The modern human foot walked 1.5 million years ago
Modern humans emerged from the African mists about 50,000 years ago, but modern human feet appeared much earlier -- at least 1.5 million years ago, according to fossilized footprints found on a riverbank near Ileret, Kenya.
The several sets of footprints indicate that the hominids had a height, weight and gait similar to that of modern humans, a team reported Friday in the journal Science.
Most important, the footprints showed a pronounced arch, the big toe was parallel to the other toes and all the toes were shorter than those of apes -- structural traits characteristic of modern humans and ones that enabled them to run faster while chasing prey.
The footprints represent the earliest evidence of a modern humanlike foot anatomy, said coauthor John W. K. Harris, a Rutgers University anthropologist.
Earlier footprints found in Laetoli, Tanzania, and dating back about 3.6 million years, show less of an arch and a longer big toe splayed off to one side like apes’ -- an adaptation useful for grasping tree limbs but not for running. That hominid, probably Australopithecus afarensis, also walked upright, but more slowly.
The Ileret footprints were most likely made by Homo ergaster, more commonly known as an early form of Homo erectus. It was the first hominid to have the longer legs and shorter arms of modern Homo sapiens.
Such footprints are rare, because they require a precise set of conditions: The river must flood and cover them with sand before they can be washed away or obliterated by animals, Harris said.
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