I didn’t think we’d get another big Neanderthal story before the end of 2013, but boy was I wrong. Apparently, Neanderthal’s aren’t so 60,000 years ago after all. Scientists have just finished mapping our predecessor’s entire genome, and in doing so have confirmed some hypotheses and a slew of new information about our predecessors, as well as about modern humans.
Scientists used a toe bone of a Neanderthal woman that dates back approximately 50,000 years in order to conduct their tests. While researchers have been constructing the genome map for a long time, this was the first complete sequence that resembles the type of thorough and complex genetic sequencing we do today. The study, recently published in Nature, indicates that Neanderthals had big families, complete with half-siblings, and confirms that we Homo sapiens did indeed breed with them—a point that has become controversial and led to arguments among different camps for years. Homo sapiens and Neanderthals also both mated with Denisovans. Scientists learned that nearly 2.1% of modern human DNA in people of European descent is linked to Neanderthals, with the highest percentage belonging to people of Asian and Native American descent—many of whom also have a small amount of Denisovan DNA.
And if the family tree hasn’t gotten complicated enough, scientists also learned that Denisovans bred with some other ancient species, which remain a mystery. These findings, along with others from earlier this year, contest the previously held theory that modern humans descend from a single African exodus.
The findings also may shed some light on why Neanderthals and Denisovans became extinct. Very few cell-protein-generating genes—96, to be exact—separate modern humans from Neanderthals, and some of those involve immune response and the development of brain cells. Scientists believe the key to their extinction may lie somewhere within those 96 genes.
Back in November we learned of a Neanderthal virus still present in modern humans, and the recent genomic mapping also revealed a sequence associated with type 2 diabetes. Apparently, that’s another gene Homo sapiens inherited when they bred with Neanderthals. Scientists are just beginning to understand the implications of the genome and the genes they passed on to modern humans, but pinpointing the origin of some of the key sequences may give us clues about how to treat associated diseases. One of the takeaways for me is how progressive folks were back then, mating not just with different races but different species. I guess that alien love child doesn’t sound so weird now, does it?