SHORTLY AFTER the teenage Grenadian athlete Kirani James streaked away with the 400 metres in the Olympic final on Tuesday night, BBC presenter John Inverdale turned to his studio guests and posed a potentially incendiary question.

“It’s simplistic I’m sure,” he suggested to former Olympic champions Michael Johnson and Denise Lewis, “in a way there is a certain resignation that Ethiopians and Kenyans will dominate distance running and you suddenly see West Indian heritage athletes dominating the 400 metres. What does that say to runners in this country?”

Johnson, the greatest 400 metres runner of all time, was uncharacteristically equivocal in his answer. “You can’t buy into the clichés and the sweeping generalisations about what makes an athlete successful. Certainly genealogy plays a part in it. It doesn’t mean that if you are of African descent that you are going to dominate sprints and those who aren’t won’t.”

The notion that some ethnic groups might be genetically predisposed to sporting success is fraught with difficulties. Those opposed to such generalities argue that if you suggest, first instance, that African-American or Afro-Caribbean athletes have a genetic advantage in sprinting, you could argue all kinds of traits for different ethnic groups such as intelligence or aptitude.

Johnson himself tackled the question in a recent Channel 4 documentary in which he argued that being descended from the slave trade gave African-American and Afro-Caribbean athletes (as opposed to west African athletes themselves) a leg up.

The theory, often advanced, is that the slave trade was so brutal that only those who were physically fittest survived through the generations.

As Johnson put it: “Slavery was kind of an unnatural selection, a speeded-up evolution, a mass murder of the weakest, only the fittest able to survive and pass on their genes. Difficult as it was to hear, slavery has benefited descendants like me. I believe there is a superior athletic gene in us.”

Johnson drew attention to the fact that in the 100 metres Olympic final in Beijing all the sprinters were Americans or from Caribbean islands. In the four years since that nothing has changed judging by the line-up for last Sunday’s 100 metres final. In the intervening years since Beijing, a white sprinter, Christopher Lemaitre, has broken the 10-seconds barrier for the 100 metres, which he did in 2010. Incredibly, that was 42 years since the record was first broken. Hundreds of black athletes have broken it in the intervening years.

Even Lemaitre ducked out of the 100 metres because he was ranked only 10th in the world in the event. He came sixth in the men’s 200m final in a time of 20.19 seconds.

Australian scientists thought in 2003 that they had gone some way to explaining the proficiency of black sprinters by identifying a gene called ACTN3, which is involved in fast muscle twitching and helps gives the muscles the power to run fast. It appears to be more common in Jamaicans and those of west African origin.

Professor Bill Amos, an evolutionary geneticist at the University of Cambridge, says people have no difficulties in accepting that some population groups are taller or smaller than others or more susceptible to certain conditions, but are troubled by a notion that might manifest itself in superior athletic ability.

“There are a bunch of people who believe there are no differences between population groups and then there are the other group of sceptics that say proving those differences is too difficult given environmental factors,” he says. “As a biologist and evolutionary geneticist, I’m more than comfortable with the idea that all population groups vary.”

Dr Amos says the slave trade was “inadvertently almost the perfect gene pool in which to find high levels of talent in that there are a number of aspects to it. You put everybody through this horrendous condition where many of them die. Those with slight genetic weakness were going to die.”

Dr Yannis Pitsiladis from the University of Glasgow, who has studied the phenomenon of sprinters and East African runners who dominate middle- and long-distance running, said he could find no genetic evidence of inherent greater ability, though he does not rule out that possibility.

“Let me be very clear, on the basis of the data we and others have published and the newer data we have that is unpublished it is unlikely that these athletic phenomena in places such as Kenya, Ethiopia and Jamaica are genetically mediated,” he said.

He says socio-economic factors are more important. In Jamaica, for instance, the annual boys and girls athletic championships attract crowds of 30,000 and competitors from every school on the island.

Being a sprinter is the ultimate aspiration where in other societies sportsmen might aspire to being a footballer, for instance.

In such circumstances, he believes that the Jamaicans are better at identifying those who have the talent to start with.

Adharanand Finn, the author of Running with the Kenyans, says it is the sheer numbers participating that makes the East Africans such a formidable force in middle- and long-distance running.

The conventional wisdom has been that these athletes are born and train at altitude, giving them greater lung capacity. Finn believes that most other runners have sought to minimise that advantage by training at altitude themselves. Instead, he believes it is down to the virtuous circle that is common in sporting success. One successful athlete inspires others and the success is passed from one generation to another.

“In Kenya, Ethiopia and Jamaica, there is a huge running culture. In Africa there is nothing to compete with it, they are not good at anything else. There are no other sports, arts or music which interest them the same way and running is cheap.”