A 400,000-year-old thigh bone found at the Atapuerca archaeological complex in northwestern Spain has yielded the oldest known human DNA.
A collaboration between the Atapuerca team and Germany’s Max Planck Institute for Evolutionary Anthropology enabled scientists to sequence the mitochondrial DNA of the fossil unearthed from the underground Sima de los Huesos, or Pit of Bones.
The species of human represented at Sima de los Huesos shows a combination of ancient characteristics with Neanderthal traits, the scientists say in an article in the latest issue of Nature.
The researchers compared the genome extracted from Femur 13 from Sima de los Huesos with that of closer still-living species, specifically modern day humans and great apes, as well as the fossils of Neanderthals and another extinct human species, the Denisovans.
Though related to Neanderthals, the Denisovans, named for a cave in Siberia, were genetically distinct and appeared to have lived in East Asia.
From the genetic data, researchers calculated an approximate age for the Atapuerca fossil of about 400,000 years.
To the surprise of the scientists, the mitochondrial DNA showed that the fossil shared a common ancestor not with Neanderthals, but with Denisovans.
Hardly any morphological information is available about the Denisovans, and so it is not possible to establish anatomical comparisons with Sima de los Huesos fossils.
Being able to obtain DNA from hominid remains 400,000 years old constitutes a revolution both in terms of scientific methodology and in terms of the possibilities it opens up for future research, scientist Juan Luis Arsuaga told Efe.
Arsuaga, who is the scientific director of the Museum of Human Evolution in Burgos, Spain, is “eager” to witness the scientific debate that opens up as a result of sequencing the almost complete genome of the femur from Atapuerca.