Some anthropologists believe that the Neanderthals (Homo neanderthalensis) were sub-species of modern humans. Our genes even indicate that Homo sapiens have interbred with the Neanderthals in the past. Some experts, however, disagree.
Now, findings of a new study could possibly settle the debate over whether or not the now extinct Neanderthals that thrived 20,000 to 35,000 years ago were sub-species of modern humans and the evidence has something to do with the Neanderthals' nasal anatomy.
For the new study, Samuel Marquez, from the Department of Otolaryngology at the SUNY Downstate Medical Center in Brooklyn, New York, and colleagues examined the nasal region of different population groups of modern human and compared the data they have gathered with those of the Neanderthals' fossils from European museums using traditional morphometrics, CT imaging and geometric morphometric methodology.
The researchers found that while the Neanderthals' external nasal aperture, a heart- or pear-shaped opening in the skull, is similar to that of the modern humans, the protrusion in their midface called midfacial prognathism is different, a nasal trait that suggest the evolutionary development of Neanderthals was different from that of the modern humans.
"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," said study author Jeffrey Laitman, from the Icahn School of Medicine. "By looking at the complete morphological pattern, we can conclude that Neanderthals are our close relatives, but they are not us."
Earlier research has compared the noses of the Neanderthal with those of modern Europeans and Inuits, who have adapted to cold and dry climates. However, the new study, which was published in The Anatomical Record on Oct. 14, suggests that these previous studies approached the nasal complex from a wrong prospective.
The current study offers additional evidence that the upper respiratory tracts of the Neanderthals function differently because of a different evolutionary history and overall cranial body plan indicating that Neanderthals is not a subspecies of modern human.
"Comparison of Neanderthal nasal morphology with that of modern humans from cold climates may not be appropriate as differences in overall craniofacial architecture may constrain the narrowing of the piriform apertures in Neanderthals," the researchers wrote. "They retain primitively long, low crania, large maxillary sinuses, and large piriform aperture area similar to mid-Pleistocene Homo specimens such as Petralona 1 and Kabwe 1."
The study also suggests that the extinction of the group may have happened not because their noses could not adapt to cold and dry climates but because of competition with modern humans.