Fourth European ancestor added to mix

“Research shows Europeans are a mixture of three major ancestral populations - indigenous hunters, Middle Eastern farmers and a population that arrived from the east in the Bronze Age.

“DNA from ancient remains in the Caucasus has now revealed a fourth population that fed into the mix.

“The first layer of European ancestry, the indigenous hunter-gatherers, entered Europe before the Ice Age 40,000 years ago. But 7,000 years ago, they were swept up in a migration of people from the Middle East, who introduced farming to Europe.

“About 5,000 years ago, herders called the Yamnaya entered Europe from the eastern Steppe region - in present day Ukraine and Russia.”

http://www.bbc.com/news/science-environment-34832781