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Why did Neanderthals use the teeth as a third hand?

A discussion between experts would find the cause

It is demonstrated that they used them as a tool more frequently than any Homo sapiens

It is one of the few cases in human evolution with diverse points of view about the same hypothesis

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Neanderthals used the teeth as a third hand. There are evidences. Why did they do it? “Perhaps it is related to a limitation of Neanderthals for coordinate brain-eye-hand”, affirms Marina Lozano, IPHES (Institut Català de Paleoecologia Humana i Evolució Social) researcher. This would be a possibility, but today there isn’t a clear answer.

For this reason, Marina Lozano and Emiliano Bruner (responsible of the Group of Paleoneurology at the Centro Nacional de Investigación sobre Evolución Humana – CENIEH) has opened a forum to know if this has been determined by different visuospatial capacities between Neanderthals and Homo sapiens. The discussion is doing in the Journal of Anthropological Sciences. Specifically, it is the second part of a series of scientific comments about a few possible limitations in the integration between brain, body and material culture in the Neanderthals.

Reconstruction of the left hand of a Neanderthal - Carlos Lorenzo/IPHES
Reconstruction of the left hand of a Neanderthal – Carlos Lorenzo/IPHES

They invited several researchers: Karenleigh Overmann (University of Colorado), Enza Spinapolice (University of Cambridge), Joseba River Garaizar (CENIEH), Ariane Burke (University of Montreal), Carlos Lorenzo (IPHES) and Duilio Garofoli (University of Tübingen) so that they will contribute with its vision to resolve the problem from its specializations.

“It is one of the few cases in the study of the human evolution with several possibilities about the same hypothesis: spatial archaeology, cerebral anatomy, dental wear, anatomy of the hand, etc”, observes Marina Lozano.

Apparently, from the point of view of the material culture, Neanderthals had a complex cultural system.  Also they controlled their territory with great efficiency. “Their hands had some small anatomical differences, but they hadn’t any functional limitation to realize the same tasks or movements that the sapiens”, said Carlos Lorenzo.

Marina Lozano / IPHES
Marina Lozano / IPHES

Emiliano Bruner and Marina Lozano considered that this could have been a consequence of a less specialized capacity of integration between eye and hand, and between brain and object than other species, and they would compensate this with the help of the mouth.

But, “in fact, the answer remains open since there are no clear evidence to stablish the cause of this generalized habit (third hand) among Neanderthals and much less frequent in our species”, affirms Marina Lozano.

Bibliographical references

Bruner, E. & Lozano, M. 2015 Three hands: one year later. Journal of Anthropological Sciences 93: 191-195

Lorenzo, C. 2015 The hand of the Neandertals: dexterous or handicapped? Journal of Anthropological Sciences 93: 181-183 doi 10.4436/jass.93014