An astonishing new study suggests that modern humans may have mixed and mingled with the Denisovans, an ancient human species, at multiple times through the world. The findings are based on 5,500 genomes that were examined that show that humans bred with Deniovans twice, and it could change our understanding about early human history.

It’s been about a decade since we first discovered the Denisovans, after we found some DNA from a portion of the bone from a pinkie and a molar tooth in a cave in Siberia back in 2008. Once we figured out that these were not from Neanderthals, it became apparent that we were dealing with an entirely separate form of early human species.

Now, new research suggests that the early humans and Denisovans were quite familiar with each other, not just once, but twice. And it indicates that the breeding happened not just in Siberia, but also in South Asia.

“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.”