I've
already mentioned the GE potatoes that can resist serious diseases.
That's one example of how genetic engineering might be useful
in the future (for people, that is). And here's another i
nteresting
idea: glowing fish. Scientists have added a selection of genes
from humans, rats, trout and fireflies (insects that have tails
that glow) to a fish called a zebra fish[1]. Why?
This
special mix of genes means that the modified fish glows in the
dark when the water it's living in is polluted. It turns out
that, like other fish (or flesh-eating animals), zebra fish
tend to 'collect' - to bioconcentrate - pollutants like PCBs
and dioxins in their flesh. (This is why it can be very dangerous
to eat fish from polluted lakes, rivers or sea.) If these modified
fish are put in a cage in polluted water, the glow soon switches
on.
Long
ago, coal miners used to take canaries down the mines they worked
in. The poor birds would keel over and die before poisonous
or explosive gases built up to danger levels for miners. They
were the first 'pollution sentinels'. The zebra fish, like the
canaries, are so sensitive that they show even tiny traces of
poisons by glowing - traces which scientists would only be able
pick up with the best equipment they have. Another advantage
is that the fish are quite similar to mammals (including humans)
in the way their bodies process food and poisons. So if you
ever catch
a glowing zebra fish, don't eat it or drink the water!
Of course, none of this would be necessary in the first place if humans hadn't made such a terrible mess.
1. New Scientist, 'The tough get glowing', 12/1/02, 36-37.