Early human interbreeding with our “cousins” the Denisovans and Neanderthals is an established fact but newly sequenced Neanderthal Y-chromosomes tell scientists that modern humans are the product of a complex history of interspecies sex. Neanderthals had lived in Eurasia for more than 300,000 years, when our modern human ancestors left Africa in the most recent wave some 60,000–70,000 years ago. When the two groups met in Eurasia around 45,000-years-ago they mated and a whole new kind of human was formed. Recent research confirms early human interbreeding but also provides evidence that makes our earliest encounters with both Neanderthals and Denisovans a much more complicated relationship.
According to the 2010 publication of the Neanderthal draft genome sequence, a comparison of the Neanderthal draft genome with modern human sequences revealed that about “2 percent of the DNA in the genomes of modern-day people with Eurasian ancestry, is Neanderthal in origin,” most notably expressed in the skin, hair and diseases of modern people. While it is known that Neanderthals left their genetic mark in the DNA of modern humans, less was known about the reverse flow of Homo sapiens’ DNA into Neanderthals when the two species met in Eurasia around 45,000 years ago.
Read Full Article »