Incest is generally frowned upon (to say the least) among most humans, but I’m wondering if animals know enough to know when they’re mating with their brother/sister/aunt/father. I would imagine a mother would know not to mate with her son.
The social taboos don’t exist, of course, but is there some genetic instinct among animals not to mate with a close relative?
I don’t think so. Inbreeding is actually fairly common in the animal kingdom, and some domestic breeding programs actually inbreed on purpose.
Robin
Cats will breed with their near relatives- it’s a problem for cat hoarders. They start out by taking in a couple of unaltered stray cats, and pretty soon they’ve got a large number of cats that breed indiscriminately.
There have been people who thought that, because their male and female cats were littermates, that it wasn’t necessary to spay and neuter them because they were brother and sister. That doesn’t stop the cats from breeding with each other.
Chimpanzees (cite any Jane Goodall book) frequently engage in “play sex” with their siblings when young.
But female chimps leave the troop when they’re old enough to mate. It’s faily common among social mammals that either the males or the females are ejected from or leave the group upon reaching sexual maturity. Whether or not this behavior evolved primarily to prevent incest is hard to know for sure.
If they have the choice, some animals will prefer to mate with unrelated individuals rather than close relatives. There has been quite a bit of research done on this subject in rodents.
Evolution of MHC genetic diversity: a tale of incest, pestilence and sexual preference.
Assorative mating in mice and the incest taboo
Incest avoidance and bonding between siblings in gerbils
This said, if animals don’t have a choice, they have no compunctions against mating with parents, offspring, or siblings.
As a veterinarian I can attest to the fact that I’ve seen several instances of bewildered owners finding out that their female animals are pregnant. The owners thought that impossible because the only intact male around the female was a close relative - brother or father and the owners assumed that they would observe the incest taboo.
Animals don’t generally care too much.
Is there a difference between tame and wild animals? Will related housecats mate, but lions won’t? How about among species (baboons won’t, but alligators will?)
I’m thinking I should have called this “inbreeding” and not incest. Incest has connotations that inbreeding does not.
I think it’s more a matter or whether the animal has a choice or not. Animals confined in a cage, or domestic animals together in a house, will be more likely to mate with relatives than if they had a choice of a wide variety of mates.
I believe inbreeding avoidance has been best studied in mammals. Offhand I don’t recall studies that have demonstrated it in other groups, but it may exist.
I’ve seen at least one nature program where a couple of young lions take over a pride, kill the young cubs and mate with the females one of which was their mother. So it does seem to happen
Do the Ozarks and the rural south count as part of the animal kingdom?
Well we had two kittens and were rather surprized when they started bonking.
Not that we thought they wouldn’t, but they were very young.
Gerald Durrell wrote a book about his time as a trainee keeper at Whipsnade, one of his points was that most people would be rather alarmed by the amount of incest that took place.
Is the risk of genetic mutation not that great among animals?
Valteron. Probably a bit out of place in General Questions.
samclem GQ moderator
Assume it’s the same, but the risk from inbreeding doesn’t come from “inbreeders having more mutants”, it comes from “negative recessive genes having a greater chance to pair up when the two parents have said gene; and related parents having a greater chance of having common genes”. IOW: it’s not a mutation that happens as the bunnies breed, but something they both had before getting horny.
The thing is… if you were the last lass on earth, and the last lad was your brother and you were both as horny as… as horny rabbits… perhaps you would forget the taboos (or me and one of my bros, eh, not singling anybody out).
If hens had an incest taboo, chicken farms wouldn’t have a single cock.
Nava:
The Biblical story of Lot and his daughters is exactly this case, as long as “being horny” and “feeling a duty to perpetuate the species” are identical…they certainly can’t be too different. FWIW, the Bible does not condemn them for it.
The book Dr. Tatiana’s Sex Advice to All Creation is a very well written overview of the biology of sexual reproduction.
According to this text, incest is common among some species of insects and crustaceans.
Well… Incest is alive and well in my sheep herd. I will say the mother of my ex-ram did resist more than I would think was normal but probably more of a response to her fairly young son “acting that way”. She ran around head butting him until she figured out that he was twice as big as she is and was just going to get herself killed (he was very reluctant to fight back, he just wanted the “love”). She ended up having an outstanding set of triplets, no two-headed specimens. I did recently sell him though, it was getting a little too “close” in my little flock.
Those lions, they’re really know how to party.
So did Hal Briston
::d&r:: 