Scientists at the University at Buffalo in the United States have concluded that descendants of indigenous Andean peoples who speak the Quechua language developed a unique genetic adaptation to starchy foods following the domestication of the potato. The findings, published in the journal Nature Communications, show that Peruvians from Andean regions carry an average of about ten copies of the AMY1 gene, which is responsible for producing amylase — a salivary enzyme that breaks down starch. For comparison, most other populations around the world have two to four fewer copies of AMY1. The researchers analyzed the genomes of more than 3,700 individuals from 85 populations, including 81 Andean Native Americans, and linked the increase in AMY1 copy numbers to the period of potato domestication, which occurred approximately 6,000 to 10,000 years ago.
The increase in AMY1 gene copies became fixed through evolution because it helped ancient people more efficiently digest starch-rich foods, providing a survival advantage to those whose diets depended heavily on potatoes. The authors also noted that amylase not only affects starch digestion but also influences the composition of the gut microbiome. Scientists view this as another striking example of how diet has shaped human biology over the course of evolution, drawing a parallel to the ability of some adult humans to digest lactose.
