Traces of long-lost human relatives could be hiding in our own DNA, a new computer analysis concludes. According to the study, people from Melanesia, a region in the South Pacific, may carry genetic evidence of a previously unknown extinct hominid species.
According to Ryan Bohlender, the species is probably not Neanderthal or Denisovan, but a different, related hominid group.
“We’re missing a population or we’re misunderstanding something about the relationships,” Bohlender, a statistical geneticist, commented.
Scientists believe this mysterious relative was from a third branch of the hominid family tree that produced Neanderthals and Denisovans. While many Neanderthal fossils have been uncovered in Europe and Asia, Denisovans have only been identified from DNA in a finger bone and teeth discovered in a cave in Siberia.
Though controversial, Bohlender isn’t the only one to suggest that the remnants of our relatives have been preserved in human DNA. In 2012, a separate group of researchers suggested that some people in Africa also carry “DNA heirlooms.” And it was less than a decade ago that scientists discovered that human ancestors bred with Neanderthals.
Bohlender and his colleagues calculate that Europeans and Chinese people are made up of about 2.8 percent Neanderthal DNA. Though Europeans have no hint of Denisovan ancestry, people in China have about 0.1 percent. The population in Papua New Guinea is a different story. 2.74 percent of the DNA in people in the area comes from Neanderthals, and Bohlender estimates the amount of Denisovan DNA is about 1.11 percent.
“Human history is a lot more complicated than we thought it was,” Bohlender said, reaching the conclusion that the third group of hominids likely bred with the ancestors of Melanesians.
“Who is this group we don’t know,” Eske Willerslev, another evolutionary geneticist, said. He believes they could be Homo erectus or the extinct hominids from Indonesia known as Hobbits.
Source: Science News