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- Michael Pollan Evolution is a rather delicate balancing act, to coin a widely overused term. It is true though. The selective breeding humans practice (see Siberian foxes, Selective Breeding and Our Furry Friends) is clumsy and heavy handed compared to Nature's evolutionary dance. As an example of evolution in action, natural selection at its finest, it is time to look at guppies. Female guppies prefer to mate with brightly colored males. The brighter the fish, the easier it is for a predator to spot it. So the trade off is clear. The bright (in terms of color) fish don't live very long but tend to be busy mating the entire time. The dull fish, on the other hand, don't mate very often at all, but tend to live long, healthy lives (for a guppy, anyway). Like the motorcycle-riding jock and the nerd who wears kneed pads to jog. Back to guppies, though. As one might expect, without predators, brightly colored males dominate the guppy world and successive generations become even more and more colorful to compete (Palumbi). The brightly colored male is in great demand, or as Dr. Palumbi puts it, "The bright male has become a harlequin gigolo with a Casanova attitude and the power to beguile." The bright male dominance comes crashing down as soon as a few predators are added to the mix. The brightest males are the first to become lunch and in a very short period of time, the dull colored guppies become dominant. Females still prefer to mate with brightly colored males, there simply are none. So it is up to nature find the balance between attraction and danger. The male must be bright enough to attract females but dull enough to evade predators. Natural selection attempts to find a perfect balance of many traits -- perfection, of course, takes a while to achieve. Selective breeding, on the other hand focuses on a single trait but tends to yield rapid evolutionary change. See: Darwin's Origin of Species |