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Some ethnicities are more susceptible to certain diseases. Is that a social construct? Obviously not. But quoting Wikipedia[1], an average of 85% of genetic va

by cygx 10y ago

Some ethnicities are more susceptible to certain diseases. Is that a social construct? Obviously not. But quoting Wikipedia[1], an average of 85% of genetic variation exists within local populations, ~7% is between local populations within the same continent, and ~8% of variation occurs between large groups living on different continents, whereas [a]pproximately 10% of the variance in skin color occurs within groups, and ~90% occurs between groups, which indicates that this attribute has been under strong selective pressure. When defining human race, we hone in on a few easily identifiable characteristics that have remained stable due to selective pressure (eg skin colour) and overblow their significance. Eg we suspect that humanity went through a genetic bottleneck when it left Africa, decreasing diversity. And yet, we generally lump the rather diverse African population that did not go through it into a single race. It's probably more useful to just look at specific genetic traits of interest instead of drawing somewhat arbitrary boundaries. [1] https://en.wikipedia.org/wiki/Human_genetic_variation https://en.wikipedia.org/wiki/Human_genetic_variation

fdsaaf 10y ago
> 85% of genetic variation exists within local populations That's Lewontin's Fallacy [1]. There's no logical reason to think that genome-wide diversity within populations somehow proves that large-scale impactful allele frequency differences between conventionally understood races do not exist. They do. You can measure them. Given someone's DNA, you can identify his content-scale race. (You can actually narrow someone's ancestry much more narrowly too. Race is a cakewalk.) [1]: http://onlinelibrary.wiley.com/doi/10.1002/bies.10315/abstract http://onlinelibrary.wiley.com/doi/10.1002/bies.10315/abstra... "In popular articles that play down the genetical differences among human populations, it is often stated that about 85% of the total genetical variation is due to individual differences within populations and only 15% to differences between populations or ethnic groups. It has therefore been proposed that the division of Homo sapiens into these groups is not justified by the genetic data. This conclusion, due to R.C. Lewontin in 1972, is unwarranted because the argument ignores the fact that most of the information that distinguishes populations is hidden in the correlation structure of the data and not simply in the variation of the individual factors. The underlying logic, which was discussed in the early years of the last century, is here discussed using a simple genetical example."
- notahacker 10y ago
  There is also no logical reason to believe that allele frequency differences betwen conventionally understood races are in any way "impactful" relative to the heterogenity of respective groups or relative to allele frequency differences between populations not generally understood as distinct races. We can reliably identify haplogroups associated with certain phenotypes popularly categorised as "races", but we can also [more] reliably identify genetic markers associated with other phenotypical differences which have little or no correspondence with haplogroups. The presumption of greater significance of haplogroup-associated differences is the social construct here.
  - fdsaaf 10y ago
    There are strong reasons to believe that the observed genetic differences between races have profound phenotype effects. After all, the races are different, physically. It's not "just skin color". Can you really argue that Koreans and bantus have the same physical characteristics except for skin color? Facial structure, stature, metabolic diseases, hair texture, and even earwax differ markedly between different heredity groups. These differences persist even when koreans and bantus move to the United States and have children; it's the people, not the dirt. These physical differences are heritable. Mixed-race children usually exhibit some mixture of the characteristics of their parents. If we don't agree that people from different races can differ across an array of physical characteristics and that these differences are genetically encoded, I'm not sure we can have a conversation. I bet you're also the kind of person who denies that men are much physically stronger than women. But suppose you accept physical differences. Why would you then reject cognitive ones out of hand? Evolution and genetic drift act on the mind as much as they do the body, since the brain is a physical organ built with proteins encoded by the same sorts of genes that code for eye color. The persistent very large racial gaps in IQ (one whole standard deviation) across different studies and population groups tells us that population differences are not merely physical. These differences are robust under twin studies and other measures that control for shared environment. Given that IQ is tightly coupled to life outcome, I'd call these differences quite "impactful". I know that nobody likes to read a paragraph like the one I just wrote, but we can't hide from facts. We can't make effective policy unless we start acknowledging reality, however unpleasant it may be.

by cygx 10y ago

fdsaaf 10y ago

> 85% of genetic variation exists within local populations That's Lewontin's Fallacy [1]. There's no logical reason to think that genome-wide diversity within populations somehow proves that large-scale impactful allele frequency differences between conventionally understood races do not exist. They do. You can measure them. Given someone's DNA, you can identify his content-scale race. (You can actually narrow someone's ancestry much more narrowly too. Race is a cakewalk.) [1]: http://onlinelibrary.wiley.com/doi/10.1002/bies.10315/abstract http://onlinelibrary.wiley.com/doi/10.1002/bies.10315/abstra... "In popular articles that play down the genetical differences among human populations, it is often stated that about 85% of the total genetical variation is due to individual differences within populations and only 15% to differences between populations or ethnic groups. It has therefore been proposed that the division of Homo sapiens into these groups is not justified by the genetic data. This conclusion, due to R.C. Lewontin in 1972, is unwarranted because the argument ignores the fact that most of the information that distinguishes populations is hidden in the correlation structure of the data and not simply in the variation of the individual factors. The underlying logic, which was discussed in the early years of the last century, is here discussed using a simple genetical example."

notahacker 10y ago
There is also no logical reason to believe that allele frequency differences betwen conventionally understood races are in any way "impactful" relative to the heterogenity of respective groups or relative to allele frequency differences between populations not generally understood as distinct races. We can reliably identify haplogroups associated with certain phenotypes popularly categorised as "races", but we can also [more] reliably identify genetic markers associated with other phenotypical differences which have little or no correspondence with haplogroups. The presumption of greater significance of haplogroup-associated differences is the social construct here.
- fdsaaf 10y ago
  There are strong reasons to believe that the observed genetic differences between races have profound phenotype effects. After all, the races are different, physically. It's not "just skin color". Can you really argue that Koreans and bantus have the same physical characteristics except for skin color? Facial structure, stature, metabolic diseases, hair texture, and even earwax differ markedly between different heredity groups. These differences persist even when koreans and bantus move to the United States and have children; it's the people, not the dirt. These physical differences are heritable. Mixed-race children usually exhibit some mixture of the characteristics of their parents. If we don't agree that people from different races can differ across an array of physical characteristics and that these differences are genetically encoded, I'm not sure we can have a conversation. I bet you're also the kind of person who denies that men are much physically stronger than women. But suppose you accept physical differences. Why would you then reject cognitive ones out of hand? Evolution and genetic drift act on the mind as much as they do the body, since the brain is a physical organ built with proteins encoded by the same sorts of genes that code for eye color. The persistent very large racial gaps in IQ (one whole standard deviation) across different studies and population groups tells us that population differences are not merely physical. These differences are robust under twin studies and other measures that control for shared environment. Given that IQ is tightly coupled to life outcome, I'd call these differences quite "impactful". I know that nobody likes to read a paragraph like the one I just wrote, but we can't hide from facts. We can't make effective policy unless we start acknowledging reality, however unpleasant it may be.