Advances in genetics are finally allowing us to get to the bottom of long-held racial mythsby Tim Harris / July 21, 2010 / Leave a comment
In the swim: African-American world and Olympic champion Cullen Jones has confounded racial stereotyping in sport
In the ten years since its sequencing was (prematurely) announced, the human genome may not have delivered the hoped-for quick fixes for disease. But in sport, it is helping to disentangle the vexed issues of genetics, race and talent.
In July, the Science Museum hosted an event called “Black Men Can’t Swim?”—a question that was answered by Cullen Jones, the African-American world and Olympic champion and 100m freestyle record-holder. The debate arises partly from the low participation rates among African-Americans; as few as 30 per cent of black children have learned to swim well, according to the governing body USA Swimming. As well as its reputation as a whites-only, “country club” sport, swimming has a long history of segregation and exclusion in the US, dating from the days when west African slaves—who were usually good swimmers—were banned from teaching their children, for fear of them escaping. Ignoring this history, past academic studies made great play of the lower buoyancy of black Americans. While some black populations do have a higher average bone density and mass than whites—about 300gm—buoyancy varies for every swimmer, and differences within races are far greater than those between them. As Matt Bridge, senior lecturer in coaching and sports science at Birmingham University, points out: “Thousands of black Americans have taken the US Marines’ compulsory swimming test and none have failed.”
Before the sequencing of the genome, debates like the Science Museum’s might not have been held publicly. Any suggestion of a racial or genetic component in sporting success was seen as demeaning to the athletes, and either avoided by newspapers and scientific journals or self-censored by sports presenters. But now new genetic evidence is decoupling race and genetics and reframing the debate.
Since 2004, Cambridge University epidemiologist Robert Scott has studied the DNA of Kenyan distance runners, who dominate events like the 3,000m steeplechase and have recorded 22 of the 25 best times. Scott has focused on highland provinces such as Nandi, which has supplied all but one of Kenya’s national record holders. Clearly, there are environmental factors at work: the physiological effects of high altitude, a local enthusiasm for running, coaches who scour the region for talent, and the economic factors that keep highland Kenyans driving cattle while highland Swiss drive Mercedes. That aside, there are inherited advantages too. Long legs and a short torso can certainly help with distance running—though Scott cautions against ignoring other successful body shapes. (The women’s marathon world-record holder Paula Radcliffe, rarely mistaken for a highland Kenyan, has run the distance three minutes faster than Catherine N’dereba, the only east African in the top ten.)
More tellingly, Scott’s latest studies reveal huge genetic variations within a small sample of east African runners—far greater than in the white European population, whose remote ancestors left the Rift Valley 150,000 years ago. From this perspective, the racial “black vs white” division makes less sense than the genetic “set vs subset.” If, as Bridge argues, favourable genes can “raise the ceiling” that individual athletes reach through hard work, then a population with a greater genetic variety will tend to over-perform—even if the average measurable differences between overall black and white populations are very small. The result? Track athletes with African genes hold every men’s world record from the 100m to the marathon.
Scott is at pains to stress the complexity of the genome and how far we are from predicting sporting success. A good example is height—obviously a key determinant in sports like basketball—where “all the genes known to be associated explain just 5 per cent of the observed variation.” This leaves 95 per cent down to environment, unrecognised genes or heredity—the interaction between the two.
A simple “on” or “off” gene for athleticism has so far proved elusive. One 2003 study of Australian sprinters identified the gene ACTN3, which promotes fast-twitch muscle, but Scott found it was absent in two Jamaica track stars. Among distance runners, maternally inherited mitochondrial DNA has been linked to aerobic efficiency, but he could find no significant genetic difference between Ethiopian track champions and layabout Ethiopian students.
Though disappointing for those hoping to identify talent cheaply, this inability to predict success genetically may be a good thing for sport, which has long had an unhealthy obsession with “voodoo genetics.” In horseracing, for instance, families of trainers have bred families of horses for families of aristocrats for over 300 years—and conspicuously failed to predict success. Sport is still shaped by the belief that innate talent must be identified very young, drilled for years and then spat out. Matt Bridge quotes a “failure” rate of 99.4 per cent for British football academies, currently under fire for producing “two-touch” footballers, incapable of beating individual opponents or retaining possession—a problem underscored by England’s lacklustre 2010 World Cup campaign.
Conversely, history shows us that the greatest champions can succeed without years of specialised graft. Before 1976, 20-year-old engineering student Ed Moses had run just one 400m hurdles, yet that summer he won an Olympic gold medal, part of his record of 122 races unbeaten.
What the “can’t swim” debate shows is how easily athletic talent can be lost into sporting silos. Well-muscled and heavily boned sportspeople of any colour, used to excelling in power and speed events, are easily lost to a sport like swimming which—at first—rewards technique over strength. (In Cullen Jones’s case, a near-fatal waterslide accident led to him being signed up for swimming lessons, switching him from the more welcoming basketball court to the occasionally racist pool.) Now Australia, the first country to search for “magic genes” like ACTN3, has set up talent assessment centres to comb the country for potential stars, encouraging them to try new sports or switch to events in which they might perform better.
Identifying new genetic factors will become easier as increased processing power and gene-amplifying techniques shrink the time needed to locate individual genes. Already it takes just days, rather than years, to locate genes with specific functions. But even with costs and timings tumbling, it seems impossible that we can ever hope to identify every gene that might help exceptional performances.
This July marks the centenary of the fight that made Texan Jack Johnson the first undisputed black heavyweight world champion. An extraordinarily evasive fighter, Johnson must have had fast-twitch muscles coming out of his ears, but what really broke boxing’s “colour bar” was his refusal to be cowed by the violent racism of his time. Musician, entrepreneur, inventor, fantasist and fashion-plate, Jack was, as he put it, “a deep and colourful personality.” No geneticist could hope to identify such a personality from DNA alone. When we look at champion athletes—of any race—we will always be arguing from exceptions.