Indigenous communities in the Andes domesticated the potato between 6,000 and 10,000 years ago, making this nutrient-rich tuber a dietary staple. New genomic research reveals that this longstanding reliance on starches led to genetic adaptations that persist in their Peruvian descendants today.
The study, published in Nature Communications, found that Quechua-speaking individuals from the Andes carry an average of ten copies of the AMY1 gene, which is crucial for starch digestion. This is two to four more copies than most people worldwide, and the highest number observed globally. The timing of this genetic change coincides precisely with the advent of potato domestication.
“It is a wonderful case of culture shaping biology,” said Omer Gokcumen, an evolutionary geneticist at the University at Buffalo and senior author of the study. The researchers analysed genomic data from over 3,700 people across 85 populations, including 81 native Quechua speakers in Peru. They hypothesise that individuals with more AMY1 copies had an advantage in processing starch-rich foods like potatoes, leading to more descendants over generations.
Potatoes were a reliable food source that thrived at high altitudes and were central to the Inca food supply. “They were one of the main sources for calories in the ancient Andean diet,” said Kendra Scheer, a doctoral student and co-lead author. The findings highlight how dietary adaptation can shape human evolution, with implications for metabolism and health.
