Threatened species may spiral into oblivion


      Katherine Unger

      19:00 27 October 04

      Exclusive from New Scientist Print Edition. Subscribe and get 4 free
issues.

      Rampant inbreeding can put panthers, cheetahs and other endangered
species at increased risk from parasites and infections, a new study
suggests. That could create a vicious cycle capable of driving the remaining
population to extinction.

      Inbreeding is known to increase the prevalence of certain genetic
diseases and is also suspected of weakening the immune system, rendering
animals more susceptible to other kinds of illness.

      The endangered Florida panther, for example, of which fewer than 100
individuals remain, is unusually prone to infections. And in the 1980s, an
outbreak of feline infectious peritonitis killed more than half of an
extremely inbred cheetah population, even though it rarely causes illness in
most cats.

      But one of the few previous experimental tests of these ideas seemed
to contradict the hypothesis that inbred animals find it hard to fight off
disease. In 1997, when biologist Lori Stevens and colleagues at the
University of Vermont looked at beetles infected with a tapeworm, they found
that inbred beetles were just as good at resisting the parasite as
genetically diverse ones.

      Now, conservation biologist Richard Frankham of Macquarie University
in North Ryde, Australia, has revisited the idea. His team studied fruit
flies, which reproduce so quickly that several inbred populations could be
created in a matter of weeks.

      Full Text at NewScientist
      http://www.newscientist.com/news/news.jsp?id=ns99996581

      Posted by
      Robert Karl Stonjek
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