DNA analysis of 400,000-year-old bones found is providing key information about Neanderthal origins and the evolution of early humans, a study published in the journal Nature reports.
The study focused on 28 hominins that were uncovered in 2013 at the Sima de los Huesos (“Pit of Bones”) site in Spain, the only non-permafrost spot in the world where researchers can analyze DNA sequences dating from before 125,000 years ago.
Initially, researchers thought the bones belonged to Homo heidelbergensis, a species believed to be an ancestor of Neanderthals. However, mitochondrial DNA analysis showed that the hominins in the pit were more closely related to Denisovans, another species of early human. This was baffling because the physical features of the remains appeared more Neanderthal-like.
To clear up the confusion, researchers at the Max Planck Institute for Evolutionary Anthropology conducted a new analysis, which showed that the specimens in the cave were indeed early Neanderthals, UPI reports.
“The recovery of a small part of the nuclear genome from the Sima de los Huesos hominins is not just the result of our continuous efforts in pushing for more sensitive sample isolation and genome sequencing technologies,” said lead author Matthias Meyer of the Max Planck Institute for Evolutionary Anthropology, in a statement. “This work would have been much more difficult without the special care that was taken during excavation.”
The new analysis produced some surprising results. It shows that Neanderthals and Homo Sapiens likely split off from their last common ancestor some 600,000 years ago — a few hundred thousand years earlier than previous estimates. The data also reveals that the 400,000-year-old Sima de los Huesos hominins were related to Denisovans and Neanderthals who lived 40,000 years ago.
Researchers now plan to re-analyze other fossils dating back to between 400,000 and 800,000 years ago in order to better understand the evolution of the Denisovan, Neanderthal, and Homo sapien lineages.