Did Human Ancestors Walk on Their Knuckles Like Today's Chimpanzees? New Research Adds More Evidence to the Debate

Michele D'Amico supersky77 / Getty Images Walking upright all the time is one of the unique features that sets Homo sapiens apart from other primates still around today. But, before we stood up and started strolling, how did our ancestors move through the world? As they ambled around on all fours, did they navigate on their knuckles, like bonobos, chimpanzees and gorillas do, or did they clamber about with flat palms, like macaques and capuchins?

New research, published May 20 in the journal Proceedings of the Royal Society B, seems to strengthen the case for knuckle walking. But the study’s co-authors caution their results are not conclusive and, until scientists find fossils of the common ancestor species we shared with nonhuman apes, we may never fully solve the mystery of our ancestors’ gait.

Roughly eight to six million years ago, an unknown common ancestor species roamed around the planet. That species eventually split into hominins, such as Neanderthals, Denisovans and H. sapiens, and nonhuman apes, such as chimpanzees and bonobos.