Not much is known about the mysterious Denisovans, a species of early human that scientists did not even know existed until about 10 years ago. Now, incredible new research suggests that not only did Denisovans interact with modern man, but they may have interbred based on an analysis of 5,500 genomes.

Humans bred with Denisovans in not just one region, but at least two, claims the new study. The evidence suggests that these two regions are in Siberia and southeast Asia, very distant from each other. It is a major new finding that could totally change our understanding of the human race.

The Denisovans were first discovered in 2008 after a pinkie bone and a molar tooth was found in a Siberian cave. Scientists realized that these did not belong to Neanderthals or modern humans, and determined that it must be an entirely separate species of humans.

“What was known already was that Oceanian individuals, notably Papuan individuals, have significant amounts of Denisovan ancestry,” says senior author Sharon Browning, a research professor of biostatistics, University of Washington School of Public Health. “The genomes of modern Papuan individuals contain approximately 5% Denisovan ancestry.”