CNN ONLINE

The humble modern-day potato, first domesticated about 10,000 years ago, got its start in the Andes mountains before becoming a key crop the world depends on. But because plants don’t preserve well in the fossil record, its lineage has remained largely a mystery.

Now, a team of evolutionary biologists and genomic scientists has traced the origins of this starchy staple to a chance encounter millions of years ago involving an unlikely plant relative: the tomato.

The researchers analysed 450 genomes from cultivated and wild potato species, and the genes revealed that an ancient wild tomato plant ancestor naturally bred with a potato-like plant called Etuberosum 9 million years ago — or interbred, as both plants had originally split off from a common ancestor plant about 14 million years ago, according to a study published Thursday in the journal Cell.