Fruit fly study sheds light on rarity

MISSISSAUGA, Ontario, May 14 (UPI) -- Canadian Professor Marla Sokolowski has identified the benefit of rarity in populations of fruit flies with two varying versions of the foraging gene.

Sokolowski, a biologist at the University of Toronto-Mississauga, said there is considerable genetic variation in nature but scientists have not been able to explain why it persists, since natural selection ensures that only the best survive.

In the new study, Sokolowski, doctoral student Mark Fitzpatrick and colleagues found flies carry one of two versions of the foraging gene -- either the "rover" or "sitter" type. Rover larvae move around more than sitter larvae while feeding and they are also more likely to explore new food patches than sitters.

The researchers found that when the fruit fly larvae were competing for food, those that did best had a version of the foraging gene that was rarest in a particular population. For example, rovers did better when there were lots of sitters and sitters did better when there were more rovers.

The study appears in the May 10 issue of the journal Nature.