According to a new study that analyzed different aspects of the nasal complex in Neanderthals and other later Pleistocene fossils from Europe and Africa, Neanderthals were a distinct species of the genus Homo, and not a subspecies of anatomically modern humans (Homo sapiens neanderthalensis) as some scientists thought.
A model of a Neanderthal man in modern clothing. Image credit: H. Neumann / Neanderthal Museum.
The study indicates that the nasal complex of Neanderthals was not adaptively inferior to that of anatomically modern humans, and that the Neanderthals’ extinction was likely due to competition from modern humans and not an inability of the Neanderthal nose to process a colder and drier climate.
The authors argue that studies of the Neanderthal nose, which have spanned over a century and a half, have been approaching this anatomical enigma from the wrong perspective.
Previous work has compared Neanderthal nasal dimensions to modern human populations such as the Inuit and modern Europeans, whose nasal complexes are adapted to cold and temperate climates.
However, the current study joins a growing body of evidence that the upper respiratory tracts of Neanderthals functioned via a different set of rules as a result of a separate evolutionary history and overall cranial bauplan (bodyplan), resulting in a mosaic of features not found among any population of Homo sapiens.
“The strategy was to have a comprehensive examination of the nasal region of diverse modern human population groups and then compare the data with the fossil evidence,” said Dr Samuel Márquez of SUNY Downstate Medical Center in Brooklyn, NY, who is the first author of the paper published in the journal Anatomical Record.
“We used traditional morphometrics, geometric morphometric methodology based on 3D coordinate data, and CT imaging.”
“The strength of this new research lies in its taking the totality of the Neanderthal nasal complex into account, rather than looking at a single feature. By looking at the complete morphological pattern, we can conclude that Neanderthals are our close relatives, but they are not us,” said study senior author Dr Jeffrey Laitman of the New York Consortium in Evolutionary Primatology and the Icahn School of Medicine at Mount Sinai.
Dr William Lawson from the Icahn School of Medicine at Mount Sinai, NY, a co-author on the study, explained: “the external nasal aperture of the Neanderthals approximates some modern human populations but that their midfacial prognathism (protrusion of the midface) is startlingly different.”
“That difference is one of a number of Neanderthal nasal traits suggesting an evolutionary development distinct from that of modern humans.”
“This study is a significant contribution to the question of Neanderthal cold adaptation in the nasal region,” said Dr Laitman, “especially in its identification of a different mosaic of features than those of cold-adapted modern humans.”
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Márquez, S. et al. 2014. The Nasal Complex of Neanderthals: An Entry Portal to their Place in Human Ancestry. Anat Rec, 297: 2121–2137; doi: 10.1002/ar.23040
