tag:blogger.com,1999:blog-26741618.post8371399020746476551..comments2024-02-28T02:22:20.886-08:00Comments on homunculus: The gene delusionPhilip Ballhttp://www.blogger.com/profile/09986655706443117158noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-26741618.post-22422528123076497392018-11-30T02:24:52.313-08:002018-11-30T02:24:52.313-08:00Novelty seeking gene is a personality trait reflec...<a href="https://originalgene.com/dna-tests/genetic-personality-traits-testing" rel="nofollow">Novelty seeking gene</a> is a personality trait reflecting excitement in response to novel stimuli.<br />alvinahttps://www.blogger.com/profile/02167303188786895138noreply@blogger.comtag:blogger.com,1999:blog-26741618.post-54299638757790945972014-11-16T11:52:16.650-08:002014-11-16T11:52:16.650-08:00Dear Phillip,
While I think the overall argument ...Dear Phillip,<br /><br />While I think the overall argument is well made, I want to take issue with one aspect. You say:<br />"So, then, to Wade’s claims that genetics causes racial differences in traits such as the propensity for violence or the organization of social institutions. As Wade’s book has shown, the issue of race and genes remains as tendentious as ever. On the one hand, of the total genetic variation between random individuals, around 90% is already present in populations on a single continent – Asia, say – and only 10% more would accrue from pooling Europeans, Africans and Asians together. Some biologists argue that this makes the notion of race biologically meaningless. Yet ancestry does leave an imprint in our genomes: for example, lactose intolerance is more common in Africa and Asia, sickle-cell anemia in people of African origin, and cystic fibrosis in white northern Europeans. That’s why the concept of race is useful as a proxy for medical risk assessment and diagnosis. Besides, arguments about statistical clusters of gene variation don’t alter the fact that culturally conventional indicators of race – pigmentation and eye shape, say – are genetically determined."<br /><br />The idea that this constitutes "race" in any "culturally conventional" sense is both mistaken and dangerous. Jerry Coyne, one of the biologists I most respect, accepts this notion even as he goes on to say that of course by any of the current "scientific" ideas, there could be anywhere from 5 to 33 "races". Ascribing scientific value to such an indeterminate concept strikes me as mistaken. (Coyne has a number of entries on his blog about the Wade book where he also addresses the scientific validity of the notion of "race"; H. Allen Orr's article on the book is similarly toned.) I think the use of race in this way is also dangerous because it validates race as a "usable" notion, even though race is conceptually inextricable from hierarchical divisions of capability, intelligence, "civility", maturity, moral integrity, etc. I understand the desire to recognize that some phenotypic distinctions are genetically grounded in more or less distinct groupings within the human species as a whole, but that the groupings shifts dramatically depending on what one is looking at would seem by itself to militate for a different nomenclature, unless you would suggest that the natural sciences are incapable of establishing their own, unconventional and yet more accurate nomenclature. Especially when what scientists are proposing is a way of comprehending and predicting medically-relevant differences in human biology that are not intended to indicate a hierarchical division within the human species.<br /><br />In relation to this, I would note that the last sentence of the paragraph takes for granted, naturalizes if you will, "culturally conventional indicators of race", something that ought to be avoided at all costs given the hierarchical and discriminatory "culturally conventional" meanings and politics of race. To put it another way, naturalizing historical or cultural concepts like race is virtually a definition of ideology and to do so is not scientific, but the very opposite of science. <br /><br />Finally, I would add that pigmentation in Africa is so diverse and covers such a range that it overlaps dramatically with a variety of other "races" (sub-continental Indians, themselves diverse in pigmentation; Australian aboriginals; Sicilians; and so on), as to be meaningless scientifically as a "racial indicator" and the idea of pigmentation as a "culturally conventional indicator of race" is logically and empirically incoherent.<br /><br />Warmest regards,<br />Chris WrightChris Wrighthttps://www.blogger.com/profile/14364071049767652706noreply@blogger.comtag:blogger.com,1999:blog-26741618.post-49119075013511351792014-11-14T10:34:17.900-08:002014-11-14T10:34:17.900-08:00[ Sorry, I originally submitted this on your follo...[ Sorry, I originally submitted this on your follow up blog post, but it addresses the article above. ]<br /><br />Hi Philip,<br /><br />This is indeed a touchy subject. Given your interest, you might find this overview of use:<br />http://arxiv.org/abs/1408.3421<br /><br />"Gene for" may be OK terminology for Mendelian traits that are controlled by something akin to an on/off switch. But for polygenic traits (also known as quantitative traits), such as height or intelligence, one has to talk about "causal variants" with specific effect sizes. As a former physicist, you might find it striking (as do I) that most of the variation in polygenic traits tends to be linear (additive). That is, to first approximation one can simply sum up individual effects to get a prediction for the phenotype value. Thus, we can talk about individual variants that (on average) increase height or intelligence by a certain fraction of a cm or even IQ point. There are deep evolutionary reasons for this (see section 3 in the paper linked above), as well as quite a bit of experimental evidence.<br /><br />Finding causal variants is a matter of sample size, or statistical power. At present, almost 1000 such variants are known for height, accounting for about 20% of population variation. Available genomic datasets for which we have IQ scores are much smaller, hence the more limited results. I expect that as sample sizes continue to grow we will eventually capture most of the heritability for these traits; see section 4 and figure 13 in the paper. (Note heritability by itself can be estimated using different methods, from much smaller sample sizes.)Steve Hsuhttps://www.blogger.com/profile/02428333897272913660noreply@blogger.com