The study dates back to a more ancient date than the current scientific consensus, the age of the last common ancestor of Homo sapiens and Neanderthals, 800,000 years instead of 400,000 to 600,000 years ago.
Scientists who are studying the origins of humans have made tremendous progress with recent improvements in ancient DNA analysis techniques. A new study is based on an alternative method to go back in time: the analysis of fossilized human teeth.
The study, published Wednesday, May 15 in the journal Science Advances, dates back to a more ancient date than the current scientific consensus of the age of the last common ancestor of Homo sapiens (our species) and Neanderthal, or 800,000 years old From 400,000 to 600,000 years.
But this work, conducted by Aida Gomez-Robles of the University College of London, is debated by anthropologists, some of whom question the accuracy of the methodology used by the researcher. The study begins with about 30 molars and premolars found in the caves of Sima de los Huesos in Spain, which belonged to the first Neanderthal men and women. He also analyzed fossils of seven other ancient human species.
The teeth of Sima de los Huesos were dated in 2014 with reliable techniques at 430,000 years. This dating already indicated that the "divergence" between sapiens and Neanderthals had therefore taken place before 400,000 years ago. But when? To calculate when this common ancestor dates back, the researcher used a statistical model that assumes that the shape of human teeth evolves at a steady pace. The goal is to go far enough back in time to find an ancestor who was able at the same time to bring teeth to the human Sima de los Huesos and to the teeth of modern humans.
It is with this calculation that Aida Gomez-Robles reaches the conclusion that our ancestors and those of Neanderthals "diverged" 800 000 years ago. The immediate consequence of this work is that they would eliminate the Heidelberg man (Homo heidelbergensis) as the much sought after common ancestor.