All Europeans have a bit more in common than they might expect—family wise, anyway.
A new analysis suggests that all Europeans share at least one common ancestor—a great-great-great-and so on grandmother or grandfather—from as recently as 1,000 years ago. Unsurprisingly, people who live in the same country are likely to share a more recent ancestor, but, according to University of Southern California researcher Peter Ralph, someone living in Estonia almost certainly shares a common ancestor with someone in France. Perhaps a bit of sibling rivalry helped inspire the roughly thousand years of off-again, on-again infighting between European nations.
"It's actually pretty intuitive. A thousand years ago is approximately 30 generations," Ralph says. "Everyone has two parents, four grandparents and so on. Taken 30 generations back, that's more than a trillion ancestors, which is more than the total population of the time."
To test the theory, Ralph and his colleague, Graham Coop, compared genomes of more than 2,250 Europeans included in the Population Reference Sample dataset of genetic data. They published their data Tuesday in the journal PLOS Biology.
"What's remarkable about this is how closely everyone is related to each other," Coop said in a statement. "On a genealogical level, everyone in Europe traces back to nearly the same set of ancestors within a thousand years. This was predicted by theory over a decade ago, and we now have concrete evidence from DNA data."
Going further out geographically, all humans likely share a common ancestor going back approximately 3,000 years, Ralph says.
"It depends a lot on historical migration, but it's probably surprisingly recent," he says.
The fact that some Europeans might be more closely related than they thought is nothing new—last month, an "incest prevention app" was released for Android in Iceland to help people make sure they weren't sleeping with a close relative. According to Ralph, the average European shouldn't be worried about that—people living on opposite ends of the continent likely only share about 1/100th of a chromosome's worth of the same genetic material with each other.