Last year, it was suggested Neanderthals starting breeding with archaic modern humans around 100,000 years ago. These two new papers pushes that back even further to between 130,000 to 145,000 years ago. And location of these sub-species encounters probably happened in the Middle East or the Arabian Peninsula, and before modern humans spread en masse into Europe and Asia. When comparing Vindija 33.19 genome to the UK Biobank database, with 112,338 modern individuals, the group identified that modern populations carry between 1.8 to 2.6% of Neanderthal DNA, which is higher than the previous estimates of about 1.5 to 2.1%. Curiously, East Asians carry about 2.3 to 2.6% Neanderthal DNA, while people from western Europe and Asia, on the other hand have retained about 1.8 to 2.4% DNA. African populations have virtually none because their ancestors did not mate with Neanderthals.
Evolutionary geneticist Sarah Tishkoff of the University of Pennsylvania, the lead author of the new study measured the reflectance of light on the skin of 2,092 people from Ethiopia, Tanzania, and Botswana along with Nicholas Crawford. The eastern African groups, like the Mursi and Surma, had the darkest skin on objective reflectance assessments, and the lightest are the San with shades between such as the Agaw.
Concurrently, they collected blood samples of 1,570 of these people for genetic studies and sequenced more than 4 million SNPs. They found 8 sites of the human genome that are particularly associated with the level of skin pigmentation which makes up for 30% of the variation in skin tone we see. Four key areas of the genome, which emerged 900,000 years ago, have specific SNPs that correlate directly with skin color.
SLC24A5, that gene I commented on before, and that we’ve known about for over 12 years to be associated with lighter skin tones, is common in some Ethiopian populations. Variants of this gene appeared 30,000, likely from Middle Eastern groups returning to eastern Africa. Variants of two neighboring genes, HERC2 and OCA2, which are also associated with light skin, eyes, and hair phenotypes seen in Europeans ultimately arose in Africa. The SNPs we see in Europeans are ancient and common in the light-skinned San people. The team proposes that these SNPs arose in Africa over 1 million years ago and spread later to Europeans and Asians. Which is incredible and I’ll comment on later.
I think the most dramatic discovery is of MFSD12. Two SNPs which decrease expression of this gene were found in high frequencies in people with the darkest skin. They confirmed in culture cells that these mutant MFSD12 genes lead to more eumelanin. These variants arose about a 500,000 years ago, suggesting that human ancestors before that time may have had moderately dark skin, rather than the deep black hue created today by these mutations. These same two variants are found in Melanesians, Australian Aborigines, and some Indians, which implies that these groups may have inherited the variants from ancient migrants from Africa who followed a “southern route” out of East Africa, along the southern coast of India to Melanesia and Australia.
The latest findings suggest that some particularly dark skin tones evolved relatively recently from paler genetic variants, and these people migrated out of Africa. SNPs in OCA2 and HERC2 that are associated with lighter skin are ancient, over 1 million years old and come from Africa.
A new study in Current Biology analyzed the entire genome of the Tianyuan man who was found near Beijing, China and lived around 40,000 years ago. The Tianyuan man’s genome marks the earliest ancient DNA from East Asia, but this is not the first time we have studied Tianyuan’s genes.
The Tianyuan skeleton was unearthed near the Zhoukoudian site, about 50 km southwest of Beijing. In 2013 paper in PNAS, the same group that published the Current Biology paper showed there is a closer relationship of Tianyuan to present-day Asians, based off his genes, than to present-day Europeans. At that time it was suggested that present-day Asian history has a deep lineage as far back as 40,000 years ago. In the last 4 years, we have had more data showing that modern Europeans derive from more prehistoric populations which separated early from other early non-African populations soon after the migration out of Africa. This hasn’t changed our understanding of East Asian ancestry however, showing that Tianyuan’s genetic similarity to Asians remained in comparisons including ancient Europeans without mixed ancestry… But, most interestingly it was surprising that when they compared Tianyuan to the 35,000-year-old individual from Belgium, GoyetQ116-1, who in other ways reflected an ancient European, he shared some genetic similarity to the Tianyuan individual that no other ancient Europeans shared. This suggests that the two populations represented by the Tianyuan and GoyetQ116-1 individuals derived some of their ancestry from a sub-population prior to the European-Asian separation.
-- http://www.nbcnews.com/id/27240370/ns/technology_and_science-science/t/worlds-first-dog-lived-years-ago-ate-big/#.WeI7H7pFzDd An international team of scientists has just identified what they believe is the world's first known dog, which was a large and toothy canine that lived 31,700 years ago and subsisted on a diet of horse, musk ox and reindeer, according to a new study. The discovery could push back the date for the earliest dog by 17,700 years, since the second oldest known dog, found in Russia, dates to 14,000 years ago. Remains for the older prehistoric dog, which were excavated at Goyet Cave in Belgium, suggest to the researchers that the Aurignacian people of Europe from the Upper Paleolithic period first domesticated dogs. Fine jewelry and tools, often decorated with depictions of big game animals, characterize this culture.