08.11.12 8:45 AM ET
What Makes a Great Olympian? Sometimes It’s Genetics
This year’s record-breaking group of sprinters has undoubtedly been aided by superior DNA, writes Jon Entine—and it shouldn’t be taboo to say so.
Led by irrepressible record-breaker Usain Bolt, Jamaican men swept the sprinting events at this year’s Olympics, a huge feat for the tiny Caribbean nation. But it’s no big surprise. For the last several years, West African nations—or nations with West African–descended athletes, like the United Sates, Jamaica, Grenada, and Trinidad and Tobago—have each turned out more elite sprinters than all of white Europe and Asia combined.
Running is the most egalitarian of sports, a natural laboratory. Unlike the props and costumes required for, say, fencing, or the intense coaching demanded of gymnastics, one can just lace up and go for a jog. Ethiopia’s Abebe Bikila proved this quite memorably in the 1960 Rome Olympics, when—shoeless, coachless, and inexperienced—he won the marathon.
Theoretically, then, the medal podium for runners should resemble a rainbow of diversity. But just the opposite has happened: running has become segregated. The trends are eye-opening: Among men, athletes of African ancestry hold every major running record, from the 100m to the marathon. Of the past seven Olympics men’s 100m races, all 56 finalists have been of West African descent. Only two non-African runners, France’s Christophe Lemaire, who is white, and Australia’s Irish-aboriginal Patrick Johnson, crack the top 500 100-meter times. There are no elite sprinters who are Asian—or, intriguingly, East African.
The story of distance running is equally remarkable. Runners of West African ancestry don’t tend to do well at endurance races, which are dominated by North and East Africans—note the medal haul in London by Kenyans and Ethiopians—who themselves are often less well known for sprinting.
What’s going on here? The most frequently heard explanation is that African athletes just work harder at running. It’s one of their few outlets, the story goes, to escape the trap of limited opportunities. There’s a tradition of running that young athletes emulate; they’ve been running to school since kindergarten; they train harder for a chance at the golden ring that athletic success offers; athletes from other parts of the world have developed a toxic inferiority complex; blah, blah, blah.
National Public Radio recently wrote 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.
No one outside of the most politically correct circles really believes that. Certainly scientists don’t. The director of the Copenhagen Muscle Research Institute, Bengt Saltin, has concluded that an athlete’s “environment” accounts for no more than 25 percent of athletic ability. The rest comes down to the roll of the genetic dice—with each population group having distinct advantages. In other words, running success is “in the genes.”
Here are the facts. 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.
It’s controversial stuff. Michael Johnson, the 400m world-record holder, recently postulated that black sprinters benefit from the outsize presence of ACTN3. The “speed gene” as it’s been dubbed, makes fast-twitch muscles twitch fast. Lacking the ACTN3 protein does not seem to have any harmful health effects but does affect running ability. Scientists conclude that it is almost impossible for someone who lacks the ACTN3 protein to become an elite sprinter. The so-called sprint gene is more common in those of West African descent than in Europeans, according to a study published in the American Journal of Human Genetics.
Is this running’s “smoking gun” gene? No. Sports ability, like IQ, is the product of many genes with environmental triggers influencing the “expression” of our base DNA. But its isolation does underscore that when it comes to performance, genes matter.
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.”
But we have no choice but to face this third rail of race. Over the past decade, human genome research has moved from a study of human similarities to a focus on patterned, 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?
It’s the exaggeration, not the factual core of truth that human “populations” exist, that stirs fear and ire. The difficulty, of course, is sorting out how much of a trait is genetically inbred, how much may be shaped by culture and opportunity, and what is just plain poppycock.
“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.”
Indeed, Empirical evidence makes hash of the myth that culture makes the athlete. Look at Kenya: with but 43 million people, the country holds more than one third of top times in distance races. What explains this phenomenon? It’s in their culture, say many social scientists. Kenyans dominate distance races because they “naturally trained” as children—by running back and forth to school, for example.
“That’s just silly,” Kenyan-born Wilson Kipketer told me. Kipketer currently holds eight of the 17 all-time fastest 800m times, a middle-distance track event. “I lived right next door to school,” he laughed, dismissing cookie-cutter explanations. “I walked, nice and slow.”
What motivated Kipketer to pursue running? Like most young Kenyans, while growing up Kipketer hoped that he might catch the eye of a coach who combs the countryside to find the next generation of budding stars. He had dreams of being cheered as he entered the National Stadium in Nairobi.
Only one problem: the national sport, the hero worship, the adoring fans, the social channeling—that all speaks to Kenya’s enduring love affair with soccer, not running. And Kipketer, like many Kenyans, was not very good at soccer; Kenyans simply don’t seem to have the genetic package to make them world-class sprinters. But East Africans do tend to excel at long-distance running, and many suggest that’s due to an increased natural lung capacity and a preponderance of slow-twitch muscles. That’s a perfect biomechanical package for long-distance running, but a disaster for sports that require anaerobic bursts, like sprinting or soccer. Indeed, Kenya’s fastest 100m time, 10.26, is a half second slower than Bolt’s world record. There are more than 5,000 times ranked higher than Kenya’s best.
Although people in every population come in all shapes and sizes, body types and physiological characteristics follow a distribution curve as a result of evolutionary adaptations by our ancestors to extremely varied environmental challenges. Elite sports showcase these differences.
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 Olympics 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: larger and relatively 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 Ukraine. Despite the image of the sculpted African body, no African nation won an Olympic lifting medal.
What about 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.
“Evolution has shaped body types and in part athletic possibilities,” Joseph Graves, Jr. told me. Graves is an evolutionary biologist at North Carolina Agricultural and Technical State University and UNC Greensboro. “Don’t expect an Eskimo to show up on an NBA court or a Watusi to win the world weightlifting championship. Differences don’t necessarily correlate with skin color, but rather with geography and climate. Endurance runners are more likely to come from East Africa and sprinters from West Africa. That’s a fact. Genes play a major role in this.”
There’s no need to make consideration of race in sports a taboo. In fact, sports provide the most rigid laboratory control possible—the level playing field—to guide us through the thicket of ideological correctness. So kick back and celebrate the triumphs of the DNA Olympics.