* Astronomy

Title: Genotypes of predomestic horses match phenotypes painted in Paleolithic works of cave art
Authors: Melanie Pruvost, Rebecca Bellone, Norbert Benecke, Edson Sandoval-Castellanos, Michael Cieslak, Tatyana Kuznetsova, Arturo Morales-Muñiz, Terry O'Connor, Monika Reissmann, Michael Hofreiter, and Arne Ludwig

Archaeologists often argue whether Palaeolithic works of art, cave paintings in particular, constitute reflections of the natural environment of humans at the time. They also debate the extent to which these paintings actually contain creative artistic expression, reflect the phenotypic variation of the surrounding environment, or focus on rare phenotypes. The famous paintings "The Dappled Horses of Pech-Merle," depicting spotted horses on the walls of a cave in Pech-Merle, France, date back ~25,000 y, but the coat pattern portrayed in these paintings is remarkably similar to a pattern known as "leopard" in modern horses. We have genotyped nine coat-colour loci in 31 predomestic horses from Siberia, Eastern and Western Europe, and the Iberian Peninsula. Eighteen horses had bay coat colour, seven were black, and six shared an allele associated with the leopard complex spotting (LP), representing the only spotted phenotype that has been discovered in wild, predomestic horses thus far. LP was detected in four Pleistocene and two Copper Age samples from Western and Eastern Europe, respectively. In contrast, this phenotype was absent from predomestic Siberian horses. Thus, all horse colour phenotypes that seem to be distinguishable in cave paintings have now been found to exist in prehistoric horse populations, suggesting that cave paintings of this species represent remarkably realistic depictions of the animals shown. This finding lends support to hypotheses arguing that cave paintings might have contained less of a symbolic or transcendental connotation than often assumed.

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The white horse has been an enduring icon in human mythology and history, in books, on battlefields and at many a finishing post.
Its special place has been enhanced after a weekend report suggesting that almost every white horse that ever inspired a legend, or carried a King, or won the King George IV Chase, may have had a common ancestor: a single mare or stallion that lived thousands of years ago.

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Never look a gift horse in the mouth, right? But what if you're looking for clues about how long, how cold and when was the biggest climate change since the age of dinosaurs.
Scientists reported Wednesday they study equine teeth.
Palaeontologist Bruce MacFadden of the University of Florida.MacFadden likened ancient horses' teeth to "little time capsules that allow us to analyse chemicals captured millions of years ago within the animals' skeletons."

Earth's temperature dropped by 15 degrees Fahrenheit during a period of 400,000 years some 33.5 million years ago, researchers said in the current edition of the journal Nature.
That temperature change is so drastic the impact was striking in terms of animal extinctions, even though 400,000 years seems like a long time, said MacFadden, one of the study's authors.
For comparison, a report last week by the Intergovermental Panel on Climate Change said dramatic consequences -- rising sea levels, changing ocean currents and more intense storms -- could result from an estimated temperature increase of 3 to 7 degrees Fahrenheit this century.

"If we're talking about major changes at 2 to 4 degrees Celsius, if we go to 8 degrees Celsius, the latitudinal seasonal temperature belts would shift, the tropics would contract, there would be huge differences. It would be incredible, profound, whatever superlative you'd like to use" - Bruce MacFadden .

Palaeontologists have known for more than a century many species went extinct at the transition between the Eocene and Oligocene, based on the fossil record before and after the shift. However, they lacked the analytic tools to determine how much temperature change there was over how long a period, and exactly when it occurred.
Fossil research showed creatures that might be at home in the tropics, like warm-loving crocodilians, roamed what is now Nebraska on the American Great Plains before the temperature transition. After the transition, they were gone.
Scientists believe changes in ocean currents were to blame for the shift.
To work out the details of what French researchers dubbed Grande Coupure -- "big cut" -- MacFadden and his co-authors examined the preserved teeth and bones of fossil horses and another cloven-hoofed mammal called an oreodont.
They analysed oxygen and carbon isotopes contained in the samples; oxygen isotopes told the scientists at what temperature the teeth were formed and carbon isotopes revealed the relative humidity, the University of Florida said in a statement.
Using isotope data and precise locations and dates for the fossil teeth, the researchers were able to pinpoint the details of the transition, the biggest climate change since the end of the dinosaurs about 65 million years ago.

(Agencies)