As Stephen Jay Gould says, evolution does *not* work "for the good of species" (see my post titled "Stephen Jay Gould: 'We Might Ask Why Males Exist At All'"); otherwise, you might have been Kelley's sexual appendage, since the only necessary contribution that "males" make to "the continuity of the species" is sperm delivery. Gould is eminently more qualified to speak about biological facts than you are. Nature doesn't think of "the good of species." Nature is "amoral," so to speak, except that even to discuss the morality (or its absence) of "nature's lessons" is already misleading due to its anthropomorphism. Quit being so obnoxiously androcentric & anthropocentric. To think in terms of "species" and to define & limit the essence & freedom of _only one half of humanity_ by its _temporary_ reproductive capacity (which not every individual called "female" even possesses) _is_ a political act. More specifically, thinking in terms of "the good of the species" has, among its implications, the negation of individuality and freedom of reproductive choices (to give or not to give birth). Such thinking is anti-feminist & anti-queer, and it creates & stigmatizes a category of "disabled" individuals (to the benefit of "fertility doctors"); it moreover opens a door to eugenic discourse. In contrast, the mature Marx proclaimed the following as the communist ideal: "In place of the old bourgeois society, with its classes and class antagonisms, we shall have an association, in which *the free development of each* is the *condition* for the free development of all" (emphasis mine). In other words, Marx did not mistake society for an integrated "organism" whose members exist for the reproduction of the "whole."
Stephen Jay Gould also writes of "a single ground plan" in human biology in "Male Nipples and Clitoral Ripples," _Bully for Brontosaurus: Reflections in Natural History_ (1991):
***** If you are committed -- as Erasmus [Darwin, grandfather of Charles] was, and as a distressingly common version of "pop," or "cardboard," Darwinism stil is -- to a principle of pervasive utility for all parts of all creatures, then male nipples do raise an insoluble dilemma, hence (I assume) my voluminous correspondence [from the readers puzzled by the existence of male nipples]. But as with so many persistent puzzles, the resolution does not lie in more research within an established framework but rather in identifying the framework itself as a flawed view of life.
Suppose we begin from a different point of view, focusing on rules of growth and development. The external differences between male and female develop gradually from an early embryo so generalized that its sex cannot be easily determined. The clitoris and penis are one and same organ, identical in early form, but later enlarged in male fetuses through the action of testosterone. Similarly, the labia majora of women and the scrotal sacs of men are the same structure, indistinguishable in young embryos, but later enlarged, folded over, and fused along the midline in male fetuses.
I do not doubt that the large size and sensitivity of the female breast should count as an adaptation in mammals, but the smaller male version needs no adaptive explanation at all. *Males and females are not separate entities, shaped independently by natural selection. Both sexes are variants upon a single ground plan, elaborated in later embryology. Male mammals have nipples because females need them -- and the embryonic pathway to their development builds precursors in all mammalian fetuses, enlarging the breasts later in females but leaving them small (and without evident function) in males.* (emphasis mine) *****
Moreover, in "Hyena Myths and Realities," _Hen's Teeth and Horse's Toes_, Gould writes of a male course of development as a "modification" of the "female course of development...biologically intrinsic to all mammals":
***** Mammals share a common pattern for the embryology of sexual organs, and we may therefore use humans as an example. The early embryo is sexually indifferent and contains all precursors and structures necessary for the development of either male or female organs. After about the eighth week following conception, the gonads begin to differentiate as either ovaries or testes. The developing testes secrete androgens, which induce the development of male genitalia. *If androgens are absent, or present at low levels, female genitalia are formed.*
The internal and external genitalia develop in different ways. For internal genitalia, the early embryo contains precursors of both sexes: the Mullerian ducts (which form the Fallopian tubes and ovaries of females) and the Wolffian ducts (which form the vas deferens -- the ducts that carry sperm from the testes to the penis -- in males). In females, the Wolffian ducts degenerate and the Mullerian ducts differentiate; males develop by the opposite route.
The external genitalia follow a markedly different pattern. Individuals do not begin with two distinct sets of precursors and then lose one while strengthening the other. Rather, the different organs of male and female develop along diverging routes from the _same_ precursor. The male's penis is the same organ as the female's clitoris -- they form from the same tissues, are indistinguishable in the early embryo, and follow different pathways later. The male's scrotum is the same organ as the female's labia majora. The two lips simply grow longer, fold over, and fuse along the midline, forming the scrotal sac.
*The female course of development is, in a sense, biologically intrinsic to all mammals. It is the pattern that unfolds in the absence of any hormonal influence. The male route is a modification induced by secretion of androgens from the developing testes.* (emphasis mine) *****
Both from evolutionary and embryological points of view, we must proclaim: "One is not born a man, but rather becomes one" (to paraphrase Simone de Beauvoir).
evolveanglerfish,
Yoshie