Scientists studying the genomes of West Africans reported this week that they had "detected signs" of an extinct human species that they're calling a "ghost population." The discovery was detailed in a study published this week in the Science Advances journal, per a Reuters report from Thursday.
"We estimate interbreeding occurred approximately 43,000 years ago, with large intervals of uncertainty," Sriram Sankararaman—human genetics and computer science professor at UCLA—said of this development.
Sankararaman added that this species likely diverged from the evolutionary line that resulted in Homo sapiens approximately 650,000 years ago. Prior research in the genetic field showed that our species "interbred" with the previously known Neanderthals and Denisovans, the former of which boasts a significant fossil record, while the latter also has a fossil record, though not as dense. With this newly detected so-called "ghost population," however, many unknown factors remain.
It hasn't yet been determined where this extinct human species resided, or whether they have any connection to known fossils. Additionally, researchers aren't sure of the details of its eventual fate or whether West Africans "derived any genetic benefits." According to the study, "some 2 percent to 19 percent" of West Africans' genetic ancestry has been traced to this extinct human species.
For more on these developments, head over to Science Advances.