Authors: Asher Price
In the mid-1970s, the Báránys found work in the biochemistry department at the University of Illinois at Chicago. Their partnership led to many joint publicationsâ72 full papers and a dozen book chapters. “To my parents, science was a safe haven because it could not be taken away, as so much else had been,” George would later say. “Science was
logical and predictable in a world where they had experienced so much suffering based on the arbitrary prejudices and madness of human beings.” George and his brother, Francis, both prodigies (one graduated from Stuyvesant High School at 16 and went
straight to graduate school), became scientists in their own right. At Chicago, Kate and Michael Bárány walked to work together every day; they became known on campus as “the
professors who held hands.”
Kate died in June 2011; Michael, six weeks later.
To understand the relationship between the speed gene and muscle performance, you need to understand something about how muscles work. Muscles are the body's most bounteous type of tissue, and arguably the most trainable. They are like sets of Russian nesting dolls, with one biological structure nestled within another. Every
muscle fiber, as long as a foot but thinner than a strand of hair, is composed of long tubes called myofibrils. These, in turn, are made up of thin and thick protein filaments running in parallel. Every muscle fiber, be it fast- or slow-twitch, has both sets of proteins. A muscle contracts when the thick set of protein filaments grabs the thin set; because the thin set of filaments is attached to the end of a muscle fiber component, the entire fiber is thus shortened.
A biology researcher once explained it this way in the magazine
Nature
: Picture yourself standing
between two hefty bookcases. These bookcases, being in the basement of a massive archive, are on rails so they can be easily moved. It's your job, standing between them, to bring the bookcases together, but you're limited to using only your arms and ropes hanging down from each bookcase. (Your arms are the thick filaments; the ropes are the thin filaments; the bookcases are the ends of the muscle fiber.) Standing between the bookcases, you pull on the two ropesâone per armâthat are tied tight to each bookcase. In a repetitive fashion, you yank each rope toward you, re-grasp it, and then yank again. Eventually, as you make your way through the length of each rope, the bookcases move together.
This effortâof pulling bookcases together in a stuffy basementâis sweaty business. It requires energy, especially if you want to tug those ropes (that is, contract your muscles) quicklyâthis was the relationship that Bárány had illuminated. Flush with mitochondriaâthe little power centers within each cell that use oxygen gas to convert sugar into chemical energy moleculesâslow-twitch muscles can perform low-intensity exercises for long stretches. Thus, the Ethiopian distance runner Haile Gebrselassie, at one point the holder of 27 world records, has
muscles that are likely beefsteak-red, juiced with oxygenated blood. Fast-twitch muscles, on the other hand, are short on mitochondria. Were we to peel away Usain Bolt's skin like an onion, we would likely see
a
paler, whiter set of musclesâsomething like the color of pork. When a burst of energy is required, rather than undertake the plodding oxidation method of their slow-twitch counterparts (also known as aerobic metabolism), these muscles quickly break down their large reserves of stored sugar via anaerobic metabolism, which is much faster but also much less efficient. Scientists think humans working at their maximum speeds can rely on non-oxidized forms of energy conversion (or anaerobic metabolism) for about 30-some seconds before lactic acid develops and muscle fatigue sets in. By then the fast-twitch muscles, contracting roughly twice as fast as their slow-twitch counterparts, have done their job, like overdrive on a sports car.
Each of us is born with a
certain ratio of fast- and slow-twitch fibers. That raw number does not change. But when we work out, our muscles clearly get bigger. That's due to an increase in the number of those protein filaments within each fiber, not an increase in the number of fibers. So while the number of fibers is not changing, individual fibers are gaining protein and thus gaining in size. We can focus that growth within a certain fiber type: We can increase the size and strength of fast-twitch fibers or slow-twitch fibers, depending on the exercises and training we do (in my case, fast-twitch muscle training). This will not change a slow-twitch fiber into a fast-twitch fiber. Suppose your muscles are 50 percent of each. Training will not change that percentage, but it can make the fast-twitch fibers larger, so an entire muscle group like the biceps is now more than 50 percent fast-twitch by mass or bulk. That would make you more fast-twitchy even though the raw number of fibers of either type has not changed.
Back to the speed gene: Scientists are still unsure exactly what ACTN3 contributes to the performance of fast-twitch musclesâand most think it pales as a determinant of athletic ability compared to training time and competitive will. But they suspect
ACTN3 influences the speed with which we grab energy-bearing molecules to do work in explosive activity. Every one of us has two copies of the ACTN3 geneâor its variant, a mutant that coincides with a deficiency in the actin-building protein associated with fast-twitch muscles. (We have two copies because we inherit one copy of the gene or its variant from each of our parents.) So it follows that each of us has one of three possible pair combinations of these two genes: two ACTN3 genes, suggesting we're predisposed for power events; two mutant genes, suggesting we're predisposed for endurance challenges, like long-distance running; or one of each, suggesting we might be decentâbut not necessarily greatâat both sorts of activities.
Researchers have consistently found that power athletes have at least one, if not two, copies of ACTN3. In a 2008 paper in the journal
Genetics and Microbiology
, a team of Greek researchers reported that the
ACTN3 gene showed up in the top power-oriented athletes considerably more often than in a representative random sample of the Greek population. Even among non-professionals the presence of the gene correlates with what might be called your twitchiness: Another Greek studyâthe Greeks, haunted by their long-faded Olympic glory, evidently obsess over the science of track and fieldâfound that boys who lacked a copy of the ACTN3 gene were
significantly slower in a 40-meter sprint. In a nutshell, the gene “has a predictive value if you're fast-twitch dominant or not,” Lieberman, the Harvard biologist, told me.
Still, a surfeit of fast-twitch or slow-twitch muscles does not mean you will be a great sprinter or a great long-distance runner. Training, courage, and tenacity play bigger roles. But Lieberman tried to disabuse me of my leaping hope. “If you never have had the great dominance of a fast-twitch athlete, you'll never be a great fast-twitch athlete,” he said. And then, twisting the dagger with what I could swear was a bit of glee, he told me: “I'm willing to bet that
you'll never become a great jumper. The older you get, the harder it is to change that muscle fiber composition.”
Genes alone don't make someone a good basketball player. Writing of his fellow African-Americans, John Edgar Wideman once observed that “our stories, songs, dreams, dances, social forms, style of walk, talk, dressing, cooking, sport, our heroes and heroines provide a recordâ¦so distinctive and abiding that its origins in culture have been
misconstrued as rooted in biology.”
Families build identities in similar ways. Keen to suggest bookishness runs in our blood, my own family fancifully traces its lineage to a fifth-century BC scholarâBC! Take that, you
Mayflower-
descended motherfuckers!ânamed Ezra the Scribe. Twenty-five hundred years ago, with many of the Israelites stranded in Babylonian exile, the Persian king granted Ezra, a renowned scholar eager to return his people to their homeland, passage to Jerusalem to teach the laws of God. When he arrived, after a six-month journey, he found that left-behind Jewish men had been marrying non-Jewish womenâSamaritans, actually. (The good ones didn't come around until centuries later, materializing when people needed help with their flat tires.) Ezra tore his garments in despair before ordering and enforcing the dissolution of such sinful wedlocks. He then declaimed the Torah to assembled Jews, and the people and the chief rabbis swore to keep themselves separate from gentiles. I take an amused, skeptical pleasure in my rabbinical roots, but I was disappointed, having scoured the Bible and the Midrash, the Talmud, and other sources, to find no evidence that Ezra had any jumping abilities. Nothing.
We like to gaze upon the more recent, greener branches of our
family trees to explain our current generation's talents and predilections. I tell the story that I chose journalism in part because it was my dad's first careerâbut it was an inheritance separate from the blue eyes he bestowed upon me. As a swashbuckling college reporter in the late 1950s, he wrote dispatches from Russia and revolutionary Cuba. My father had himself been enthralled by the ultimately grim stories about his Viennese great-uncle, Gabor Engelsman, who ran the
Sonn-und-Montag Zeitung
, a newspaper with a reputation for reportage and satire discomfiting to the Austrian authorities and hardly reverential toward the Germans. With the Anschluss, the annexation of Austria by the Third Reich that precipitated my grandparents' flight to the U.S.,
Gabor knew the Nazis would arrest him, and he jumped from an office window to his death. As a boy, the fates of my forebears were relayed to me, of course, as reminders of the Holocaust. But they were also meant to describe lives that might have been, and one of those was another in a dynasty of quick-thinking journalists.
But is there anything in my genetic code that suggests a talent for asking questions or sharing stories? Sounding out the echo of the parent in the kid is an old and confounding pastime. Maybe one can tell whether a toddler has the mouth of the mother. But the gait of the fatherâis that inherited, or learned? To what extent was Allex Austin's jumping ability learned through the intimate, lifelong observation of his father, Charles, and to what extent was it genetically conferred upon him? I asked Terry Todd, the former champion weightlifter who presides over the Lutcher Stark Center, an Austin museum and library dedicated to the study of what the human body can do, whether strength ran in his family. Visitors to the center are greeted by a cast of the colossal Farnese Herculesâvulgar, carnivorous, and mounted on a faux-marble, slow-spinning turntable. We were seated at the large oval mahogany table in the center's library, a life-size oil painting of Arnold Schwarzenegger, in Speedo and mid-flex,
looming behind us. Todd, still a massive, broad-chested man at age 76, looks as if he could overturn all sorts of furniture, even this table, if he were so inclined. The question, straightforward as it was, is one he had long pondered himself. When he was about nine years old, he told me, out fishing with his grandfather, a “mallet-handed” 5â²10â³ Texas rancher, the old man picked up a native pecan, an oblong nut guarded by a shell so tightly constructed it requires a special nutcracker to break, and crushed it between his thumb and forefinger. “Bud,” he told Todd, “few men and no boys can do that.” Todd himself would become a world champion power-lifter, but try as he might, he was never able to duplicate the feat his grandfather pulled off. It's a story he also tells in “Philosophical and Practical Considerations for a âStrongest Man' Contest,” an essay about designing obstacle courses challenging enough for outsized humans. His grandfather “broke quite a few more such pecans for me, and each time he did it he chuckled, especially since
it was a feat I was never able to match no matter how large I became or how hard I tried,” he writes. “How was it that a man in late middle age who had done no systematic training could be as strong in any part of his body as a much younger man who stood four inches taller and outweighed him by over a hundred pounds?”
I was gathering spit in my mouth, hovering over the little tube I had ordered from 23andMe, a genetic testing company named for the number of pairs of chromosomes coded with genetic information that are littered throughout our bodies. I was hoping to learn more about the genetic makeup of my muscles. Rebecca was sitting next to me, directions in hand, eyes averted.
“You don't mind terribly, right?” I said to her as I gathered a bit more saliva on my tongue. For years following my cancer diagnosis, Rebecca treated the slightest symptoms with obsessive anxiety. She worried that headaches might be signs of brain tumors; that a cramping foot was an early signal of MS; that a sore throat suggested esophageal cancer. The idea of a test that promised something like medical clairvoyanceâmy future health history laid out for meâboth drew and appalled her.
Seven years out from my cancer, I still make annual visits to my oncologist. Routine as they areâa draw of blood; a listen, by stethoscope, to my lungs; a gentle squeeze of my remaining testicle; a quick massage of my lymph nodes; an X-ray, to see whether any new tumors are forming about my chestâthey fill Rebecca with a profound anxiety. Though she's a confirmed atheist, after my initial chemotherapy treatment she bought me a jade Chinese talisman of an abstracted unicorn. (Einhorn, the name of my oncologist, means unicorn in German.) She thought I could wear it for luck, not so much as a safeguard of good health as a symbol of it. One evening, I foolishly, accidentally, broke it, dropping it into our porcelain sink as I prepared for bed. It cracked in jagged halves. Of course the accident meant little, other than the breaking of a gift from my dearest, but the split medallion gained for her, despite herself, a half-real cosmic significance. With Rebecca fretting about the smallest possible ache, I had to check myself before telling her about back pains or headaches and stifle coughsâall, oddly enough, possible signs of a return of the cancer. But I myself didn't get anxious about these doctor visits. I was, in a sense, a lightbulb, and Rebecca the moth.