed dinosaurs – or hadrosaurs - were the World's dominant herbivores. They must have been able to break down their food somehow, but without the complex jaw joint of mammals they would not have been able to chew in the same way, and it is difficult to work out how they ate. It is also unclear what they ate: they might have been grazers, cropping vegetation close to the ground - like today's cows and sheep - or browsers, eating leaves and twigs - more like deer or giraffes. Not knowing the answers to these questions makes it difficult to understand Late Cretaceous ecosystems and how they were affected during the major extinction event 65 million years ago.

"Our study uses a new approach based on analysis of the microscopic scratches that formed on hadrosaur's teeth as they fed, tens of millions of years ago. The scratches have been preserved intact since the animals died. They can tell us precisely how hadrosaur jaws moved, and the kind of food these huge herbivores ate, but nobody has tried to analyse them before."

The researchers say that the scratches reveal that the movements of hadrosaur teeth were complex and involved up and down, sideways and front to back motion. According to Paul Barrett palaeontologist at the Natural History Museum "this shows that hadrosaurs did chew, but in a completely different way to anything alive today. Rather than a flexible lower jaw joint, they had a hinge between the upper jaws and the rest of the skull. As they bit down on their food the upper jaws were forced outwards, flexing along this hinge so that the tooth surfaces slid sideways across each other, grinding and shredding food in the process".

The scratch patterns provide confirmation of a theory of hadrosaur chewing first proposed 25 years ago, and provides new insights into their ecology, say the researchers.

The research also sheds light on what the dinosaurs ate. Vince Williams of the University of Leicester said: "Although the first grasses had evolved by the Late Cretaceous they were not common and it is most unlikely that grasses formed a major component of hadrosaur diets. We can tell from the scratches that the hadrosaur's food either contained small particles of grit, normal for vegetation cropped close to the ground, or, like grass, contained microscopic granules of silica. We know that horsetails were a common plant at the time and have this characteristic; they may well have been an important food for hadrosaurs".

Has anyone done this for ceratopsians?

Quantitative analysis of dental microwear in hadrosaurid dinosaurs, and the implications for hypotheses of jaw mechanics and feeding

1. Vincent S. Williams (a),
2. Paul M. Barrett (b)
3. Mark A. Purnell (a,1)


a. Department of Geology, University of Leicester, Leicester LE1 7RH, United Kingdom;
b. Department of Palaeontology, Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom

Abstract:

Understanding the feeding mechanisms and diet of nonavian dinosaurs is fundamental to understanding the paleobiology of these taxa and their role in Mesozoic terrestrial ecosystems. Various methods, including biomechanical analysis and 3D computer modeling, have been used to generate detailed functional hypotheses, but in the absence of either direct observations of dinosaur feeding behavior, or close living functional analogues, testing these hypotheses is problematic. Microscopic scratches that form on teeth in vivo during feeding are known to record the relative motion of the tooth rows to each other during feeding and to capture evidence of tooth–food interactions. Analysis of this dental microwear provides a powerful tool for testing hypotheses of jaw mechanics, diet, and trophic niche; yet, quantitative analysis of microwear in dinosaurs has not been attempted. Here, we show that analysis of tooth microwear orientation provides direct evidence for the relative motions of jaws during feeding in hadrosaurid ornithopods, the dominant terrestrial herbivores of the Late Cretaceous. Statistical testing demonstrates that Edmontosaurus teeth preserve 4 distinct sets of scratches in different orientations. In terms of jaw mechanics, these data indicate an isognathic, near-vertical posterodorsal power stroke during feeding; near-vertical jaw opening; and propalinal movements in near anterior and near posterior directions. Our analysis supports the presence of a pleurokinetic hinge, and the straightness and parallelism of scratches indicate a tightly controlled occlusion. The dominance of scratched microwear fabrics suggests that Edmontosaurus was a grazer rather than a browser.

1. To whom correspondence should be addressed. E-mail: mark.purnell@le.ac.uk

Link to paper.