Around five hundred thousand years ago our evolutionary ancestors diverged creating archaic humans outside of Africa, including Neanderthals (H neanderthalensis) in Europe and the Middle East. Modern humans (H sapiens) emerged in Africa by two-hundred thousand years ago and when they started migrating out of Africa, they encountered Neanderthals. But when?

Modern humans left Africa in multiple waves over hundreds of thousands of years based on fossil evidence.¹ Today, all humans with ancestry outside of Africa have neanderthal gene markers.² New research found that all of today’s Neanderthal gene markers in modern humans are from a period of around six-seven thousand years starting around forty thousand years until Neanderthals went extinct (around forty thousand years ago).

This means that all of us humans with ancestry outside of Africa have some of these forty to forty-seven thousand year old Neanderthal gene markers, which includes Aboriginal Australians, and this important for understanding how and when our species migrated around the world. We know that humans were in Australia tens of thousands of years before that, due to artefacts discovered at finds at Madjedbebe near Arnhem, Australia, dated to fifty to sixty-five thousand years old. How is that possible if the ancestors of Aboriginal Australians needed to be bumping uglies with Neanderthals’ in Europe or the Middle East forty to forty-seven thousand years ago?

“Priya Moorjani, a population geneticist at the University of California, Berkeley, and colleagues analyzed previously sequenced genomes from 59 ancient H. sapiens, mostly from Western Europe and Asia, dating from between 45,000 and 2200 years ago. The oldest included DNA from Ust’-Ishim man in western Siberia (45,000 years old), the Czech Republic’s Zlatý kůň woman (45,000 years old), and individuals from Bulgaria’s Bacho Kiro caves (35,000 to 45,000 years old) and Romania’s Peștera cu Oase caves (40,000 years old).”

Price, Michael. 21 May 2024. “Neanderthals and modern humans made babies 47,000 years ago.” Science.

They found evidence of prior Neanderthal and human admixing but none of those genes are conserved in modern humans, including Aboriginal populations. This means that either the earlier human populations went extinct before or were made extinct by the ancestors of today’s populations. If they were made extinct, a form of genocide may be the cause but it could also be unintentional, such as carrying a disease which was mild for the new population but wiped out the old, or climate change that new population was technologically or culturally adapted for but the old populations weren’t. But it goes to show that humans have migrated, displaced, absorbed, wiped out, etc. other human populations since the very beginning. We’re a species of “colonizers.” It’s not a “them” or “us” issue, it’s a H. sapiens issue.

Sources

Eisenstein, Michael. 24 May 2024. “Neanderthal–human baby-making was recent — and brief.” Nature. (paywall)

Price, Michael. 21 May 2024. “Neanderthals and modern humans made babies 47,000 years ago.” Science.

1. https://www.bbc.com/news/science-environment-48913307 ↩︎
2. Involving skin pigmentation, immune response, and metabolism. ↩︎