Researchers have identified new evidence supporting the growing belief that Neanderthals were a distinct species separate from modern humans, and not a subspecies of Homo sapiens.
The research also indicates that the Neanderthal nasal complex was not adaptively inferior to that of modern humans, and that the Neanderthals' extinction was likely due to competition from modern humans and not an inability of their nose to process a colder and drier climate.
Samuel Marquez, from SUNY Downstate Medical Centre in New York, and his team 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 - a group of culturally similar indigenous peoples inhabiting the Arctic regions of Greenland - 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 this extinct group functioned via a different set of rules as a result of a separate evolutionary history and overall cranial 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. We used traditional morphometrics, geometric morphometric methodology based on 3D coordinate data, and CT imaging," Marquez said.
Anthony S Pagano, anatomy instructor at NYU Langone Medical Centre, a co-author, travelled to many European museums carrying a microscribe digitiser, the instrument used to collect 3D coordinate data from the fossils studied in this work.
Co-author William Lawson, from the Icahn School of Medicine at Mount Sinai, notes that the external nasal aperture of the Neanderthals approximates some modern human populations but that their mid-facial prognathism (protrusion of the mid-face) is startlingly different.
That difference is one of a number of Neanderthal nasal traits suggesting an evolutionary development distinct from that of modern humans.
The study was published in The Anatomical Record journal.
