Rough features and big noses of Neanderthals provided exceptionally active breathing, heating and humidifying cold air during heavy hunting for large game.
If we dressed the Neanderthal man in modern clothes, cut his hair and combed it, his face would still attract the attention of casual passers-by. The faces of our extinct relatives were noticeably different from ours – heavy brow ridges, a large nose, and generally rougher features. In an article published by Proceedings of the Royal Society B, Stephen Wroe and his colleagues from the Australian University of New England tried to explain these differences.
The division of our ancestors and Neanderthals occurred between 700 and 900 thousand years ago. Neanderthals first migrated from Africa to Eurasia and mastered it for hundreds of thousands of years, having survived several glacial eras. It was then that they could develop and consolidate features that facilitate their existence in a severe and cold climate. And although they are very, very similar to us, their growth was noticeably less, and the physique is denser and more powerful. A large, forward-looking face was distinguished by a reduced chin and a large broad nose.
Several hypotheses have been put forward to explain these differences. Perhaps the appearance of Neanderthals allowed them to actively use jaws and teeth to chew raw and coarse meat of large game – woolly rhinoceroses, mastodons and so on. A large nose with large sinuses could enhance the heating and moistening of cold air by inhalation. In general, more intense breathing was supposed to promote accelerated burning of calories to maintain body temperature in a cold climate (it was shown that Neanderthals consumed an average of 1.5-2 times more energy than modern humans).
The team of scientists evaluated these hypotheses, relying on three-dimensional models of Neanderthal skulls, modern man, and H. heidelbergensis, which could be our common ancestor and possess features that existed before the separation of both species. According to Roe, these are the first computer models that take into account the anatomy of internal surfaces, such as the nasal cavity. Their comparison showed significant differences between the strength of the bite in different species, and not in favor of Neanderthals. To the great surprise of the authors, among modern people it is more powerful, which allows one to drop one of the old hypotheses.
3D model of the Neanderthal skull / © Wroe et al., 2018
The cavity of the nose of the Neanderthals and Sapiens was much more effective in heating and moistening the cold air than in the Heidelberg ancestors. The main advantage of Neanderthals is the more intense breathing, which, apparently, allowed them to provide their “high-energy lifestyle”. According to the authors’ calculations, their large noses with capacious internal cavities were capable of pumping (and at the same time warming and moisturizing) twice as much air volumes as ours. It seems that the recognizable face of Neanderthals was the result of adaptation to active, physically loaded hunting in the severe climate of ancient Eurasia.