Body: Born to run… and throw

“HUMANS are remarkable in many ways, but in terms of physical attributes, we generally get out-muscled by other animals. Pound for pound, a chimp is about four times as strong as a human. Our jumping and gymnastic abilities are similarly weak, and we are sluggish sprinters. If there were an Animal Olympics, we would finish, feebly, near the bottom of the medals table.

But let’s not be so quick to write ourselves off. It turns out that there are two events in which we would challenge for gold. Both require talents that reveal our body to be a remarkable piece of machinery. What’s more, without these physical abilities we might never have acquired the mental adroitness we prize so highly.

At first glance the idea that we excel at running sounds unlikely. Usain Bolt can briefly hit a maximum velocity of about 45 kilometres per hour. Cheetahs can easily double that; greyhounds, horses and even chimps can beat it too. Mo Farah won the 2012 Olympic 10,000 metres in just over 27-and-a-half minutes. A racehorse could run the same distance in less than 20 minutes.

Beyond 10 kilometres, though, the playing field starts to level out. At marathon distances and beyond humans are up there with the best. A well-conditioned athlete can run at 20 kilometres per hour for several hours, which is comparable to nature’s endurance specialists, including wild dogs, zebras, antelopes and wildebeest.

This ability depends on anatomical adaptations to the feet, legs, hips, spine and even rib cage that appeared in our lineage about 2 million years ago. In 2004, two biologists proposed that the human body is specialised for long distance running, perhaps as an adaptation for hunting (by running prey to exhaustion) or scavenging (allowing us to compete with dogs and hyenas for widely dispersed carcasses). Either way, endurance running could have supplied early humans with a rich source of protein that supported the flowering of our extraordinary brains.

If the marathon glory is a possibility, the javelin gold is a certainty. Other primates can fling objects with force, but underarm and with a poor aim. Only humans can launch a projectile such as a spear or a rock from over the shoulder with power and precision. This ability depends on several unique anatomical features. The shoulder is more forward-facing than in other apes and is capable of freer rotation. The wrist, too, seems to be uniquely adapted for a throwing action.

Evolutionary biologist Paul Bingham of Stony Brook University in New York argues that our “accurate overarm throw” was a key force in human evolution. As well as allowing hunting and scavenging for all-important protein, it has also been credited with driving brain changes involved in fine motor control, which underpin the evolution of language and technology. Most important, being able to kill at a distance led to a social revolution. No longer could powerful individuals browbeat their way to dominance. Cooperation became crucial, leading to the unique social arrangements that make civilisation possible.

So give your amazing physique the credit it deserves. Human achievement is not the product of brains alone.”

This article was written by Graham Lawton is New Scientist‘s deputy editor