science
Andean Populations Show Genetic Adaptation to Potato-Rich Diet
Indigenous communities in the Andes domesticated potatoes between 6,000 and 10,000 years ago, leading to genetic changes that persist in their descendants. A new study found that Quechua speakers in Peru have an average of 10 copies of the AMY1 gene, which produces an enzyme that breaks down starch. The research examined genomic data from more than 3,700 people across 85 populations.
The IndependentAudio version
Tap play to generate a narrated version.
Developing·Limited corroboration so far. This page will refresh as more sources emerge.
Indigenous communities in the Andes domesticated the potato between 6,000 and 10,000 years ago, making the starch-rich tuber a central part of their diet. This long-term reliance on potatoes as a reliable food source at high altitudes led to genetic adaptations that remain observable in Peruvian descendants who speak the Quechua language.
A study published this week in the journal Nature Communications found that these individuals possess an average of 10 copies of the AMY1 gene. That is two to four more copies than most people have, and the highest number recorded globally. The timing of the genetic changes coincided with the advent of potato domestication.
The AMY1 gene governs production of the enzyme amylase in saliva, which breaks down starch in the mouth when eating starchy foods. Individuals with more copies of the gene may produce more of the enzyme, facilitating better metabolism of high-starch diets.
Researchers said the greater dosage may also influence the body's microbiome. "It is a wonderful case of culture shaping biology," said one of the study's senior authors. The research analyzed genomic data from more than 3,700 people across 85 populations in the Americas, Europe, Africa and Asia, including 81 native Quechua speakers of Andean ancestry in Peru.
Over time, evolutionary forces favored extra copies of the AMY1 gene in ancient Andean populations. A genetic variant must provide some advantage to become widespread in a population. "Therefore, one hypothesis is that people with more copies of AMY1 may have been better able to process starch-rich foods, including potatoes," said a doctoral student and co-lead author of the study.
