STANFORD, Calif. - After decades of laboratory work studying how
animals evolve, researchers sometimes need to put on the hip
waders, pull out the fishing net and go learn how their theory
compares to the real world. According to a Stanford University
School of Medicine study published in the March 25 issue of
Science, Mother Nature is more predictable than lab experiments
suggest. In a diverse group of fish called the stickleback,
nature took advantage of the same genetic trick time and again
to allow freshwater species to shed their burdensome body armor
and transform into a lighter, spryer fish. This is among the
first times scientists have shown that the same genetic change
is responsible for an evolutionary adaptation in disparate
populations. "Almost every time the stickleback evolves in fresh
water it loses the armor," said David Kingsley, PhD, professor
of developmental biology and lead author of the study. "Although
the trait evolved many times all over the world, nature uses the
same gene each time.