What the study found
The study found that many hundreds of alleles were affected by strong directional selection in West Eurasia over the past ten millennia. It also found changes in combinations of alleles that today predict complex traits, including lower predicted body fat and schizophrenia and higher predicted cognitive performance.
Why the authors say this matters
The authors conclude that ancient DNA can reveal more about human evolutionary biology than previously realized. They also suggest that the findings show sustained changes in allele frequency were widespread in this period, rather than rare as previously assumed.
What the researchers tested
The researchers presented a method for detecting directional selection in ancient DNA time-series data, meaning data collected across time to track changes in genetic variants. They tested for consistent trends in allele frequency change over time and applied the method to 15,836 West Eurasians, including 10,016 newly generated samples.
What worked and what didn't
The method identified many hundreds of alleles as having experienced strong directional selection in the last 10,000 years. The study also estimated selection coefficients at 9.7 million variants, and reported one-standard-deviation changes on the scale of modern variation in allele combinations linked to complex traits.
The abstract states that classic hard sweeps, where a strongly advantageous mutation rises to fixation, have been rare over the broad span of human evolution. It also notes that the trait effects were measured in industrialized societies, and it remains unclear how they relate to phenotypes that were adaptive in the past.
What to keep in mind
The abstract says the trait associations were measured in industrialized societies, so their relevance to past environments is unclear. It also notes the difficulty of distinguishing directional selection from changes due to migrations, population structure, or non-adaptive purifying or stabilizing selection.
Key points
- The study analyzed 15,836 ancient West Eurasian genomes, including 10,016 new samples.
- Many hundreds of alleles were found to have undergone strong directional selection in the past 10,000 years.
- The authors estimated selection coefficients at 9.7 million variants.
- Allele combinations linked to complex traits showed changes that included lower predicted body fat and schizophrenia and higher predicted cognitive performance.
- The abstract says trait effects were measured in industrialized societies, and their past adaptive meaning is unclear.
Disclosure
- Research title:
- Ancient DNA shows widespread directional selection in West Eurasia
- Authors:
- Ali Akbari, Annabel Perry, Alison R. Barton, Mohammadreza Kariminejad, Steven Gazal, Zheng Li, Yating Zeng, Alissa Mittnik, Nick Patterson, Matthew Mah, Xiang Zhou, Alkes L. Price, Eric S. Lander, Ron Pinhasi, Nadin Rohland, Swapan Mallick, David Reich
- Institutions:
- Broad Institute, Broad Institute, Broad Institute, Broad Institute, Broad Institute, Broad Institute, Broad Institute, Broad Institute, Broad Institute, Center for Systems Biology, Evolutionary Genomics (United States), Evolutionary Genomics (United States), Harvard University, Harvard University, Harvard University, Harvard University, Harvard University, Harvard University, Harvard University, Harvard University, Harvard University, Harvard University, Harvard University, Harvard University Press, Harvard University Press, Howard Hughes Medical Institute, Howard Hughes Medical Institute, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Max Planck Institute for Evolutionary Anthropology, Technical and Vocational University, The University of Texas Health Science Center at Houston, University of Michigan, University of Southern California, University of Southern California, University of Vienna, Yale University
- Publication date:
- 2026-04-15
- OpenAlex record:
- View
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