4 ms·

More like no one would ever write about the need for Jews to outbreed, and if they did they would be rebuffed with a bazillion qualifications about the science

More like no one would ever write about the need for Jews to outbreed, and if they did they would be rebuffed with a bazillion qualifications about the science being uncertain. You only get to make sweeping statements when politics are on your side.

mikeash 11y ago
The Jews are several orders of magnitude more numerous than these small island populations, and even then there are genetic diseases that are far more common among them.
- formulaT 11y ago
  So since the science of recessive genes is so well understood, how big does the population need to be before scientists instruct the group to start outbreeding?
  - mikeash 11y ago
    Scientists typically don't outright instruct, but merely describe the consequences of various options. Sometimes (e.g. with global warming and the "keep dumping massive amounts of CO2 into the atmosphere" option) the consequences are "lots of people die horribly." But outright instructions are typically left up to the nice men with large guns.
    - formulaT 11y ago
      My point was that the quantity of the effect matters. If the science can't quantify how bad having a population of 150 is, then we can't say we understand things well enough to recommend "outbreeding", as the original post did.
      - mikeash 11y ago
        Why do you think it can't be quantified?
        formulaT 11y ago
        Let me put it another way: Can you or anyone else provide scientific studies that would directly back the claim The level of inbreeding on that island is quite scary. Although if they purged a lot of the deleterious alleles from the population, if they outbred with others, they could produce much healthier offspring and a lower likelihood of various genetic ailments. And not the general statements that have been made in this thread, but something that would pin down a specific numeric relationship between population size in humans, and health. EDIT: and for reference, the prevalence of Asthma may be purely due to the founder effect, not an effect of inbreeding per se. Two or three of the original settlers suffered from asthma[0]. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2222.1974.tb01373.x/pdf http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2222.1974....
        defen 11y ago
        http://www.nature.com/nature/journal/v397/n6717/abs/397344a0.html http://www.nature.com/nature/journal/v397/n6717/abs/397344a0... Rougly 1.5 new deleterious mutations per diploid genome per generation. If you have closely related individuals having children, there is a greater chance that the deleterious mutations will overlap.
        formulaT 11y ago
        But the question is how the population size relates to health, which you haven't answered here. You have numbers for the number of deleterious mutations, but that doesn't directly give a quantitative relationship between population size and health.
        defen 11y ago
        It's because your question isn't really properly formed. What do you mean by "health"? The chance of a person having a really shitty genetic disorder? The fitness cost of inbreeding as a function of coefficient of relationship? The probability that a bottlenecked population will go to zero due to harmful mutations, as a function of the bottleneck size?

mikeash 11y ago

The Jews are several orders of magnitude more numerous than these small island populations, and even then there are genetic diseases that are far more common among them.

formulaT 11y ago
So since the science of recessive genes is so well understood, how big does the population need to be before scientists instruct the group to start outbreeding?
- mikeash 11y ago
  Scientists typically don't outright instruct, but merely describe the consequences of various options. Sometimes (e.g. with global warming and the "keep dumping massive amounts of CO2 into the atmosphere" option) the consequences are "lots of people die horribly." But outright instructions are typically left up to the nice men with large guns.
  - formulaT 11y ago
    My point was that the quantity of the effect matters. If the science can't quantify how bad having a population of 150 is, then we can't say we understand things well enough to recommend "outbreeding", as the original post did.
    - mikeash 11y ago
      Why do you think it can't be quantified?
      - formulaT 11y ago
        Let me put it another way: Can you or anyone else provide scientific studies that would directly back the claim The level of inbreeding on that island is quite scary. Although if they purged a lot of the deleterious alleles from the population, if they outbred with others, they could produce much healthier offspring and a lower likelihood of various genetic ailments. And not the general statements that have been made in this thread, but something that would pin down a specific numeric relationship between population size in humans, and health. EDIT: and for reference, the prevalence of Asthma may be purely due to the founder effect, not an effect of inbreeding per se. Two or three of the original settlers suffered from asthma[0]. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2222.1974.tb01373.x/pdf http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2222.1974....
        defen 11y ago
        http://www.nature.com/nature/journal/v397/n6717/abs/397344a0.html http://www.nature.com/nature/journal/v397/n6717/abs/397344a0... Rougly 1.5 new deleterious mutations per diploid genome per generation. If you have closely related individuals having children, there is a greater chance that the deleterious mutations will overlap.
        formulaT 11y ago
        But the question is how the population size relates to health, which you haven't answered here. You have numbers for the number of deleterious mutations, but that doesn't directly give a quantitative relationship between population size and health.
        defen 11y ago
        It's because your question isn't really properly formed. What do you mean by "health"? The chance of a person having a really shitty genetic disorder? The fitness cost of inbreeding as a function of coefficient of relationship? The probability that a bottlenecked population will go to zero due to harmful mutations, as a function of the bottleneck size?