Ezra Klein asks "How Quickly Do Genes Change?" in response to Andrew Sullivan gushing over Greg Clark's new book, A Farewell to Alms. Clark offers the hypothesis that the industrial revolution in England was catalyzed in part by changes in behavior which might have been reinforced by selection for particular alleles. In terms of the specific hypothesis, I'm skeptical and would probably bet that Clark has overplayed his hand and put too many eggs in one basket. But, in response to Ezra's question I threw down a flurry of comments (with a lot of grammatical errors due to my haste) which you can see over at the post. The short answer of course is: the rate of change of allele frequencies depends on the parameters. Molecular genetics is often about positing deterministic biophysical pathways, but evolutionary genetics is just as interested in the fluctuations and variations of alleles over time, and those variations are contingent on a host of factors. There isn't one specific answer, just a range depending on your assumptions or the empirical realities (e.g., selection coefficient, heritability of the character, demographic history, meta-population dynamics, etc.). So whether Clark's hypothesis is right or wrong as an empirical question, not a theoretical one. One can't rule it out a priori.

TNR has an interesting piece (here is a cache version of the first page) about Jewish-Christian polemics (in both directions). It is mostly a review of Peter Shaeffer's Jesus in the Talmud; a scholarly work which predictably appeals to anti-Semites. My comment on Noah Feldman and his perceptions of Orthodox Judaism elicited a lot of response. Most of it was interesting, though of course some individuals across the web became convinced that I was an anti-Semite who was a Muslim working against Jews. This missed the whole greater thrust of my point: it isn't always about you, context and situation are not only critical, but often they are determinative. In the TNR piece the author notes now anti-Christian invective was much more pronounced in the Babylonian Jewish literature than in the Palestinian equivalents. Is this because Babylonian Jews were naturally more anti-Christian than Palestinians? As a matter of fact the Palestinian Jews were under the rule of a Christian Empire which was just initiating a long history of focused anti-Jewish persecutions and forced conversions. In contrast, Babylonian Jews were numerically preponderant across broad swaths of southern Mesopotamia, and though under the rule of the Zoroastrian Sassanids, there was no great threat of being forcibly converted or oppressed for religious reasons. Rather, under the Sassanids both the Christians and the Jews were at parity, and Schaefer suggests apparently that Jews had an advantage, unlike Christians they had no notional affiliation with a foreign empire (Rome). I think the TNR piece has to be careful here, because it is important to remember that the Christians within the Sassanid Empire were generally of the Church of the East, whose intellectual and institutional origins were are sharp variance with both the Jacobite (anti-Imperial) sects across the border in Syria as well as the Chalcedonian orthodoxy promoted by Constantinople. There was a reason that these eastern groups were sometimes termed the Persian Church.

Hung with old college friends last night. We kept referring to South Park episodes to illustrate a point or make an analogy so as to clarify an issue. Interesting that this is a common touchstone for my generation.

Just How Hot Is That Red Hot Chili Pepper?.