Free Homo Mysterious: Evolutionary Puzzles of Human Nature by David P. Barash Page B

women to engage in intercourse. In a renowned essay titled
Knight’s Move
, literary theorist Viktor Shklovsky pointed out that “If you take hold of a samovar by its stubby legs, you can use it to pound nails, but that is not its primary function.” Shklovsky went on to note that during the Russian civil war,
With my own hands I stoked stoves with pieces of a piano … and made bonfires out of rugs and fed the flames with vegetable oil while trapped in the mountains of Kurdistan. Right now I’m stoking a stove with books. … But it’s wrong to view a samovar with an eye to making it pound nails more easily or to write books so that they will make a hotter fire. 3
     
    Almost certainly, it is equally wrong to view the female orgasm as designed to induce sexual intercourse, just because it may provide an occasional payoff for doing so. The question of orgasm’s “primary function” remains open.
A Nonadaptive By-Product?
     
    Also open is an important possibility, analogous to what scientists call the “null hypothesis,” which is to say, the possibility that nothing especially interesting is going on. Much of evolutionary biology involves searching for the adaptive significance of things, whether structure, physiology, or behavior. But we must always consider the chance that a trait in question has no adaptive significance at all, that it does not owe its existence to the direct action of natural selection.
     
    This prospect has been raised with regard to female orgasm, first by anthropologist Donald Symons, 4 then by paleontologist/author Stephen Jay Gould, 5 and later by philosopher of science Lisa Lloyd. 6 Their argument is that female orgasm does not owe its existence to any biological payoff associated with it, but rather to the fact that it is a nonadaptive tag-along trait, unavoidably linked to what really matters, namely, male orgasm. It is a claim that must be taken seriously, if only because to be sure, not all traits have been selected for in themselves; some occur simply because of an unavoidable connection with something else (in which case the “something else” typically
is
adaptive).
    At first blush, it might seem absurd and demeaning of women as well to claim that women’s orgasms are merely secondary byproducts to the Real Thing—namely, orgasm in men. Indeed, it is reminiscent of Simone de Beauvoir’s contention that women are the “second sex,” an eternal Other compared to men who are genuine Subjects, where the Real Action resides. The “by-product” hypothesis points, however, to a powerful metaphor: the case of male nipples. Men don’t lactate, so why do they have nipples? The classic and almost certainly correct answer is: because women have nipples, and they do lactate, and the complex developmental pathway during human embryology that eventually gives rise to nipples in women necessarily engenders nipples in men, too, where theyare unnecessary, unselected for, and even downright silly. Although no one claims that orgasms are silly, those who deny adaptational status maintain that they are like male nipples, without biological significance in themselves, and that they exist only because they are tightly bound to something strongly selected for in the opposite sex.
    The by-product hypothesis has a superficial plausibility. Embryonic development is typically a package deal, with various traits dependent on preceding stages. Since male and female embryos undergo a common developmental pathway, it would be a major fitness burden to interfere and redesign an unnecessary independent pathway that led to nipple-less men. After all, if nipples don’t do any good, at least they don’t do any harm, so presumably they are simply along for the ride. If they caused trouble, perhaps if they frequently became cancerous or if they required a lot of metabolic energy to create and maintain, they doubtless would have been selected against, but they ain’t broke—merely irrelevant—so evolution