Posted on August 14, 2012

The DNA Olympics — Jamaicans Win Sprinting ‘Genetic Lottery’ — and Why We Should All Care

Jon Entine, Forbes, August 12, 2012

Segregation was on display in London over the past two weeks — which, surprisingly, should spark no concerns and may even help educate us all about the wonders of human biodiversity. Let me explain.

Led by 100-meter world record holder Usain Bolt, Jamaican men swept the sprinting events at the London Olympics. It was a stunning feat for the small Caribbean nation. But as part of a broader trend, it’s hardly surprising. Runners of West African descent are the fastest humans on earth.

For decades, a bushel of developing countries — Jamaica, Cuba, Trinidad and Tobago, Saint Kitts, Barbados, Grenada, Netherlands Antilles and the Bahamas in the Caribbean and Nigeria, Cameroon, Ivory Coast, Senegal and Namibia in western Africa, as single countries, have each produced more elite male sprinters than all of white Europe and Asia combined. Yet West African descended runners are laggards at the longer races.

Remarkably, the story of East African runners is the mirror image of the West African success story. While terrible at the sprints, runners Kenya, Ethiopia, Uganda and Somalia, along with a sprinkling of North and Southern Africans, regularly dominate endurance running.

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The trends are eye opening: Athletes of African ancestry hold every major male running record, from the 100 meters to the marathon. (Although these same trends hold for female runners, the pattern is more dominant among male runners. This analysis focuses on men because the playing field for them is far more level, as social taboos remain that restrict female access to sports in many parts of the world.) Over the last seven Olympic men’s 100-meter races, all 56 finalists have been of West African descent. {snip}

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What’s going on here? The most frequently heard explanation is that African athletes just work harder at running. {snip}

National Public Radio recently carried just such a speculative piece on Kenya, and CNN had its own version on Jamaica. Never did the word “genetics” find its way into the story. It’s all nurture, they concluded — the long since scientifically discredited tabula rasa theory of human achievement that attributes all success to individual effort and societal “forces.”

No one outside of the most politically correct circles really believes that. {snip}

Here are the facts. Athletic achievements, like success of all kind, is a bio-cultural phenomenon. Yes, Usain Bolt earned his victories. He may have been born gifted but he has worked his tail off to achieve greatness. He and he alone is responsible for his gold medal haul. But humans are not blank slates. {snip}

Genetically linked, highly heritable characteristics such as skeletal structure, the distribution of muscle fiber types (for example, sprinters have more natural fast twitch fibers, while distance runners are naturally endowed with more of the slow twitch variety), reflex capabilities, metabolic efficiency and lung capacity are not evenly distributed among populations. {snip} Slowly, geneticists will link human performance, including sports skills, to our DNA and more specifically to our ancestral roots — populations.

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Yet the subject remains a prickly one to many journalists and the ‘liberal’ chattering classes. {snip}

{snip} Sports ability, like IQ, is the product of many genes with environmental triggers influencing the “expression” of our base DNA. {snip}

Why touch this third rail of race? After all, as UCLA’s Jared Diamond has noted, “Even today, few scientists dare to study racial origins, lest they be branded racists just for being interested in the subject.”

As I explained in Taboo: Why Black Athletes Dominate Sports and Why We’re Afraid to Talk About It, athletic achievement has long been a Catch-22 for blacks in general and African Americans in particular. In the early part of the 20th century, when blacks first got a chance to compete in sports, every defeat encouraged simplistic, racist beliefs that blacks were an inferior “race,” too frail to handle extreme physical challenges and not smart enough to plan a race strategy.

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The hard truth is that we cannot avoid confronting the fact of our patterned human biodiversity. Over the past decade, human genome research has moved from a study of human similarities to a focus on population-based differences. Such research offers clues to solving the mystery of disease, the Holy Grail of genetics. So why do we readily accept that evolution has turned out Jews with a genetic predisposition to Tay-Sachs, Southeast Asians with a higher proclivity for beta-thalassemia and blacks who are susceptible to colorectal cancer and sickle cell disease, yet find it racist to suggest that Usain Bolt can thank his West African ancestry for the most critical part of his success — his biological possibility?

“Differences among athletes of elite caliber are so small,” said Robert Malina, a retired Michigan State University anthropologist and former editor of the Journal of Human Genetics, “that if you have a physique or the ability to fire muscle fibers more efficiently that might be genetically based … it might be very, very significant. The fraction of a second is the difference between the gold medal and fourth place.”

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{snip} Asians, on average, tend to be smaller with shorter extremities and long torsos — evolutionary adaptations to harsh climes encountered by Homo sapiens who migrated to Northeast Asia 40,000 years ago. China, for example, excels in many Olympic sports, for a variety of reasons. One of those reasons, according to geneticists, is that they are more flexible on average — a potential advantage in diving, gymnastics (hence the term “Chinese splits”) and figure skating.

Whites of Eurasian ancestry are mesomorphic: they have larger and relatively more muscular bodies with comparatively short limbs and thick torsos. No prototypical sprinter or marathoner here. These proportions are advantageous in sports in which strength rather than speed is at a premium. Predictably, Eurasians dominate weightlifting, wrestling and most field events, such as the shot put and hammer. At the London Olympics, with the exception of North Korea, the top lifters come from a band of Eurasian countries: China, Kazakhstan, Iran, Poland, Russia and the Ukraine. Despite the image of the sculpted African body, no African nation won an Olympic lifting medal.

What about West Africans and North American, Caribbean and European blacks who trace their ancestry to the Middle Passage? They generally have: bigger, more developed overall musculature; narrower hips, lighter calves; higher levels of plasma testosterone; faster patellar tendon reflex in the knee; and a higher percentage of fast-twitch muscles and more anaerobic enzymes, which can translate into more explosive energy. Blacks in general have heavier skeletons and less body fat — key genetic hindrances when it comes to such sports as competitive swimming.

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