Skip to navigation | Skip to content

I run, therefore I am


Running made us human, at least anatomically (Image: iStockphoto)

Humans were born to run and evolved from ape-like creatures into the way they look today probably because of the need to cover long distances and compete for food, U.S. scientists say.

From tendons and ligaments in the legs, feet that act like springs, skull features that help prevent overheating, to a well-defined bum that stabilises the body, the human anatomy is shaped for running.

Daniel Lieberman, a professor of anthropology at Harvard University and Dennis Bramble, a biology professor at the University of Utah published their research in today's issue of the journal Nature.

"We [run] because we are good at it. We enjoy it and we have all kinds of specialisations that permit us to run well," said Lieberman

"There are all kinds of features that we see in the human body that are critical for running."

Lieberman and Bramble studied more than two dozen traits that increase humans' ability to run.

They suspect modern humans evolved from their ape-like ancestors about 2 million years ago so they could hunt and scavenge for food over large distances in the African savannah.

But the development of physical features that enabled humans to run entailed a trade-off: the loss of traits useful for climbing trees.

"We are very confident that strong selection for running, which came at the expense of the historical ability to live in trees, was instrumental in the origin of the modern human body form," Bramble said.

Against the grain

The conventional theory is that running was a by-product of bipedalism, or the ability to walk upright on two legs. This evolved in ape-like human ancestors called Australopithecus at least 4.5 million years ago.



"We're saying 'no, walking won't do that, but running will'."

If natural selection did not favour running, the scientists believe humans would still look a lot like apes.

"Running has substantially shaped human evolution. Running made us human, at least in the anatomical sense," Bramble said.

A running machine

Among the features that set humans apart from apes to make them good runners are: longer legs to take longer strides, shorter forearms to enable the upper body to counterbalance the lower half during running; and larger vertebral discs to give better shock absorption.

Big buttocks are also important.


Humans lean forward when they run and the buttocks "keep you from pitching over on your nose each time a foot hits the ground", he said.

Commenting on the study, French CNRS researcher Dr Yvette Deloison said the ability to run away from predators would also have been important.

"Instead of being able to pursue prey for long distances, the first human beings probably had the ability to sprint to quickly get away from predators," she said.

Tags: archaeology, biology, palaeontology