Given that my (female) dog will occasionally hump my leg, I don’t think animals have very complex notions of how sex works or when it might be a bad idea.
Do zombie animals hump their own relatives?
Doesn’t inbreeding sometimes happen when a population becomes isolated, and sometimes lead to speciation?
[QUOTE
http://lynx.uio.no/jon/lynx/cheetahg.htm
Some other links were talking about how it probably came about because of two big population crisis’.[/QUOTE]
Lynx links! Love it.
The obligatory Wikipedia link.
It seems we don’t really need those complex social mores that much - as long as the siblings are raised together, nature will take care of things. Of course if that’s not the case, well … another obligatory Wikipedia link.
African Wild Dogs are endangered. One of the theorized causes is that they are all descendents of a small surviving and incestuous pocket from an ice age era. They are very susceptible to disease.
In horses, that is referred to as linebreeding for father-daughter or mother-son crosses, vs. inbreeding for brother-sister crosses. Many hoirse breeders claimed that linebreeding was OK, but not inbreeding.
But from what I know of genetics, I don’t see that there is any difference between them.
I was going to mention that. But you left out the most interesting part. Similar studies show that, when it comes to visual cues, both women and men tend to pick people who look more similar. It seems we have two competing urges.
I have no idea if this applies to other animals.
Through chance.
As Blake mentioned, most great apes have a female dispersal system, although, in practice, both sexes disperse. Most intelligent primates recognize kin and avoid mating with them, although how they do this, we don’t know. Among the capuchins I studied, males disperse, but sometimes the alpha male will remain in a group after his daughters grow. His daughters never solicit him for sex and he shows no sexual interest in them.
Hey! Here’s a suggestion–perhaps animals who tend to be predatory kick out the females, whereas animals who tend to be prey kick out the males when they come of age. Horse herds for example kick out the males, whereas great apes as has already been stated tends to kick out the females. My guess is that a group of young female prey animals would have a far smaller chance of survival in the wild than a group of young males would; on the other hand, males of more predatory groups tend to rule the roost over females in a way which does not happen nearly as often among prey animals [if at all, fuzzy on the details I just remember my generalities from my “Kratt’s Creatures” phase]. Thus the males of predatory groups would be less likely to leave, especially because a young group of female lionesses, for example, would have a much easier time of it trying to survive than a group of young does or impalas or even zebras would.
Just a suggestion–but a sound one, don’t you think?
To say nothing of the Hapsburgs:
No, it doesn’t really hold water.
The most obvious problem is that it is the male lions who are expelled from the pride, not the females. As a result one will commonly find groups of young lions, but never groups of young lionesses. The young lions survive just fine.
Added to that, stallions have a far, far more rigid control over their harem than any lion does.
Ok. so it is possible to over crossbreed a tank of gold fish?
Other posters have covered how animals manage to avoid incest, or don’t, for most large critters.
Oddly enough, some insects not only don’t avoid incest, they are pretty much obligated to practice incest. Stephen J. Gould wrote a couple of essays on wasps, aphids, and midges that practice incest either exclusively or occasionally.
Some years back, my sister owned a male, purebred Italian greyhound, and on one occasion she sent the dog back to the breeder to provide stud service with his mother. Apparently, this was not out of the ordinary.
OTOH, my sister’s “fee” was that she got any males from the resulting litter (turned out to be just one), and that male was probably the stupidest dog I’ve ever encountered. He got his ass kicked by my mom’s cat every time my sister brought him over, and just never learned to leave that cat alone. He was also smaller than typical for the breed.