The theory had been that the ancestors of modern humans separated from Neanderthals and Denisovans between 550,000 and 765,000 years ago. Whereas Neanderthals and Denisovans settled in Eurasia, modern humans stayed in Africa till about 70,000 years ago. Then they migrated towards Europe.
For almost a century, Neanderthals were thought of the ancestors of modern humans. there’s ample proof of mating between Neanderthals and the ancestors of modern humans regarding 50,000 years ago. However in a very new plot twist within the evolution mystery of how Neanderthals were associated with modern humans, it currently appears that members of our lineage were among the ancestors of Neanderthals. Researchers sequenced ancient DNA from the mitochondria—tiny energy factories inside cells—from a Neanderthal who lived about 100,000 years ago in southwest Germany. They found that this DNA, that is inherited solely from the mother, resembled that of early modern humans.
The DNA within the energy-producing mitochondria in our cells is completely different from that in our cell nuclei, and is passed down solely within the female line. Puzzlingly, the mtDNA in Neanderthal bones is more like that of modern humans than it’s to that of the Denisovans.
A feminine member of the lineage that gave rise to Homo sapiens in Africa mated with a Neanderthal male over 220,000 years ago—much sooner than other known encounters between the two hominids. Her children spread her genetic inheritance through the Neanderthal lineage, and in time her African mtDNA fully replaced the ancestral Neanderthal mtDNA.
Researchers checked out differences between the mtDNA in this femur and in other Neanderthals, and that they used mutational rates to calculate that the bone is 124,000 years old. The approach additionally indicates that this Neanderthal split from all other known Neanderthals sometime between 316,000 and 219,000 years ago. However it still contains key components of early-human mtDNA.
This means that modern human ancestors should have interbred with Neanderthals before 219,000 years ago and thus might have migrated out of Africa and into Europe much sooner than we thought.
The team says an earlier migration event is additionally compatible with proof of archaeological similarities between Africa and western Eurasia. This and previous findings are lending support to models with frequent interbreeding events.