Mystery Human Species Bred with Our Ancestors, Study Suggests
New evidence of rampant interspecial breeding suggests that when it came to sex, our ancestors were not picky about their partners, which included a potentially new and mysterious species of hominin.
Researchers sequenced genomes from two extinct human relatives known as Neanderthals and Denisovans, and in doing so uncovered signs that anatomically modern humans interbred liberally with both, as well as a third extinct group that occupied Asia more than 30,000 years ago.
Presented at a Royal Society meeting in London, the findings set the room "abuzz" with questions regarding the identity of the group, according to Nature.
"We don't have the faintest idea," Chris Stringer, a paleoanthropologist at the London Natural History Museum, told the science journal.
Though not involved in the work, Stringer said one possibility is that the group is somehow related to Homo heidelbergensis, a group from Africa many believe is a direct ancestor of Europe's Neanderthals. "Perhaps it lived on in Asia as well," he said.
Another, though less likely, candidate is Homo erectus, New Scientist reported Stringer as saying. Homo erectus lived from roughly 1.89 million to 143,000 years ago throughout much of Africa and Asia. However, whether or not the western population of this group, which would have occupied a similar region to the Denisovans, survived long enough to play a role is unclear.
"We don't know," the researcher said.
One way to solve the puzzle would be to uncover more pieces in the form of new DNA samples. Doing so is difficult, however, for those species that roamed hot, wet climates where fossils are less likely to survive the millennia.
Reacting to the study, evolutionary geneticist Mark Thomas from University of College London told Nature: "What it begins to suggest is that we're looking at a 'Lord of the Rings'-type world -- that there were many hominid populations." NWN