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Featured recently in ,�� a member of the Environment Institute and researcher at the �Ӱ�ֱ��n Centre for Ancient DNA has commented and shared what he and his team know about human evolution and adaptation, based on their landmark 2022 study.

Modern Europeans can trace their ancestry to three major groups:

• Hunter-gatherers

• Anatolian farmers

• Steppe pastoralists

To investigate, Dr Yassine Souilmi and his team analysed 1,162 ancient DNA samples, as . They searched for “hard sweeps,” which are signs of strong, rapid natural selection that helped early humans survive environmental pressures.

The team identified 57 such sweeps in genes linked to fat storage, metabolism, immunity, neural function, and skin physiology. These traits were likely shaped by the colder climates encountered by early Eurasians. These changes were not found in sub-Saharan African genomes, suggesting they emerged after migration out of Africa.

The study also revealed a major gap in past research. Most adaptation studies rely on modern DNA, which can mask earlier selection events due to admixture, or interbreeding, between populations. As a result, many signals of adaptation may have been overlooked.

Using ancient DNA, Souilmi’s team found that over 50 past sweeps had been erased from modern European genomes. Their findings suggest that strong adaptation was far more common in human history than previously thought.

One standout discovery was a hard sweep in the MHC III region of chromosome 6, which is crucial for immune response, in ancient Anatolian farmers. Normally, this region shows high genetic diversity. Instead, the team found what Souilmi called a “distinctive trough of genetic diversity.”

“The population had been exposed to something so severe that it wiped out all the diversity that is generally favoured in that region,” he told SCIAM��“It was one of the strongest, if not the strongest, adaptation signals we have ever seen in humans.”

However, as these farmers later mixed with other groups, the signal faded. Similar patterns were found across many traits. Once-advantageous genes were diluted or lost over time through interbreeding or genetic drift.

The findings challenge the assumption that modern humans are protected from evolution by intelligence and technology. “It tells us our social fabric and technologies do not necessarily shield us from everything nature has to throw at us,” Souilmi said.

This research reframes human adaptation as dynamic and easily obscured. With ancient DNA, we can now begin to uncover the full story.