Study Evaluates Body Shape of Neanderthal Children

[Judi Lynn]

1. Newborn Neanderthals had a robust and broad thoracic cage just like adults

OCTOBER 8, 2020
by CENIEH

Today, the journal Science Advances published a study showing that newborn Neanderthals possessed a broad thoracic cage similar to adults, capable of sustaining the demanding energy expenditure of a large and broad body. The study was led by Daniel García Martínez, a paleoanthropologist at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH). This finding implies that the Neanderthal thorax was genetically determined and not the outcome of development, a point of major evolutionary significance, as it would have been inherited from earlier species like Homo erectus.

Genetic determination implies that the differences between human species were already present at birth, and would have become only slightly more marked as individuals grew. This means that the shape of a newborn Neanderthal thorax differed from the modern thoracic cage of Homo sapiens. Nevertheless, the similarities in thoracic shape and development between Neanderthals and other species like Homo erectus suggests the hypothesis that their stocky build was not only the result of genetic inheritance transmitted from parents to children, but could also have been inherited at the evolutionary level.

In comparison with modern humans, the adult Neanderthal thorax was shorter, slightly deeper and much wider. These anatomical traits are related to the Neanderthal body, with its broad pelvis, robust bones and strong musculature. It would also be linked to the metabolic demands of these hunter-gatherers, who would have needed considerable amounts of energy and oxygen. Nonetheless, up to now, it was not known whether these differences were already established at birth or appeared later, during development.

3-D reconstructions of the Neanderthal thorax

To look into this question, Daniel García Martínez, together with an international team of experts, used virtual reconstruction and traditional and geometric morphometry to reproduce, for the first time, the thoracic shape of four Neanderthal individuals. These reconstructions, performed for Neanderthal remains from three countries, show how they evolved from birth up to three years of age: Mezmaiskaya 1 (Russia), Le Moustier 2 (France), Dederiyeh 1 (Syrian Kurdistan) and Roc de Marsal (France).

More:
https://phys.org/news/2020-10-newborn-neanderthals-robust-broad-thoracic.html