Neanderthal pelvises reveal how modern men's hips evolved for efficient walking

A team led by Prof. Yoel Rak of Tel Aviv University's Department of Anatomy and Anthropology published a study in Scientific Reports, announced on 17 August 2026, that turns a common assumption about human evolution on its head. Working with colleagues from Spain, the Technion, Bar-Ilan University and Ono Academic College, including co-author Prof. Ella Been, the researchers compared the two most complete male Neanderthal pelvises ever found with dozens of modern human pelvises.

The two fossils come from Kebara Cave on Mount Carmel in Israel, excavated in 1982, and from the Sima de los Huesos site in northern Spain. To the team's surprise, in their measurements and proportions both male Neanderthal pelvises looked much more like the pelvises of modern women than those of modern men. Rak told The Times of Israel that the researchers were astonished when they finally had two specimens to compare.

The key difference lies in the position of the hip socket. In modern men it sits farther forward on the pelvis than in modern women or in male Neanderthals. That shift lets the thigh muscles work like springs, absorbing impact and returning energy with each step, which makes walking long distances more efficient. In women, the demands of childbirth, which require a wide birth canal, kept the pelvis closer to the ancestral shape shared with Neanderthals. In other words, the researchers argue, the Neanderthal pelvis is not the oddity that needs explaining; the modern male pelvis is.

The authors acknowledge that the conclusions rest on just two fossil pelvises. Rak suggested, speculatively, that the change may relate to how early humans divided labour, and said the findings could also be relevant to modern medicine, including research on back pain, gait and injury prevention.