Matthias Meyer of the the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany and his colleagues extracted mitochondrial DNA from the femur of a 400,000-year-old hominin found in the Sima de los Huesos ("pit of bones"), an underground cave in northern Spain.
Because the early hominins looked a little like Neanderthals, researchers expected their mitochondrial DNA to share a common ancestor.
However, mitochondrial DNA from the Spanish hominin was found instead to share a common ancestor with an enigmatic eastern Eurasian sister group to the Neanderthals, the Denisovans.
"The fact that the mtDNA of the Sima de los Huesos hominin shares a common ancestor with Denisovan rather than Neanderthal mtDNAs is unexpected since its skeletal remains carry Neanderthal-derived features," Meyer said.
Writing in the journal Nature, the researchers said the ability to study DNA from human ancestors that are hundreds of thousands of years old opens the way to tracking the genes of the ancestors of both Neandertals and Denisovans.
"This unexpected result points to a complex pattern of evolution in the origin of Neanderthals and modern humans," Juan-Luis Arsuaga, director of the Center for Research on Human Evolution and Behavior, said.
The findings are important because it pushes our understanding of the genetics of human evolution some 200,000 years or so further back in time, the researchers said.
From UPI
