Landmark ancient-genome study shows surprise acceleration of human evolution

Big picture

It has been reported that the biggest-ever survey of ancient human DNA finds an unexpected surge in natural selection over the past 10,000 years. Researchers led by David Reich and Ali Akbari assembled genomes from 15,836 ancient people across western Eurasia — more than 10,000 of them newly sequenced — and scanned for gene variants that rose or fell consistently through time. The result? Hundreds of candidates for directional selection. Dramatic, even gobsmacking, depending on who you ask.

What they found

The team developed methods to distinguish genuine selection from the noise of genetic drift and from massive population turnovers — think hunter‑gatherers replaced by incoming farmers. Using those controls, they flagged 479 variants showing strong directional change. Many hit immune genes; others touch skin pigmentation and traits linked to behaviour. Evolution, the paper argues, sped up particularly during the Bronze Age about 5,000 years ago as societies, diets and disease ecologies transformed. Some variant frequencies even “rode a rollercoaster,” rising and falling in ways that complicate simple narratives of steady advantage.

Debate and implications

Not everyone is sold. Some researchers remain unconvinced by the scale of the claims and question whether selection genuinely targeted highly polygenic traits — allegedly including aspects of cognition and mental‑health risk — or whether subtle biases remain in the data. Fair point. Ancient DNA is a powerful lens, but it’s also messy: sampling gaps, migration sweeps and complex trait architecture can fool the eye. Still, the study pushes a big idea: recent human evolution may have been faster and more mosaic than many expected. Are we still evolving? If this holds up, the short answer is: yes — and the story is far from over.

Sources: nature.com, Hacker News