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I'm sure a proper taxonomist would be able to speak more authoritatively, but I rather doubt it. Subspecies tend not to interbreed for whatever reason, whether

I'm sure a proper taxonomist would be able to speak more authoritatively, but I rather doubt it. Subspecies tend not to interbreed for whatever reason, whether geographic isolation, sexual selection, or other factors, whereas humans rather enthusiastically behave in the opposite fashion. I don't think one could convincingly argue that humans are geographically isolated, either. You might be able to make an argument that human races are akin to pet breeds, but my understanding is that zoologists don't really consider pet breeds as subspecies.

jimmyk 10y ago
>whereas humans rather enthusiastically behave in the opposite fashion. What are the worldwide rates of interracial marriage? I see in the US (a country where the majority race makes up about 60% of the population) that it's now around 10% for new marriages, and has historically been much much lower. If your statement were true, wouldn't we expect to see much higher rates of interracial marriage than 10% in the US? Wouldn't we expect that the historical rate was also much higher?
- bzbarsky 10y ago
  Please don't confuse interracial marriage (a social construct, and prevented by law in many places in the US until 1967) with interracial breeding (the thing that would matter for biological definitions). They can have very different rates, and surely did in the US in the 18th and early 19th century.
  - jimmyk 10y ago
    I'm not suggesting they're the same thing at all. They're just the best approximation I could quickly find any decent statistics for. What were these higher rates you refer to? Were they as high as would be expected if humans 'enthusiastically' interbred, or even as high as would be expected if humans had no preference one way or the other?
    - bzbarsky 10y ago
      > What were these higher rates you refer to? I don't have exact numbers, and no one does that I've seen. Due to social disapproval people tended to keep such activities somewhat hidden. That said, genetic analysis of African-American populations shows a significantly higher percentage of European-origin genes than can be accounted for by marriage rates, yes? > Were they as high as would be expected if humans 'enthusiastically' interbred What rates would you expect? To make this more specific and avoid questions of lack opportunity vs lack of enthusiasm, what rate of slaveowners having children with at least one of their slaves would you expect under the "enthusiastic" hypothesis? (There's the complicating factor that in that situation at least one of the parties here might or might not have taken measures to avoid pregnancy even if sexual intercourse did occur; it's not clear to me how to account for that.)
      - jimmyk 10y ago
        >That said, genetic analysis of African-American populations shows a significantly higher percentage of European-origin genes than can be accounted for by marriage rates, yes? Yes, and a much lower percentage of European genes than you'd expect if there were no preference one way or the other for interracial breeding, and a much much lower percentage than you'd expect if humans enthusiastically interbred. >What rates would you expect? To make this more specific and avoid questions of lack opportunity vs lack of enthusiasm, what rate of slaveowners having children with at least one of their slaves would you expect under the "enthusiastic" hypothesis? In the early 1800's, blacks were about 20% of the population, and whites were most of the rest. If there were no preference one way or the other, we'd expect 20% of children of white women to be fathered by black men, and 80% of children of black women to be fathered by white men. If the actual rates are lower than that, then some kind of self-segregation is happening. Pointing out that slavery or other social institutions limited the rate of interbreeding is not an argument in favor of the idea that humans enthusiastically interbreed. If when living in close proximity they tend to set up systems that limit interbreeding, that is evidence that they don't enthusiastically interbreed. >(There's the complicating factor that in that situation at least one of the parties here might or might not have taken measures to avoid pregnancy even if sexual intercourse did occur; it's not clear to me how to account for that.) We don't have to account for that because we're discussing rates of interracial breeding, not rates of interracial sex.

jimmyk 10y ago

>whereas humans rather enthusiastically behave in the opposite fashion. What are the worldwide rates of interracial marriage? I see in the US (a country where the majority race makes up about 60% of the population) that it's now around 10% for new marriages, and has historically been much much lower. If your statement were true, wouldn't we expect to see much higher rates of interracial marriage than 10% in the US? Wouldn't we expect that the historical rate was also much higher?

bzbarsky 10y ago
Please don't confuse interracial marriage (a social construct, and prevented by law in many places in the US until 1967) with interracial breeding (the thing that would matter for biological definitions). They can have very different rates, and surely did in the US in the 18th and early 19th century.
- jimmyk 10y ago
  I'm not suggesting they're the same thing at all. They're just the best approximation I could quickly find any decent statistics for. What were these higher rates you refer to? Were they as high as would be expected if humans 'enthusiastically' interbred, or even as high as would be expected if humans had no preference one way or the other?
  - bzbarsky 10y ago
    > What were these higher rates you refer to? I don't have exact numbers, and no one does that I've seen. Due to social disapproval people tended to keep such activities somewhat hidden. That said, genetic analysis of African-American populations shows a significantly higher percentage of European-origin genes than can be accounted for by marriage rates, yes? > Were they as high as would be expected if humans 'enthusiastically' interbred What rates would you expect? To make this more specific and avoid questions of lack opportunity vs lack of enthusiasm, what rate of slaveowners having children with at least one of their slaves would you expect under the "enthusiastic" hypothesis? (There's the complicating factor that in that situation at least one of the parties here might or might not have taken measures to avoid pregnancy even if sexual intercourse did occur; it's not clear to me how to account for that.)
    - jimmyk 10y ago
      >That said, genetic analysis of African-American populations shows a significantly higher percentage of European-origin genes than can be accounted for by marriage rates, yes? Yes, and a much lower percentage of European genes than you'd expect if there were no preference one way or the other for interracial breeding, and a much much lower percentage than you'd expect if humans enthusiastically interbred. >What rates would you expect? To make this more specific and avoid questions of lack opportunity vs lack of enthusiasm, what rate of slaveowners having children with at least one of their slaves would you expect under the "enthusiastic" hypothesis? In the early 1800's, blacks were about 20% of the population, and whites were most of the rest. If there were no preference one way or the other, we'd expect 20% of children of white women to be fathered by black men, and 80% of children of black women to be fathered by white men. If the actual rates are lower than that, then some kind of self-segregation is happening. Pointing out that slavery or other social institutions limited the rate of interbreeding is not an argument in favor of the idea that humans enthusiastically interbreed. If when living in close proximity they tend to set up systems that limit interbreeding, that is evidence that they don't enthusiastically interbreed. >(There's the complicating factor that in that situation at least one of the parties here might or might not have taken measures to avoid pregnancy even if sexual intercourse did occur; it's not clear to me how to account for that.) We don't have to account for that because we're discussing rates of interracial breeding, not rates of interracial sex.