May I ask why you don't believe the alternative evolutionary explanation? Forced (to some extent) penetration has been with humanity for a long time, and will likely be with humanity for a long time. It was not until relatively recently that it is generally accepted as a bad thing, and even in our "enlightened" age, there is a great deal of misinformation.
Removing the moral implications, rape is really bad PHYSICALLY unless the act is lubricated (the point the article makes). So a woman needs to be PHYSICALLY ready for sex, even if not EMOTIONALLY or MENTALLY willing.
That leads to a decoupling of mental and sexual desire from physical response.
Call me unPC, but that seems to fit the evidence they present!
I can't really think of a specific example but it seems that a whole host of things about humanity would be different if forced sex was the main method of procreation in the ancestral environment.
