Why does incest result in birth defects? - eviltoast

Just to be well and truly fuckin clear. I am not now nor have I ever been nor will I ever be contemplating shagging a family member.

  • where_am_i@sh.itjust.works
    link
    fedilink
    arrow-up
    1
    ·
    9 months ago

    And so the reason for malfunctioning alleles not to be dominant is probably natural selection. E.g. you select away bad dominant alleles, but if we assume a low pct of inbreeding, the recessive ones are irrelevant and so they stay.

    • Th4tGuyII@kbin.social
      link
      fedilink
      arrow-up
      2
      ·
      9 months ago

      Pretty much…

      Recessive malfunctions can hide away amongst carriers for generations before manifesting any deformities, during which time they have no effect on the carrier’s survival, so there’s very little selective pressure against them.

      Dominant malfunctions which cause deformities simply can’t hide away, so have enormous selective pressure against them.

      Interestingly enough though, there are times where dominant malfunctions can survive that pressure…
      For example, having Sickle cell disorder increases your resistance to Malaria, so even though the full form is rarely passed on, the single allele form (which caused partial disorder) is passed on due to a slight positive selection pressure.