 Imagine
a dodo bird waddling on a pond near your house. Or a woolly
mammoth lumbering along. How about a pterodactyl soaring overhead?
Sound far out? Genetic
engineering (GE) makes it possible to "resurrect" extinct
species, just like in the movie Jurassic Park. As an
animated tour guide in the movie explains, it all comes down
to DNA. If you can recover a useable sample of an organism's
DNA (easier said than done), then biotechnology gives you the
tools to clone (copy) that DNA, insert it into an egg, and develop
it into a dinosaur or any extinct animal. This process is not
just movie make-believe though, it is really happening! In Iowa,
a cow named Bessie bore a calf that was not a cow at all but
a gaur, an ox-like animal native to the jungles of India and
Burma. The gaur DNA was cloned into a cow's egg, which had its
own DNA removed. That egg was then implanted into Bessie who
carried the gaur and gave birth to it. (Sadly, the gaur died
shortly after its birth due to a bacterial infection.)
The
gaur is not extinct, but endangered, which brings up an important
point. GE could actually help save species teetering on the edge
of extinction, an opportunity in the eyes of some scientists.
They view GE as a way to preserve biodiversity,
keeping as many species in the mix as possible. They also see
it as a way to reverse the harmful effects humans have on the
animal kingdom. Not everyone shares that sunny outlook though.
Critics say the technology will produce herds of animals that
are genetically identical. These identical herds would share not
only the same strengths, but the same weaknesses. This would leave
them vulnerable to diseases that could wipe out the entire herd,
actually reducing biodiversity. Another concern centers on habitats
for these cloned
animals. Many animals face endangerment and extinction because
their natural habitat is disappearing, or because the habitat
no longer has the food, water, or shelter the animal needs to
survive. Will a zoo be the only place these clones can live?
GE
gives researchers a lot of tools to tinker with, and a lot of
questions to consider when it comes to "engineering" the animal
world.
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Cloning Candidates 
Which
animals represent the best bets for cloning and which ones aren't
such hot prospects?
More
Tasmanian
Tiger
 Bringing
Back the Tasmanian Tiger! Scientists hope DNA will allow cloning
of an extinct marsupial. More
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