Updated

Updated · spacedaily.com · Jun 24

DNA Study Finds 3 Neanderthal-Human Mixing Waves Over 250,000 Years, Recasting Their End

Updated

Updated · spacedaily.com · Jun 24

DNA Study Finds 3 Neanderthal-Human Mixing Waves Over 250,000 Years, Recasting Their End

Q: Neanderthals disappeared 40,000 years ago. If their genes are in us, did they truly go extinct?

Yes—Neanderthals went extinct as a distinct population, but not in the sense of leaving no descendants at all. The key distinction is between biological extinction and genetic survival. Neanderthals no longer existed as a separate breeding population after roughly 40,000 years ago. By that standard, they are extinct. But modern DNA research shows they were not simply wiped out without trace. Parts of their genome were absorbed into Homo sapiens through repeated interbreeding. Joshua Akey and Liming Li’s 2024 study in Science strengthens that view. Using IBDmix on genomes from about 2,000 living people and archaic genomes, they found at least three waves of mixing between modern humans and Neanderthals, stretching back 200,000 to 250,000 years. They also detected modern-human ancestry inside Neanderthal genomes, showing gene flow went both ways. That supports Akey’s argument that “extinction” can be misleading here. Neanderthals appear to have been demographically absorbed into larger modern human populations rather than cleanly replaced. Today, most people outside Africa carry about 1% to 4% Neanderthal ancestry, and across all living populations, an estimated 20% of the Neanderthal genome still survives in fragments. Some of those inherited variants still affect immunity, skin biology, and other traits. So the best answer is that Neanderthals disappeared as a separate people, but part of them persists in living humans. Their population ended; their genetic legacy did not.

3 articles · Updated · spacedaily.com · Jun 24

Three separate interbreeding waves over roughly 250,000 years led Princeton geneticist Joshua Akey to argue Neanderthals were absorbed into modern humans rather than simply wiped out.
About 2,000 living genomes compared with three Neanderthals and one Denisovan pointed to mixing around 200,000-250,000 years ago, 120,000 years ago, and most strongly 50,000-60,000 years ago.
Neanderthal genomes themselves carried an estimated 2.5% to 3.7% modern-human ancestry, evidence of earlier Homo sapiens migrations that older methods had largely missed.
The finding does not dispute that Neanderthals as a distinct population disappeared about 40,000 years ago; it shifts the explanation from clean replacement to long demographic incorporation.
Researchers still debate how far to push the word "absorbed," and more ancient DNA is needed to refine the number, timing and biological impact of the mixing events.

Sources

spacedaily.com15h ago

Joshua Akey: Neanderthals Absorbed by Modern Humans After Three Interbreeding Waves Over 250,000 Years

The Associated Press15h ago

New study shows how humans and Neanderthals coupled up | AP News

Facebook15h ago

Neanderthal men interbred with modern human women

Neanderthals disappeared 40,000 years ago. If their genes are in us, did they truly go extinct?

Geneticists use conflicting methods to trace our origins. How much of our Neanderthal story is still a mystery?

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200,000 Years of Gene Flow: The Absorption of Neanderthals into Modern Human Populations

Overview

Recent research led by Joshua M. Akey has transformed our understanding of the relationship between Neanderthals and modern humans. Instead of a single interbreeding event, the study revealed multiple waves of genetic mixing over at least 200,000 years. This ongoing exchange of genes shows that Neanderthals and modern humans had a much more interconnected history than previously thought. The findings support the 'absorption' model, suggesting Neanderthals were gradually integrated into modern human populations rather than simply going extinct. This new perspective highlights a dynamic and shared evolutionary past between the two groups.

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