Who We Are: Genes and Environment"Creativity runs in the family." "I inherited this bad back." "All the women in my family live past 80." People often wonder how they acquire their traits, from talents to ailments. Genes we inherit from our parents do indeed guide how the body develops and functions. But where we live, what we do—our individual environment, starting in the womb—also plays a large role in determining the outcome.
Nutrition, exercise and education are some of the influences on our health and behavior. Identical twins, for example, share the same genes. But twins develop unique personalities, disabilities, skills and sometimes looks based on environmental factors.
Researchers are now finding connections between genes and human characteristics ranging from athletic ability to aging. But for the most part, our genes are not our ultimate fate. Instead, we are a product of interactions between genes and our environment, nature and nurture.
Athletic AbilityGoing for Gold"You're only born with so much good speed and you can only learn how to use that speed better."
—
Michael Johnson, dubbed "the world's fastest man"
Speed, endurance, strength and coordination—core physical elements of any athletic performance—are all affected by the genes that guide the ability to contract and fuel our muscles. Researchers found a link between endurance and a gene called ACE; one version of this gene appears in elite runners, climbers and rowers more often than in non-athletes. But genes alone won't enable you to win an Olympic gold medal. Intense training, nutrition and rest are environmental factors that produce the best possible results.
Musical TalentThe Key to Success"You have to practice a lot, and you're not going to get it right away. You just have to stick with it."
—Amanda Shaw, released her first CD at age 10
It's tempting to think there must be a genetic component to account for a child prodigy's extraordinary ability. But so far, scientists can't point to many genes involved in musical talent. One exception is perfect pitch: research shows that this ability is inherited. Another study suggests that tone deafness may also have a genetic element. But nature aside, all aspiring musicians need training and practice. Children who begin music lessons after the age of nine almost never retain perfect pitch, and one study found that those considered most likely to become "star soloists" practiced the most.
Asthma
Disorder on the Rise
Worldwide, more than 150 million people are affected by asthma, an allergic reaction of the lungs to inhaled particles. And since 1980 the incidence of asthma increased alarmingly—in the United States, by about 75 percent. Scientists suspect this disorder, spurred by an overactive immune system, is rooted in several genes. But the recent increase of cases also points to new environmental factors. Interestingly, children who grow up clean and pristine are more likely to have problems. The oldest child in the family is also at greater risk than younger siblings. Theories abound, but one explanation is that early childhood exposure to dirt and germs may help develop the immune system to be resistant.
AgingSecrets of a Long Life
"I use butter liberally, breathe New York City air deeply and never exercise. Frankly, no one can figure out why I lived past 40!"
—Al Hirschfeld, 97 years old and still drawing caricatures
Like Ponce de León searching for the Fountain of Youth, researchers today scour the genomic frontier for genes to increase longevity. Scientists have closed in on a group of 60 genes associated with aging, namely how cells malfunction and die. One gene, called p21, affects the whole group; damage to this gene can speed the aging process. Meanwhile, other research is helping us learn more about environmental factors that may lengthen life span. Cutting calories by 30-50% in laboratory animals has extended lives and reduced the risk of age-related diseases.
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