Genetics: Andean populations show genetic adaptation to starch-rich diets (Nature Communications)
6 May 2026
Indigenous Peruvian Andean populations have among the highest-known copy number for the salivary amylase gene, which encodes an enzyme involved in starch digestion, according to research published in Nature Communications. These findings may reflect adaptation to a starch-rich diet in the Andes, as the timing of the expansion coincides with the domestication of potatoes in the region.
Amylase, an enzyme found in human saliva and pancreas, plays a key role in the breakdown of starch into simple sugars. The gene responsible for encoding salivary amylase, AMY1, varies widely in the number of copies per person (known as copy number) across human populations. This variation may be linked to different diets, but localised associations in smaller populations have been difficult to determine. The Andes, where early communities shifted from foraging to cultivating starch-rich crops such as potatoes and quinoa between 10,000 and 6,000 years ago, offers an important setting for examining dietary adaptation.
Omer Gokcumen, Abigail Bigham, and colleagues analysed genetic data from 3,723 individuals across 85 global populations, which included the Americas, Europe, Africa, and Asia. The Peruvian Andean population was found to have among the highest observed AMY1 copy numbers, with approximately 60% of the cohort having 10 or more AMY1 copies. The authors identify several lines of evidence pointing to recent positive selection for increased copy number of AMY1 in Andean populations. They suggest that the timing of the copy number expansions coincides with archaeological estimates for early potato domestication approximately 10,000 years ago.
These findings improve our understanding of the role of dietary preferences in shaping the selection of genes.
- Article
- Open access
- Published: 05 May 2026
Scheer, K., Landau, L.J.B., Jorgensen, K. et al. Rapid adaptive increase of amylase gene copy number in Indigenous Andeans. Nat Commun 17, 3822 (2026). https://doi.org/10.1038/s41467-026-71450-8
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