# How do wild animals avoid incest and inbreeding? **URL:** \ **Category:** Factual Questions\ **Created:** [September 15, 2005, 5:02am UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735 "2005-09-15T05:02:32Z")\ **Posts on this page:** 16\ **Page:** 2
**Author:** ![Tom\_Tildrum](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@Tom\_Tildrum](https://boards.straightdope.com/u/Tom_Tildrum)\ **Post date:** [September 10, 2010, 2:16pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/21 "2010-09-10T14:16:47Z")
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. ---
**Author:** ![Annie-Xmas](https://avatars.discourse-cdn.com/v4/letter/a/ecc23a/32.png) [@Annie-Xmas](https://boards.straightdope.com/u/Annie-Xmas)\ **Post date:** [September 10, 2010, 2:39pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/22 "2010-09-10T14:39:55Z")
Do zombie animals hump their own relatives? ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [September 10, 2010, 4:01pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/23 "2010-09-10T16:01:08Z")
> [@Leaffan](#): > > Surely inbreeding is something that limits the gene pool over many successive generations, and doesn’t at all mean that an entire litter will die because of “inbreeding.” Limiting the gene pool potentially makes offspring more susceptible to disease, or malformations, if a gene or set of genes is missing. It’s not an instant killer. Doesn’t inbreeding sometimes happen when a population becomes isolated, and sometimes lead to speciation? ---
**Author:** ![flano1](https://avatars.discourse-cdn.com/v4/letter/f/f14d63/32.png) [@flano1](https://boards.straightdope.com/u/flano1)\ **Post date:** [September 10, 2010, 7:29pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/24 "2010-09-10T19:29:03Z")
[QUOTE [http://lynx.uio.no/jon/lynx/cheetahg.htm](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. ---
**Author:** ![Arrogance\_Ex\_Machina](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/arrogance_ex_machina/32/192_2.png) [@Arrogance\_Ex\_Machina](https://boards.straightdope.com/u/Arrogance_Ex_Machina)\ **Post date:** [September 10, 2010, 8:49pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/25 "2010-09-10T20:49:41Z")
> [@md2000](#): > > I remember reading once about the cultural result of kibbutz life in Israel; some psychologist observed that guys were less interested in the girls they were raised with than with strangers. Unrelated children are raised in an almost communal lifestyle as close as brothers and sisters - and the theory was that there’s an instinctive desire for strangers instead. (Of course, like any human urge, the rule is never 100%). [The obligatory Wikipedia link.](http://en.wikipedia.org/wiki/Westermarck_effect#Westermarck_effect) 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.](http://en.wikipedia.org/wiki/Genetic_attraction) ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [September 10, 2010, 10:36pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/26 "2010-09-10T22:36:42Z")
> [@micco](#): > > The [Ngorongoro lions](http://www.ntz.info/gen/n00443.html) are an example of a group that is significantly inbred because of their small numbers and isolation from other groups. 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. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [September 11, 2010, 12:13am UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/27 "2010-09-11T00:13:32Z")
> [@rainy](#): > > I can’t find a cite now, but I’ve always heard that straight line breeding (fathers impregnating daughters) doesn’t produce the defects that brother sister crosses do. 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. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [September 11, 2010, 5:40am UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/28 "2010-09-11T05:40:25Z")
> [@Der\_Trihs](#): > > Another possible example would in fact be humans; women can according to some studies detect how similar the [major histocompatibility complex](http://en.wikipedia.org/wiki/Major_histocompatibility_complex) of a man is to that of her father by scent, and [tend to find](http://en.wikipedia.org/wiki/Major_histocompatibility_complex#MHC_and_sexual_selection) the scent of males with highly similar MHCs a turn off. 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. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [September 11, 2010, 7:57am UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/29 "2010-09-11T07:57:20Z")
> [@astro](#): > > Just curious. Humans have complex social arrangements and to prevent this. How do animals manage to avoid incest and inbreeding? > > As a second question, beyond animals in general, specifically how do the great apes prevent this? Through chance. ---
**Author:** ![kimera](https://avatars.discourse-cdn.com/v4/letter/k/f0a364/32.png) [@kimera](https://boards.straightdope.com/u/kimera)\ **Post date:** [September 12, 2010, 7:33pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/30 "2010-09-12T19:33:02Z")
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. ---
**Author:** ![Shekinah](https://avatars.discourse-cdn.com/v4/letter/s/7ab992/32.png) [@Shekinah](https://boards.straightdope.com/u/Shekinah)\ **Post date:** [January 11, 2011, 4:44am UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/31 "2011-01-11T04:44:32Z")
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? ---
**Author:** ![RadicalPi](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/radicalpi/32/9806_2.png) [@RadicalPi](https://boards.straightdope.com/u/RadicalPi)\ **Post date:** [January 11, 2011, 6:40am UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/32 "2011-01-11T06:40:09Z")
> [@astro](#): > > It may not be incestual inbreeding, but limited mate selection and a small population leads to a raft of [genetic diseases](http://www.cbsnews.com/stories/2005/06/08/60II/main700519.shtml) that affect the Amish. To say nothing of the Hapsburgs: From [Inbreeding - Wikipedia](http://en.wikipedia.org/wiki/Inbreeding) > [@](#): > > The most famous example of a genetic disorder aggravated by royal family intermarriage was the House of Habsburg, which inmarried particularly often. Famous in this case is the Habsburger (Unter) Lippe (Habsburg jaw/Habsburg lip/“Austrian lip”), typical for many Habsburg relatives over a period of six centuries. The condition progressed through the generations to the point that the last of the Spanish Habsburgs, Charles II of Spain, could not properly chew his food. (See mandibular prognathism.) > > Besides the jaw deformity, Charles II also had a huge number of other genetic physical, intellectual, sexual, and emotional problems. It is speculated that the simultaneous occurrence in Charles II of two different genetic disorders: combined pituitary hormone deficiency and distal renal tubular acidosis could explain most of the complex clinical profile of this king, including his impotence/infertility which in last instance led to the extinction of the dynasty. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [January 11, 2011, 1:21pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/33 "2011-01-11T13:21:41Z")
> [@Shekinah](#): > > 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? 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. ---
**Author:** ![FuzzyOgre](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@FuzzyOgre](https://boards.straightdope.com/u/FuzzyOgre)\ **Post date:** [January 11, 2011, 1:36pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/34 "2011-01-11T13:36:51Z")
Ok. so it is possible to over crossbreed a tank of gold fish? ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 11, 2011, 2:01pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/35 "2011-01-11T14:01:30Z")
> [@astro](#): > > Just curious. Humans have complex social arrangements and to prevent this. How do animals manage to avoid incest and inbreeding?? 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. ---
**Author:** ![Mister\_Rik](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mister_rik/32/491_2.png) [@Mister\_Rik](https://boards.straightdope.com/u/Mister_Rik)\ **Post date:** [January 11, 2011, 4:23pm UTC](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735/36 "2011-01-11T16:23:26Z")
> [@t-bonham@scc.net](#): > > 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. 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. [Previous page](https://boards.straightdope.com/t/how-do-wild-animals-avoid-incest-and-inbreeding/321735.md?page=1)