system
Given the following post, respond as if you're commenting on Reddit:
human
Why isn't forced copulation the norm in the Animal Kingdom?

Wikipedia has a brief section on it, citing several examples of forced copulation but it appears from there that it is not the norm across the Animal kingdom. This seems puzzling to me since it would seem to carry a massive evolutionary benefit to those males who could copulate with females regardless of cooperation.

I would speculate that the reason is because females have generally evolved methods for preventing it (I believe this is true in ducks, with the shape of the vagina). But is this true in other species?

Edit: Thinking some more, I woud imagine that if 'rape prevention' in females has evolved, then sexual attractiveness from a male standpoint, should include this ability. Has this been established?
gpt
Females evolving methods to prevent forced copulation is part of the story - there is strong selection on males to mate with as many females as possible (whether or not the female wants to cooperate), but there is also strong selection on females to be picky. Another part of the story is cryptic female choice, in which females in many groups have control over whether to fertilize their eggs with a male's sperm after mating with him. This means that even if a male was successful in forcing a copulation, he may not end up producing any offspring, and selection would thus favour the male who can convince females to willingly use his sperm.