The Potato's Rise in the Andes Left a Mark on Human DNA

A 2026 study of ancient DNA has traced the agricultural revolution of the Andes down to a single food and into the human genome. The potato — domesticated some 8,000 years ago in the high altiplano of modern Peru and Bolivia — appears to have left a distinctive evolutionary signature in the descendants of the people who grew it.

The researchers sequenced ancient genomes from multiple Andean populations spanning thousands of years and compared them against related groups that never adopted potato agriculture in the same intensity. Across the potato-domesticating lineages, they found unusually strong signals of natural selection in genes involved in carbohydrate metabolism — including variants that improve starch digestion — and in genes tied to immune defense against pathogens associated with stored tubers.

The finding is one of the cleanest examples yet of crop domestication driving human genetic change outside the well-worn examples of dairy lactase persistence and high-altitude hemoglobin adaptation. Unlike those traits, which each reflect a single dramatic environmental shift, the potato signature is diffuse — a collection of small selective advantages that, together, favored populations that could extract more energy from a starchy crop and defend against the storage-borne microbes it carried.

What makes the study compelling is the geographic resolution. The potato signal was strongest in groups living along the traditional altiplano cultivation belt and faded progressively with distance — a pattern consistent with selection acting on populations that actually depended on the crop, not merely lived near it. That gradient is a rare fingerprint in ancient DNA, because most selection signals are either continent-wide or confined to a single isolate.

Beyond the evolutionary detail, the work reframes what we mean by 'agriculture'. Farming was not just a technological shift — humans did not merely invent the crop and then carry on living the same way. The crop shaped us back. In the case of the Andean potato, that back-shaping is now readable at the nucleotide level, eight thousand years later.