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- WASHINGTON (Reuters) - People
who complain that their children are driving them to an early grave may
be closer to the truth than they thought, researchers said on Thursday.
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- They said they had found definitive evidence of what
parents and biologists had suspected for a long time -- that reproducing
takes a deadly toll on the body.
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- Linda Partridge and Carla Sgro of University College
London bred various lines of fruit flies, some of which produced eggs at
a very young age and others that reproduced when they were older, by fruit
fly standards.
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- The flies that bred while young died at an earlier age
than the ``old'' flies. When the younger-reproducing flies were sterilized
with X-rays, they began living as long as their ''old'' counterparts.
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- ``These results suggest that aging has evolved primarily
because of the damaging effects of reproduction earlier in life, rather
than because of mutations that have detrimental effects only at late ages,''
they wrote in their report, published in the journal Science.
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- Patridge and Sgro said they were basing their study on
solid science. Fruit flies, known by scientists as Drosophila melanogaster,
are clearly affected by reproducing.
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- ``Egg production, exposure to males and mating have all
been shown to reduce survival in female D. melanogaster,'' they wrote.
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- They believe that the genes that cause an animal to be
highly fertile when young can have the reverse effect as the creature gets
older. And the act of having offspring may be what does the genetic damage.
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- ``Reproduction may cause damage directly, and the effects
may accumulate with time,'' they wrote.
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- David Reznick of the University of California in Riverside
pointed out that people do have one extra chance in life. Writing in a
commentary, he and colleagues pointed out that the death rate in humans
and other animals level off after a certain point, suggesting that the
wearing effects of having children do wane, if the parent survives long
enough.
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