The Sports Gene: Inside the Science of Extraordinary Athletic Performance (31 page)

In recent years, Eero has had several bouts of pneumonia that his doctors think could be related to his thick blood, so he is now on blood-thinning medication. Iiris adds that the redness of his skin is also a recent development. During his competitive days, Eero showed no ill effects of his EPOR mutation, and other Mäntyrantas with the mutation have remained healthy into old age.

While the extensive scientific documentation of the Mäntyranta family’s mutation is unique in sports, there have certainly been other successful athletes with preternaturally high hemoglobin levels. Endurance sports like cross-country skiing and cycling have set up systems whereby an athlete with abnormally high hemoglobin or red blood cell levels can earn a medical exemption to compete if that athlete can prove that his hemoglobin is naturally elevated. A number of athletes have been given such exemptions, and have gone on to great success.

Italian cyclist Damiano Cunego was granted a medical exemption by the International Cycling Union and at twenty-three years of age became the youngest road cyclist ever to be ranked number one in the world. Frode Estil, a Norwegian cross-country skier who was given an exemption by the International Ski Federation, won two golds and one silver medal at the 2002 Winter Olympics in Salt Lake City. Neither of
these men had hemoglobin levels as high as Eero’s—the normal range for men is 14 to 17 grams of hemoglobin per deciliter of blood, and Eero was high even compared with his own family members, consistently over 20 and as high as 23—but Cunego and Estil nonetheless had elevated levels that they could prove were natural and that were higher than those of their teammates and competitors who trained in similar manners.

Like the naturally fit six from the York University study, there was just something innately different about them.

•

With the three-hour drive back to Luleå in mind, Iiris tells Eero and Rakel that she will see them soon for Christmas, and tells me that we should hit the road.

As we are getting ready to leave, I suddenly chide myself for nearly forgetting to ask an obvious question. When I was told that the EPOR mutation will not continue down Eero’s direct line of descendants, I was disappointed that there would be no way to see whether it might push younger Mäntyrantas to athletic success. But from de la Chapelle’s family tree I know that there are extended family members who have the mutation.

“Do Eero’s siblings have the mutation?” I ask Iiris.

One of them does, she tells me. His sister Aune, and two of Aune’s children have the mutation, her son Pertti and her daughter Elli.

And did they ski? I ask.

They did, she tells me.

And were they any good?

Elli was twice a world junior champion in the 3×5K relay in 1970 and ’71. And Pertti, competing at the site of his uncle’s most famous triumphs, won an Olympic gold medal in the 4×10K relay in 1976 at the Innsbruck Winter Games. In 1980 he added a bronze at the Lake Placid Games.

No one else in the family races.

The Perfect Athlete

E
ero Mäntyranta’s life story is a paragon of a 10,000-hours tale.

Mäntyranta grew up in poverty and had to ski across a frozen lake to get to and from school each day. As a young adult, he took up serious skiing as a way to improve his life station—to land a job as a border patrolman and escape the danger and drudgery of forest work. The faintest taste of success was all Mäntyranta needed to embark on the furious training that forged one of the greatest Olympic athletes of a generation. Who would deny his hard work or the lonely suffering he endured on algid winter nights? Swap skis for feet and the Arctic forest for the Rift Valley and Mäntyranta’s tale would fit snugly into the narrative template of a Kenyan marathoner.

If not for a batch of curious scientists who were familiar with Mäntyranta’s exploits and invited him to their lab twenty years after his retirement, his story might have remained a pure triumph of nurture. But illumined by the light of genetics, Mäntyranta’s life tale looks like something entirely different: 100 percent nature and 100 percent nurture.

Obviously, Mäntyranta had rare talent. Just as clearly, he needed to train assiduously to alchemize that talent into Olympic gold. As psychologist Drew Bailey told me: “Without both genes and environments, there are no outcomes.” Instances in which a single gene has a dramatic effect, as in Mäntyranta’s case, are extremely rare, and finding athleticism genes is extraordinarily complex and difficult. But a
present inability to pinpoint most sports genes doesn’t mean they don’t exist, and scientists will, slowly, find more of them.

One of the concerns held by Yannis Pitsiladis, the scientist who traverses Africa and Jamaica to collect athlete DNA, is that discovering genes that influence athletic performance will detract from the hard work undertaken by athletes if those genes turn out to be more concentrated in one ethnic group or region than another. But we already know that certain ethnic groups have genes that equip them superiorly or inferiorly for particular athletic endeavors. To use Yale geneticist Kenneth Kidd’s example, we can agree that Pygmy populations are unlikely to be founts of NBA stars, given that Pygmies tend to have few gene variants that result in tall stature compared with other populations.

Height is clearly an innate advantage in basketball. But does it detract from Michael Jordan’s achievements that he had the good fortune to be endowed with genes that contributed to his being taller than Pygmies, and than most other men on earth? If there exists a scientist or sports fan who would denigrate Jordan’s hard work and skill because of his obvious gift of height, I didn’t meet him in the reporting of this book. In fact, the opposite extreme—ignoring gifts as if they didn’t exist—is much more common in the sports sphere.

Consider this title and subtitle of a
Sports Illustrated
story: “The Fire Inside: Bulls center Joakim Noah doesn’t have the incandescent talent of his NBA brethren. But he brings to the game an equally powerful gift.” The “gift” is Noah’s desire to win. Never mind that he is the 6'11" son of a French Open tennis champion and has a wingspan of 7'1¼" and a 37½" vertical jump. If those aren’t incandescent athletic endowments, then what, pray tell, are? Noah’s lack of talent referenced in the headline—and by Noah himself in the story—would seem to describe the fact that he’s a graceless ball handler and mediocre jump shooter. Which, based on the sports science, probably has more to do with the specific work he has put in to develop dribbling and shooting skills than with his hereditary gifts. A more honest headline might
read: “The Talent Outside: Joakim Noah has not acquired basketball-specific skills to the extent of his teammates, but he is at the upper extreme of humanity in terms of his physical gifts and therefore can be a good NBA player anyway.”

Acknowledging the existence of talent and of genes that influence athletic potential in no way detracts from the work it takes for that talent to be transformed into achievement. The studies undertaken by K. Anders Ericsson—the so-called father of the 10,000-hours “rule”—and his colleagues typically don’t address the existence of genetically based talent because their work begins with subjects of high achievement in music or sports. When most of humanity has already been screened out of a study before it begins, the study often has little or nothing to say about the existence or nonexistence of innate talent.

In reality, any case for sports expertise that leans entirely on either nature or nurture is a straw-man argument. If every athlete in the world were an identical sibling to every other athlete, then only
environment and practice would determine who made it to the Olympics or the professional ranks. Conversely, if every athlete in the world trained in exactly
the same way, only genes would separate their performances on the field. But neither of those scenarios is ever the case.
*
(The occasional example of same genes/same training tells the expected story. I was standing beside the finish line of the London Olympic 400-meter final when Belgian identical twins and training partners Kevin and Jonathan Borlée, despite running in lanes on the extreme opposite sides of the track, finished 0.02 of a second apart.) Athletes are essentially always distinguished by both their training environments
and
their genes.

In some cases, as with the ability of baseball hitters to react to a pitch, a skill that seems based on superhuman reflexes is largely the
result of a learned mental database. (Once the database is in place, however, an athlete who possesses outstanding visual hardware can put it to superior use.) In others, as with the ability to respond rapidly to endurance exercise, genes mediate the very improvements that come from hard training. In all likelihood, we overascribe our skills and traits to either innate talent or training, depending on what fits our personal narratives.

Steve Jobs famously said that he had long thought his personality was entirely the result of his life experiences until, as an adult, he met for the first time novelist Mona Simpson, the sister he did not know he had. Jobs marveled at how similar he was to Simpson despite having grown up with a different family. “I used to be way over on the nurture side, but I’ve swung way over to the nature side,” Jobs told the
New York Times
in 1997. “And it’s because of Mona and having kids. My daughter is fourteen months old, and it’s already pretty clear what her personality is.”

As the study of genes matures, we will increasingly find genetic inputs—some large and many trivial—behind the sports stories we tell. But we are unlikely ever to receive complete answers from genetics alone, and not merely because environment and training are always critical factors. Recall that even for height, an easily measurable trait, scientists needed several thousand subjects and hundreds of thousands of spots of DNA code to account for even half of the variance in height between adults. It is increasingly clear that many traits are influenced by the interplay of large numbers of DNA variations. Thus, studies will require hundreds or even thousands of subjects to get at the genetic root of such traits. But there aren’t thousands of elite 100-meter runners in the world. Additionally, the gene variants that make one sprinter fast may be completely distinct from those that make her competitor in the next lane fast. Remember, with HCM, the disease that leads to sudden death in athletes, most of the distinct, known gene variants that cause the disease are “private” mutations.
That is, they have thus far been located only in a single family. The same physical outcome can sometimes be reached via many different genetic pathways.

Nonetheless, as I am writing this, headlines are erupting with the news that Japanese scientists have created fertile eggs from mouse stem cells. On the radio, a scientist just speculated that the breakthrough will ultimately lead to the ability to engineer offspring for specific traits, including athleticism.
We can build the perfect athlete
, the scientist implied. “It will give parents a great ability to choose the genetic traits of their children,” Stanford bioethicist Hank Greely told NPR.

With respect to athletic traits, though, we have no clue at this point which versions of most athleticism genes even to choose. There are the rare genes—like EPOR, or myostatin—that alone can have a significant impact on athleticism, but single genes with large impacts have proven the exception. For the foreseeable future, we cannot engineer a genetically ideal athletic specimen. A genetically perfect athlete would simply have to luck into the “right” versions of the genes for her sport.

What are the chances?

•

Alun Williams, a geneticist at Manchester Metropolitan University in England, was kept awake by that question. So he and his colleague Jonathan P. Folland combed through scientific literature for the twenty-three gene variants that have (so far) been most strongly linked to endurance talent, and then they compiled information about how frequently those gene variants occur in humans.

Some of the variants are found in more than 80 percent of people and others in fewer than 5 percent. Using the gene frequencies, Folland and Williams made statistical projections of how many “perfect” endurance athletes (people with two “correct” versions of the twenty-three genes) walk the planet.

Williams assumed that perfection—even based on the limited number of identified genes—would be uncommon. A Greg LeMond or Chrissie Wellington, after all, is a rare find. But Williams was dumbfounded when he ran the statistical algorithm on his computer and saw that the odds of any single human possessing the perfect set of gene variants was less than one in a quadrillion. To put that in perspective: If you bought twenty lottery tickets per week, you’d have a better chance of winning the Mega Millions
twice in a row
than of hitting that genetic jackpot. Just based on the small number of genes that Folland and Williams included, there is no genetically perfect athlete on earth. Not even close. Given the paltry seven billion people on our planet, chances are that nobody has the ideal endurance profile for more than sixteen of the twenty-three genes. Conversely, an individual is also unlikely to have very few of those endurance genes. Essentially everybody falls in or near the muddled middle, differing by only a handful of genes. It’s as if we’ve all played genetic roulette over and over, moving our chips around, winning sometimes and losing other times, all of us gravitating toward mediocrity. “We’re all relatively similar because we’re all relying on chance,” Williams says.

There are, however, certain elite athletes who do not rely on chance: Thoroughbreds. Because athletic ability involves a complex mix of genes, champion racehorses tend to result from multiple generations of mating among athletic horses. The more genes that are involved in an athletic trait, the more generations of athlete-to-athlete breeding it will likely take to get an offspring that has collected enough of the right gene variants to make the winner’s circle. The lone safe bet at the racetrack is that every top horse has racehorses not only for parents but also for grandparents and great-grandparents.

Racehorse breeders have done an outstanding job; the best Thoroughbreds run a mile in a minute and a half. Nonetheless, in many of the world’s marquee horse races, the speed of the winners plateaued decades ago. Thoroughbreds may have either reached their physiological terminal velocity or simply run out of new athleticism genes
within the breeding population. (Thoroughbreds are relatively inbred, with more than half of the genes of modern racehorses tracing back to only four individual horses—the Godolphin Arabian, the Darley Arabian, the Byerley Turk, and the Curwen Bay Barb—that traveled from North Africa and the Middle East to England in the late seventeenth and early eighteenth centuries.)

As Pitsiladis put it, to be a world-beater, “you absolutely must choose your parents correctly.” He was being facetious, of course, because we can’t choose our parents. Nor do humans tend to couple with conscious knowledge of one another’s gene variants. We pair up more in the manner of a roulette ball that bounces off a few pockets before settling into one of many suitable spots. Williams suggests, hypothetically, that if humanity is to produce an athlete with more “correct” sports genes, one approach is to weight the genetic roulette ball with more lineages in which parents and grandparents are outstanding athletes and thus probably harbor a large number of good athleticism genes. Yao Ming—at 7'5", once the tallest active player in the NBA—was born from China’s tallest couple, a pair of ex–basketball players brought together by the Chinese basketball federation. As Brook Larmer writes in
Operation Yao Ming
: “Two generations of Yao Ming’s forebears had been singled out by authorities for their hulking physiques, and his mother and father were both drafted into the sports system against their will.” Still, the witting merger of athletes in pursuit of superstar progeny is rare.

Even that would not guarantee athletic success for any individual offspring of great athletes. In fact, the better the parents are, the less likely it is that the child will be equally good. In any trait that is influenced by many genes, it is simply statistically unlikely that a child is going to get as lucky as a very lucky parent. The phrase “regression to the mean” sprang in part from the study of height. Of course, the child of two seven-footers is very likely to be taller than average, but not likely to be as significant of an outlier as his parents. Similarly, the child of two extraordinarily gifted athletes will likely have more of the gene combinations that contribute to athleticism than a randomly
selected person, but will be hard-pressed to get as lucky as her mother and father.

In large part, humanity will continue to rely on chance and sports will continue to provide a splendid stage for the fantastic menagerie that is human biological diversity. Amid the pageantry of the Opening Ceremony at the 2016 Olympics in Rio de Janeiro, make sure to look for the extremes of the human physique. The 4'9" gymnast beside the 310-pound shot putter who is looking up at the 6'10" basketball player whose arms are seven and a half feet from fingertip to fingertip. Or the 6'4" swimmer who strides into the Olympic stadium beside his countryman, the 5'9" miler, both men wearing the same length pants.