On the genetic architecture of intelligence and other quantitative traits

the rapidly decreasing cost of genotyping, it is possible that within the coming decade researchers will identify loci which account for a significant fraction of total g variation." Block(1996) also incorrectly asserts that: > IQ is enormously affected by normal environmental variation, and in ways that are not well understood. [...] IQ is very reactive to changes in environments in the normal range. From Hsu(2014): "[W]ithin a range of favourable environments (i.e., providing good nutrition, hygiene, and access to education) evidence strongly supports the claim that individual differences in cognitive ability are largely associated with genetic differences.

unintended good consequences, mostly additive so the extrapolations will work out at least several SDs, etc, all of which implies that very large boosts in intelligence are possible. And if BGI had been able to merely 10x its sample size, it really would have managed to find interesting things due to the enrichment & better phenotyping than SSGAC; but it was too small then (the approach works better, just not better enough). The main implication of the BGI failure is mostly that selection has a bit more potential than thought (more small variants to gradually increase), and editing will be a bit harder than thought (no big rare variants to edit one by one).

than biologists - especially evo-devo biologists like Myers - believe, and since chickens can be bred to be bigger and faster maturing, so can human be bred to be more intelligent. Hsu's response depends strongly on 1) being able to measure a correlation between intelligence and SNPs, and 2) the assumption that these SNPs are "roughly additive" in benefit. See his preprint at http://arxiv.org/abs/1408.3421 . I attempted to read it, but Gould's "The Mismeasure of Man" strongly affect my understanding of the topic; and Hsu's preprint appears to accept what Gould calls the two deep fallacies of reification and ranking. I do not not have the knowledge to evaluate the abstract in its full context. I do think his discussion of the Flynn effect reveals a severe misunderstanding of history and people. Hsu does not address the ethical and moral issues that Myers raised.

improbable and therefore require exponentially more time than simple adjustment of frequencies of alleles of linear effect.) One might say that to first approximation, Biology = linear combinations of nonlinear gadgets, and most of the variation between individuals is in the (linear) way gadgets are combined, rather than in the realization of different gadgets in different individuals. Linear models works well in practice, allowing, for example, SNP-based prediction of quantitative traits (milk yield, fat and protein content, productive life, etc.) in dairy cattle. ...

effects. There is a deep evolutionary reason behind additivity: nonlinear mechanisms are fragile and often "break" due to DNA recombination in sexual reproduction. Effects which are only controlled by a single locus are more robustly passed on to offspring. Fisher's fundamental theorem of natural selection says that the rate of change of fitness is controlled by additive variance in sexually reproducing species under relatively weak selection. Many people confuse the following statements: "The brain is complex and nonlinear and many genes interact in its construction and operation." "Differences in brain performance between two individuals of the same species must be due to nonlinear effects of genes." The first statement is true, but the second does not appear to be true across a range of species and quantitative traits. Final technical comment: even the nonlinear part of the genetic architecture can be deduced using advanced methods in high dimensional statistics (see section 4.2 in [1] and also http://arxiv.org/abs/1408.6583).