March 22, 1997

Letters

Advantages of sex for animals

A couple of statements in "Animals' Fancies" (SN: 1/4/97, p. 8) puzzle me: "The idea that animals may have sex just because it feels good proves difficult for some people to accept" and "Sexual selection theory holds that animals pick partners that will increase their chances of passing on their genes."

These are animals we're talking about. Animals don't choose partners that "will increase their chance of passing on their genes," they choose partners that are big, strong, fast, healthy, and so on -- in other words, partners they find attractive. And since they don't understand the biology of reproduction, they mate because they enjoy it.

After all, why do you think we animals enjoy sex so much? Because all the animals that didn't are extinct.

Patrick J. Murphy
Albuquerque, N.M.

To say that homosexuality "has no evolutionary reproductive benefits" is to miss some of the best findings in the animal studies cited!

Since when has the emotional well-being of social animals not been an advantage to group social stability, individual child-rearing capacity, and the physical health of those involved? The lesbian gulls seem to be very fit parents and are obviously very able to perpetuate their own genes, even if they do not couple with males "just for the pleasure of it."

Nicole LeFavour
Boise, Idaho

To hear you tell it, current scientific thinking insists that observed variations in animal behavior must have a sound basis of advantage somewhere in the genetic selection process. Huh?

Does any scientist really suggest that current Darwinian theory has no room for ongoing random variation, of which only the tiniest fortuitous percentage ever happens to further genetic success?

As I understand it, of the variations that are not outright fatal to the individual, most are detrimental to its genetic transmission or, at best, innocuous. The fact that some of those harmless variations show reliable rates of recurrence (for example, eye color or handedness) surely says more about their relative probability in the given gene pool (or the relative stability of relevant external factors, or both) than about any evolutionary advantage.

Seeking only evolutionary advantage as the explanation of these variations smacks of an anthropocentric version of Darwinism: that evolution's random variation is no longer ongoing everywhere -- that it has somehow been suspended now that we've arrived and discovered it.

Christopher M. Coffin
Corvallis, Ore.