There is much excitement – and no small number of puns – greeting the news that ancient footprints found in Kenya show our distant ancestors were striding around on feet very like ours some 1.5 million years ago.
Writing in Science, researchers report that after laser scanning the sets of prints, they concluded these are “the oldest evidence of an essentially modern human–like foot anatomy”. While the famous Laetoli prints from Tanzania are substantially older, at 3.75 million years, those prints showed a more ape-like foot.
Study leader Matthew Bennett, of Bournemouth University in the UK, notes the importance of the find in the Times:
Now we know that 1.5 million years ago, Homo erectus had feet with an anatomy very similar to modern humans. It could essentially walk with the same biomechanical efficiency as you or I.
Susan Antón, of New York University, told Science News the prints could have come from Homo habilis or Paranthropus boisei, rather than Homo erectus. The New York Times though says:
Although the discoverers were cautious in attributing the prints to Homo erectus, [Harvard’s Daniel] Lieberman and other experts said in interviews that it was highly unlikely they could have been made by other known hominid contemporaries. “The prints are what you would expect from the erectus skeleton we have,” said Leslie C. Aiello, president of the Wenner-Gren Foundation for Anthropological Research, which supported the research.
Reuters spoke with paper author David Braun of the University of Cape Town in South Africa, who says:
It was kind of creepy excavating these things to see all of a sudden something that looks so dramatically like something that you yourself could have made 20 minutes earlier in some kind of wet sediment just next to the site. These could quite easily have been made on the beach today.
Ars Technica explains how the new prints differ from the older find:
Modern humans begin with our heel making the first contact with the ground; the pressure is then transferred along the outside of the foot, travels across the ball of our foot, and we finally push off using our hallux—the big toe (the one that went to market).
Other primates will place the heel and outside of the foot on the ground first, and weight will be transferred to the middle toes, and then a variety of push-off motions occur.
Headline watch
Modern feet step back 1.5 million years – Science News
These feet were made for walking: upright and long distances – Ars Technica
Walking tall: oldest footprints show a distinctly modern gait – Sydney Morning Herald
Image: Matthew Bennett