Neanderthals first interbred with Homo Sapiens approximately 100,000 years ago, experts have recently discovered, rectifying previously established timelines by about 50,000 years.
The findings were featured in the journal Nature, on Wednesday, February 17, following research conducted by Adam Siepel, computational biologist affiliated with the Cold Spring Harbor Laboratory from New York.
Back in 2010, it was revealed by German experts at the Max Planck Institute for Evolutionary Anthropology that people outside Africa still owe between 1 and 4% of their genetic makeup to Neanderthals, following ancient interbreeding which span across thousands of years.
Apparently, this DNA is responsible for immune system disorders, increased allergy risk, and other conditions such as actinic keratosis (skin lesions that appear after sun exposure).
Given the fact that modern Africans didn’t appear to have any genetic mutations in common with Neanderthals, it had been believed that Homo Sapiens only encountered Neanderthals after they left Africa, venturing into Central Asia, Europe and the Middle East.
This migration was estimated to have happened approximately 50,000 to 65,000 years ago. Mating between Neanderthals and Homo Sapiens was further proven in 2013, when researchers managed to recreate the complete genome of a Neanderthal male unearthed in the Siberian Altai Mountains.
Now, it has recently been proven that not just modern humans have Neanderthal DNA, but even remains pertaining to Neanderthals bear evidence of these interactions, which began much earlier than previously thought.
Researchers identified gene sequences corresponding to modern human genome in about 1 to 7% of the genetic makeup identified in another Neanderthal fossil unearthed in Siberia.
These DNA fragments were associated with mutations encountered among modern-day Africans, and had never been discovered among Neanderthals from Europe, or among Siberian Denisovans.
As study authors explain, the similarities show that groups of Homo Sapiens from Africa actually mated with Altai Neanderthals approximately 100,000 years ago, thousands of years before humans were thought to have departed from the Dark Continent.
Now it becomes obvious that long-held beliefs regarding Homo Sapiens’ exodus from Africa will have to be re-evaluated.
Past research had already alluded to a migration that happened more than 65,000 years ago. For instance, in October 2015 María Martinón-Torres and her team of archaeologists unearthed Homo Sapiens teeth in Fuyan Cave, from southern China.
The bones were around 80,000 to 120,000 years old, therefore dating back from a time when modern human populations were believed to be confined to Africa only.
A similar discovery had also been made in April 2014 at an excavation site from the Arabian desert, where German paleoanthropologist Katerina Harvati brought to light ancient stone artifacts dating back to 100,000 years ago.
It’s even clearer now that early humans departed from Africa long before it had been formerly established, mingling with Neanderthal populations that they first met in the Middle East, and building interspecies families together.
Researchers even believe that such hybrids were equally accepted in Homo Sapiens groups and in Neanderthal communities as well, although they probably had slightly lower fertility than their counterparts.
In fact, it may be that Neanderthals were actually more of a subspecies than a completely different species, as evidenced by the fact that interbreeding occurred so naturally between two groups, with genes being passed in both directions.
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