# How many generations needed until breeding between descendants doesn't matter? **URL:** \ **Category:** Factual Questions\ **Created:** [June 15, 2025, 3:59pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658 "2025-06-15T15:59:50Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [June 16, 2025, 6:26pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/21 "2025-06-16T18:26:59Z")
> [@md-2000](#): > > Sounds a lot like North America today, except for the much smaller, less diverse gene pool. As a result, some people may not be terribly familiar with their extended families. I don’t understand that - what does the size or diversity of a gene pool have to do with knowing your extended family? Plenty of people in the US barely know who their first cousins and don’t know second cousins at all. The size and diversity has a lot to do with why any two random Icelanders are likely to be at least sixth or seventh cousins to each other - but that’s a different question than whether they know who their second cousins are. That well-documented genealogy means that two Icelanders can compare their family trees in a way two Americans generally can’t - but that just means an Icelander will be able to look at the website and find out if the new boyfriend is their third cousin once removed while the American might not know until the wedding where the bride’s grandfather recognizes his cousin who is the groom’s great aunt. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 16, 2025, 6:35pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/22 "2025-06-16T18:35:22Z")
> [@Q.Q.Switcheroo](#): > > Though some communities have introduced pre-marriage screening for certain genetic diseases - e.g. Tay-Sachs tests for Ashkenazi Jews. If carriers still have as many children as they would otherwise have, though, just with non-carriers, then this would have no effect on the incidence of the gene. At least, not by itself: It’s also possible that some carriers might choose not to have children at all, or might do genetic testing on gametes or embryos to ensure non-carrier children, or whatever. ---
**Author:** ![echoreply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/echoreply/32/3641_2.png) [@echoreply](https://boards.straightdope.com/u/echoreply)\ **Post date:** [June 16, 2025, 6:35pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/23 "2025-06-16T18:35:59Z")
> [@Chronos](#): > > Keep doing that, and eventually you’ll breed the trait out of the population entirely It does not work this way, though. Unless you can identify carriers before they reproduce, the recessive allele will stay in the population. There are naturally occurring alleles where the recessive homozygous version is fatal, and those alleles persist in the population. Artificially removing the homozygote recessive individuals will change the ratio of alleles, but won’t (on its own) drive the recessive to 0. > [@StarvingButStrong](#): > > basically, how many generations apart would two people have to be that their genes have no more in common than those randomly picked pair? I don’t think I can answer this directly, because it is going to depend a tremendous amount on the population you’re talking about. Even if we defined that, it would still take knowledge of that populations level of background inbreeding. The modern way of thinking about this is runs of homozygosity (RoH) are stretches of DNA where an individual has inherited identical copies from both parents. Individuals who are more inbred will have longer and more frequent RoH. In humans isolated or bottlenecked populations will have long RoH, and admixed ( “mixed race”) individuals will have short RoH. Different traits respond differently to different levels of RoH. If I recall, some traits like height are reduced (on average) in individuals with greater RoH, but other traits show no correlation with RoH. These are all empirical questions that can be tested in large samples, like the UK Biobank. A search for runs of homozygosity and inbreeding depression should find some articles. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 16, 2025, 6:47pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/24 "2025-06-16T18:47:06Z")
> [@echoreply](#): > > It does not work this way, though. Unless you can identify carriers before they reproduce, the recessive allele will stay in the population. There are naturally occurring alleles where the recessive homozygous version is fatal, and those alleles persist in the population. Artificially removing the homozygote recessive individuals will change the ratio of alleles, but won’t (on its own) drive the recessive to 0. Well, by the simple (continuous) models, the rate of the recessive gene would asymptotically approach 0, but in reality, you can’t have fewer than 1 individual with the gene, so an asymptotic approach to 0 will eventually actually reach 0. And it’ll happen much more quickly if you’re deliberately inbreeding the organisms, as is done with purebred animals. ---
**Author:** ![echoreply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/echoreply/32/3641_2.png) [@echoreply](https://boards.straightdope.com/u/echoreply)\ **Post date:** [June 16, 2025, 7:16pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/25 "2025-06-16T19:16:09Z")
> [@Chronos](#): > > the rate of the recessive gene would asymptotically approach 0 Yes, you can use Hardy-Weinberg equilibrium to compute the decrease in the recessive (q) allele in each generation. If you have a small population and fast enough generation times, then you could eliminate it. Particularly if you can cull (or sterilize) entire litters and the parents whenever a homozygous individual is born to eliminate carriers from the breeding pool. In humans though, with a generation time of one generation per generation, this could take longer than your thousand year reich if you just rely on eliminating the homozygous. There are also other troublesome issues in the real world, such as complex traits that involve many genes, de novo mutations, desirable alleles being in disequilibrium with undesirable ones, and loss of genetic diversity by removing haplotypes (and their people) from the gene pool. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 17, 2025, 1:13am UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/26 "2025-06-17T01:13:30Z")
But it could all be done viss a computer! ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 17, 2025, 2:05am UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/27 "2025-06-17T02:05:49Z")
> [@echoreply](#): > > In humans though, with a generation time of one generation per generation, this could take longer than your thousand year reich if you just rely on eliminating the homozygous. That’s true, too. I was just eliding over all of that because it doesn’t even come up unless you ignore the ethical problems with selective breeding of humans. ---
**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:** [June 17, 2025, 3:32am UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/28 "2025-06-17T03:32:28Z")
> [@StarvingButStrong](#): > > And menopause pretty much takes care of grandmother/grandson having children. Er… no. Let’s assume a family where the women have their first child at, say, 12. Definitely young by our standards, but all too often physically possible. So, a woman has a child as 12. Her child has a child at twelve, resulting in a 24 year old grandmother. The grandchild has a child at 12, resulting in a 36 year old great-grandmother And the great-grandchild has a child at 12, so the 48 year old woman is now a great-grandmother. And quite likely has NOT gone through menopause and, though a bit unlikely, could potentially give birth to a child both her own child _and her own great-great-grandchild._ Although it’s actually more probable from a fertility standpoint that she’d give birth to a child/grandchild (at 24) or child/great-grandchild (at 36) What about a child/great-great-great-grandchild? Under this scenario that would be when the originally woman was 60. Huh. According to the Guinness information I could google the oldest _natural_ conception was at 58 with a child being birthed when the woman was 59. Um… _extremely_ unlikely but actually possible in theory. So no, menopause is not a barrier to a grandmother/grandson pairing. It is a potential barrier to hold old of a woman that could happen to, but not to the pairing occurring. Yes, this post is full of squick. I am not off to find brain bleach. ---
**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:** [June 17, 2025, 3:49am UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/29 "2025-06-17T03:49:46Z")
> [@md-2000](#): > > Also brings to mind the history of Easter Island, where supposedly one or two large canoes landed a thousand years ago, and by the time European sailing ships encountered them, they’d populated the Island with up to several thousand people before a serious ecological collapse. No indication that those inhabitants were any less robust than a random pool of humans. Quite a few isolated populations in the Pacific where, shall we say, very active in eliminating bad traits. They were basically a breeding population of humans that culled themselves. Nomadic hunter-gatherers likewise did some culling (birth defects incompatible with their lifestyle, and in some cases always reducing multiple births down to a single child post-birth. There are documented instances of small groups practicing female infanticide to control the population). This had the effect of keeping isolated populations that were so small inbreeding was inevitable healthy enough to continue to survive. You can still get recessive traits that are seen as negative (such as achromotopsia on the island of Pingelap affecting one in ten natives) but as long as people with the trait can survive and reproduce the trait won’t disappear. But you’ll never _entirely_ eliminate negative traits because there’s always a certain amount of mutation in each generation. > [@Chronos](#): > > It’s also possible that some carriers might choose not to have children at all, or might do genetic testing on gametes or embryos to ensure non-carrier children, or whatever. I’ve know a number of people who elected NOT to reproduce at all out of concern for passing on traits they felt undesirable. I have personal knowledge of one couple who used _in vitro_ fertilization and pre-implantation testing to avoid having a child with debilitating gene possessed by one of the parents. Otherwise, they probably would not have had children. So, not only is it possible to “scrub” a gene from reproduction, thereby ensuring subsequent generations of a family will never have to worry about that negative thing ever again (outside of spontaneous mutation) it is actually happening now. ---
**Author:** ![PatrickLondon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/patricklondon/32/4422_2.png) [@PatrickLondon](https://boards.straightdope.com/u/PatrickLondon)\ **Post date:** [June 17, 2025, 10:40am UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/30 "2025-06-17T10:40:46Z")
> [@LSLGuy](#): > > What you need for diversity are people not in your nearby family tree. Which is also why isolated villages historically turned into inbred basket cases And the Spanish Habsburgs. As for the Bill in the UK against first cousin marriage, it’s brought in under a provision that gives it no priority unless it either gets unanimous support or is adopted by the government. No chance, therefore, though I could imagine the government taking it up as a health/education issue rather than one of legal proscription. ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [June 17, 2025, 12:56pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/31 "2025-06-17T12:56:33Z")
> [@md-2000](#): > > Also brings to mind the history of Easter Island, where supposedly one or two large canoes landed a thousand years ago, and by the time European sailing ships encountered them, they’d populated the Island with up to several thousand people before a serious ecological collapse. No indication that those inhabitants were any less robust than a random pool of humans. Recent studies have shown that the Easter Island population wasn’t as isolated as previously thought (and that the collapse wasn’t as severe as previously thought). [https://doi.org/10.1038/s41586-024-07881-4](https://doi.org/10.1038/s41586-024-07881-4) > “Two prominent contentions have arisen from the extensive study of Rapa Nui. First, the history of the Rapanui has been presented as a warning tale of resource overexploitation that would have culminated in a major population collapse—the ‘ecocide’ theory2,3,4. Second, the possibility of trans-Pacific voyages to the Americas pre-dating European contact is still debated. Here, to address these questions, we reconstructed the genomic history of the Rapanui on the basis of 15 ancient Rapanui individuals that we radiocarbon dated (1670–1950 ce) and whole-genome sequenced (0.4–25.6×). We find that these individuals are Polynesian in origin and most closely related to present-day Rapanui, a finding that will contribute to repatriation efforts. Through effective population size reconstructions and extensive population genetics simulations, we **reject** a scenario involving a severe population bottleneck during the 1600s, as proposed by the ecocide theory. Furthermore, the ancient and present-day Rapanui carry similar proportions of Native American admixture (about 10%). Using a Bayesian approach integrating genetic and radiocarbon dates, we estimate that this admixture event occurred about 1250–1430 ce.” ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 17, 2025, 1:33pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/32 "2025-06-17T13:33:40Z")
> [@Andy\_L](#): > > Here, to address these questions, we reconstructed the genomic history of the Rapanui on the basis of 15 ancient Rapanui individuals that we radiocarbon dated (1670–1950 ce) and whole-genome sequenced (0.4–25.6×). We find that these individuals are Polynesian in origin and most closely related to present-day Rapanui, a finding that will contribute to repatriation efforts. Given that the nation of the remains and of the modern people have the same name, it sounds like this was something that was already well-known? ---
**Author:** ![Gordon\_G](https://avatars.discourse-cdn.com/v4/letter/g/3da27b/32.png) [@Gordon\_G](https://boards.straightdope.com/u/Gordon_G)\ **Post date:** [June 17, 2025, 1:51pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/33 "2025-06-17T13:51:56Z")
It’s common for laymen to overestimate the danger of cousin marriage. Marriage of 1st cousins does not have particularly high risk (unless part of a group where cousin marriages are quite common since consanguinity can “build up” in a complex pedigree). Marriage more distant than 1st cousins is seldom a problem. Mating with one’s great-grandparent yields the same inbreeding coefficient as 1st cousin mating. (Remember that _both_ grandfather and grandmother contribute to inbreeding in marriage of _full_ cousins.) It is also common to over-estimate the inbreeding in royal pedigrees. Some accuse the British royal family of inbreeding. Nonsense! Of course _some_ royal families were inbred: As a result of much incest, the King of Spain Carlos II _“El Hechizado”_ was slightly more inbred than the product of sibling marriages; his inbreeding symptoms were _extreme_. Note that if both mother and father are _very_ inbred, but inbred from _different families_, the inbreeding coefficient drops to zero in their offspring! (In fact the offspring may have genes slightly better than average since inbreeding eliminates some bad alleles due to early deaths.) ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [June 17, 2025, 1:58pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/34 "2025-06-17T13:58:37Z")
> [@DrDeth](#): > > Most laws allow 2nd cousins to marry, iirc. And some allow 1st cousins to marry as long as they are not ortho-cousins. Genetically speaking, “Variety is the spice of life.” Reproducing via a first or even second cousin is genetically unwise and markedly riskier in terms of possible genetic defects. I can’t imagine why it is legal. Political reasons, perhaps? ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [June 17, 2025, 5:19pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/35 "2025-06-17T17:19:55Z")
Political reasons in England and thus Commonwealth countries being that Henry VIII wanted to marry his deceased wife’s cousin five centuries ago. And yet, the possibility of first cousin marriage within England and other countries does not appear to have contributed to major genetic issues over the past five centuries. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 17, 2025, 7:04pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/36 "2025-06-17T19:04:55Z")
> [@Gordon\_G](#): > > It’s common for laymen to overestimate the danger of cousin marriage. Marriage of 1st cousins does not have particularly high risk (unless part of a group where cousin marriages are quite common since consanguinity can “build up” in a complex pedigree). Marriage more distant than 1st cousins is seldom a problem. Correct- good point- unless you keep doing it, over and over. > **[Cousin marriage](https://en.wikipedia.org/wiki/Cousin_marriage)** > > A cousin marriage is a marriage where the spouses are cousins (i.e. people with common grandparents or people who share other fairly recent ancestors). The practice was common in earlier times and continues to be common in some societies today. In some jurisdictions such marriages are prohibited due to concerns about inbreeding. Worldwide, more than 10% of marriages are between first or second cousins. Cousin marriage is an important topic in anthropology and alliance theory. > In some cultures... _While recent studies have cast serious doubt on whether cousin marriage is as dangerous as is popularly assumed_… I_n April 2002, the Journal of Genetic Counseling released a report which estimated the average risk of [birth defects](https://en.wikipedia.org/wiki/Congenital) in a child born of first cousins at 1.1–2.0 [percentage points](https://en.wikipedia.org/wiki/Percentage_points) above the average base risk for non-cousin couples of 3%, or about the same as that of any woman over age 40_ > [@Jasmine](#): > > Genetically speaking, “Variety is the spice of life.” Reproducing via a first or even second cousin is genetically unwise and markedly riskier in terms of possible genetic defects. I can’t imagine why it is legal. Political reasons, perhaps? Only if a family keeps doing it. If you marry your cousin, the risks are slight. However, if all your kids marry _their_ cousins, and so forth, things can get bad. > [@Northern\_Piper](#): > > And yet, the possibility of first cousin marriage within England and other countries does not appear to have contributed to major genetic issues over the past five centuries. Correct. Good point. ---
**Author:** ![zimaane](https://avatars.discourse-cdn.com/v4/letter/z/a3d4f5/32.png) [@zimaane](https://boards.straightdope.com/u/zimaane)\ **Post date:** [June 17, 2025, 7:13pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/37 "2025-06-17T19:13:00Z")
In some cultures, cousin marriage is allowed, and even preffered over marrying some who is not related. The reasons are complex, but a lot of boils down to not risking bringing an outsider into the extended family. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 17, 2025, 7:30pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/38 "2025-06-17T19:30:08Z")
> [@Northern\_Piper](#): > > Political reasons in England and thus Commonwealth countries being that Henry VIII wanted to marry his deceased wife’s cousin five centuries ago. Surely, the simpler solution would have been to amend the inbreeding laws to apply only to blood relatives. It’s interesting that, in some cultures, a widower could be prohibited from marrying his wife’s cousin, while in other cultures, a man might be obligated to marry his brother’s widow. ---
**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:** [June 17, 2025, 8:56pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/39 "2025-06-17T20:56:18Z")
> [@Jasmine](#): > > Reproducing via a first or even second cousin is genetically unwise and markedly riskier in terms of possible genetic defects. I can’t imagine why it is legal. Political reasons, perhaps? Sometimes practical - if you’re living on a low-population where distance travel is very difficult folks will usually wind up related to each other after a few generations people the gene pool is limited. This happened in some areas of Appalachia - mountainous terrain pre-motorcar made distance travel quite difficult so finding someone you were truly, completely unrelated to after a century or so became nearly impossible. Once automobiles arrived people traveled more and inbreeding dropped. Religion and other cultural norms can also limit gene pools, even when living in densely populated areas. There was a Native American tribe in an arctic area that practiced polyandry. Every woman had two husbands because (apparently) it took the efforts of two male hunters to provide for a woman and her children. They also practiced female infanticide to maintain the 2:1 male to female ratio. I don’t remember the name of the group or if they still maintain polyandry or have changed with exposure to the outside world. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [June 17, 2025, 10:57pm UTC](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658/40 "2025-06-17T22:57:26Z")
> [@doreen](#): > > I don’t understand that - what does the size or diversity of a gene pool have to do with knowing your extended family? Sorry - poor composition. the tendency to serial pairing (?) where the parents of a first child move on to marry/pair with others, often with little contact afterwards, means the children have little contact with one parent’s (presumably the father’s) extended family, and the relative connections become very tangled. If Ann and Bob have a child, Charles, then Bob moves on to Dora and has a child Ellie, and then moves on to Frieda… Other than knowing they have a half-brother or sister, the next generation may not know the connection. If Bob moves all over the country, New York to Chicago to LA, then the risk of the offspring of Charles and Ellie becoming “acquainted” is less; Or Bob’s sister and her offspring in the mix; etc.; in a small environment like Iceland, apparently this is a larger risk. Estranged baby-daddy and no regular contact with that side of the family is not a new thing or unusual. One aspect of Icelandic socety according to the article on the “relationship app” was that a couple having a child early in life and then moving on to other partners later was not uncommon. > [@Broomstick](#): > > Quite a few isolated populations in the Pacific where, shall we say, very active in eliminating bad traits. What makes Easter Island interesting is that the other islands were well aware of each other and traded regularly, so not really isolated gene pools. Easter Island seems to have been completely isolated - the articles suggest they managed to reach and trade with South America for a while, until they could no longer put together decent sized vessels. IIRC one of the early explorers mentioned when they arrived, the few small canoes were stitched together from pieces, since the large trees were all gone. Jared Diamond’s _Collapse_ has a discussion of Easter Island. Infanticide as a means of population control was common in many early societies. Sadly, female infanticide was more common because the number of women determined the number of births, while extra men were just more labour (or warriors). [Previous page](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658.md?page=1) [Next page](https://boards.straightdope.com/t/how-many-generations-needed-until-breeding-between-descendants-doesnt-matter/1019658.md?page=3)