![]() The latter’s feet maintains greater flexibility overall and grasping abilities that enable climbing trees as well quadrupedalism on the ground. The former’s foot is adapted for a stiff push-off which is necessary for bipedal locomotion. A major difference between the two stems from flexibility. As reasonable as it may seem to draw comparisons between the two, the clear divergence between the genera from a last common ancestor (LCA) means that hominins and panins evolved feet to suit their needs. One of the things we can say with certainty is that the modern human foot did not evolve from the chimpanzee foot. The human foot evolved independently of other developments within human evolution and at different rates between species. In piecing together these discoveries, it became clear that the evolutionary story of the human foot wouldn’t be explained linearly. Scientists believed that the foot of Australopithecus was adapted for bipedalism but it also allowed this early human ancestor to take refuge in the trees if needed. This was based on the discovery of “Little Foot,” an almost complete Australopithecus fossil skeleton recovered from Sterkfontein, South Africa dating to 3.3 million years ago, which exhibited similar hindfoot traits. ![]() However, in 1995, scientists proposed that the anatomy of the ankle joint and heel (the hindfoot) existed before the anatomy of the human forefoot as it pertains to bipedalism. It belonged to a member of Homo habilis family and includes the the left tarsal and metatarsal bones - the tarsals are a series of bones that comprise the plane of the foot leading to the toes - but no actual toes. Taken together with the discovery of Lucy, as well as the Laetoli footprints, OH 8 served the story that the human foot was adapted from the arboreal chimpanzee foot. OH 8 refers to Olduvai Hominid number 8 and dates to about 1.8 million years old. The discovery of OH 8 in 1960 by the Leakey team in Olduvai Gorge propelled us forward. These ideas were fine, but what we needed were fossils. In later stages, the foot would have moved away from these traits, although it may have retained the “grasping” ability with the big toe. In the first instance, the foot would have possessed more “ape-like” qualities with greater grasping abilities and flexibility, and notably an elongated midfoot region. In 1935 anatomy professor Dudley Morton proposed the modern human foot is the result of two distinct transitions. Huxley would make comparisons to gorilla feet and call out that while they were also inverted and possessed grasping tendencies, they also shared muscular similarities with the human foot. The quest to know ourselves begins in 1699 with an anatomical assessment of modern chimpanzees by Edward Tyson who labeled them quadrumanous, meaning all of their appendages were adapted to function as hands. What has emerged is a story of diversity in locomotion that supports a case for mosaic evolution making the story of the foot overall (not just ours) a remarkable one.Ī recent review article from researchers Ellison McNutt and colleagues tracks the literature on the evolution of the human foot. Understanding differences between our feet and those of other apes (both ancestral and contemporary), can give us clues into the changes that were necessary for bipedalism - and perhaps for bipedalism itself. It is after all linked to the pivotal development of bipedalism in our history. The bones that make up the feet represent a quarter of the human skeleton, and yet, despite comprising such a large percentage of the body, they have largely eluded us in the fossil record until recently. This is frustrating because it's clear that this story - the evolution of the human foot - has captivated us for hundreds of years.
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