Shapes of the fossil and modern footprints are indistinguishable.
Homo erectus last walked the Earth tens of thousand of years ago. But how they walked it — and how much their walking style resembled that of modern humans — has been a great mystery.
Sparse fossil evidence makes it difficult to gage how these hominids moved. The few remains that could be informative — a pelvis and a few foot bones — bear shapes that differ from modern humans’, suggesting H. erectus would have walked in quite a different manner than us.
But in 2009, an unprecedented number of hominid footprints were discovered in Kenya. 97 tracks made by at least 20 different individuals, all of them presumably H. erectus, were preserved in the ground.
A group of researchers, led by Kevin Hatala from the Max Planck Institute for Evolutionary Anthropology and The George Washington University, compared these ancient footprints with newer ones created by habitually barefoot people inhabiting the same region.
The shapes of the footprints from the two sets were indistinguishable, leading the researchers to believe the extinct hominids had a modern human style of walking.
“Our analyses of these footprints provide some of the only direct evidence to support the common assumption that at least one of our fossil relatives at 1.5 million years ago walked in much the same way as we do today," Hatala said in a press release.
The researchers were also able to estimate body masses from the tracks, which allowed them to infer the sexes of some of the hominids who had walked there. At all 5 sites examined, there was evidence of several adult males being present, implying they tolerated each other and perhaps even cooperated. Male cooperation underlies many of the social behaviors that distinguish modern humans from other primates.
"It isn't shocking that we find evidence of mutual tolerance and perhaps cooperation between males in a hominin that lived 1.5 million years ago, especially Homo erectus, but this is our first chance to see what appears to be a direct glimpse of this behavioural dynamic in deep time," he says.
The findings are published in the journal Scientific Reports.
You might also like: Hobbits' Ancestors Have Been Discovered