Mean Genes
San Diego Union Tribune
11-Sep-2000 Monday
BODY AND SOUL | KEEPING FIT
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Today, the hunter-gatherer
orders a pizza
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JACK WILLIAMS
Left to our
own devices -- or vices, as the case may be -- we would rather eat than
exercise and sleep than sweat.
Call it the
energy-conservation instinct, the path of least resistance, where the
footprints of our hunter-gatherer heritage are permanently implanted in our
DNA.
So the next
time you declare your body a fat-free zone, honor tradition and allow a
little margarine for error.
Just don't
slather it on too generously.
Some of those
genes you're carrying around like excess baggage were designed more for
surviving in the wild, where the next meal was a rumor, than in an
industrialized society where our needs are virtually at our fingertips.
Without a
refrigerator at their disposal, those resourceful ancestors stored what we
would consider leftovers as fat, the better for lean times ahead.
As Jay
Phelan, a researcher in evolutionary genetics and aging, puts it: "Our
genes haven't had a chance to catch up to the world we're living in, with all
the extra food."
That may not
be the source of obesity, eating disorders or sloth – especially in a society where health
advice is as abundant as exercise equipment -- but it's a likely contributor.
Phelan, a
UCLA biology professor, collaborated with fellow scholar Terry Burnham in
writing "Mean Genes," (Perseus Publishing), which examines, among
other things, why we're sometimes more prone to use a remote control than
self-control.
In a genetic
context, survival of the fittest translates to survival of the
hunter-gatherers who moved when they had to and ate whenever they could.
The irony is
that extra food in the wild increased longevity. In our society, it limits
it.
"But our
ancestors were expending calories to get food and, too often, we don't,"
said Phelan, who has a doctorate in biology.
That genetic
component, however valid, has been overcome by generations of
health-conscious individuals who have learned not to trust their instincts
even as they acknowledge them. In a sense, they've reinvented themselves.
For Phelan
and Burnham, whose doctorate is in economics, willpower isn't enough. There
has to be a worthy goal involved -- a means to an end that can neutralize
what some have labeled our "laziness gene."
Burnham, who
studied at San Diego State before earning his doctorate from Harvard, went
without a car for a while, so he was forced to ride his bike.
He also
discovered that team sports were a better exercise option than the gym.
"Teammates
are counting on you," he said. "I don't think of it as a workout. I
just go. Exercise is part of my transportation and part of my social
life."
Burnham took
a trip back in time in researching his book, studying wild chimpanzees in the
rain forest of Uganda and visiting primitive societies where food is a
luxury.
"I saw
one black woman running in Uganda," he said. "As it turned out, she
was from Switzerland. No Ugandans jog. There's no way they can understand an
eating disorder like bulimia. They're problem is exactly the opposite –
they're hungry all the time."
Phelan once
tamed his mean genes on a long-distance flight by smearing a small packet of
mayonnaise on the brownies provided on his airline meal. Instead of being
tempted, he was repulsed.
Now he dreads
the day when a Krispy Kreme doughnut shop (there are nearly 150 of them
nationwide) could be within sniffing distance of his environment.
"Right
now, the closest one is 18 or 19 miles away," he said. "But the
company's doing so well, they're ready to expand."
And so are we
if we give in to those primal instincts too often.
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