Posted on 09/11/2007 7:51:26 AM PDT by blam
Ancient humans walked but 'struggled to run'
By Roger Highfield and Nic Fleming
Last Updated: 12:01pm BST 11/09/2007
Ancient humans almost certainly walked upright on two legs millions of years ago but may have struggled to run at even half the speed of modern man, according to computer simulations.
A University of Manchester study - presented to the British Association for the Advancement of Science Festival of Science in York- 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 early ancestors preferred to walk a little slower than we do
"How we evolved from our common ancestor with chimpanzees six million years ago is a fundamental question," said Dr Bill Sellers.
"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 key findings are that by 3.5 million years ago we would predict fully upright, efficient walking", he said.
His research also showed that our early ancestors preferred to walk a little slower than we do but only because they were much smaller and had quite short legs.
"Our research supports the belief that the earliest humans used efficient bipedal walking rather than chimp-like 'Groucho' walking," said Dr Sellers, who led the study.
"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.
The Achilles tendon 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.
"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 meat-eating dinosaurs, used the same computer software to generate a walking virtual human 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," 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."
The studies show that "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," he said, adding "we have only just started to look at running and so there are still plenty of questions to answer."
"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. 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."
"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."
He suggested that the tendon was probably developed some time between two and three and a half million years ago.
Dr Sellers said his work on "making dead men walk" is also relevant to athletics, where amputee athletes, such as South African 400m runner Oscar Pistorius, have been accused of gaining an unfair advantage by running on carbon fibre blades, providing more of a spring than a conventional Achilles tendon.
This ancient human certainly struggles to run. Interesting article.
GGG Ping.
I still don’t understand how we could have evolved.
A University of Manchester study - presented to the British Association for the Advancement of Science Festival of Science in York- 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... "How we evolved from our common ancestor with chimpanzees six million years ago is a fundamental question," said Dr Bill Sellers.No, the interpretation of fossil forms in the study as being ancestral is a fundamental question. The question of whether we 23 chromosome pair humans have an ancestor in common with 24 chromosome pair chimps, gorillas, gibbons, and orangutans is a fundamental question.
Big deal. So do I.
How could we not evolve? The slower runners got eaten, the faster runners got to be parents.
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When a critter such as a bear is chasing you, you better learn to run or get eaten...Run Forest, Run!
Better yet, learn that you can't out run the bear but you don't really have to...just out run the people in your party.
It ain't that hard................
Fine, that is micro-evolution, the survival of the fittest within the given parameters of the species.
So how did we develop an Achilles Tendon if ape chromosomes don't produce it?
I walk, and I struggle to run.
Ours is just longer and ‘springier’.
If a critter spends most of its time in the trees running isn’t much needed. Therefore apes and monkeys don’t need to be spring loaded.
It becomes important on open savannas. Our ancestors needed to outrun predators and chase down prey. They needed the energy recovery/efficiency that a springy tendon provided. The ones that had that edge were more likely to live long enough to reproduce.
I would think that the controlled use of fire would have been the essential key to allow our ancestors to move from a largely herbivorous diet to the much more familiar hunting activities. Long distance running was probably a latter development associated with adapting to life on long narrow outer banks islands with only limbless palm trees to climb and wide channels to swim across.
Take a google map look at the east coast of Africa between South Africa and Ethiopia (where all earliest evidence of modern humans is found). Think of a lifestyle based on daily running to the end of a 20+ mile long beach and herding the flightless birds back to the waiting campers. Add to the mix ocean side diving for lobster & seaweed, bayside wading for shellfish & flounder gigging, climbing limbless palm trees for coconuts (and safety from predators), and then swimming to the next island when the protein supply gets sparse. The long term result is quite an evolutionary leap from bipedal apemen scavenging the savanna.
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