Scientists have finally solved a mystery that has puzzled researchers for years: where did the modern-day potato come from?
A new international study has revealed that potatoes began as a natural hybrid between ancient wild tomatoes and potato-like plants about 9 million years ago in South America.
Published in the journal Cell, the study shows that this surprising plant “romance” triggered the development of the tuber—the underground structure we know as a potato.
Tubers store nutrients and allow plants to survive tough conditions, grow back year after year, and reproduce without seeds.
The potato is one of the most important crops in the world today.
But its exact origin was unclear. Oddly, the plant looks nearly identical to three wild species found in Chile, called Etuberosum. However, these lookalikes don’t actually grow tubers.
On the other hand, potatoes are more closely related to tomatoes in terms of genetics, which added to the confusion.
To get to the bottom of this puzzle, scientists studied the DNA of 450 types of cultivated potatoes and 56 wild potato relatives.
It turned out that every potato species shared a balanced mix of genes from both Etuberosum and tomato plants. This means that the first potatoes were the result of natural interbreeding between these two different species.
Although tomatoes and Etuberosum had already been evolving separately for 5 million years, they were still genetically similar enough to produce hybrid offspring. This rare event gave rise to the very first potato plants—with tubers—about 9 million years ago.
The researchers also tracked down the specific genes responsible for tuber formation. One key gene, called SP6A, came from the tomato side. It acts as a switch that tells the plant when to start growing tubers.
Another gene, IT1, came from the Etuberosum side and helps shape the underground stems that form the tubers. Without both of these, tubers wouldn’t exist.
This evolutionary leap happened at a time when the Andes Mountains were rapidly rising, creating new and challenging environments. The tuber gave early potato plants a major survival advantage, helping them thrive in harsh mountain conditions.
Because tubers can sprout new plants without pollination, potatoes were able to spread quickly and adapt to a wide range of climates—from grasslands to cold alpine meadows. This helped create the incredible variety of potatoes we know today.
“This discovery shows how mixing genes between species can lead to entirely new traits and open up new paths in evolution,” said lead researcher Sanwen Huang. “Now, we finally understand where the potato came from.”
