It also is charming, tho its explanation of breasts is more prosaic: Babies had to have something to cling to when women lost their fur. It is remarkably evenhanded for a book on this subject, which is rife with party questions. (After my animadversions on the prevalence of party questions in economics, I was amused to read: "I can think of only one other subject which in the same period has spawned so many experts all heatedly contradicting each other, and that is economics".)
I have not kept up with the subject, about which she says "primate studies are progressing so fast that any book dealing with them (this one, too) is liable to get shot full of holes a few months later"; so I cannot say what the state of opinion on her guesses is. They all seem plausible to me, which is perhaps the most one can hope for in Darwinian explanation. As to the facts of evolution (who descended from whom, what are the orders of magnitude of m & n such that that dandelion & I are mth cousins n times removed, etc.) one may hope that evidence will render this or that hypothesis more likely or less so; but as to explanations (what was selected for & why, how we ended up with elephants & spiders & human beings, etc.) perhaps the best we can expect is stories that are not absurd: This is the kind of thing one might reasonably expect to happen.
At the very beginning she quotes Genesis to the effect that "Woman was not only an afterthought, but an amenity", and she goes on to say that Darwinian accounts have been as androcentric in their own way. True enough, and worth debunking; but it would have been gallant to mention that there have been men of independent mind who criticized that foolishness & even made fun of it. I thought at once of Burns:
Auld Nature swears, the lovely Dears
Her noblest work she classes, O:
Her prentice han' she try'd on man,
An' then she made the lasses, O.
God made man first, as in Genesis, but he was only practicing! (Of course, to mention God would be blasphemy, so Burns has Nature --- female --- stand in for Him. That maneuver was congenial to the 18th century, and still has some popularity.)
Shaw wrote a whole play, Man and Superman, in which (I know from folklore; I haven't read it) "Superman" alludes to Nietzsche's hero, but turns out to be woman. (The witticism wouldn't work in German; the "Mensch" in "Uebermensch" means human being, not adult male.) That no doubt irritates Nietzche, a notorious misogynist, when the play is performed for him in Hell.
Mencken (1919) says: "Women have a hard time of it in this world. They are oppressed by man-made laws, made-made social customs, masculine egoism, the delusion of masculine superiority. Their one comfort is the assurance that, even though it may be impossible to prevail against man, it is always possible to enslave and torture a man. This feeling is fostered when one makes love to them.... To shrink from giving so much happiness at such small expense, to evade the business on the ground that it has hazards --- that is the act of a puling and tacky fellow."
Mention of "Mensch" recalls a dubious remark Morgan makes later in her first chapter: She thinks evolutionists & ethologists might have been seduced into androcentric theorizing, in part, by the fact that "man" can mean either the species or the male of the species. That is an accidental & probably temporary defect that English shares with French & Hebrew but not with German, Old English, Latin, Greek, Russian, or their IndoEuropean ancestor. In language after language, there has been a word for human being, men have appropriated it to themselves, both men and women have found that to be a nuisance, and so a new word for human being has been invented. English happens to be at the nuisance stage, but its speakers are not thereby rendered any more sexist than the Germans etc.