Thursday, November 16, 2017

“Genomic Anthropology” Introduces the Denisovans

“The bone was no bigger than a coffee bean. It was a bit of pinky from a young girl that could have easily been missed among the thousands of bones dug up by archaeologists at the site each year. Yet the unassuming fossil made it out of Denisova Cave in Siberia’s Altai Mountains and into the Max Planck Institute’s ancient DNA laboratory in Leipzig, Germany, where in 2010 it yielded a complete genome of a previously unknown type of human.”

No one had previously suspected such a population was out there.
That partial finger bone was the first evidence of the Denisovans (a distinct branch of the Homo family tree), whose members mated with both Neanderthals and modern humans during the past 100,000 years.....

.....everything we know about Denisovans comes from their DNA. Never before has the history of an extinct human been told by its genome, rather than its fossils and artifacts....

DNA extracted from all four Denisovan fossils determined that the specimens came from different individuals. Based on accumulated genetic differences among them, two of the individuals lived roughly 65,000 years before the others; the Denisovan lineage was around for quite some time.

Denisovans, Neanderthals and modern humans descend from the same population of ancestors, who most likely lived in Africa between 550,000 and 765,000 years ago. Some of these early humans spread to Eurasia, where they split into Neanderthals in Europe and Denisovans in Asia.....

My Comment: The fact that two of the individuals lived 65,000 years before the others evokes an odd sense of isolation. That’s a long time. And imagining the Stone Age comings and goings over such a long period of time from one identifiable location (the cave) gives us a unique perspective.