The notion of mankind as special creation was overthrown with Darwin. Since then, a series of anthropological finds have continued to illuminate a startling picture: Not only are we not the center of the universe, but there were a lot of different breeds of us. The earliest evolutionary family portrait is starting to look a lot more like a snapshot of diverse birds at a feeder.
By now, the existence of the “hobbits” (Homo florensis) is well-established. Now we meet another lost relative, named Denisovans.
That may sound like an alien species from Doctor Who (Though they were assigned their name based on the cave in which their fossils were found — not on an alien world.) And like UFO enthusiasts who believe that extraterrestrials would cross interstellar distances for some nookie, it appears that Denisovans interbred with humanity. It wasn’t just the Toba eruption bottleneck that resulted in the face you see every day in the mirror, but a genetic Stone Soup, circa Stone Age.
From the article on BBC News, on the announcement in the journal Nature:
A study in Nature journal shows that Denisovans co-existed with Neanderthals and interbred with our species – perhaps around 50,000 years ago… this provides confirmation there were at least four distinct types of human in existence when anatomically modern humans (Homo sapiens sapiens) first left their African homeland. Scientists were able to analyse DNA from a tooth and from a finger bone excavated in the Denisova cave in southern Siberia. The individuals belonged to a genetically distinct group of humans that were distantly related to Neanderthals but even more distantly related to us.
The study shows that Denisovans interbred with the ancestors of the present day people of the Melanesian region north and north-east of Australia. Melanesian DNA comprises between 4% and 6% Denisovan DNA….”It could be just 50 Denisovans interbreeding with a thousand modern humans. That would be enough to produce this 5% of those archaic genes being transferred….