Modern humans have been breeding with Denisovans more recently than previously believed as scientists find evidence of interbreeding from just 15,000 years ago.
An international team of researchers conducted a comprehensive genetic analysis on hominins living in Asia, finding that the relationship between Homo sapiens and Denisovans persisted until fairly recently. They also reveal that there are two separate Denisovan group that lived in Papua New Guinea and mated with humans.
Denisovans: A Mysterious Species
Little is known about the elusive Denisovans. So far, the only signs of their existence are a few teeth and bone fragments found in Siberia as well as traces of their DNA in modern people all over Asia.
Just as humans interbred with Neanderthals, humans also interbred with Denisovans as they moved along their path of migration out of Africa.
The new research reveals that humans possibly mated with Denisovans as recently as 15,000 years ago in Papua New Guinea.
"This study is giving us insight into the real pattern of human diversity," John Hawks of the University of Wisconsin-Madison tells New Scientist. "It opens a window to the fact that there was once a population that was as rich and diverse as modern humans that's now gone."
New Findings On Denisovan Populations
According to a press release, researchers sequenced DNA from 161 people from four groups in Indonesia and Papua New Guinea. They found traces of Denisovan DNA in the tissue samples of the individuals from Papua New Guinea.
Interestingly, the evidence of Denisovan DNA from Papua New Guinea are from populations different from the Denisovans living in the Siberian cave where the only physical samples of the species were found.
Findings indicate that two populations of Denisovans appeared to have interbred with the humans in Papua New Guinea. Both populations, called D1 and D2 by the researchers, were found to be distinctly different from the Denisovans from Siberia, called D0.
Researchers say that that the D1 and D2 groups diverged at least 283,000 years ago and the D2 population is particularly distant from the D0 population, splitting off approximately 363,000 years ago. This means that these two groups are as related to each other as they are to the Neanderthals.
Murray Cox, a population biologist from Massey University who led the study, suggests that the D2 may even get its own name or classification.
The study also found evidence indicating the D1 DNA entered the Homo sapiens genome roughly 15,000 to 30,000 years ago.
This means that a group of Denisovans survived longer than the other populations and mated with modern humans.
The team presented their findings at the annual meeting of the American Association of Physical Anthropologists, saying that their findings show that Denisovans are far from being a single group.