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Will last 2 Wolly-rhinos (siblings) in US mate?

  1. Jul 22, 2013 #1
    Apparently wolly rhinos are on the brink of extinction and there are only two left in America, a brother and sister, that what, zoologist are trying to get to mate. Isn't there some instinctual taboo the siblings will detect preventing them from mating? Surely this can be argued on Darwinian grounds right?

    I just cannot see how selective pressures layered down in their genotypes would allow them to mate easily, or "naturally" I mean.

    Or is it common for (mammalian) siblings to mate in Nature?
  2. jcsd
  3. Jul 22, 2013 #2
    No and no and yes.

    There is nothing that prevents sibling breeding. It is a very good way of removing bad genes from a population.
  4. Jul 22, 2013 #3
    I thought the opposite was true. Inbreeding increases the chance for bad recessive genes to show. I could definitely see how natural selection would dictate a sort "taboo" against it.

    I know, Wikipedia isn't a great source but check this link out.

  5. Jul 22, 2013 #4
    In the Wikipedia article about inbreeding at least as it relates to lion prides:

    "There is no mechanism for preventing inbreeding or to ensure outcrossing"

    And I guess I'm surprised to see that. If inbreeding is an undesirable trait, then isn't Natural Selection deselecting (reducing their frequency) this practice of breeding? Surely in the wild, non-related potential sexual partners are seen as more fit than related partners since I assume non-related sexual selection in Nature dominates over related paring. If that's true as I believe it is, then there must be some selective force at work in the female selection process choosing appropriate non-related mates over related ones.

    I'm not sure about this however so I wish to run a test: observe two sets of wolly-rhinos: The first set, completely unrelated, bring them (male and female) together and observe their behavior. Second set: brother and sister likewise.

    Am I to believe I will not observe any difference in behavior between the sets?
    Last edited: Jul 22, 2013
  6. Jul 22, 2013 #5
    It does seem odd(at least to a math major, rather than a biologist), given the negative effect of inbreeding on a gene pool, that animals have no predisposition against inbreeding, and yet to my (limited)knowledge it does not happen often.

    Is it possible that inbreeding does occur more often that we are assuming, only Natural Selection weeds out these less fit offspring before they are allowed to reproduce?

    Any experts out there?

    Definitely an interesting question. I hope someone can shed some more light on this.
    Last edited: Jul 22, 2013
  7. Jul 22, 2013 #6


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    You aren't thinking this through properly.

    If there the second set don't inbreed, they are guaranteed to go extinct in one generation.

    If they do inbreed, they may or may not go extinct.

    So which option does natural selection favor?
  8. Jul 22, 2013 #7
    Wait a minute now. You're referring to just the two wolly-rhinos and in that particular case, yes, I agree with you: inbreeding is preferred over extinction. But in the wild, there are usually more than two individuals, even whole breeding populations. And in that population, inbreeding is to my knowledge, even the Biology expert on the CBS video about it argued, inbreeding is not done often.

    Why then in the wild is inbreeding not done often? The females in the wild, almost exclusively, determines the mating paring: she chooses her mate carefully I believe (from watchin' Nature programs) so I assume she's using some sort of criteria in that selection.

    I wish to argue that perhaps the female has a way of detecting inbreeding during her choice for a mate, and in a large breeding population when it's not do or die in the case of the two wolly-rhinos, she avoids inbreeding.
  9. Jul 22, 2013 #8
    Say what???

    Not sure what y'all are talking about, but it might help to bear a few facts in mind.

    Woolly Rhinos- as in wool, obviously- have been extinct for 10,000 years.
    Mating in a zoo is more unnatural than mating between siblings.
    If there were two rare rhinos in a zoo, they would have likely grown up with no social modeling. In most mammals prohibitions against close breeding typically come from social learning more than instinct.
    Study after study has shown that Wiki is pretty reliable.
  10. Jul 22, 2013 #9
    Fine, I made a small mistake. Those two Sumatran rhinos then:

    http://www.cbsnews.com/8301-205_162-57594746/ohio-zoo-tries-to-mate-rhino-siblings/rare rhinos [Broken]

    That would offer some solution to the problem of why it doesn't happen often.

    Can someone contact Jane Goodall? Is she a member of PF? Well why not? I would like her opinion in this matter. I am not yet completely convinced.
    Last edited by a moderator: May 6, 2017
  11. Jul 23, 2013 #10


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    Depends upon the species and social network does it not?
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