Rape would increase reproduction so why have they evolved to prevent it?
Please post the research to which you are referring.
Evolution occurs in part due to non-random mating, so I would assume that females evolved to prevent reproducing with just any male, so that way they can selectively choose with whom they mate. We always see examples of various females from various species that will only choose the more dominant and successful males, but rape would bypass this selective process.
So you're saying that because females resist rape, increasingly complex vaginas would somehow be favored in evolution? I don't see that connection.
I'm speaking with the authority of a lackadaisical AP Biology student. All I can definitively tell you is that non-random mating contributes to evolution, and if male ducks were able to reproduce with any female they wanted, rather than the females selectively choosing superior males, then this would eliminate the non-random mating aspect.
Not exactly what I had expected. Interesting.
They were probably bred by Republicans.
Old male Republicans, of course. I wonder how eggs hold up under ultrasound.
Without detail, fairly obvious general background is that birds have an (energy) expensive lifestyle, starting from totally helpless chicks who need devoted and collaborating parents to make it to adulthood. So, notoriously they go to a lot of lengths about the couple forming with all their courtships, dances and displays; another aspect is how for the privilege of feeding demanding family the male has the expense of fine feathers and has to sing as well. They are mostly monogamous though a bit of cheating and exceptions have been detected.
I have only seen a bit of it but I think the a series of brilliant films by David Attenborough explains a lot about their lifestyle and dynamics.
While we are on the topic... "Why you can't rape an elephant"
why would you think this to be true ? why would you think that it is easy as eating or drinking ? Reproduction is expensive and time consuming process irrespective of species. Just because rape is possible, does it improve reproductive fitness of a species. what about protecting the offspring once it is born.
Although in many species of birds, both parents help raise the chicks (i don't know about this particular one) it is the female that has to also bear the eggs i.e. for a given number of offspring the female expends more energy. Females try to mate with the best males and males likewise try to mate with the best females so that they end up with the best kids ('best' is used in the context of fitness). But the penalty for choosing the wrong mate is greater for the female than for the male. And so these birds end up with their courting rituals etc. where the female will only agree to mate if the male satisfies certain criteria. Dawkins has explained this nicely in one of this books.
Why not? If a morphological modification gave females the power to mate with only the male she wants to mate with, it'd favoured in the course of sexual selection. On the other hand, males which can bypass this, will be favoured by sexual selection as well since it is in his interest to mate with as many females as possible.
Suppose two female ducks are born and that they only can give birth to female ducks. Now suppose that one has the power to mate only with the male she wants to mate with. The other doesn't.
The one that can choose her mates might be more selective and only reproduce with one mate. She passes her genes and so the offspring also can choose her mates.
The other might reproduce more due to rape and would have 3 offsprings that cannot choose their mates.
The problem is that females ducks all attempt to prevent rape.
Also, it seems like rape is a good gene to have. So why haven't the males for all species convergently evolved to rape?
The female duck with no say in chosing her partner will have less fit offspring than the choicy one.
There are plenty of examples of the evolutionary war between sexes. Why is the ovulation in females of our own species hidden? To force male to stay by side of the female and help raise the kids. It is not different.
Is it not that the mating display is a way to identify a member of the same species, given that migrating birds are prone to be faced with many different types of mate? So I think we should see this more in migrating birds than in land animals.
The second paper you posted is free, and is a long discussion of your question.
Somewhat tangential, but from the paper: "A study by Tryjanowski et al. (2007) of the great gray shrike Lanius exubitor, a passerine species, found that both males and females choose more secret locations for EPC than for pair copulations, and the same could be true in some species of waterfowl. The hypothesis that female waterfowl only consent to EPC when well hidden would be difficult to prove for obvious reasons" !
This is a tremendous and ultimately incorrect assumption. Remember it isn't about just having offspring. What if all those offspring die out quickly? Then you are no better off (evolutionary speaking) than an organism that didn't parent any children.
Your children really only count if they get a shot to grow up and reproduce as well. Females are choosy for this reason.
Until you get to humans. Motives change when you're not governed by only genetics.
Be ready for a surprise. There are serious theories that explain many of our strategies of selecting sexual partners in terms of evolution and genetics. See The Red Queen: Sex and the Evolution of Human Nature by Matt Ridley.
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