Flies From Nowhere

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It's always annoying to go to the fruit bowl and find a flock of tiny fruit flies buzzing around the ripe fruit.  They seem to come from nowhere.  Fortunately, they are quite harmless.  The fruit you buy in your local supermarket often contains scores of small white fruit fly eggs on it's surface.

Bananas are particularly appealing to fruit flies.  Green bananas often travel several thousand kilometres from the tropics to your kitchen.  Since it takes about two weeks for the fruit fly eggs to develop into mature flies, by the time the bananas have ripened, the eggs are usually ready to hatch.

These tiny flies, called drosophila, are actually very useful to scientists.  Much of our knowledge of genetics has been discovered by working with them.  They breed quickly and prolifically, and can be easily raised using just a little mashed banana in an ordinary glass container.

Although they have a simple genetic makeup, they display scores of different inherited characteristics that can easily be observed.  There are some with white eyes and some with red eyes, there are flies with different wing shapes, and there are mutants that are not attracted by visible light.  Even the learning ability of fruit flies, and their sense of smell can be altered and then studied after mutations are induced.

So next time fruit flies bother you, remember, they've provided us with a great deal of important scientific information.