razib | May 12, 2007Over the past few years I've reach a position which I'm not particular happy with: religious neutrality & diversity together are pretty much doomed. In the United States the separation of church & state crystallized at a time when Protestantism was normative, and despite all their differences this branch of Christianity shares some commonalities. With the entrance of Catholicism and Judaism into the religious matrix there was some accommodation, but the reality is that to a great extent American Judaism & Catholicism have been "Protestantized" through various Kulturkampfs (e.g.,…
razib | May 10, 2007Science Daily has a summary of new fly research in behavioral genetics which puts the spotlight on deep time evolutionary dynamics. Here's the important bit:
The researchers found that when the fruit fly larvae were competing for food, those that did best had a version of the foraging gene that was rarest in a particular population. For example, rovers did better when there were lots of sitters, and sitters did better when there were more rovers.
In short the researchers here are pointing to negative frequency dependent selection, where traits/alleles exhibit a fitness as an inverse…
razib | May 9, 2007I have two blogs from The Atlantic's small flotilla, Ross Douthat & M. Yglesias, in my RSS reader. Now, one thing I notice is that there is a faux-tab1 at the top that allows you to toggle between these two blogs, as well as James Fallow's & Andrew Sullivan's Daily Dish. But here's the thing: Sullivan's site doesn't have a tab to toggle back to the other sites within The Atlantic's blog confederacy! I suppose it is fair since he has the highest profile and brings the most readers, but I suspect that Jakob Nielsen might have a word to say about this sort of design architecture in…
razib | May 9, 2007Via William Saletan, Prenatal Test Puts Down Syndrome in Hard Focus. Being an numbers man, I found this interesting:
Until this year, only pregnant women 35 and older were routinely tested to see if their fetuses had the extra chromosome that causes Down syndrome. As a result many couples were given the diagnosis only at birth. But under a new recommendation from the American College of Obstetricians and Gynecologists, doctors have begun to offer a new, safer screening procedure to all pregnant women, regardless of age.
About 90 percent of pregnant women who are given a Down syndrome…
razib | May 9, 2007The American Naturalist is celebrating 140 years. Check out their list of most cited papers over the decades, gives you a good flavor of major issues in evolution & genetics.
razib | May 8, 2007A local coffee shop that I frequent carries Barista Magazine. Though I'm not a "coffee nerd," I pick it up to pass the time, and I noted an article which mentioned that the coffee is New York City is shockingly bad. Not that it is as bad, for example, as the coffee in Billings, Montana (no offense Billiings!). Rather, for a city famous for its food & culture it seems surprising that one would have to rely upon Starbucks as the font of all bean goodness. So what is it? Do people here disagree?*
* Please don't offer an opinion if you haven't had Pacific Northwest coffee!
razib | May 8, 2007Most of you know that I am generally skeptical of first order functional explanations of religion (I am more open to second order explanations which posit religion as one of the manifold social glues which bind together communities and facilitate sociality). That being said, I did find this interesting, from PLOS Biology, Mental Training Affects Distribution of Limited Brain Resources:
...We found that three months of intensive meditation reduced brain-resource allocation to the first target, enabling practitioners to more often detect the second target with no compromise in their ability…
razib | May 7, 2007I have stated before that additive genetic variance is the relevant component of variance when modeling the response to selection in relation to a quantitative trait. In other words:
Response = (additive genetic variance)/(total phenotypic variance) X Selection
Consider height, which is about 80% heritable in the narrow sense in modern developed nations. What do I mean 80% heritable in the narrow sense? I mean that 4/5 of the variation in height, which is distributed in a normal fashion, is controlled by additive variation in the genotype. In other words, if I substitute allele 2 for…
razib | May 7, 2007I'm reading Derek Roff's chapter in Evolutionary Genetics: Concepts and Case Studies about quantitative genetics and the G Matrix. He revisits some of the territory covered in Evolutionary Quantitative Genetics, but his tone is strikingly pessimistic on both theoretical and empirical grounds. I'm still chewing over some issues, so for now I recommend two posts on the G Matrix elsewhere. Also, this review covers a lot of G Matrix ground....
razib | May 5, 2007I don't follow non-science news very closely. Most of my RSS feeds are science related. Nevertheless, I'm starting to get the sense that a recession is in the offing, and that we might be in the beginning of one right now. Anyone else get that feeling???
razib | May 4, 2007Here's an article on The Grandmother Hypothesis. Personally, I didn't take the idea seriously until a biological anthropologist told me that menopause was a tightly integrated proactive cascade of biochemical changes which shuts down female procreative capacity. In contrast, human males exhibit declining fertility in a gradual fashion due to a generalized breakdown of bodily function. I am generally suspicious of some sort of adaptation when something so precise in our physiology seems on the surface to reduce fitness.
Update: Here is an article from the originator of The Grandmother…
razib | May 4, 2007The post below about the decline of biological anthropology as a concentration at Harvard elicited many responses. To some extent the columnist was framing the argument in a Two Cultures fashion. This is an expansive and thoroughgoing argument. I am personally unaware of the direct benefits of studying mathematics and English Literature simultaneously, though I do know that my old secondary school experimented with mixing subjects such as physics and history after my graduation. But though I am unclear as to the direct benefits, I think that the indirect long term fruit can be substantial…
razib | May 3, 2007Check out this Harvard Crimson column on the death of the biological anthropology concentration:
The root cause is a language barrier. Faculty members of the sciences and the humanities strongly adhere to the belief that the world can either be exclusively expressed in math or in words. Social science also splits off the world in this manner. Any student who is taking intermediate microeconomics needs to decide if he wants to take a class taught in English or in math. If the former, he is to take Economics 1010a, "Microeconomic Theory." If the latter, Economics 1011a, "Microeconomic Theory."…
razib | May 2, 2007I've talked about "the breeder's equation," R = h2S, before.
R = response
S = selection differential
h2 = narrow sense heritability
For example, if you have a population where the mean phenotypic value is 100, and you select a subpopulation with a mean value of 125 to breed the next generation, and the heritability is 0.50, then:
R = 0.50 * (125 - 100) = 12.5
In other words, the response to selection in this case where the differential is 25 units in the parental generation would be 12.5 units in the offspring with respect to the original population. This is because the "narrow sense…
razib | May 2, 2007The Washington Post has an article up on recent controversies regarding the relationship between Neandertals and our own lineage. Nothing too surprising, though I did note one point:
But one genetic trait of modern Europeans makes him [Chris Stringer] doubt there was any major Neanderthal input -- the fact that most humans today are genetically ill-adapted to cold weather. Only some native Indian populations, as well as people in the north of Eurasia and aborigines in Australia (who experience deep cold at night), have good genetic defenses to cold. Since Neanderthals lived in Europe for…
razib | May 1, 2007Apparently Toxoplasma gondii, a parasite implicated in human behavior modification, might have its origins in South America. This puts a whole new spin on The Columbian Exchange. One of the underemphasized aspects of the meeting of "Old" and "New" World, to my mind, are the first order biological dynamics. That is, there is plenty of discussion of the transmission of potatoes to various Eurasian cultures and how it revolutionized agriculture there, but it seems likely (as documented by Charles C. Mann in his book 1491) that biological interaction between human populations was just as…