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This Week in Science: Nov 7, 2014

In this week's Science, an international team of researchers report on their genetic analysis of DNA obtained from the leg bone of an ancient European Russian man — one of the earliest examples of a modern human — and showed that western Eurasian and East Asian lineages had already split from each other by about 37,000 years ago. The findings indicate that major components of the modern European genome may date back 50,000 years to 100,000 years ago, further than previously thought. They specifically found that the genome of the ancient man was similar to that of a 24,000-year-old boy found in central Siberia, European hunter-gatherers from the Mesolithic period, contemporary western Siberians, and many Europeans, but not eastern Asians. They also discovered that the Russian man shared many gene variants with European Neolithic farmers and contemporary people from the Middle East, and that he harbored about one percent more Neanderthal DNA than modern humans, suggesting that his genes hadn't had much time to recombine after interbreeding events that took place about 54,000 years ago. GenomeWeb Daily News has more on this here.

Also in Science, a team of researchers from Germany, China, and elsewhere detail a timeline of insect evolution based on the analysis of 1,478 protein-coding genes from all of the major insect orders still in existence. When compared with the fossil record, the researchers were able to determine that insects likely originated during the Early Ordovician Period, about 479 million years ago. Insects' capacity for flight arose about 406 million years ago, while most insects currently in existence originated about 345 million years ago. Taken together, the findings suggest that insect flight did not emerge until the establishment of complex terrestrial ecosystems and that the radiation of flowering plants was accompanied by a burst of diversity among flying insects. The data also indicate that parasitic lice did not diversify until after avian and mammalian host became available, refuting the theory that they originated on feathered dinosaurs, and that cockroaches and termites evolved after the only known mass extinction of insects 252 million years ago.