Although we have long known that humans share a common ancestor with Neanderthals, we haven't ever known what they looked like due to a lack of fossils from the Middle Pleistocene period. However, researchers from the University of Cambridge have used digital "morphometrics" and statistical algorithms of cranial fossils that span the evolutionary history of Homo sapiens and Neanderthals to create a 3-D skull of the our last common ancestor for the first time ever.
The fossil samples provided the researchers with landmarks that were used to create an evolutionary framework that allowed them to predict the skull structure timeline of our ancestors and then combined this data with a digital scan of a modern skull. The results allowed the researchers to determine the nature of the morphology convergence between both species in the last common ancestor's skull during the Middle Pleistocene era approximately 800 to 100 thousand years ago.
"We know we share a common ancestor with Neanderthals, but what did it look like? And how do we know the rare fragments of fossil we find are truly from this past ancestral population? Many controversies in human evolution arise from these uncertainties," Aurélien Mounier, lead author of the study, said in a press release.
"We wanted to try an innovative solution to deal with the imperfections of the fossil record: a combination of 3D digital methods and statistical estimation techniques. This allowed us to predict mathematically and then recreate virtually skull fossils of the last common ancestor of modern humans and Neanderthals, using a simple and consensual 'tree of life' for the genus Homo."
The findings were published in the Journal of Human Evolution.