There are over a hundred ways to prepare a potato, and countless stories have begun with a shot of vodka made from this tuber. For centuries, the potato has been key to feeding the world’s growing population. According to one study, the introduction of the potato from the Americas accounted for about a quarter of the population growth in the Old World between 1700 and 1900.
Now, science uncovers the vegetable’s surprising origins: It emerged 9 million years ago due to an unusual hybridization between an ancestor of the tomato and an ancient South American plant. This discovery rewrites the evolutionary history of one of the world’s most widely consumed foods and explains how a simple tuber became a global diet staple.
Researchers at the Chinese Academy of Agricultural Sciences carried out the most extensive genomic analysis to date on the domesticated potato. They studied cultivated varieties along with 44 wild species, conducting unprecedented genetic sequencing. The results showed a stable mixture of genetic material between Solanum tuberosum (the traditional potato) and an ancestor of Solanum lycopersicum (the tomato).
The finding suggests that potatoes as known today arose from hybridization between an ancient tomato plant and other Solanum-related species from the Etuberosum family, which, until then, did not produce tubers. The results are published in the journal Cell.
Both the potato and the tomato share a common ancestor from about 13 million years ago. Four million years later, their descendants successfully interbred. This union led to a new plant capable of forming tubers: underground structures storing energy as carbohydrates and allowing reproduction without seeds or pollination. This biological innovation facilitated the first potatoes’ expansion into regions with diverse climates, from warm to cold environments.
The study also uncovered revealing genetic details. The SP6A gene, considered the “switch” that determines tuber development, comes from the tomato. In contrast, the IT1 gene, which regulates the growth of the underground stems forming the edible tuber, comes from plants of the Etuberosum family, native to South America.
Considering the chronology of hybridization and the geolocation of the species involved, the researchers proposed a hypothesis about the potato’s origin. During the Miocene, between 10 and 6 million years ago, the Andes’ abrupt geological uplift, driven by two tectonic plates’ collision, created new cold climate regions. Scientists believe this geological change forced plants to adapt, with two joining to form Solanum tuberosum, which millions of years later would end up accompanying your hamburger as French fries.
This story originally appeared on WIRED en Español and has been translated from Spanish.