7 ms·

>That said, genetic analysis of African-American populations shows a significantly higher percentage of European-origin genes than can be accounted for by marri

by 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.

bzbarsky 10y ago
> blacks were about 20% of the population, and whites were most of the rest Yes, but this ignores the geographic inhomogeneity of both populations. For example, in Boston blacks were a much smaller fraction than 20%. Obviously if you're white and you live in a village in which everyone else is white too, your chances of having kids with someone who is not white are pretty low. This is why I suggested the more specific metric. > then some kind of self-segregation is happening. You're assuming either homogenous population distribution or a lot more population mobility than was happening at the time, I think. That is, you can conclude there is segregation in mating, but the extent to which it's _self_-segregation is a much harder question. Also, there were non-racial and non-geographic sources of segregation, like class/income. Note the comments in the wikipedia link below about black/Irish couples being a thing because the Irish were very poor. I'm pretty sure it's possible to account for these effects and discover that there were still racial self-segregation effects, but they will not be nearly as large as a naive 80-20 calculation like yours would suggest. They would, I expect, be larger than the (also existing!) self-segregation effects amongst white people of different ethnicities. An interesting thought experiment here is what you would expect to happen if you drop two (cis, straight) people of opposite gender but different races on a deserted island for a few years and how this compares to what happens when members of different subspecies are placed in proximity to each other with no other available mating partners. I don't know the answer to the latter, unfortunately. > Pointing out that slavery or other social institutions limited the rate of interbreeding I'm not doing that, precisely for the reasons you describe. I'm suggesting that limiting to my specific scenario removes issues of access due to population distribution effects and asks a specific question: given a white male who has the option of having children with black females (yes, the "enthusiasm" is very not symmetric here), what is the chance he will do so? Yes, this ignores the white-female-black-male case (though according to https://en.wikipedia.org/wiki/Mulatto#Antebellum_era https://en.wikipedia.org/wiki/Mulatto#Antebellum_era claims this was also going on; I'd have to look up numbers on "free people of color in the 1790–1810 censuses in the Upper South" to have an idea of how common it was). > We don't have to account for that because we're discussing rates of interracial breeding Well, we're discussing level of enthusiasm. Which as I said above was probably not symmetric, for reasons not necessarily related to race per se. I expect male white masters of female white indentured workers were also more enthusiastic about having kids than the workers were.
- jimmyk 10y ago
  >Yes, but this ignores the geographic inhomogeneity of both populations. For example, in Boston blacks were a much smaller fraction than 20%. The fact that the races end up living in different areas is strong evidence that when put in close proximity, different races don't want to interbreed. >You're assuming either homogenous population distribution or a lot more population mobility than was happening at the time, I think. That is, you can conclude there is segregation in mating, but the extent to which it's _self_-segregation is a much harder question. The vast majority of blacks came over as slaves. That means they all started out living in white areas. If they later chose to move away from white areas, for whatever reason, I don't see how anyone can possibly argue that they interbreed enthusiastically. When they find themselves in close proximity, they choose to segregate by race. >Also, there were non-racial and non-geographic sources of segregation, like class/income. Note the comments in the wikipedia link below about black/Irish couples being a thing because the Irish were very poor. The reason for segregation is not relevant, as long as it's not a one-off occurrence. If the segregation occurs because the dominant race prevents the subordinate race from succeeding economically, segregation is still occurring. >what is the chance he will do so? This doesn't give us any insight whatsoever into the question. We'd have to compare this to how white men behave when they have white women as slaves. >claims this was also going on There's no doubt that some interracial breeding was occurring. There's also no doubt that it's far less than would occur if there were no preference one way or the other for interracial breeding, and far far less than would occur if humans enthusiastically interbred, rather than self-segregating when given the opportunity. >Well, we're discussing level of enthusiasm. I don't think we're talking about how emotionally happy humans are when doing something, I think we're talking about how likely a certain event is to occur. The overall topic is whether humans can be considered sub-species, and the argument was that they shouldn't be because they interbreed enthusiastically. I'm pointing out that they don't actually end up interbreeding nearly as much as you'd expect if, for some reason, they had no way of distinguishing members of their own race from members of other races.
  - bzbarsky 10y ago
    > The fact that the races end up living in different areas is strong evidence that when put in close proximity, different races don't want to interbreed. That's true, but (1) that's not what I was talking about; I was talking about geographic inhomogeneity in original migration patterns and (2) this argument applies to ethnic/language/religious groups in general, not just races. More on this below. > That means they all started out living in white areas. Sort of. https://en.wikipedia.org/wiki/List_of_U.S._states_by_historical_population https://en.wikipedia.org/wiki/List_of_U.S._states_by_histori... shows that in 1850 South Carolina had 668k people of whom 385k were enslaved (hence not choosing where they lived, exactly). I didn't look up the number of free blacks, but I expect it was quite small given the laws about re-enslavement at the time. Anyway, more like the white people were living in a black area there. ;) But the real point is that for a while there various parts of the country did _not_ have appreciable black populations because slaves had not been brought there while your typical plantation had a much larger black population than white population. Voila, _involuntary_ geographic inhomogeneity. > The reason for segregation is not relevant That really depends on the question you're trying to answer. > We'd have to compare this to how white men behave when they have white women as slaves Sure. But the worst case for the "enthusiastic" hypothesis is that in this situation they always end up with kids, right? There may be value in comparing to this worst case, even. > There's also no doubt that it's far less than would occur if there were no preference one way or the other for interracial breeding Sure. I don't think anyone reasonable is arguing there was no preference on the matter. But if we're going to talk about sub-species, exact frequencies and cutoffs do matter if the whole thing is to make sense other than as a mood-affiliation labeling exercise ("_these_ two groups are different sub-species, but these two other groups are just less likely than average to intermarry/interbreed"). There is good data showing that breeding across religious and language boundaries is less common (and was even less common in the past) than breeding within those boundaries. And yet very few people nowadays will argue that, say, the French and the Germans are separate sub-species, or were separate sub-species 100 years ago. Yes, I realize that 100 years ago people were in fact likely to make just such an argument. :) Heck, inter-political-party marriage is a lot less common than within-political-party marriage in the US. And the rate of inter-political-party marriage, in the US, is dropping, while the rate of interracial marriage is rising. According to http://fivethirtyeight.com/features/how-many-republicans-marry-democrats/ http://fivethirtyeight.com/features/how-many-republicans-mar... the former is sill more common than the latter but not _that_ much more common. I expect the lines to intersect within the next decade or two if current trends continue... I guess we could argue that sub-species boundaries are malleable and they can merge or separate over a timescale of a few generations. That would be a valid take on the whole thing, I guess, but then I question the usefulness of the "sub-species" labeling; it seems to not have a useful definition in this situation from my point of view.

by jimmyk 10y ago

bzbarsky 10y ago

> blacks were about 20% of the population, and whites were most of the rest Yes, but this ignores the geographic inhomogeneity of both populations. For example, in Boston blacks were a much smaller fraction than 20%. Obviously if you're white and you live in a village in which everyone else is white too, your chances of having kids with someone who is not white are pretty low. This is why I suggested the more specific metric. > then some kind of self-segregation is happening. You're assuming either homogenous population distribution or a lot more population mobility than was happening at the time, I think. That is, you can conclude there is segregation in mating, but the extent to which it's _self_-segregation is a much harder question. Also, there were non-racial and non-geographic sources of segregation, like class/income. Note the comments in the wikipedia link below about black/Irish couples being a thing because the Irish were very poor. I'm pretty sure it's possible to account for these effects and discover that there were still racial self-segregation effects, but they will not be nearly as large as a naive 80-20 calculation like yours would suggest. They would, I expect, be larger than the (also existing!) self-segregation effects amongst white people of different ethnicities. An interesting thought experiment here is what you would expect to happen if you drop two (cis, straight) people of opposite gender but different races on a deserted island for a few years and how this compares to what happens when members of different subspecies are placed in proximity to each other with no other available mating partners. I don't know the answer to the latter, unfortunately. > Pointing out that slavery or other social institutions limited the rate of interbreeding I'm not doing that, precisely for the reasons you describe. I'm suggesting that limiting to my specific scenario removes issues of access due to population distribution effects and asks a specific question: given a white male who has the option of having children with black females (yes, the "enthusiasm" is very not symmetric here), what is the chance he will do so? Yes, this ignores the white-female-black-male case (though according to https://en.wikipedia.org/wiki/Mulatto#Antebellum_era https://en.wikipedia.org/wiki/Mulatto#Antebellum_era claims this was also going on; I'd have to look up numbers on "free people of color in the 1790–1810 censuses in the Upper South" to have an idea of how common it was). > We don't have to account for that because we're discussing rates of interracial breeding Well, we're discussing level of enthusiasm. Which as I said above was probably not symmetric, for reasons not necessarily related to race per se. I expect male white masters of female white indentured workers were also more enthusiastic about having kids than the workers were.

jimmyk 10y ago
>Yes, but this ignores the geographic inhomogeneity of both populations. For example, in Boston blacks were a much smaller fraction than 20%. The fact that the races end up living in different areas is strong evidence that when put in close proximity, different races don't want to interbreed. >You're assuming either homogenous population distribution or a lot more population mobility than was happening at the time, I think. That is, you can conclude there is segregation in mating, but the extent to which it's _self_-segregation is a much harder question. The vast majority of blacks came over as slaves. That means they all started out living in white areas. If they later chose to move away from white areas, for whatever reason, I don't see how anyone can possibly argue that they interbreed enthusiastically. When they find themselves in close proximity, they choose to segregate by race. >Also, there were non-racial and non-geographic sources of segregation, like class/income. Note the comments in the wikipedia link below about black/Irish couples being a thing because the Irish were very poor. The reason for segregation is not relevant, as long as it's not a one-off occurrence. If the segregation occurs because the dominant race prevents the subordinate race from succeeding economically, segregation is still occurring. >what is the chance he will do so? This doesn't give us any insight whatsoever into the question. We'd have to compare this to how white men behave when they have white women as slaves. >claims this was also going on There's no doubt that some interracial breeding was occurring. There's also no doubt that it's far less than would occur if there were no preference one way or the other for interracial breeding, and far far less than would occur if humans enthusiastically interbred, rather than self-segregating when given the opportunity. >Well, we're discussing level of enthusiasm. I don't think we're talking about how emotionally happy humans are when doing something, I think we're talking about how likely a certain event is to occur. The overall topic is whether humans can be considered sub-species, and the argument was that they shouldn't be because they interbreed enthusiastically. I'm pointing out that they don't actually end up interbreeding nearly as much as you'd expect if, for some reason, they had no way of distinguishing members of their own race from members of other races.
- bzbarsky 10y ago
  > The fact that the races end up living in different areas is strong evidence that when put in close proximity, different races don't want to interbreed. That's true, but (1) that's not what I was talking about; I was talking about geographic inhomogeneity in original migration patterns and (2) this argument applies to ethnic/language/religious groups in general, not just races. More on this below. > That means they all started out living in white areas. Sort of. https://en.wikipedia.org/wiki/List_of_U.S._states_by_historical_population https://en.wikipedia.org/wiki/List_of_U.S._states_by_histori... shows that in 1850 South Carolina had 668k people of whom 385k were enslaved (hence not choosing where they lived, exactly). I didn't look up the number of free blacks, but I expect it was quite small given the laws about re-enslavement at the time. Anyway, more like the white people were living in a black area there. ;) But the real point is that for a while there various parts of the country did _not_ have appreciable black populations because slaves had not been brought there while your typical plantation had a much larger black population than white population. Voila, _involuntary_ geographic inhomogeneity. > The reason for segregation is not relevant That really depends on the question you're trying to answer. > We'd have to compare this to how white men behave when they have white women as slaves Sure. But the worst case for the "enthusiastic" hypothesis is that in this situation they always end up with kids, right? There may be value in comparing to this worst case, even. > There's also no doubt that it's far less than would occur if there were no preference one way or the other for interracial breeding Sure. I don't think anyone reasonable is arguing there was no preference on the matter. But if we're going to talk about sub-species, exact frequencies and cutoffs do matter if the whole thing is to make sense other than as a mood-affiliation labeling exercise ("_these_ two groups are different sub-species, but these two other groups are just less likely than average to intermarry/interbreed"). There is good data showing that breeding across religious and language boundaries is less common (and was even less common in the past) than breeding within those boundaries. And yet very few people nowadays will argue that, say, the French and the Germans are separate sub-species, or were separate sub-species 100 years ago. Yes, I realize that 100 years ago people were in fact likely to make just such an argument. :) Heck, inter-political-party marriage is a lot less common than within-political-party marriage in the US. And the rate of inter-political-party marriage, in the US, is dropping, while the rate of interracial marriage is rising. According to http://fivethirtyeight.com/features/how-many-republicans-marry-democrats/ http://fivethirtyeight.com/features/how-many-republicans-mar... the former is sill more common than the latter but not _that_ much more common. I expect the lines to intersect within the next decade or two if current trends continue... I guess we could argue that sub-species boundaries are malleable and they can merge or separate over a timescale of a few generations. That would be a valid take on the whole thing, I guess, but then I question the usefulness of the "sub-species" labeling; it seems to not have a useful definition in this situation from my point of view.