We need to rethink our story of human evolution!
Scientists in Spain have found a femur bone in a cave that shows the oldest DNA evidence yet of humans’ biological history. But instead of clarifying human evolution, the finding is adding new mysteries.
The DNA found tells a very different story. It most closely resembles DNA from an enigmatic lineage of humans known as Denisovans, who were known only from DNA retrieved from 80,000-year-old remains in Siberia. In a paper in the journal Nature, scientists reported Wednesday that the fossil found in Spain dates back about 400,000 years.
Based on previously discovered ancient DNA and fossil evidence, scientists generally agreed that humans’ direct ancestors shared a common ancestor with Neanderthals and Denisovans that lived about half a million years ago in Africa.
Their shared ancestors split off from humans’ lineage and left Africa, then split further into the Denisovans and Neanderthals about 300,000 years ago. The evidence suggested that Neanderthals headed west, toward Europe, and that the Denisovans moved east.
Humans’ ancestors, meanwhile, stayed in Africa, giving rise to Homo sapiens about 200,000 years ago. Humans then expanded from Africa into Asia and Europe about 60,000 years ago. They then interbred not only with Neanderthals, but with Denisovans, too. Later, both the Denisovans and Neanderthals became extinct.
“Now we have to rethink the whole story,” Dr. Arsuaga said.
Dr. Arsuaga doubts that Denisovans were spread out across so much of the Old World, from Spain to Siberia, masquerading as Neanderthals.
One alternative explanation is that the humans of Sima de los Huesos were not true Neanderthals, but belonged to the ancestors of both Denisovans and Neanderthals. Read more on The New York Times.
The photos from Jimmy Nelson, 100 tribes around the world that have not yet embraced technology, make me wonder how is it that we all came from the same tribes? I feel I see the resemblance on similar genes in people’s eyes, in their noses, their resilience and curiosity, and their inventiveness to thrive under new circumstances.