Evolution may not be slow or random
By Susan Milius
Studies of fruit flies taking over the New World and stickleback fish adapting to Canadian lakes suggest that evolution can move fast and take predictable paths.
An Old World fruit fly, Drosophila subobscura, turned up in Chile in 1978 and seems to have liked the Americas. It has already spread as far north as Vancouver Island and as far east as Utah. George W. Gilchrist of Clarkson University in Potsdam, N.Y., warns that this interloper is crowding out a native fruit fly, although the public isn’t weeping at the tragedy yet.