Upstanding Neanderthals

Reconstruction of the La Chapelle-aux-Saints Neanderthal spine superimposed onto the radiograph of a modern human

Martin Haeusler, University of Zurich

A common misconception paints Neanderthals as stereotypical “cavemen,” hunched in their stance and gait. This depiction was borne of early anthropological work dating back over a century and exacerbated by reliance on the skeletal evidence of an elderly Neanderthal male with spinal osteoarthritis that was excavated in La Chapelle-aux-Saints, France. Over the past several decades, further work has suggested that the prehistoric humans possessed an unusually straight spine, which would have made their posture precarious and unbalanced, and their walking style not-quite-human. Now a study, relying on a first-of-its-kind virtual reconstruction of a Neanderthal pelvis, indicates that Neanderthals had a curved lumbar region and neck, implying that they walked upright in the manner of modern-day Homo sapiens.

Researchers led by Martin Haeusler, head of the evolutionary morphology group at the University of Zurich, took high-precision 3D surface scans of the same well-preserved La Chapelle-aux-Saints specimen that first gave rise to the erroneous caveman posture. Because the specimen’s right hip bone was not part of its recovered remains, the team incorporated a hip bone cast into an anatomical computer simulation. They then created a computer-generated model of the specimen’s skeleton.

The model revealed that the position of the Neanderthal’s sacrum—the shield-shaped base of the spine that connects to the pelvis—relative to the hip bone aligns with that of extant humans, pointing to similar lower back curvatures. Further evidence came from placing the lumbar and cervical vertebrae into the model. Projections off these vertebrae, called spinous processes, made close contact, indicative of spinal curvature. Finally, wear marks in the hip joint dovetailed with an upright, rather than a stooped, posture.

Comparisons with other Neanderthal skeletons support this view of Neanderthal posture. “We show,” said Haeusler, “that there is hardly any evidence that would point to Neanderthals as having a fundamentally different anatomy than ours.”

The researchers argue that, moving forward, Neanderthal research should focus less on the historically over-emphasized differences in anatomy that render them less “human” than Homo sapiens. Instead, subtle shifts in general human anatomies during our shared evolutionary history, as well as potential behavioral distinctions, should be grounds for gauging where we and our Neanderthal brethren ultimately went down different paths. (Proceedings of the National Academy of Sciences)