to expand, it's a scientific theory by rich, educated by patriarchal western systems, white men to justify the continuation of the systems that privilege them in the first place (eg sexism and misogyny, racism, classism). evolutionary psychology, natural selection, and so forth would be interpreted radically differently from how they currently are if women of all races and men of colour were the ones cultivating these theories.
here's a couple examples:
rape - they try to argue that the desire for rape is biologically inherent within men as a result of natural selection so they can "spread their seed" to as many women (read: vaginas) as possible, thereby increasing chances of reproducing their genes, and demonstrating their "potency." one particularly notorious offender is the excuse of a book called "a natural history of rape" by thornhill and palmer (http://www.amazon.ca/Natur
this is one of the worst examples of it's justification of misogyny and rape. the vast majority of rape doesn't even have the chance of resulting in pregnancy, consider many of the victim groups of which this almost always is true:
men (1 in 9 of all reported adult rapes, 98% by men),
boys (1 in 6 boys will be sexually abused by the age of 18, about 85% by men),
prepubescent girls (nearly 40% of girls will be sexually abused by the age of 18, 95% of the time by men, with the average age being 11)
menopausal women (no longer fertile; see below because the rate of victimization for women 40 and older is not that much lower than for women in their 20s and 30s)
menstruating women (not fertile during menstruation; see below)
2/3 of women will experience sexual assault during their lives; US statistics on rape as legally defined range from 1 in 3 to 1 in 8, depending on sample group, which legal wording/definition, etc)
transpeople, esp transwomen (have victimization rates comparable to or slightly higher than the rates for women, and far higher than the ones for men)
rarer groups that are targeted for rape include: corpses, animals that are usually female, and babies of either/any sex
Now, compounding the above is the fact that most rape isn't vaginal penetration with the rapist's penis--such as orally, anally, with the rapist's hand, objects such as bottles, broomsticks, pool cues, dildoes, tree branches, knives, and guns--one is left wondering:
how can all this result in pregnancy?
the additional fact of women using birth control pills, the morning after pill, and abortion to control their fertility--and which can be used in the result of a rape--really "problematises" (read: calls bullshit) on the theory that rape is
but, you may say, birth control didn't exist thousands of years ago, when this primitive rape instinct developed in men. but it did--contraception dates back over 4000 years, abortion is even older, and infanticide is the oldest.
i would also add: what about the rapists who, in spite off all those classes of victims and types of rape listed, went with the less-common-than-believed form of rape regarded as "actual" or "real" rape (penis-in-vagina) with a woman who could be fertile, use a condom?
but, but! someone may have the gall to say, rape is still an instinct within men! if it were, wouldn't the vast majority of men rape, if "sex" (read: penis-in-vagina "thrusting") is an "instinct" as strong as hunger and the avoidance of death(!), and rape is instinctual, too, wouldn't all men be slavering rapists? or at least, most of them? and why would men visit prostitutes, one of the most abusive uses of women, children, and men that the johns most decidedly do not want to result in any consequences for them, including children. if men are as awful as the theory suggests, wouldn't men be better off killing themselves off? why should women put up with men biologically programed to be rapists?
i guess that's what makes feminists the manhaters--the belief that women shouldn't have to endure rape as the price of men existing, the view that the theory serves to excuse men's choices, conditioning, and benefits within a rape culture.