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Saturday, September 30, 2006
GSS SCITEST4 asks
In your opinion, how true is this? ... D. Human beings developed from earlier species of animals.
As you would expect, this also holds for BIBLE:
The trend holds when you compare across groups by educational attainment. Here is a table of the average response to SCITEST4 (lower = better).
From The God Delusion:
1) 1,074 Fellows of the Royal Society were emailed 2) 23 percent responded 3) They were asked various propositions, such as, "I believe in a personal God, that is one who takes an interest in individuals, hears and answers prayers, is concerned with sin and transgressions, and passes judgement." 4) They were invited to choose a number from 1 to 7 indicating strong disagreemant to strong agreemant. 5) 3.3% agreed strongly with the statement that a personal god exists (chose 7), while 78.8% strongly disagreed (chose 1). In the United States the National Academy of Sciences members exhited theism to the tune of 10%. Related: God & the scientists, God & the evolutionists.
Over the past few months I've read Winning the Race by John McWhorter and The Burden of Bad Ideas by Heather Mac Donald. One thing that both books assert is that in the late 1960s and early 1970s there was a proactive campaign by the National Welfare Rights Organization to get as many people on the rolls in places like New York City as possible. McWhorter also notes that there seems to have been a special emphasis on recruiting black Americans to heighten and exacerbate the racialized dimension of the problem. But getting poor people on welfare was only a means to an ends, and that ends was bankrupting the government and overturning the established social order. In other words, to overthrow the Great Society welfare state (and presumably replace with something more politically revolutionary). But in any case, the only reason I bring this up it that as I was reading this I was struck by an analogy to the Starve-the-beast philosophy promoted by Grover Norquist, except in the opposite direction. The key goal in both cases is to "break it" so that you can build it anew....
Friday, September 29, 2006
A question from Jason Malloy prompted a quick search of the GSS for data on the cause of the Black-White IQ gap. In 1982, the GSS characterized the skin color of Black participants on a 5-point scale (1:very dark brown to 5:very light brown). The very dark/light categories consist of only 50 and 14 individuals, respectively, and so in the following analysis I merged them with the dark/light brown categories, to give three COLOR levels: dark, medium, and light. In the web application, use COLOR(r:1-2;3;4-5) instead of COLOR. The WORDSUM variable is a 10 question vocabulary test, which I'm treating as a proxy for IQ. It is correlated with educational attainment (~.4), and also correlates (~.4-.5) with tests of reasoning and basic knowledge that were given in some years. These other tests are not available for 1982. In the all-subject all-year GSS data set, WORDSUM varies by SEX, and in 1982 COLOR also varies by SEX. Thus, SEX is controlled for in each analysis. WORDSUM is lower in the youngest and oldest age groups, so an AGE(25-65) filter was used.
Table 1. Mean WORDSUM score by COLOR and SEX with ANOVA
color indicates T-statistic, and thus p-value
We can quantify the effect size of each skin color class using Cohen's d statistic, which measures the mean difference in standard deviation units. In the 1982 dataset, the overall d for the Black-White gap on WORDSUM is -0.63 (among males d=-0.51, among d=-0.74). For comparison, the 1982 male-female gap among Whites is d=-.12, favoring females. Table 2. Effect size (d) of COLOR on WORDSUM using "light" as a control group
We can also use Whites as the control group. Table 3. Effect size (d) of COLOR on WORDSUM using Whites as a control group
Thus, there are substantial (moderate to large effect size) differences in WORDSUM scores between the darkest and lightest Blacks in 1982. As reported by Rushton and Jensen (2005), Shuey (1966) reviewed 18 studies which used skin color as a measure of racial admixture to compare with IQ. Of those 18, 16 found a significant effect of the kind found here, but the overall correlation with IQ was low (r=.1). In this data, the COLOR WORDSUM correlation is r=.31 among males and r=.18 among females, with an overall correlation of r=.23. Off the top of my head, I'm not certain what the expected correlation would be between IQ and skin color among Blacks for a given measure of "between-group heritability" (BGH) as described by Jensen (1998). I'll leave it as an exercise for our mathematically skilled commentators to derive a formula for this relationship and to evaluate the signficance of this finding in explaining the cause of the Black-White IQ gap.
As part of background reading for 10 Questions for A. W. F. Edwards I re-read R. A. Fisher's Genetical Theory of Natural Selection, and noted some points of interest. Over the next few weeks I hope to explore these.
The first concerns Fisher's views on the effective population size of species. It is well known that Sewall Wright attached great importance to the internal population structure of species, while Fisher in contrast thought that for most purposes a species could be treated as a single randomly interbreeding population. This contrast is sometimes posed in stark terms. For example, the historian William B. Provine, in a comment on one of Sewall Wright's papers, says: 'Fisher wrote to Wright to say that he believed effective population size to be a crucial variable, but that he considered most species to be panmictic (random breeding) throughout their ranges, even if their range was the entire world. Wright disagreed strongly'. [4, p. 71] If this were an accurate representation of Fisher's views, then of course Wright would be right. Most species are obviously not panmictic throughout their ranges. But this in itself should raise suspicions. Scientists seldom espouse views that are obviously absurd. So what did Fisher actually say about population size? To explore this will take several posts. Here is a first instalment, covering the period before the publication of GTNS in 1930. Most of Fisher's papers and letters are available online here, but there are a few exceptions. It turns out that some of Fisher's most explicit comments on population size came in a book review in 1921 [1] that is not available online. The Dutch biologists A. L. and A. C. Hagedoorn were early proponents of what is now called genetic drift. In the 1920s and 30s it was often described (by Fisher and Wright among others) as the Hagedoorn Effect. In his review of their book Fisher commented: The present reviewer has examined this particular point, and finds that in the absence of mutation or crossing [i.e. interbreeding with individuals from outside the group], a perceptible reduction of variability will take place in a number of generations equal to four times the number of the species breeding. In the case of great seasonal fluctuations in number, it is only fair to take the number of interbreeding individuals at its lowest point, but even so the number of interbreeding individuals in any group will seldom be less than five figures...[i.e. less than 10,000]. This book review comes nearly 10 years before the publication of GTNS. It also precedes Fisher's own first published calculations on the rate at which random fluctuations would affect genetic diversity. It is however clear that Fisher had already gone far enough into the problem to say that significant loss of diversity would take a number of generations longer than the relevant number of individuals in the population. In saying that 'it is only fair to take the number of interbreeding individuals at its lowest point', Fisher also shows an understanding that the effective population size may well be less than its current size. But Fisher makes no claim that breeding, even within a local area, is literally random (panmictic). The point he makes is that in the absence of geographical barriers (such as in his hypothetical Isle of Man example), the 'blood' of any local group would spread over a much wider area in the course of a thousand generations. In the following year (1922), Fisher published his first major paper [2] on population genetics. In this paper he considered the rate at which the genetic variance in a population would decline as a result of random processes in the absence of selection, mutation, and migration. Under these conditions each individual gene will have a certain probability of reproducing, or of dying without descendants, in each generation. As each line of descent, once lost, cannot be revived, any original variance of gene types (alleles) will progressively be reduced. In the absence of mutation and migration every gene at a given locus in the population will ultimately be descended from the same ancestral gene, so that all variance will be extinguished. In the paper Fisher shows that the rate of decline of variance depends on the total population size, being slower with larger populations. He calculates that variance will be reduced substantially in 4n generations, where n is the diploid population size. (He later corrected this to 2n, after finding an error in the calculation. Wright, using a different method, had already reached the figure 2n and pointed out the discrepancy to Fisher.) Fisher remarks that: This is a very slow rate of diminution; a population of n individuals would require 4n generations breeding at random to reduce its variance in the ratio 1 to e, or 2.8n generations to halve it. As few specific groups contain less than 10,000 individuals among whom interbreeding takes place, the period required for the action of the Hagedoorn effect, in the entire absence of mutation, is immense. I think it is unfortunate that Fisher refers here to 'random breeding', as this may give the impression that the breeding structure of the population affects the outcome. Given Fisher's other assumptions, this is not the case. With the assumptions of zero migration, mutation, and selection, each individual gene can be regarded as one of 2n asexually reproducing entities, with equal reproductive prospects, and this is in fact how Fisher treats it in his calculations. This population of genes can be divided up in any way whatsoever, without affecting the rate of loss of variance in the population of genes as a whole. Imagine that we assign each gene in the original population to a notional 'group' in an entirely arbitrary way, and then trace the descendants of each gene and group through succeeding generations. There will be two simultaneous processes going on: groups will grow, shrink, or become extinct; and within each group the number of descendants of each original gene will increase or decline. Ultimately all the members of the group will be descended from a single gene. Within any group, variance will decline more quickly than in the total population, but in the total population this will be partly offset by increasing variance between groups. Even after each group has become 'fixed' for a particular allele, variance in the overall population will continue to decline due to random-walk fluctuation in the size of the groups, including extinctions. But the original division of the population into groups was imaginary, and the mere act of assigning a gene to an imaginary group cannot influence the course of evolution. The notional division of the population into groups therefore does not affect the outcome. But neither does the existence of real subdivisions such as geographical or breeding groups, provided this does not affect the number of descendants of each individual gene, and by Fisher's assumptions it does not. Random breeding is therefore in this case a red herring. So far as I am aware, Fisher's next relevant comment on population size came in a letter to Leonard Darwin early in 1929. This was a response by Fisher to a letter from Darwin enclosing an old letter from Francis Galton, discussing the number of ancestors of village-dwellers. Galton noted that in the case of an isolated village the number of ancestors, in any generation far enough back, would hardly exceed the present number of villagers. Fisher expressed interest in Galton's letter, but commented: It is perfectly true that village communities may be much isolated, but I wonder if Galton ever considered (or people like Fleure, who find 'Neolithic' villages all over the place) how complete the isolation must be to be worth anything genetically. This appears to be the first time that Fisher explicitly commented on the effects of migration. The 'King Solomon' example is also interesting. First, there is the claim that if Solomon has any living descendants, he is probably in the ancestry of all of us. Fisher does not explain how he reached this view, but evidently, if all lines of descent do not die out by chance at an early stage, and allowing for an average of around two descendants per generation, the potential number of Solomon's descendants will increase explosively until it is far greater than the actual population of the human species. It does not follow that he is yet in the ancestry of all of us, because even in the absence of geographical barriers, there might not have been time for his 'blood' to have spread throughout the world. If we suppose, for example, that that none of his descendants moved more than 10 miles from their place of conception, then none of his descendants after 100 generations could be more than 1000 miles from Israel. However, recent calculations of the date of the 'Most Recent Common Ancestor' tend to support Fisher's 'wager', with the possible exception of a few isolated tribes like the Andaman Islanders. There might be more dispute about the stronger claim that Solomon would be in the ancestry of all of us 'in nearly equal proportions'. It is not clear how Fisher would have justified it in 1929. But one must remember that he was a physicist by training, and he may have intuitively seen an analogy with physical diffusion processes. If a substance is diffusing through a gas or fluid, in the absence of impermeable barriers, or pumps to reverse the flow, the substance will always flow from areas of greater to lesser concentration (subject to minor stochastic fluctuations), until it is evenly distributed throughout. The 'diffusion' of ancestry would obey the same principle, so it would be reasonable to wager that at some stage Solomon's share in everyone's ancestry would be approximately equal. But the speed with which this outcome was reached would be affected by geographical and behavioural barriers, and it is not obvious whether 100 generations would be long enough to reach an equilibrium state. (To preempt an obvious comment, having Solomon in one's ancestry does not imply having any of his genes. These would be diluted by half at each stage of reproduction, so that after 100 generations most lines of descent would contain none of his genes at all. If he has any living descendants, his average expected share in their genes would only be 1/n, where n is the number of individuals in Solomon's time who have left living descendants.) Later in the same year (1929) Fisher had a further occasion to discuss the question of migration, as part of a correspondence with Sewall Wright. In 1928 Fisher had begun to expound his theory of the evolution of dominance. Noting that harmful mutations tended to be recessive, Fisher sought to explain this by the selection of modifier genes at other loci tending to suppress the effect of harmful mutations. He recognised that for various reasons this would be a weak form of selection, but considered that if it operated over very long periods of time, in response to recurring mutations, it could have the effect he claimed. Sewall Wright had a number of objections to this. For the present purpose Wright's most important point was as follows : Selection controls the situation if s [a measure of selective intensity] is larger than 1/2n [where n is effective population size], but is of little importance below this figure. In small inbred populations (1/2n large) even vigorous selection is ineffective in keeping injurious factors from drifting into fixation... In the case of Dr Fisher's modifiers of dominance with selection coefficients at best of the order of mutation rate, the latter must be greater than 1/2n if the gene is not to drift back and forth in the course of geologic time from one state of approximate fixation to the other and practically as freely in the face of the selection pressure as with it. In correspondence with Wright Fisher responded to several of Wright's criticisms. On the question of population size he wrote as follows: I am not sure I agree with you as to the magnitude of the population number n. To reduce it [as Wright had done] to the number in a district requires that there shall be no diffusions even over the number of generations considered. For the relevant purpose I believe n must usually be the total population on the planet, enumerated at sexual maturity, and at the minimum of the annual or other periodic fluctuations. For birds twice the number of nests would be good. I am glad, however, that you stress the importance of this number.[3, p.273] It is this passage on which William Provine bases his claim that Fisher 'considered most species to be panmictic (random breeding) throughout their ranges, even if their range was the entire world'. It should be evident that Fisher said nothing of the kind. First, as a pedantic point, Fisher did not claim that any species had a range over 'the entire world'. Very few species do, even if we treat land and sea species separately. More important, Fisher did not maintain that species were literally panmictic throughout their range, but only that 'for the relevant purpose' [the relative effects of drift and selection] the appropriate number must 'usually' be the total breeding population of the species, at its periodic minimum size. His reason for this belief was evidently related to the question of 'diffusion', including migration between districts. As he had indicated in his letter to Leonard Darwin, Fisher doubted that isolation of local groups would usually be strict enough, over a period of many generations, to prevent a significant diffusion of genes between localities, which would tend to equalise gene frequencies between them. Fisher's letter prompted Wright himself to think about the effects of migration (apparently for the first time), and he replied to Fisher as follows: I was much interested in your comment on the population number... Since I wrote, I have been trying to get a clearer idea of the effect of diffusion, and I see, at least, that isolation in districts must be much more nearly complete than I realized at first, to permit random fixation of strains.[5, p.256] Wright then discussed the effect of migration into a district at random from the entire population, and concluded: I must admit that rather strict isolation is necessary on this basis to maintain appreciable variation of q, and I recognise of course that variation in q does not interfere much with selection unless it is so great as to bring about a U-shaped piling up close to q = 0 and q = 1. I am not entirely clear as to the effects of interchange between adjacent districts with similar q's. Presumably there could be considerably more such interchange without preventing a drifting apart of the q's for more remote districts. However, it seems clear that N must be based on the entire species, unless isolation is substantially complete, in considering the interference with selection.[5, p.256] Thus, we reach the remarkable result that far from 'disagreeing strongly' with Fisher's position on the point at issue in the correspondence, Wright explicitly agreed with him! In the same letter Wright asked Fisher whether he had published anything on the 'diffusion problem', and Fisher replied: I have so far published nothing on the 'diffusion problem', but have in the press a book on 'The Genetic [sic] Theory of Natural Selection', which has part of a chapter on the cohesion of species in relation to the problem of their fission. I think it must be generally true that the ancestry of all individuals of a species is practically the same except for the last 100 or perhaps 10,000 generations, and that a gene frequency gradient is maintained by selection between different parts of a species' range. So that well-marked local variations may or may not be incipient species, according as real fission, cessation of diffusion, ultimately supervenes.[5, p.258] This appears to be Fisher's last comment on the subject before the publication of GTNS in 1930, to which I will turn in a further post. References [1] R. A. Fisher: Eugenics Review, 13, 1921, 467-70, review of A. L. and A. C. Hagedoorn, The Relative Value of the Processes Causing Evolution. [2] R. A. Fisher: On the Dominance Ratio, 1922 (online) [3] J. H. Bennett (ed.): Natural Selection, Heredity and Eugenics, Including selected correspondence of R. A. Fisher with Leonard Darwin and others. 1983. [4] Sewall Wright, Evolution: Selected Papers, ed. William B. Provine, 1986. [5] William B. Provine: Sewall Wright and Evolutionary Biology, 1986.
Thursday, September 28, 2006
Not by Genes Alone, Peter Richerson and Robert Boyd, eds., Chicago, 2005. Moral sentiments and Material Interests is, from my point of view, an enormous advance on all the orthodox economics I've ever read. My primary complaint is "What took so long?" For decades now economics has been spreading disinformation, and it's about time that they started looking at reality. (The ev psych ideas found in the Gintis book are more fully developed in Not by Genes Alone. I should note that both books include a lot of technical argument which I haven't even touched upon. What I've written here is only a summary of the conclusions, written from the point of view of a non-biologist and a non-economist). The book's starting point is an empirical look at the actual economic behavior of individuals, in order to see whether it matches the rational-self-interest assumed by economic theory. It is found that it doesn't, and the actual behavior observed is next interpreted in terms of evolutionary psychology. Finally, the political and social significance of these new observations is sketched. The empirical studies are standard cash-incentive psych lab tests designed to find out where people actually stand on the altruism / self-interest scale. In general, the tests find that people behave more altruistically than they would if they decided according to rational self-interest. (The tests also find that the degree of altruism varies according to culture, and is not a universal). The results of these experiments square with my own convictions, but I've always felt that this kind of artificial, low-payoff game-playing is of only moderate scientific value -- there's even some evidence that the authors themselves think this way. To me the real story is that there's never been any evidence at all that economics' assumption of individual economic rationality is valid, and a lot of evidence that it isn't. The rationalizations found in Friedman's Positive Economics have allowed economists to rely thoughtlessly on these unproven assumptions for about five decades, and if a few little experiments are required to convince them to drop this inaccurate and unproven default, that's cool with me. But it's a little like someone cherry-picking Bible verses to make their point to the Vatican. The authors define three mechanisms leading to altruism and social cohesion: strong reciprocity, conformity, and "costly signaling". These are made possible by innate dispositions evolved in two steps -- simple reciprocity first at the early primate small group level, and the more complex behaviors next at the early human. Altogether they make possible genetic selection for altruism, via net fertility advantages for all members of organized social groups (not simply biological groups or kinship groups) which are successful because their members behave altruistically. Biological competition within the group is suppressed by non-innate social and cultural mechanisms, giving an advantage to members of the group on the average, but not to every individual. This way, with gene-culture coevolution and mutualism, there can be genetic selection for a degree of innate altruism in a way that there could not be without culture and society, which form a kind of artificial environment. "Strong reciprocity" is what replaces "rational self-interest". It consists of the weak reciprocity described by Axelrod (initial cooperation, continued until the partner defects) plus an additional altruistic propensity to punish defectors even if there's no personal advantage in doing so. In a society of strong reciprocators (altruists both in giving and in punishment), defectors do not have an advantage, whereas in a society of non-punishing altruists, the defectors have an advantage which causes the defector gene to drive out the altruist gene. Two other behaviors are mentioned. "Conformity" is a weaker principle explaining social uniformity in the absence of the threat of punishment, and mostly applies to cases in which there is no clearly-perceptible advantage or disadvantage for the individual, so he just does what everyone else does. "Costly signaling" only appears in one chapter, which uses the biological concept to explain generosity of the potlatch / largesse / big man type. To me these are less immediately interesting than strong reciprocity, though "costly signaling" is a step on the way toward defining a more complex heirarchal society extending beyond the face-to-face level. A significant advantage of this book is that it describes a social world which, like the world observed and described by historians, has "multiple equilibria and tipping points" and is thus less stable and less predictable than the imaginary world of equilibrium economics. In the final chapter Bowles and Gintis point out that local community is always grounded on a fundamental ethic of strong reciprocity. They describe it as a positive force which is usually wrongly maligned by the partisans of the market, the state, and elite culture. This brings them close to the communitarians, for whom the local community is a valid and necessary third leg of society, distinguishable (and sometimes at odds with) both pure market behavior and the state. (A lot of liberationist and libertarian ideology is hostile to the naive sorts of strong retribution that make small-group community possible). The three innate principles described by these authors can be thought of as a ground for ethics, and the authors speak openly of "trust" and "fairness". However, all actual ethics involves further cultural processing, beyond the innate foundation. For one example, one of the great advances making civilization possible was the suppression of vendetta and feud, which are completely natural developments of "strong reciprocity". For another, the mechanisms of natural ethics described here work best at the face-to-face level. The description, much less the attainment, of fairness (the goal of strong reciprocity) within a large, complex, multi-level society is an extremely tricky and difficult task indeed. (The authors do touch on these questions, and they cite Fried's Evolution of Political Society, which sketches a general view of the move toward complex society). Anyway, after about fifty years, economics seems to be returning to the real world. (Slightly revised Sept 29) Update: I also have a new piece up at http://www.idiocentrism.com/lazear.htm
Wednesday, September 27, 2006
The frogs at AlphaPsy point me to this article, Anarchism and Social Nature, in a Left-anarchist publication. The focus of the piece is a review of The Blank Slate by Steven Pinker, and here is the punchline:
We, along with most other ideologies on the Left, have based our theory on a mistaken concept of human nature. We have learned over the years to distrust words like sociobiology, evolutionary psychology, cognitive science, and above all that dreaded buzzword, 'hard-wired' - yet we can no longer ignore the fact that these sciences are probably right about human nature. AlphaPsy has a detailed analysis, so I'll hand it off to them. Related: The Conflict Within - The Left's Version of Creationism, The Turning of the Tide.  From the BBC: A King's College London team found women whose ring finger is longer than their index finger are more likely to achieve higher levels in sport. The ratio between the fingers has already been linked to traits in men like cognitive ability and sperm count. The study appears online in the British Journal of Sports Medicine. The researchers, from King's Twin Research Unit, examined hand X-ray images of 607 female twins aged 25-79 from the UK. In each case they measured the lengths of the second and fourth fingers of each hand. The volunteers also ranked their highest level of achievement in a list of 12 sports on a questionnaire. The researchers found women with longer fourth fingers were significantly more likely to be among the top achievers in all the sports listed. I can't find the paper online, but I'd like to see it because the news report hints at that the result has a more fascinating twist. Lead researcher Professor Tim Spector said: "The reasons for these findings are unclear. "Previous studies have suggested the change in finger length was due to changes in testosterone levels in the womb but we also found that finger length was 70% heritable with little influence of the womb environment. "This suggests that genes are the main factor and that finger length is a marker of your genes." The ratio between the two fingers is fixed before birth and remains constant during life. As this is the case, the researchers suggest that examining finger length may help to identify talented individuals at an early, pre-competitive stage. No specific genes have yet been identified that control finger length. Experts believe it is likely that multiple genes are responsible. So perhaps the digit ratio is also largely heritable. Can anyone find the study?  I was doing a "literature survey" and I stumbled upon Daniella Alonso, the product of a marriage between a Japanese Peruvian father as a Puerto Rican mother (European + African + Amerindian). I am haunted by dreams of synergistic epistasis and Übermensch....
In case you're not enjoying it already, allow me to bring your attention to Married to the Sea. I find the more juvenile stuff the funniest, but here's some science/evolution related to justify the post. Personal favorite.
One of the common ideas for why religion appeared is that it is a way of assauging fear of death. Chris of Mixing Memory reports on research which tests this hypothesis. Here is Chris' summary:
But this science, so not everything follows our intuition:
So for some religionists death and faith seem closely coupled, but not all religionists. At least if psychological experiments give us any window into the soul.
Our old friend Brown Gaucho is hosting Tangled Bank #63. I enjoyed his post, The importance of evolution in medicine. BG is a primatologist-turned-med student, so he knows of what he speaks. But, I do have to take some issue with this contention:
Yes, anatomically modern humans emerged over 100,000 years ago, but, that does not suffice to allow us to assume that genetically humans haven't changed "all that much." Of course, that depends on how you define "all that much," but a supercharged immune system forged in the fires of the Eurasian pathogen pool & lactose tolerance don't show up in the fossil record....
The Daily Transcript reports on a PNAS study showing that transcription occurs in bursts. Transcription factors (regulators of when a gene is "on" or "off") are often characterized as 'activators' or repressors. The paper suggests activators may instead be stabilizers. Genes are always flipping back and forth between different levels of on and off states and when transcription factors bind they can hold one state steady. When upregulation happens a gene isn't 'turned on', it is just kept on. He's got a nice little def. of transcription on the left there. You are eventually gonna need to know what transcription and translation are. Might as well be now.
From PNAS:
Simpler genomes, such as those of RNA viruses, display antagonistic epistasis (mutations have smaller effects together than expected); bacterial microorganisms do not apparently deviate from independent effects, whereas in multicellular eukaryotes, a transition toward synergistic epistasis occurs (mutations have larger effects together than expected). We propose that antagonistic epistasis might be a property of compact genomes with few nonpleiotropic biological functions, whereas in complex genomes, synergism might emerge from mutational robustness. Some have argued that synergistic epistasis is the way that "sex pays off" for complex organisms. Sexual reproduction tends to break apart superfit correlations of alleles, but synergistic epistasis is a way to recoup this loss (and evade Muller's Ratchet). A figure below the fold....  Related: Through the rugged roads of gene land.
Just a heads up, a new blog which addresses culture via a naturalistic lens is now up and running, AlphaPsy. In the Cavalli-Sforza 10 Q's he stated that cultural anthropology just isn't scientific, and is positively hostile to science. This is a different direction, and very much a minority take, but good things start small.
Tuesday, September 26, 2006
From the GSS, POLIDEOFULL combines two markers (political affiation and self-description along a liberal-moderate-conservative axis) to form 21 categories. Here are the average WORDSUM scores for each group. The liberal-conservative axis has been color-coded from dark blue to dark red for each of Democrats, Independents, and Republicans. Restricted to whites only. Here's the data:  Obviously people who self-identify as extremely conservative Democrats or extremely liberal Republicans score poorly on WORDSUM. Liberal Dems, Liberal Indepedents, and Conservative Republicans socre better than average. Interestingly, Conservative Indepdents score lower.
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