Race does not stand up scientifically, period. To begin with, if race categories were meant primarily to capture differences in genetics, they are doing an abysmal job. The genetic distance between some groups within Africa is as great as the genetic distance between many “racially divergent” groups in the rest of the world. The genetic distance between East Asians and Europeans is shorter than the divergence between Hazda in north-central Tanzania to the Fulani shepherds of West Africa (who live in present-day Mali, Niger, Burkina Faso, and Guinea). So much for Black, White, Asian, and Other. [...]
It is a good time, then, to dispel some myths about genetic variation that have been promulgated by both the left and the right alike. On the left, many try to discredit the notion that genetic variation underlies group differences by pointing out that there is more genetic variation within these groups than between them. Another favorite approach is to cite the fact that all humans are 99.9 percent genetically identical and that no group of humans has a gene (i.e., a coded-for protein) that another group lacks. Both of these arguments are canards. After all, we are also 98-plus percent identical to chimps and 99.7 percent similar to Neanderthals. Oh, what a difference that 2 percent (or 0.3 percent) makes! [...]
Highlighting the fact that all humans share the same genes ignores the fact that much of evolutionary change and biological difference is less about the development of novel proteins (i.e. genes) than it is about the regulation of those genes’ expression—that is, the extent, the timing, and the location of when and where they are turned on and off. In fact, when the Human Genome Project first began, the number of human protein-coding genes was anticipated to be on the order of 100,000. After all, we are certainly more complex than Zea mays (corn) with its 32,000 genes, are we not?1 As it turns out, we have a mere 20,000 genes (or fewer). So most human difference is driven by the turning on and off of those 20,000 genes in specific tissues at particular times. The same ones may be expressed in the brain and in the liver. They may get switched on by an attacking bacterium and silenced by a hot meal. Each one is like a multitasking parent balancing home and office. [...]
Even if we had figured out a way to factor out all the cultural, historical, and economic differences that correlated with genetic ancestry, and found an effect, such a result would still raise the question: How? While it may or may not be true that brain development pathways could be implicated in test score differences, it is almost surely true that the percentage of African or European ancestry predicts physiognomy. That is, even within families, we are willing to wager that the sibling with more African genes is also the sibling with darker skin, curlier hair, and more West African facial features. There may even be other physical features that are less clearly racialized in the U.S.—such as height—that correlate with ancestry.
read the article
It is a good time, then, to dispel some myths about genetic variation that have been promulgated by both the left and the right alike. On the left, many try to discredit the notion that genetic variation underlies group differences by pointing out that there is more genetic variation within these groups than between them. Another favorite approach is to cite the fact that all humans are 99.9 percent genetically identical and that no group of humans has a gene (i.e., a coded-for protein) that another group lacks. Both of these arguments are canards. After all, we are also 98-plus percent identical to chimps and 99.7 percent similar to Neanderthals. Oh, what a difference that 2 percent (or 0.3 percent) makes! [...]
Highlighting the fact that all humans share the same genes ignores the fact that much of evolutionary change and biological difference is less about the development of novel proteins (i.e. genes) than it is about the regulation of those genes’ expression—that is, the extent, the timing, and the location of when and where they are turned on and off. In fact, when the Human Genome Project first began, the number of human protein-coding genes was anticipated to be on the order of 100,000. After all, we are certainly more complex than Zea mays (corn) with its 32,000 genes, are we not?1 As it turns out, we have a mere 20,000 genes (or fewer). So most human difference is driven by the turning on and off of those 20,000 genes in specific tissues at particular times. The same ones may be expressed in the brain and in the liver. They may get switched on by an attacking bacterium and silenced by a hot meal. Each one is like a multitasking parent balancing home and office. [...]
Even if we had figured out a way to factor out all the cultural, historical, and economic differences that correlated with genetic ancestry, and found an effect, such a result would still raise the question: How? While it may or may not be true that brain development pathways could be implicated in test score differences, it is almost surely true that the percentage of African or European ancestry predicts physiognomy. That is, even within families, we are willing to wager that the sibling with more African genes is also the sibling with darker skin, curlier hair, and more West African facial features. There may even be other physical features that are less clearly racialized in the U.S.—such as height—that correlate with ancestry.
read the article
No comments:
Post a Comment