Was ability to run early man's Achilles heel?

September 11, 2007

The earliest humans almost certainly walked upright on two legs but may have struggled to run at even half the speed of modern man, new research suggests.

The University of Manchester study – presented to the BA (British Association for the Advancement of Science) Festival of Science in York on Tuesday – proposes that if early humans lacked an Achilles tendon, as modern chimps and gorillas do, then their ability to run would have been severely compromised.

“Our research supports the belief that the earliest humans used efficient bipedal walking rather than chimp-like ‘Groucho’ walking,” said Dr Bill Sellers, who led the research in the University’s Faculty of Life Sciences.

“But if, as seems likely, early humans lacked an Achilles tendon then whilst their ability to walk would be largely unaffected our work suggests running effectiveness would be greatly reduced with top speeds halved and energy costs more than doubled.

“Efficient running would have been essential to allow our ancestors to move from a largely herbivorous diet to the much more familiar hunting activities associated with later humans. What we need to discover now is when in our evolution did we develop an Achilles tendon as knowing this will help unravel the mystery of our origins.”

Dr Sellers, who recently published research on the running speeds of five meat-eating dinosaurs, used the same computer software to generate a humanoid bipedal computer model using data from a hominid fossil skeleton called ‘Lucy’ and hominid footprints preserved in ash at Laetoli in Tanzania.

“The skeletons and footprints from some of the earliest members of the human lineage – the early hominids – provide the best clues we have to how we progressed down the pathway to modern human walking and running,” said Dr Sellers.

“We have borrowed techniques from other scientific disciplines - robotics, computer science and biomechanics - in an attempt to ‘reverse engineer’ fossil skeletons; we use what we know about skeletons and the muscles to build a computer model of the fossil species we are interested in.

“This model is a virtual robot where we can activate muscles and get it to move its legs in a physically realistic fashion; the tricky bit is getting it to actually walk or run without falling over.

“However, if we use big enough computers and let the model fall over enough times it is possible for the simulation to learn which muscles to fire and when in order to get the model to walk properly. Even better we can ask the computer to find ways of minimising fuel cost and maximising top speed since that is what we think animals have to do.”

Dr Sellers initially looked at walking and his models suggested that even as early as 3.5 million years ago our human ancestors were able to walk as efficiently as modern humans. His research also showed that they preferred to walk a little slower than we do but only because they were much smaller and had quite short legs.

The team also used the computer model to look at particular parts of the human locomotion system, including the Achilles tendon, which they showed acts like a big spring to store energy during running; when the tendon was removed from the model the top running speed was greatly reduced.

“We have only just started to look at running and so there are still plenty of questions to answer,” said Dr Sellers. “But whilst these very early fossils could walk well, our initial findings suggest that efficient running came about quite a bit later in the fossil record.

“How we evolved from our common ancestor with chimpanzees six million years ago is a fundamental question. Walking upright seems to be the very first thing that distinguishes our ancestors from other apes, so finding out about this should help us map the evolutionary pathway to modern humans.

“The next really interesting question is to look in more detail at running. It has been suggested that our ability to run for long distances took a lot longer to evolve than our ability to walk and that this is a defining feature of our very close relatives in our genus. Our techniques should let us get to the bottom of this question because it will let us measure the running abilities of our fossil ancestors directly.”

Source: University of Manchester

Explore further: In Hawaii, living with lava

Related Stories

In Hawaii, living with lava

November 25, 2015

When the most recent eruption of Hawaii's Kilauea volcano started last June, Melvin Sugimoto at first did not think much of it. Hawaii, where he has lived all his life, is made entirely of hardened lava, and Kilauea, perhaps ...

Gift Guide: Gadgets that make your wrist smarter

November 10, 2015

If you're looking for a device to track your fitness, alert you to incoming messages and occasionally let you buy stuff with a scan or a tap, there's no shortage of computerized wristwatches to choose from.

The universe as we know it

November 17, 2015

Sitting in a small French bistro across from Pershing Square in downtown Los Angeles, Clifford Johnson held the pumpkin-hued drinking straw parallel to the table.

The emerging phenomenon of "sport shopping"

October 27, 2015

Just like elite athletes, 'sports shoppers', a newly discovered breed of shopper, have timing down to the second, know just where to compete, and the trophy that must be brought home.

Recommended for you

CERN collides heavy nuclei at new record high energy

November 25, 2015

The world's most powerful accelerator, the 27 km long Large Hadron Collider (LHC) operating at CERN in Geneva established collisions between lead nuclei, this morning, at the highest energies ever. The LHC has been colliding ...

Study suggests fish can experience 'emotional fever'

November 25, 2015

(Phys.org)—A small team of researchers from the U.K. and Spain has found via lab study that at least one type of fish is capable of experiencing 'emotional fever,' which suggests it may qualify as a sentient being. In their ...

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.