Posted on 7 December 2015
The study, which included collaboration with the Natural History Museum, New York University and institutions in Spain, reveals how the development of facial bone structure creates this intriguing difference.
The findings have been published in Nature Communications and the paper explains that after birth there is a gradual increase in the layering of bone deposits in the face for both species.
While in Neanderthals bone deposits continue through teenage years, in modern humans this is counterbalanced by bone removal, resulting in a flatter face.
One of the authors was Professor Paul O’Higgins, Head of the Centre for Anatomical and Human Sciences, Department of Archaeology and Hull York Medical School (HYMS) and lead researcher at the University of York.
He said: “What this study shows is that without any doubt modern humans grew differently from their ancestors and near relatives, and it is us who are the oddities. This difference in growth at least partially explains the reduction in our faces that occurred in the last 200,000 years.
“While it is exciting to find that it is our growth pattern that is unique; this also raises lots of questions. Among the fundamental questions are: why the faces of our ancestors were so large and protruding and how did the development of a small face give rise to typical characteristics of modern humans? We look forward to pursuing this question in future work."
The research team focussed on the upper jaw bones of a young Neanderthal discovered in 1926 in deposits near Devil’s Tower, below the North face of the Rock of Gibraltar.
The specimen is one of few remains discovered of Neanderthal children and it has aided researchers in filling in gaps on what drives the growth of the Neanderthal face.
Neanderthals and their possible ancestors, the 400,000 year old hominins from Sima de los Huesos (Atapuerca) in Spain, exhibit similar bone growth patterns, albeit with some small differences. Yet they resemble each other far more closely than they resemble modern humans.
The Sima de los Huesos hominins as well as the Gibraltar Neanderthal and other Neanderthals found in France were used in this comparative study.