Is Drone Package Delivery Economically Feasible?

Just over one year ago, Amazon announced that it is developing a drone delivery service – Prime Air – in a bid to get packages into customers’ hands within 30 minutes. How feasible is this from a cost perspective? Kiva Systems co-founder indicates drone delivery could cost as low as 20 cents/package.

In the early summer I wrote an article about the economics of Amazon’s drones where I highlighted the cost of logistics to Amazon and some back-of-the-envelope calculations about the likely costs of drone delivery. In the article I indicated that Amazon would require pilots for their drones, especially in the early years of operation, and it seems far-fetched that we will have fully autonomous delivery drones in our cities within the next ten years or so without some sort of human oversight. Backing up my calculations, a recent job advert by Amazon indicates that they are looking for drone pilots, whilst similar jobs attract annual salaries of approximately $100,000 per year.

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Nigeria Unepextedly Terminates Special Forces Training by US Military

Nigeria has discontinued prematurely a US programme to train one of its army battalions without providing an explanation.

"We regret premature termination of this training, as it was to be the first in a larger planned project that would have trained additional units with the goal of helping the Nigerian Army build capacity to counter Boko Haram," a US State Department spokesman told the Military Times on 1 December.

The unit was not identified, but the US had previously said it was helping the Nigerian Army to establish a Rangers battalion for counter-insurgency operations against the militant group Boko Haram.

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Ceasefire in Ukraine? Really?

FYI, the Russians have been artillery firing across the border again.  That's not shown in the above.

May oil hit the price of $60/barrel and stay there for five years.

Australia's Collins Class Submarine Replacement Political Project's Mess

It seems as though every day brings a different “definitive” story about the Australian submarine requirement to replace its troubled Collins-class submarines.

One day we hear that Australia is going to hold a competition for the Aus$20bn (€13.6bn or US$16.8bn) contract, then we read that no, it will just buy Japan's Soryu-class submarines off-the-shelf, sinking any hope of new jobs in Australia's shipyard and associated companies. Then we read that this is out of the question and an open tender will be held ... and then the pendulum swings back the other way.

That's where we are today, or at least at the time of writing! Australian Treasurer Joe Hockey told the Australian Broadcasting Corporation yesterday (Dec.2) that: “We need to make decisions now and we don't have the time to go through a speculation process.” Reuters reported that a spokesman for Defense Minister David Johnston said no manufacturer had yet been chosen.

However, a spokesman for Saab confirmed that the Swedish company has submitted an unsolicited bid, offering a design specifically tailored for the Australian requirement and an Australian Defense Ministry spokesman has confirmed that the bid has been received.

Other submarine manufacturers are also interested in competing for the job. Germany's Thyssen Krupp Marine Systems is proposing its yet-to-be-built 4,000-ton Type 216 while French naval systems group DCNS has offered the SMX Ocean concept (for more details on these offers see the DTI issue dated Nov.17) and even opened a subsidiary, DCNS Australia, on Nov. 20.

Meanwhile, there is entertaining in-house bickering amongst members of the Australian government over the submarine replacement project.

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US Navy UCLASS Spending Restricted by Congress

The 2015 compromise defense bill places, released on Wednesday, imposes restrictions on funding for the Navy’s planned production carrier-launched unmanned aerial vehicle (UAV) over concerns the platform would lack sufficient stealth, survivability and weapons payload, according to the bill’s language.

The Fiscal Year (FY) 2015 National Defense Authorization Act (NDAA) would restrict Navy spending on the Unmanned Carrier-Launched Airborne Surveillance and Strike (UCLASS) program until the completion of a Pentagon review of its entire information, surveillance and reconnaissance (ISR) portfolio and those results were reported back to Congress.

The Navy’s FY 2015 budget submission included $403 million to further develop the UCLASS program.

The bill — which is expected to pass both the Senate and the House — also directs the Secretary of the Navy to submit a report to Congress on how the Navy decided on the most recently stated set of requirements for UCLASS through the prism of the emerging anti-access/area denial (A2/AD) threats the military has touted as a dangerous limitation to U.S. forces and future capabilities of a carrier strike group (CSG) in 2030.

The study — to be included in the FY 2017 budget submission — will require the Navy to outline its plan for how the UCLASS would work with the Navy’s EA-18G Growler electronic attack aircraft, the F-35C Lighting II Joint Strike Fighter (JSF) and the planned next generation F/A-XX naval fighter.

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Evidence of Barremian/Albian Cretaceous Anoxic Oceans Interrupted by Turbulent Mixing

Are Early Cretaceous environmental changes recorded in deposits of the Western part of the Silesian Nappe? A geochemical approach

Authors:

Wójcik-Tabo et al

Abstract:

The organic matter (OM)-rich, relatively monotonous sequence of upper Barremian–Albian deposits in the western part of the Silesian Nappe in the Polish Outer Carpathians, was investigated, using geochemical proxies to show environmental changes. The amounts of organic carbon (0.4–4.32 wt.% of TOC) co-vary with the concentration of S and/or redox sensitive trace elements (RSTE: Mo, U, Co, V, As). Kerogen is present as Type III and mixed Type II/III. Maceral assemblages consist of vitrinite, inertinite and liptinite. The carbon isotopic composition of the organic matter (δ13Corg) varies between − 25.38 and − 21.31‰ with an outlier at − 15.14‰. During the Early Cretaceous the Proto-Silesian Basin was the site of OM accumulation in a detrital oceanic anoxic event as a result of increased sedimentation rates of terrestrial organic matter. Runoff of terrestrial organic matter was accompanied by the production of plankton on an occasional basis. The marine matter contribution is inferred from occurrence of siliceous microfauna, the domination of short-chain n-alkanes, the distribution of sterane and prevalence of cholestane, and enrichment in nutrient elements (P2O5, Ba, Ag, Cd). The bottom waters could have been dysoxic to anoxic, with a mid-water oxygen minimum zone (OMZ) developed owing to the oxidation of organic matter. Anoxia is inferred from the lamination, pyritization patterns, RSTE concentration and low Pr/Ph and C23t/C30 H ratios. Intervals enriched in TOC and RSTE in the Veřovice Formation record pulses of marine productivity, preceded by volcanic (teshenite) and hydrothermal activity. They are referable to the following episodes: the Taxy (Barremian–Aptian), early Aptian Selli, Fallot and Paquier during the late Aptian and at the Aptian–Albian boundary. The initiation of turbidite deposition during the Albian led to bottom ventilation. The Lhoty Formation records the late Albian Toolebuc Episode, marked by a TOC peak, which resulted from the detrital flux. Acidic solution was responsible for reducing conditions in the sediment.

Kookiness in a Journal? Did Venera-14 Find Life?

Hypothetical flora and fauna of Venus

Author:

Ksanfomality

Abstract:

Hypothetical habitability of some of extrasolar planets is a fundamental question of science. Some of exoplanets possess physical conditions close to those of Venus. Therefore, the planet Venus, with its dense and hot (735 K) oxygen-free atmosphere of CO2, having a high pressure of 9.2 MPa at the surface, can be a natural laboratory for this kind of studies. The only existing data on the planet׳s surface are still the results obtained by the Soviet VENERA landers in the 1970s and 1980s. The TV experiments of Venera-9 and 10 (October, 1975) and Venera-13 and 14 (March, 1982) delivered 41 panoramas of Venus surface (or their fragments). There have not been any similar missions to Venus in the subsequent 39 and 32 years. In the absence of new landing missions to Venus, the VENERA panoramas have been re-processed. The results of these missions are studied anew. A dozen of relatively large objects, from a decimeter to half a meter in size, with an unusual morphology have been found which moved very slowly or changed slightly their shape. Their emergence by chance could hardly be explained by noise. Certain unusual findings that have similar structure were found in different areas of the planet. This paper presents the last results obtained of a search for hypothetical flora and fauna of Venus.

Ancient East Polynesian Voyaging Spheres

Ancient East Polynesian voyaging spheres: new evidence from the Vitaria Adze Quarry (Rurutu, Austral Islands)

Authors:

Roletti et al

Abstract:

The use of adze sourcing to study interaction spheres opens new perspectives on ancient Polynesian voyaging. Our work contributes to this effort by documenting the discovery and geochemical signature of the Vitaria Adze Quarry, a major adze quarry complex in the central East Polynesia core area. We present WD-XRF geochemical data for the Vitaria raw material and ethnographically collected adzes from Raivavae and Tubuai Islands, also part of the Australs. Comparison of our results with previously published artifact and source data shows that initial tool production at the Vitaria Adze Quarry coincides with the human colonization of East Polynesia. Artifacts from Rurutu were exchanged within the Australs, as well as to neighboring archipelagoes, indicating the importance of Rurutu as a node in voyaging networks spanning the East Polynesian homeland area. Large-scale tool production at the Vitaria Adze Quarry may have contributed to the rise of Vitaria District as the seat of the paramount chief and the center of power on Rurutu.

American Mastodon Went Locally Extinct in Alaska Prior to Climate Change or Human Presence During Pleistocene Quaternary

American mastodon extirpation in the Arctic and Subarctic predates human colonization and terminal Pleistocene climate change

Authors:

Zazula et al

Abstract:

Existing radiocarbon (14C) dates on American mastodon (Mammut americanum) fossils from eastern Beringia (Alaska and Yukon) have been interpreted as evidence they inhabited the Arctic and Subarctic during Pleistocene full-glacial times (∼18,000 14C years B.P.). However, this chronology is inconsistent with inferred habitat preferences of mastodons and correlative paleoecological evidence. To establish a last appearance date (LAD) for M. americanum regionally, we obtained 53 new 14C dates on 36 fossils, including specimens with previously published dates. Using collagen ultrafiltration and single amino acid (hydroxyproline) methods, these specimens consistently date to beyond or near the ∼50,000 y B.P. limit of 14C dating. Some erroneously “young” 14C dates are due to contamination by exogenous carbon from natural sources and conservation treatments used in museums. We suggest mastodons inhabited the high latitudes only during warm intervals, particularly the Last Interglacial [Marine Isotope Stage (MIS) 5] when boreal forests existed regionally. Our 14C dataset suggests that mastodons were extirpated from eastern Beringia during the MIS 4 glacial interval (∼75,000 y ago), following the ecological shift from boreal forest to steppe tundra. Mastodons thereafter became restricted to areas south of the continental ice sheets, where they suffered complete extinction ∼10,000 14C years B.P. Mastodons were already absent from eastern Beringia several tens of millennia before the first humans crossed the Bering Isthmus or the onset of climate changes during the terminal Pleistocene. Local extirpations of mastodons and other megafaunal populations in eastern Beringia were asynchrononous and independent of their final extinction south of the continental ice sheets.

Permian Extinctions led to Boney Fish Dominance Over Cartilaginous Fish

Today, ray-finned fish, which belong to the bony fish, are by far the most biodiverse fish group in both salt- and freshwater. Their spectacular variety of forms ranges from eels, tuna, flounders and angler fish all the way to seahorses. With around 1,100 species, the second most biodiverse group is the cartilaginous fish, which are almost exclusively marine and include sharks, rays and chimaeras. Exactly why bony fish managed to prevail in different habitats is the subject of debate: Do they have a better body plan, which is suited to more ecological niches than that of the cartilaginous fish? Or are other factors involved in their successful distribution? Paleontologists from the University of Zurich now reveal that climate catastrophes in the past played a crucial role in the dominance of ray-finned fish today.

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Paleosol Evidence of Ediacaran NeoProterozoic Gaskiers and/or Fauquier Glaciations From PaleoContinent

Petrology, mineralogy and geochemical climofunctions of the Neoproterozoic Baltic paleosol

Authors:

Liivamägi et al

Abstract:

The Oxisolic Baltic paleosol is a well preserved Neoproterozoic weathering sequence located in the Russian Platform of the East-European Craton, former Baltica continent. The Baltic paleosol is developed on different hostrock types ranging from amphibolites and metagabbros to gneissic rocks and is characterized by up to several meters of thick weathered uppermost residuum composed of kaolinite (greater than 60%), Fe-oxyhydroxides and residual quartz. The mineral index of alteration (MIA) and molecular weathering indices (CIA, CIA-K, PIA) all indicate strong and deep weathering most likely under warm and humid climate. Geochemical climofunctions, although not directly applicable to the Precambrian Baltic paleosol, agree with this interpretation suggesting high mean annual temperatures (greater than 17 °C) and precipitation (1300-1800 mm yr−1) similar to modern day tropical conditions. The age of the weathering is between 560-600 Ma. During that time interval the Baltica continent was not drifting at tropical latitudes, but it is plausible that the Baltic paleosol was formed as a consequence of increased weathering rates during greenhouse event(s) possibly related to the termination of the Ediacaran Gaskiers and/or Fauquier glaciations, or in the relation to the Shuram-Wonoka isotope excursion. The Baltic paleosol is most likely one of the few well preserved examples of paleosol formation in the latest Neoproterozoic because it developed in a tectonically stable interior of the Baltica paleocontinent while physical denudation prevailed on other continental blocks due to the build-up of Gondwana that erased weathering profiles from the geological record.

MasterCard Cites Mt Gox in Submission to Australian Senate

MasterCard has used a submission to a Senate inquiry to argue for Australian regulators to move against the pseudonymity of digital currencies such as Bitcoin.

"Any regulation adopted in Australia should address the anonymity that digital currency provides to each party in a transaction," the company's submission (PDF) states.

"Contrary to transactions made with a MasterCard product, the anonymity of digital currency transactions enables any party to facilitate the purchase of illegal goods or services; to launder money or finance terrorism; and to pursue other activity that introduces consumer and social harm without detection by regulatory or police authority."

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How Agriculture Effects the Atmospheric Carbon dioxide Level

The intense farming practices of the "Green Revolution" are powerful enough to alter Earth's atmosphere at an ever-increasing rate, boosting the seasonal amplitude in atmospheric carbon dioxide to about 15 percent during the last five decades.

That's the key finding of a new atmospheric model that estimates that on average, the amplitude of the seasonal oscillation of carbon dioxide in the atmosphere is increasing at the rate of 0.3 percent every year.

A report on the results of the model, called VEGAS, is published today in the journal Nature.

"What we are seeing is the effect of the 'Green Revolution' on Earth's metabolism," says Ning Zeng, an atmospheric scientist at the University of Maryland and the lead developer of VEGAS, a terrestrial carbon cycle model that, for the first time, factors in changes in 20th and 21st century farming practices.

"Changes in the way we manage the land can literally alter the breathing of the biosphere."

Scientists have known since the 1950s that carbon dioxide levels in the atmosphere hit an annual low during late summer and early fall in the Northern Hemisphere, which has a greater continental landmass than the Southern Hemisphere and therefore has more plant life.

The atmosphere's carbon dioxide level falls in spring and summer as the hemisphere's plants reach their maximum growth, taking in carbon dioxide and releasing oxygen.

In the autumn, when the plants are decomposing and releasing stored carbon, the atmosphere's carbon dioxide levels rapidly increase.

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Labour Issues of 2030

Has Congress Frozen the US Navy's LCS Program?

Congress has frozen the construction of several new Littoral Combat Ships until the Navy provides the House and Senate defense committees with specific analytical reports on the program, according to a newly released Congressional budget agreement.

The agreement on the National Defense Act for Fiscal Year 2015, which Congress will vote on before Christmas, emerged from conference session between House and Senate committees responsible for passing the defense budget.

Regarding the LCS, the agreement prevents the Navy from spending money toward the construction of LCS-25 or LCS-26 until certain reports are submitted by the Navy Secretary Ray Mabus.

The Congressional road block is the most recent in a string of controversies and disagreements on the LCS’s future. Many have criticized the platform on the ground that it is not lethal or survivable enough to address the current global threat environment and is poorly suited to perform its intended missions.

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Has Iran Started Conducting Air Strikes in Iraq? Pentagon: Yes! Iran: NOOOOO!!! Al Jazerra: See!

Al Jazerra Showeth:

Pentagon Sayeth:

Iran has reportedly joined the fight against Islamic State militants in Iraq, targeting insurgents in the eastern part of the country with McDonnell Douglas Phantom F-4s. News reports state that operations began in recent days, following Iranian ground operations in Iraq.

Until now, air strikes had only been carried out by the US-led coalition. Washington has been quick to reject any suggestion that the coalition is associated with or co-ordinating with the Iranian effort.

“I've seen the reports,” Pentagon press secretary Rear Adm John Kirby said on 2 December. “We have no indication that the reports are not true – that Iranian aircraft have conducted airstrikes in the last several days against ISIL [Islamic State of Iraq and Levant] targets in eastern Iraq.

“It's the Iraqi air space and Iraq’s to deconflict," Kirby says. "We are not co-ordinating with nor are we deconflicting with Iranian military. Nothing has changed about our policy of not co-ordinating military activity with the Iranians.

“Our message to Iran is the same today as it was when it started, as it is to any neighbour in the region that is involved in the anti-ISIL activities. And that's that we want nothing to be done that further inflames sectarian tensions in the country.”

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Iran Sayeth:

Iran is denying it has flown airstrikes in Iraq targeting Islamic State in Iraq and Syria (ISIS or ISIL) despite Pentagon claims at least some Iranian strikes in Iraq have occurred.

An unnamed senior official Iranian official told the Reuters news agency on Wednesday Iran has never struck at airstrikes in Iraq.

“Iran has never been involved in any air strikes against Daesh (ISIS) targets in Iraq,” read the quote by the news service.

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South Korea Does not Fund KF-X Steath Fighter Program Launch in 2015 Budget

South Korea has again declined to launch full-scale development of the proposed KF-X indigenous fighter, with the finance ministry recommending against a launch and parliament failing to fund one.

link. (paywall)

Report: Chinese Navy Will be Bigger Than US Navy by 2020

China has plans to grow its navy to 351 ships by 2020 as the Chinese continue to develop their military’s ability to strike global targets, according to a new report.

The 2014 U.S.-China Economic and Security Review Commission recommended to Congress the U.S. Navy respond by building more ships and increase its presence in the Pacific region – a strategy they U.S. military has already started.

The commission asked Congress to increase its Pacific fleet up to 67 ships and rebalance homeports such that 60-percent of the force is based in the region by 2020.

The commissions’ recommendations, which are based on Congressional testimony, expert assessments and open-source information on China’s military and U.S.-Chinese relations, are consistent with Pentagon’s stated plans for the region.

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Coniacian/Santonian Cretaceous Marine Moroccan Records of the Oceanic Anoxic Event 3

Marine palynology of the Oceanic Anoxic Event 3 (OAE3, Coniacian – Santonian) at Tarfaya, Morocco, NW Africa – transition from preservation to production controlled accumulation of marine organic carbon

Author:

Prauss

Abstract:

The paper presented is the first comprehensive, fully quantitative, high resolution study of marine palynology from an OAE3 black-shale environment. It is based on 175 m core spanning the upper Turonian to lower Santonian at Tarfaya, Morocco, NW Africa, which has been sampled from centimetre to 3 m intervals. The results are integrated and discussed with lithology and geochemistry data to (1) distinguish between potential changes in production and preservation of total organic carbon (TOC) accumulation and (2) constrain the stratigraphic position of the Oceanic Anoxic Event 3 (OAE3).

The succession is characterized by increased total organic carbon (TOC), varying between 1% and 19% (average about 6%). Distinct black-shale horizons of variable thickness appear episodically throughout the succession, with higher frequency in the late Turonian. Higher TOC contents do not strictly correlate to lithologic black-shales or peaks of a specific taxon of organic-walled algae. The palynomorph spectrum is strongly dominated by organic-walled algae, with the ratio of terrigenous sporomorphs to organic-walled algae (t/m index) varying between zero and 0.05 (average 0.01). The dominance of algal organic matter is corroborated by the prevalence of Type I kerogen identified using Rock-Eval pyrolysis. Dinocyst diversity is low, with the absolute taxa number varying from 7 to 27 between single samples. The peridinioid/gonyaulacoid ratio of dinocysts (p/g ratio) shows strong fluctuations, varying between 1 and 283 (average of about 100).

The upper Turonian interval is dominated by Bosedinia spp., a dinocyst taxon formerly described as abundant only in lacustrine sediments from the Oligocene and Miocene of SE Asia. This dominance is episodically modified by the increase of the warm-temperate waters dinocysts fraction, here mainly represented by the genera Alterbidinium, Isabelidinium and Spinidinium. Within the Coniacian-Santonian, black-shale horizons are limited in number and are concentrated within the upper Coniacian to lower Santonian interval. The dinocysts show alternating, prominent peak abundances of Palaeohystrichophora spp. and the warm-temperate water dinocysts fraction, here mainly represented by the genera Trithyrodinium and Chatangiella. However, a final episode of increased proportions of Bosedinia spp. is confined to a 5 m thick black-shale horizon closely spanning the Coniacian-Santonian boundary.

Changes in the ratio of total sulphur to total organic carbon (TS/TOC) reflect fluctuating oxygen contents of bottom waters throughout the late Turonian to Santonian. These are significantly parallelled by the alternation of dinocysts assemblages suggestive of enhanced upwelling and water column stratification respectively, probably reflecting changes in the mode of TOC accumulation. Accordingly, preservation largely prevails during the late Turonian interval and changes towards increased production within the Coniacian-Santonian. However, a final preservation-event is probably represented by the black-shale horizon closely spanning the Coniacian-Santonian boundary (top Dicarinella concavata foraminifera zone), which may reflect an episodic shutdown of a major upwelling cell. It is thus proposed, that the “culmination” of the OAE3 at Tarfaya may represent intermittent preservation of TOC within an otherwise high productivity environment related to a global cooling trend.

Embedded Clays and Sulfates in Mars' Meridiani Planum

Embedded clays and sulfates in Meridiani Planum, Mars

Authors:

Flahaut et al

Abstract:

The area of Meridiani Planum on Mars became of particular interest after the detection of coarse-grained, gray hematite, which led to the choice of this region as final landing site for the Mars Exploration Rover Opportunity. Multiple additional minerals have since been detected in the region, both from orbit and in situ. The present paper reassesses in detail the mineralogy and geomorphology of the area (between 3.5°S to 6.5°N latitude and 8.0°W to 8.0°E longitude) using visible and near-infrared hyperspectral data, merged with high spatial resolution images into a Geographic Information System. Fe/Mg-rich phyllosilicates, as well as several types of sulfates are identified within the kilometer of sedimentary deposits constituting the etched terrains and the overlying hematite-rich plains. The mineralogical stratigraphy of the etched terrains is characterized by a sulfate-rich unit, enriched in Fe/Mg-rich clays in its uppermost part. This clay-rich horizon is capped by another sulfate-rich unit, of different composition, associated with hematite detections and constituting the material of the hematite plains unit. The clay-bearing unit, which directly underlies the hematite plains, may be exposed in the rim of Endeavour Crater and could correspond to the material that is currently being analyzed by Opportunity. Diverse landforms including karsts and pan features are observed at the surface of the hydrated etched terrains and indicate past surface water and potential groundwater aquifers. Our analysis reveals that both surficial water and groundwater processes are required to explain the diversity of morphologies and mineralogies observed in the area. Although orbital detections are consistent with the hematite and sulfate detections made in situ by Opportunity in the hematite plains, they also show the presence of a clay-rich horizon at depth, overlying another, thicker, possibly chemically distinct, sulfate-rich unit within the etched terrains. Therefore we conclude that the very acidic conditions that prevailed during the formation of the topmost sulfate-rich unit, as observed in Meridiani Planum and in the hematite plains by the rover Opportunity, are not representative of the entire history of the etched terrains. In contrast, most hydrated minerals in Meridiani Planum likely formed at more neutral pH, at the beginning of the Hesperian. The overall sulfate/clay/sulfate sequence is similar to the one observed in Gale Crater, the landing site of the Mars Science Laboratory rover.

Art Predates Homo sapiens

A zigzag engraving on a mussel's shell may transform scientific understanding of what has long been considered a defining human capacity: artistic creativity.

Until now, the earliest evidence of geometric art was dated from 70,000 to 100,000 years ago. Scratched into rocks found in South African caves, those engravings signified behavioral modernity: Homo sapiens' unique cognitive journey into a sophisticated world of abstraction and symbol.

But new analysis of an engraving excavated from a riverbank in Indonesia suggests that it's at least 430,000 years old-and that it wasn't made by humans, scientists announced Wednesday. At least it wasn't made by humans as most people think of them, meaning Homo sapiens.

Rather, the earliest artist appears to have been one of our ancestors, Homo erectus. Hairy and beetle-browed, H. erectus was never before thought to have such talents.

link.

Horses, Equids Have a Complicated Evolutionary History

Speciation with gene flow in equids despite extensive chromosomal plasticity

Authors:

Jónsson et al

Abstract:

Horses, asses, and zebras belong to a single genus, Equus, which emerged 4.0–4.5 Mya. Although the equine fossil record represents a textbook example of evolution, the succession of events that gave rise to the diversity of species existing today remains unclear. Here we present six genomes from each living species of asses and zebras. This completes the set of genomes available for all extant species in the genus, which was hitherto represented only by the horse and the domestic donkey. In addition, we used a museum specimen to characterize the genome of the quagga zebra, which was driven to extinction in the early 1900s. We scan the genomes for lineage-specific adaptations and identify 48 genes that have evolved under positive selection and are involved in olfaction, immune response, development, locomotion, and behavior. Our extensive genome dataset reveals a highly dynamic demographic history with synchronous expansions and collapses on different continents during the last 400 ky after major climatic events. We show that the earliest speciation occurred with gene flow in Northern America, and that the ancestor of present-day asses and zebras dispersed into the Old World 2.1–3.4 Mya. Strikingly, we also find evidence for gene flow involving three contemporary equine species despite chromosomal numbers varying from 16 pairs to 31 pairs. These findings challenge the claim that the accumulation of chromosomal rearrangements drive complete reproductive isolation, and promote equids as a fundamental model for understanding the interplay between chromosomal structure, gene flow, and, ultimately, speciation.

Cretaceous–Paleogene Boundary Section Found in Campeche Escarpment

Cretaceous–Paleogene boundary exposed: Campeche Escarpment, Gulf of Mexico

Authors:

Paull et al

Abstract:

We present the first multibeam bathymetric maps of the Campeche Escarpment, a Mesozoic carbonate platform in the Gulf of Mexico, which represents the closest Cretaceous–Paleogene (K-Pg) boundary outcrops to the Chicxulub impact structure. The impact of an extraterrestrial-body ~ 65 million years ago on top of this platform is implicated in the end of the Cretaceous mass extinction and caused the largest debris flow yet described on Earth, which is found across the floor of the Gulf of Mexico and the Caribbean Sea. The location of the K-Pg boundary has been identified in the escarpment face by combining the new multibeam data with existing information from boreholes. The boundary is represented by an abrupt change in gradient on the escarpment face. The morphology of the escarpment combined with seismic data reveals that a significant amount of material is missing from the face, which failed catastrophically due to seismic shaking produced by the impact. The escarpment face is inferred to be an important source for the extensive debris flows triggered by the impact, whose deposits are found throughout much of the Gulf of Mexico.

A Eurypterid Lagerstätte From Pridoli Silurian Pennsylvania

A NEW EURYPTERID LAGERSTÄTTE FROM THE UPPER SILURIAN OF PENNSYLVANIA

Authors:

Vrazo et al

Abstract:

Eurypterids are generally rare in the fossil record, but occasionally occur in abundance. The genus Eurypterus, in particular, is well known from certain upper Silurian Lagerstätten of the northern Appalachian basin (New York and Ontario), but occurs far less frequently in the central and southern Appalachian basin (Pennsylvania, Maryland, and West Virginia, respectively). The recent discovery of an exceptionally preserved mass assemblage of Eurypterus in the upper Tonoloway Formation (upper Ludlow–Přídolí) of Pennsylvania provides new information on the behavior and life habitat of the genus in this region. Eurypterids at this locality are found in thinly laminated, calcareous shale deposited within the lower intertidal to shallow subtidal zone of a coastal mudflat or sabkha. Rare associated fauna of limited diversity, and evaporitic and desiccation features in associated beds, suggest a stressed environment with variable salinity and possible hypoxic conditions. Most eurypterids are disarticulated and fragmentary, but several fully articulated, exceptionally preserved specimens are present. Exoskeletal features and taphonomic indices values indicate a molt rather than death assemblage, and the presence of arthropod trackways suggests that Eurypterus sp. may have molted en masse in the vicinity of the burial site. Sequence stratigraphic interpretation of the site suggests that preservation of eurypterid remains is the result of occupation of ephemeral environmental (salinity/oxygen) conditions during a transgression. The occurrence of this new Lagerstätte within the upper Silurian succession of the central Appalachians, an interval which had heretofore yielded only rare, fragmentary remains, indicates that eurypterids were more prevalent in this region than previously thought.

Ediacaran–Silurian Nanhua Foreland Basin From South China

Detrital provenance evolution of the Ediacaran–Silurian Nanhua foreland basin, South China

Authors:

Yao et al

Abstract:

We report here in-situ U–Pb and Hf isotopic results of detrital zircons from sixteen Cambrian–Silurian siliciclastic samples across the Nanhua foreland basin, South China. Together with published data from Ediacaran–Silurian sandstones in the region, we establish the temporal and spatial provenance evolution across the basin. Except for samples from northeast Yangtze, all other Ediacaran–Silurian samples exhibit a prominent population of 1100–900 Ma, moderate populations of 850–700 Ma and 650–490 Ma, and minor populations of 2500 Ma and 2000–1300 Ma, grossly matching that of crystalline and sedimentary rocks in northern India. Zircon Hf isotopes further reveal four episodes of juvenile crustal growth at 2.5 Ga, 1.8 Ga, 1.4 Ga and 1.0 Ga in the source regions. Utilizing the basin history and late Neoproterozoic to early Paleozoic paleogeography of South China, we conclude that the Ediacaran–Cambrian sediments in the Nanhua foreland basin were mainly sourced from northern India and adjacent orogens, and the Ordovician–Silurian sediments were derived from both locally recycled Ediacaran–Cambrian rocks and eroded Cathaysian basement. The Wuyi–Yunkai late-orogenic magmatic rocks also contributed to the Silurian sediments in the basin. The upper-Ordovician to Silurian samples in northeast Yangtze received higher proportions of local Cryogenian (850–700 Ma) magmatic rocks which were uplifted during late-Ordovician to Silurian time. We speculate that there was an Ediacaran–Cambrian collisional orogen between South China and northern India, shedding sediments to the early Nanhua foreland basin. Far-field stress during the late stage of this collisional orogeny triggered the Ordovician–Silurian intraplate Wuyi–Yunkai orogeny in South China, and erosion of the local Wuyi–Yunkai orogen further provided detritus to the late Nanhua foreland basin.

How Arid Biomes React to Climate Change

Approximately 40 percent of the earth's surface is covered by drylands in which average annual precipitation is lower than evaporation. The changes projected to unfold in these areas in the course of climate change are alarming. Greater variations in annual and seasonal precipitation will lead to more frequent droughts and, presumably, longer drought periods. This means that drylands are among those areas most severely affected by climate change.

Research has thus far not adequately addressed the question of how strongly annual plant growth in pasture landscapes - hence the available food for livestock - is affected by droughts. Also, how predictable is the correlation? Yet this knowledge about vegetation stability would be essential for more accurate predictions of the effects of climate change in these areas. Over the past years, Dr. Jan Ruppert, an ecologist from the University of Cologne, has compiled hundreds of long-term studies on annual plant growth in drylands. Together with Dr. Anja Linstädter, the head of his working group at the University of Cologne, he has now completed his analysis of these data. The researchers are looking for an answer to the question of how droughts of varying intensity affect plant production - during and after the event. They are particularly interested in whether or not certain characteristics of the vegetation or the grazing regime affect the outcome. In this context, the scientists differentiate between two aspects of stability: on the one hand, the vegetation's durability to droughts of varying intensity (resistance), and on the other hand its ability to regenerate after a drought (recovery).

"We were surprised to see that the type of ecosystem (biome) is a rather poor indicator of vegetation stability in the face of drought. It does not make a large difference whether a drought occurs in a savanna, grassland or shrubland. The decisive factor is the dominant herbaceous life history - that is, whether we are dealing with annual or perennial plants", Ruppert explains. Drylands that are dominated by annual plants are more severely affected during droughts, but recover more quickly afterwards. Areas in which perennial plants dominate exhibit the opposite trend. The effect of the grazing regime on vegetation stability in the face of drought is also highly dependent on whether one is dealing with annual or perennial plants. Enduring communities of plants will react to grazing with a lower drought resistance. Grazing does not, however, have a significant effect on resistance in areas where annual plants dominate. "Our results indicate that the vegetation of drylands is not capable of optimizing its resistance and recovery potential at the same time," Linstädter concludes.

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The Son at the Beach

Lyudmila took the kids for T Day.  Orest is having a blast on his vacation.

Bulgaria Delays Fighter Purchase

The saga of Bulgaria’s long-delayed purchase of new military jet fighters to meet Nato requirements is set to continue unresolved for a few more years because the state will give no investment loans or state guarantees for large projects before 2017.

This has emerged from a transcript of the Bulgarian cabinet’s November 26 meeting, at which Prime Minister Boiko Borissov and his ministers agreed only to support a project to construction a gas interconnector link with Greece.

The cabinet declined for now to give financial support to two major projects, the Defence Ministry’s 800 million leva modernisation project and the Regional Development Ministry’s plan to repair and modernise the road network, which has a price tag of about 300 million leva. Both would require a state loan.

Finance Minister Vladislav Goranov said that going ahead with the projects would raise the risk of defaulting on fiscal spending targets and would require significant changes in spending ceilings in the 2015/17 period.

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Russia has Sold S-400 SAMs to China for $500 Million/Battalion

There’s reason this week to return to the issue of what the S-400 system costs. Specifically, what it might cost China.

Vedomosti reported Wednesday that Russia has signed a deal with China to sell it the S-400 / Triumf.

The business daily’s defense industry source claims the agreement inked by Rosoboroneksport and the Chinese military will send off not less than six battalions of the advanced SAM system for more than $3 billion.

That would be at least $500 million per battalion (against the previously ventured guess of about $320 million). Or in excess of $80 million per TEL.

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Nigeria Buying Sino-Pakistani JF-17 Fighters?

The Nigerian Air Force (NAF) is close to finalising an order for the purchase of one or two squadrons of the JF-17 Thunder fighter aircraft co-produced by Pakistan and China, a senior Pakistani Ministry of Defence official told IHS Jane's on 2 December.

Speaking at the International Defence Exhibition and Seminar (IDEAS) 2014 in Karachi, the official said the NAF finalised its recommendation for the purchase of 25-40 JF-17s after NAF chief air marshal Adesola Nunayon Amosu visited Pakistan in October. AM Amosu's engagements in Pakistan included a visit to the Pakistan Aeronautical Complex (PAC) at Kamra, north of Islamabad, where the JF-17 is manufactured.

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World's Largest Unmanned Warship is the USS Paul F Foster (EDD-964) Converted Spruance Class Destroyer

What does the Navy do when it needs to know for sure that a new weapon system or electronic countermeasure works, not just under stringent lab-like settings or at a land based range, but in its intended operating environment? They put it to sea on a giant remote controlled Destroyer and throw live missiles at it.

The USS Paul F. Foster (DD-964) is a Spruance Class Destroyer that was originally commissioned in 1976 and served till its decommissioning in 2003, between which it took part in multiple conflicts around the globe. Among many historical acts, the Foster was the first ship to fire Tomahawk missiles during Operation Desert Storm.

Today, this 529-foot-long, 8,000-ton-displacement steel beast has been given a second, albeit more precarious life as the Navy's Self Defense Test Ship. Since 2005, the re-designated Paul F. Foster (EDD-964) optionally manned full-scale test ship has been on the near-receiving end of all types of attacks and has been the Navy's one stop shop for testing everything from laser defense systems to alternative fuels.

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Petrified Wood Growth Indices as Climate Proxies For Cenomanian/Turonian Cretaceous Australia

Wood growth indices as climate indicators from the Upper Cretaceous (Cenomanian–Turonian) portion of the Winton Formation, Australia

Authors:

Fletcher et al

Abstract:

Although the mid- to Late Cretaceous is regarded as a global warm period, increasingly a more complex picture of warming and cooling is emerging. New techniques allow more precise dating of terrestrial localities, opening opportunities for using climate proxy approaches on terrestrial fauna and flora to better capture the complexity of Cretaceous climate. Here an attempt is made to understand the seasonality and inter-annual variability of two newly dated localities from the upper preserved portion (Cenomanian–Turonian) of the Winton Formation, Australia. Primarily quantitative approaches to palaeodendrology are used. The results suggest both seasonality and high variability in climate conditions that affect growth between years, including evidence for floods. The longest series (QM F44338) suggests oscillatory patterns of good and poor growth in a 15 year alternating cycle similar to the contemporary Pacific Decadal Oscillation, although other potential explanations should be considered and tested.

Martian Runoff may Have Only Been Snowmelt, not Rain

Estimating precipitation on early Mars using a radiative-convective model of the atmosphere and comparison with inferred runoff from geomorphology

Authors:

von Paris et al

Abstract:

We compare estimates of atmospheric precipitation during the Martian Noachian-Hesperian boundary 3.8 Gyr ago as calculated in a radiative-convective column model of the atmosphere with runoff values estimated from a geomorphological analysis of dendritic valley network discharge rates. In the atmospheric model, we assume CO2-H2O-N2 atmospheres with surface pressures varying from 20 mb to 3 bar with input solar luminosity reduced to 75% the modern value.

Results from the valley network analysis are of the order of a few mm d-1 liquid water precipitation (1.5-10.6 mm d-1, with a median of 3.1 mm d-1). Atmospheric model results are much lower, from about 0.001-1 mm d-1 of snowfall (depending on CO2 partial pressure). Hence, the atmospheric model predicts a significantly lower amount of precipitated water than estimated from the geomorphological analysis. Furthermore, global mean surface temperatures are below freezing, i.e. runoff is most likely not directly linked to precipitation. Therefore, our results strongly favor a cold early Mars with episodic snowmelt as a source for runoff.

Our approach is challenged by mostly unconstrained parameters, e.g. greenhouse gas abundance, global meteorology (for example, clouds) and planetary parameters such as obliquity- which affect the atmospheric result - as as well as by inherent problems in estimating discharge and runoff on ancient Mars, such as a lack of knowledge on infiltration and evaporation rates and on flooding timescales, which affect the geomorphological data. Nevertheless, our work represents a first step in combining and interpreting quantitative tools applied in early Mars atmospheric and geomorphological studies.

Studying Bantu Kinship Challenges Social Evolution Theory

Phylogenetic reconstruction of Bantu kinship challenges Main Sequence Theory of human social evolution 

Authors:

Opie et al

Abstract:

Kinship provides the fundamental structure of human society: descent determines the inheritance pattern between generations, whereas residence rules govern the location a couple moves to after they marry. In turn, descent and residence patterns determine other key relationships such as alliance, trade, and marriage partners. Hunter-gatherer kinship patterns are viewed as flexible, whereas agricultural societies are thought to have developed much more stable kinship patterns as they expanded during the Holocene. Among the Bantu farmers of sub-Saharan Africa, the ancestral kinship patterns present at the beginning of the expansion are hotly contested, with some arguing for matrilineal and matrilocal patterns, whereas others maintain that any kind of lineality or sex-biased dispersal only emerged much later. Here, we use Bayesian phylogenetic methods to uncover the history of Bantu kinship patterns and trace the interplay between descent and residence systems. The results suggest a number of switches in both descent and residence patterns as Bantu farming spread, but that the first Bantu populations were patrilocal with patrilineal descent. Across the phylogeny, a change in descent triggered a switch away from patrifocal kinship, whereas a change in residence triggered a switch back from matrifocal kinship. These results challenge “Main Sequence Theory,” which maintains that changes in residence rules precede change in other social structures. We also indicate the trajectory of kinship change, shedding new light on how this fundamental structure of society developed as farming spread across the globe during the Neolithic.

Ursolestes perpetior: a new 'Giant' Purgatoriid Plesiadapiforme From Paleocene Paleogene Montana

A ‘giant’ purgatoriid (Plesiadapiformes) from the Paleocene of Montana, USA: mosaic evolution in the earliest primates

Authors:

Fox et al

Abstract:

Ursolestes perpetior gen. et sp. nov. is a large purgatoriid plesiadapiform primate from the middle/late Puercan (earliest Paleocene) Simpson Quarry, Montana, USA. It differs from Purgatorius Van Valen and Sloan, 1965, the only other known purgatoriid and the oldest discovered primate, in its substantially larger body size as inferred from the dimensions of the known parts of its dentition, while resembling Purgatorius in possessing a large lower canine, unreduced p1, and in the upper molars, a protocone twist and weakly developed postprotocone fold; moreover, the m3 of U. perpetior possesses an expanded, plesiadapiform-like posterior lobe of the talonid that supports the hypoconulid. The large lower canine and the greater development of trenchant molar crests suggest that U. perpetior was more insectivorous, differing appreciably from the omnivorous niche long hypothesized for Purgatorius and purportedly marking the insectivore–primate transition. Hence, U. perpetior adds significant new knowledge regarding the breadth of the adaptive zone occupied by purgatoriids in their position at the very beginnings of primate evolution.

Environmental Impacts on Biotic Recovery During the Induan Triassic

Environmental controls on marine ecosystem recovery following mass extinctions, with an example from the Early Triassic

Authors:

Wei et al

Abstract:

The recovery of marine ecosystems following a mass extinction event involves an extended interval of increasing biotic diversity and ecosystem complexity. The pace of recovery may be controlled by intrinsic ecosystem or extrinsic environmental factors. Here, we present an analysis of changes in marine conditions following the end-Permian mass extinction with the objective of evaluating the role of environmental factors in the protracted (~ 5-Myr-long) recovery of marine ecosystems during the Early Triassic. Specifically, our study examines changes in weathering, productivity, and redox proxies in three sections in South China (Chaohu, Daxiakou, and Zuodeng) and one in northern India (Mud). Our results reveal: 1) recurrent environmental perturbations during the Early Triassic; 2) a general pattern of high terrestrial weathering rates and more intensely reducing marine redox conditions during the early Griesbachian, late Griesbachian, mid-Smithian, and (more weakly) the mid-Spathian; 3) increases in marine productivity during the aforementioned intervals except for the early Griesbachian; and 4) stronger and more temporally discrete intervals of environmental change in deepwater sections (Chaohu and Daxiakou) relative to shallow and intermediate sections (Zuodeng and Mud). Our analysis reveals a close relationship between episodes of marine environmental deterioration and a slowing or reversal of ecosystem recovery based on metrics of biodiversity, within-community (alpha) diversity, infaunal burrowing, and ecosystem tiering. We infer that the pattern and pace of marine ecosystem recovery was strongly modulated by recurrent environmental perturbations during the Early Triassic. These perturbations were associated with elevated weathering and productivity fluxes, implying that nutrient and energy flows were key influences on recovery. More regular secular variation in deepwater relative to shallow-water environmental conditions implies that perturbations originated at depth (i.e., within the oceanic thermocline) and influenced the ocean-surface layer irregularly. Finally, we compared patterns of environmental disturbance and ecosystem recovery following the other four “Big Five” Phanerozoic mass extinctions to evaluate whether commonalities exist. In general, the pace of ecosystem recovery depends on the degree of stability of the post-crisis marine environment.

Evidence of Minas Accretionary Orogeny From Siderian PaleoProterozoic

A juvenile accretion episode (2.35-2.32 Ga) in the Mineiro belt and its role to the Minas accretionary orogeny: zircon U-Pb-Hf and geochemical evidences

Authors:

Teixeira et al

Abstract:

Zircon U-Pb-Hf and geochemical data provide new clues for a juvenile TTG segment in the Mineiro belt, outlined by published information about the nearby 2.35 Ga Lagoa Dourada suite. The Resende Costa Orthogneiss and coeval rocks yield U-Pb crystallization ages from 2351 ± 48 to 2317 ± 16 Ma and coherent Sm-Nd TDM ages between 2.3 and 2.5 Ga. These rocks show ɛNd(2.35Ga) and ɛSr(2.35Ga) values that suggest derivation from a short-lived, slightly depleted source akin to products of island arcs, whereas the geochemistry is consistent with a tholeiitic source with minor crustal assimilation. The positive to negative zircon ɛHf(2.35Ga) suggest the subordinate involvement of crustal components during the hypothesized c. 2.35 Ga slab subduction event. In a similar manner, metabasalts (lower unit) of the adjoining Congonhas-Itaverava belt show Nd-Sr isotopic and chemical constraints indicating derivation from an early Paleoproterozoic tholeiitic source subjected to crustal assimilation. A coeval metagraywacke from the upper unit yields U-Pb zircon detrital ages as young as 2349 + 14 Ma suggesting the maximum depositional age for the precursor basin (foreland setting?) whilst most of the grains indicate contribution from nearby Archean sources. The Resende Costa-Lagoa Dourada rocks characterize the precocious arc magmatism of the Minas accretionary orogeny. This composite orogeny created the Mineiro belt and the adjoining Mantiqueira and Juiz de Fora belts in the 2.35-2.00 Ga interval. Due to such a polycyclic framework the Resende Costa Orthogneiss and coeval rocks show multiple metamorphic overprints dated at 2140 and 2050 Ma. The new and compiled data and regional geologic correlations provide evidence for a growing Paleoproterozoic landmass in the South America continent.

The Religious and the Robopocalypse

Catholic astronomers and even Pope Francis have talked about how the Catholic Church could theoretically welcome aliens from other planets into the religious fold. But believers of Catholicism and other world religions may sooner have to consider whether they would welcome human-like android robots working and living alongside humans. That potential future could prove particularly troubling in the minds of religious fundamentalists.

Religious fundamentalism seems to have some influence on believers’ attitudes toward humanoid robots, according to research by Karl MacDorman, an associate professor of human-computer interaction at Indiana University in Indianapolis, and Steven Entezari, a Ph.D. student at Indiana University. MacDorman and Entezari’s study of almost 500 college students found that religious fundamentalists tend to view human-like robots as being more creepy overall. That sensitivity to robot creepiness refers to a proposed phenomenon called the “uncanny valley”, first discussed by Japanese roboticist Masahiro Mori in a 1970 essay, that describes the feeling of eeriness or discomfort related to robots or other figures that appear almost human.

MacDorman and Entezari propose that the uncanny valley phenomenon can consist of both culturally-conditioned feelings — such as Christian beliefs in humans being unique and set apart from robots and the rest of creation — and biologically-rooted feelings involving fear and disgust. They used that mindset to analyze their latest study that looked at the relationship between individual traits and sensitivity to the uncanny valley.

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Wanderers

Wanderers - a short film by Erik Wernquist from Erik Wernquist on Vimeo.

Hi Res Chinese J-31 Stealth Fighter Pictures

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New Chinese J-20 Stealth Fighter Prototype has First Flight

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Iran's Shafaq Fighter has Evolved, but Still not Reached Prototype Stage

Despite Iran moving its indigenous fighter/light combat aircraft programme to a new design house, indications emanating from the country's latest Kish Island air show suggest nothing will take to the skies anytime soon.

Since 2001 Iran's indigenous Shafaq programme has been in what seemed an endless process of design concept development. At Iran's biennial Iran-Kish Air Show the Shafaq was displayed several times as a project being run out of the Malek-Ashtar University of Technology in Tehran.

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US Navy Carriers Cannot Cover All Commitments, Asia to Lack US Carrier for up to 4 Months in Spring 2015

Defense policymakers in Japan and the U.S. are privately voicing concern about the total absence of U.S. aircraft carriers from East Asian waters for four months next year.

Budget constraints at home, combined with the rise of the Islamic State group in the Middle East, are limiting the American fleet's ability to operate in Asia. Temporarily at least, not a single aircraft carrier will be deployed in East Asia.

Japanese and U.S. officials fear having no U.S. carriers, which have long been the bedrock of the region's stability, could tempt North Korea and China to take advantage of the power vacuum to initiate a military adventure.

The USS George Washington, the only U.S. aircraft carrier with an overseas home port, is to leave its base for nuclear refueling and an overhaul. Until the USS Ronald Reagan arrives at the Japanese port of Yokosuka, located at the mouth of Tokyo Bay, to replace the ship, there will be no American carriers in East Asia, according to persons familiar with the matter.

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Paleosol Analysis Shows Tithonian Jurassic PaleoClimate of North America was Very Varied

The climate 150 million years ago of a large swath of the western United States was more complex than previously known, according to new research from Southern Methodist University, Dallas.

It's been thought that the climate during the Jurassic was fairly dry in New Mexico, then gradually transitioned to a wetter climate northward to Montana.

But based on new evidence, the theory of a gradual transition from a dry climate to a wetter one during the Jurassic doesn't tell the whole story, says SMU paleontologist Timothy S. Myers, lead author on the study.

Geochemical analysis of ancient soils, called paleosols, revealed an unexpected and mysterious abrupt transition from dry to wet even though some of the samples came from two nearby locales, Myers said.

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Evidence of ice From the Secondary Craters on Arcadia Planitia, Mars

Expanded secondary craters in the Arcadia Planitia region, Mars: Evidence for tens of Myr-old shallow subsurface ice

Authors:

Viola et al

Abstract:

A range of observations indicates widespread subsurface ice throughout the mid and high latitudes of Mars in the form of both pore-filling and excess ice. It is generally thought that this ice was recently emplaced and is not older than a hundred thousand to a few millions of years old based on ice stability and orbital-induced climate change. We analyze the distribution of subsurface ice in Arcadia Planitia, located in the northern mid latitudes, by mapping thermokarstically expanded secondary craters, providing additional evidence for extensive excess ice down to fairly low latitudes (less than 40°N). We further infer the minimum age of this subsurface ice based on the ages of the four primary craters that are thought to be the source of a large portion of these secondaries, which yields estimates on the order of tens of millions of years old – much more ancient than anticipated. This estimated ancient age suggests that ice can be preserved in the shallow subsurface for long periods of time, at least in some parts of Arcadia Planitia where expanded secondary craters are especially abundant. We estimate the amount of ice lost to sublimation during crater expansion based on measurements of expanded secondary craters in HiRISE Digital Terrain Models. The loss is equivalent to a volume of ice between ∼140 and 360 km3, which would correspond to a global layer of 1–2.5 mm thick. We further argue that much more ice (at least 6000 km3) is likely preserved beneath the un-cratered regions of Arcadia Planitia since significant loss of this excess ice would have caused extensive terrain dissection and the removal of the expanded secondary craters. Both the loss of ice due to secondary crater expansion and the presence of this ice today have implications for the martian climate.

Acheulean Style Stone Tools From Pleistocene Quaternary China

Middle Pleistocene hominin occupation in the Danjiangkou Reservoir Region, Central China: studies of formation processes and stone technology of Maling 2A site

Authors:

Pei et al

Abstract:

Danjiangkou Reservoir Region (DRR) is one of the areas where Acheulean-like stone technology (Mode 2) was reported in central and south China. It is located at the end of the upper reaches of the Hanshui River (the largest tributary of the Yangtze River). Systematic field investigations documented more than ninety Paleolithic sites along the fluvial terraces of the Hanshui and Danjiang Rivers (the latter a tributary of the upper reach of the Hanshui River). Subsequent excavations at more than 30 sites led to the discovery of a large number of Paleolithic stone artifacts in the past decade, showing that early hominins lived in the region at least by the early part of the Middle Pleistocene. However, little is known from the archaeological record about the context of the sites and their formation processes, the technological characteristics of the stone artifact assemblages, and whether they truly belong to Mode 2 technology or just to core and flake technology, and the overall hominin behavioral patterns and adaptation during the Middle to Late Pleistocene.

Maling locality 2A (ML2A) is buried in the front edge of the third alluvial terrace of the Danjiang River. Archaeological excavations, undertaken at the site in 2011, recovered 1026 stone artifacts from a red clay deposit. Preliminary OSL dating and geomorphological comparisons between the terraces in the Hanshui River system suggest that the site is dated to the late Middle Pleistocene. Patterns of artifact concentration suggest that the site was buried in secondary context where the stone artifacts were transported by water from a relatively higher location nearby. The artifacts, primarily made on quartzite and quartz cobbles, include cores, whole flakes, various fragments, retouched pieces, two bifaces and a hammerstone. All flaking is by direct hard hammer without core preparation. The majority of flakes in the early stages of core reduction indicate that the cores are not extensively reduced. Choppers are the predominant core category, together with discoids, polyhedrons, and core scrapers. It should be noted that two bifacially flaked cobbles can classed as mode 2 implements. Eleven retouched pieces are recognized, and they were casually modified by direct hammer percussion. Although only two bifaces were excavated from this site, many more are recorded in the larger study area. The ML2A artifact assemblage may be considered as a Chinese variant of an Acheulean-like (Mode 2) industry. It can be deduced that Homo erectus was likely the responsible for manufacturing the stone artifacts.

Pleistocene Quaternary Mammals do not Match the Predicted Locations From Climate Models

Leave it to long-dead short-tailed shrew and flying squirrels to outfox climate-modelers trying to predict future habitats.

Evidence from the fossil record shows that gluttonous insect-eating shrew didn't live where a species distribution technique drawn by biologists put it 20,000 years ago to survive the reach of glaciers, says University of Oregon geologist Edward B. Davis. The shrew is not alone.

According to a new study by Davis and colleagues, fossil records of five ancient mammalian species that survived North America's last glacial period point to weaknesses in the use of ecological niche models and hindcasting to predict future animal and plant habitats. As a result, Davis says, the modeling needs to be fine-tuned for complexities that might be harvested from fossils.

Ecological niches use modern habitat distributions and climate; hindcasting adds predictive power by adding major past climate shifts into the models. That modeling combination -- as seen in a 2007 study led by Eric Waltari, then of the American Museum of Natural History in New York -- had the short-tailed shrew surviving the last ice age in mostly Texas and the Deep South. Conclusions drawn in other studies, Davis noted in the new study, also are biased toward southern locations for ice-age surviving mammals of the Pleistocene Epoch.

Short-tailed shrew, according to fossil records, did not live in the predicted ranges. Instead they lived across north central and northeast United States, closer to the glaciers and where they are widely found today.

"It's almost as though it is living in all of the places that the model says it shouldn't be living in and not in any of the places that the model says it should be living in," said Davis, who also is manager of the paleontological collection at the UO Museum of Natural and Cultural History. "This suggests to me that whatever the model is keying on is not actually important to the shrew."

Nor to the American marten, two species of flying squirrels and the Gapper's red-backed vole, all of which lived mostly outside of predicted ranges, according to the fossil record. Northern and southern flying squirrels, the Davis study found, shared a compressed geographic region. It may be, Davis said, that some species tolerate competition under harsh conditions but separate when abundant resources are available.

Davis noted that an important but under-cited 2010 paper on rodents by Robert Guralnick of the University of Colorado and Peter B. Pearman of the Swiss Federal Research Institute also showed problems with hindcast projections. Those for lowland rodents in the last ice age did not hold up, but those for a higher elevation species did.

"Our findings say that we need to pay more attention to the potential problems we have with some of our modern methods, and the way that we can improve our understanding of how species interact with the environment," said Davis, who added that his study was inspired by Waltari's. "The way to improve our forecasting is to include data from the fossil record. It can give us more information about the environments that species have lived in and could live in."

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Spore Diversity Trends From Eifelian/Givetian Devonian Argentina

Spore diversity trends in the Middle Devonian of the Chaco-Salteño Plain, northwestern Argentina

Author:

Noetinger et al

Abstract:

Devonian deposits in northwestern Argentina were historically studied with stratigraphical purposes, since these layers conform the source rocks of the producing basins of the region. A fairly well preserved palynomorph assemblage, from the Tonono Formation, provides an opportunity to perform the first quantitative analysis to study the evolution of diversity in the succession. Two associations are here defined by both, stratigraphic distribution of species and cluster analysis, ranging from the lower Eifelian to the lower Givetian. Rarefaction analysis reveals the existence of a relatively rich miospore population. Species richness increases while there is a drop in diversity and evenness towards the top of the column. The increment of the marine components towards the latter section indicates shifts in the shoreline. The influx of warmer water into higher latitudes, as highlighted by the arrival of the brachiopod Tropidoleptus, could have favored the inception of new spore species in the settled community. These results add to evidence that some groups build up the number of species in disturbed settings, and evenness is reduced with each new species introduced.

The Origin of sex Chromosomes

On the origin of sex chromosomes from meiotic drive

Authors:

Ubeda et al

Abstract:

Most animals and many plants make use of specialized chromosomes (sex chromosomes) to determine an individual's sex. Best known are the XY and ZW sex-determination systems. Despite having evolved numerous times, sex chromosomes present something of an evolutionary puzzle. At their origin, alleles that dictate development as one sex or the other (primitive sex chromosomes) face a selective penalty, as they will be found more often in the more abundant sex. How is it possible that primitive sex chromosomes overcome this disadvantage? Any theory for the origin of sex chromosomes must identify the benefit that outweighs this cost and enables a sex-determining mutation to establish in the population. Here we show that a new sex-determining allele succeeds when linked to a sex-specific meiotic driver. The new sex-determining allele benefits from confining the driving allele to the sex in which it gains the benefit of drive. Our model requires few special assumptions and is sufficiently general to apply to the evolution of sex chromosomes in outbreeding cosexual or dioecious species. We highlight predictions of the model that can discriminate between this and previous theories of sex-chromosome origins.

Paleoproterozoic to Mesoproterozoic Intracratonic Basin Cycles

Age constraints on crystal-tuff from the Espinhaço Supergroup — Insight into the Paleoproterozoic to Mesoproterozoic intracratonic basin cycles of the Congo–São Francisco Craton

Authors:

Guadagnin et al

Abstract:

The U–Pb data from the volcanic and detrital zircon grains of the Tombador Formation in Chapada Diamantina, Bahia, provide the depositional age of the top of this unit and define the main sedimentary sources of the Archean, Paleoproterozoic and Mesoproterozoic Eras. The lithofacies, petrographic and geochemical data from crystal-tuff samples indicated that a volcanic source was located to the east of the Chapada Diamantina region. The available zircon data defined three first-order intracratonic basinal cycles, including the Lower (Statherian), Middle (Calymmian) and Upper (Stenian–early Tonian) Espinhaço basins. These sequences are well exposed at the Espinhaço Supergroup type-section in the Chapada Diamantina region. The zircon Hf isotope data from the 1.4 Ga crystal-tuff in the Middle Espinhaço and the 1.2 Ga tuffaceous rock in the Upper Espinhaço suggested different sources, with model ages of 2.1 to 1.9 Ga and less than 1.9 Ga, respectively. The tectonic development of these Paleoproterozoic to Mesoproterozoic intracratonic basins can be explained by the far-field stress at the paleoplate margins, which has been shown in other Phanerozoic intracratonic basins. The data presented here support a tectonic scenario in which the Congo–São Francisco paleoplate interior recorded the main global events related to the geodynamic processes after the Columbia supercontinent collage and the formation and fragmentation of the Rodinia supercontinent.