New research has revealed that modern potatoes owe part of their genetic makeup to wild tomatoes through a natural interbreeding event. This ancient hybridization happened nearly nine million years ago in South America and reshapes our understanding of plant evolution.
Scientists previously believed that random genetic mutations were the main engine behind species evolution and diversification.
But according to the study in Cell, hybridization played a much larger role in shaping today’s biological diversity than once thought.
Potatoes Show Genetic Links to Non-Tuber-Bearing Relatives
Modern potato plants resemble species from Chile known as Etuberosum, which surprisingly don’t form edible tubers like common potatoes.
This has puzzled scientists for decades, as tubers are essential storage structures that make potatoes valuable for food production.
The Tomato Connection: Ancient Genes With Lasting Impact
Genetic analysis found potatoes carry around 60% of their DNA from Etuberosum and 40% from tomato-like ancestors.
The discovery was a “wow moment” for scientists, confirming a single ancient hybridization event, rather than multiple gene transfers over time.
Key Genes Worked Together To Enable Tuber Formation
A gene from the tomato lineage, SP6A, acts as a signal to trigger tuber formation in the plant.
But SP6A alone isn’t enough—it required IT1, a gene from Etuberosum, to enable underground stem growth necessary for tubers.
Geological Shifts May Have Enabled This Unique Evolution
The hybridization likely coincided with the Andes Mountains’ uplift, which created new ecological conditions suitable for tuber-bearing plants.
Off-target pollination by insects during this time may have brought together these distant plant relatives in fertile mountain habitats.
Why Tubers Matter: Food Storage and Asexual Reproduction
Tubers gave ancient plants a major survival edge—they store nutrients underground and allow plants to reproduce without seeds.
This asexual reproduction helped potatoes spread across South America and, eventually, the globe through human cultivation and trade.
The Future: Hybrid Potatoes That Reproduce by Seed
The research team is now working on creating a new hybrid potato that can be reproduced from seed instead of traditional tubers.
Using tomato as a synthetic biology platform, they hope to speed up breeding and improve crop resilience for global agriculture.
Final Thoughts: An Evolutionary Twist Rooted in Our Food System
This study reshapes how we view crop origins and evolution, showing that some of our most important foods came from unexpected genetic unions.
With deeper insight into potato genetics, scientists may unlock better ways to grow this global staple in a changing climate.
