razib | September 11, 2006You might remember the Donors Choose drive a few months ago. It worked out well, we here at Gene Expression raised nearly $2,000! Now that it's back to school time, I encourage you to give if you can. A few of my projects are still underfunded (though it is nice to see that most of them have hit 100%) and there are many back to school causes that are worthy. Thanks for reading this blog, and thanks very much for helping out!
razib | September 11, 2006A few days ago Alex Palazzo posted about Moral Minds: How Nature Designed Our Universal Sense of Right and Wrong. The title is pretty self-explanatory. The author has a Moral Sense Test that you can take. I took it. If you plan on taking the Moral Sense Test, please click now before you read further and get "spoilers."
Back? Below is my summary, you can compare it to yours.
The scenarios you judged in this test pit means against ends, whic is a common philosophical contrast. Each of the characters must choose whether to use bad means to acheive good ends -- for instance, whether to harm a…
razib | September 10, 2006Apropos of my comment about sex & civilization, a reader brought up Sparta, and over @ 2 Blowhards there's a nice post, Case Studies in State Formation - Sparta:
There was an extreme egalitarianism on the surface in Sparta, where all men ate in messes and dressed identically until getting married in middle age. Indeed, the Spartans called themselves the homoioi, those who are alike. While egalitarianism was a very strong trend throughout the Greek world during the archaic and classical eras, in Sparta the appearance of egalitarianism was deceptive, at least in a politically. Spartan…
razib | September 10, 2006One of the things that I like emphasize on this site is that human psychology isn't as straightforward as we might assume. In the area of religion this is important because religion intersects a great deal with public policy and culture, and, I think my fellow atheists often have a fallacious model of how religious people think. The complexity and separability of mental processes and chains of inference are important to keep in mind when we posit a model of how humans "tick," and we shouldn't dismiss rationalization or irrationality as aberrations. Here is an interesting passage from The…
razib | September 10, 2006The Guardian has a short piece titled Humans 'hardwired for religion'. The researcher quoted makes the point that humans seem to exhibit strong, powerful and sometimes
irrational intuitions and sentiments. And intuitive belief in gods is like part of this set of psychological phenomena. As I've noted before even those who disavow any supernatural beliefs often feel "creepy" when walking through cemeteries. Materialists may hold with their minds that our bodies are but elements and compounds driven to a state of dynamic flux by a series of intricate biochemical pathways, but often their (…
razib | September 9, 2006The current issue of Current Biology is about sex. I really dig David C. Queller's primer on sex ratios, Fisher in 'da house yo!
razib | September 9, 2006In the annals of they had to do "research"?, Researchers identify 'male warrior effect'":
In experiments with 300 university men and women students, Van Vugt and his team gave the volunteers small sums of money which they could either keep or invest in a common fund that would be doubled and equally divided. None of the students knew what the others were doing.
Both sexes cooperated in investing in the fund. But when the groups were told they were competing against other universities, the males were more eager to invest rather than keep their money while the number of women contributing…
razib | September 8, 2006As of this moment RPM has not commented on a new paper in Science, Gene Transposition as a Cause of Hybrid Sterility in Drosophila. Here is an accessible summary. The basic idea is found in the abstract:
...Genomic and molecular analyses show that JYAlpha transposed to the third chromosome during the evolutionary history of the D. simulans lineage. Because of this transposition, a fraction of hybrids completely lack JYAlpha and are sterile, representing reproductive isolation without sequence evolution.
JYAlpha is implicated in sperm motility. In D. melanogaster is located on the 4th…
razib | September 7, 2006A few weeks ago I explored the issue of smart individuals generally not being particularly fecund. I thought some readers might find this table from Cavalli-Sforza and Bodmer's Genetics of Human Populations interesting:
Sperm Donors
% Females Participating (p)
IQ
Mean of selected males
Minimum of selected males
% of males selected
1
5
10
20
50
100
115
105
38
100
100.2
100.4
100.8
100.9
103.8
130
122
6
100.1
100.4
100.8
101.5
103.8
107.5
145
140
.36
100.1
100.6
101.1
102.2
105.6
111.2
160
156
0.008
100.1
100.8
10.5
103.0
107.5
115.0
175
171
0.0001
100.2…
razib | September 6, 2006Janet has declared a "Nerd off." Here are two tales which made me reflect upon my nerdiness.
Once a friend and I mocked another friend because of their clumsy pipetting technique (he transferred volume like a girl! Oops, sorry Janet, that was a joke :-)
In a linear algebra study session I once made a joke which conflated 9-space with 3-space. Everyone laughed uproariously.
razib | September 4, 2006From The Genetics of Human Populations:
Considering only recessive genes for which the hetrozygotes are at present distinguishable [present is 1971]...only about 30 percent of the human population would be eligible for reproduction. These genes are, however, only a small minority of the recessive deleterious genes in existence...The probability that an individual would be free of such deleterious recessives would be e-4 or only 1/55. It might be even much less than this figure, which is computed on the assumption that all recessive deleterious genes have full penetrance, as the expected…
razib | September 3, 2006I love Thai peppers for their "fresh" flavor. The very hottest of these (according to the Scoville scale) overlap with the mildest of the Habenero. The Thai is spicy enough and slight enough that unlike the Serrano it never feels like you are a munching on a salad. My own particular favorite are the green Thai peppers, because though somewhat less spicy than their more ripe rich red cousins they impart a tangy aromatic flavor which fills out the heat with a richer taste. Also, unlike the Habenero the Thai is a small and compact package that you can keep on your side as you are downing the…
razib | September 2, 2006As I've been posting about effective population and inbreeding, I thought this re-post would be appropriate.
Begin repost
Reading a bit about inbreeding and population bottlenecks I came upon the extreme example of the northern elephant seal. In the late 19th century its population was reduced to about 20 individuals (undiscovered and isolated on a Mexican island). Today, there are around ~100,000 northern elephant seals. Compared to the southern elephant seal the northern hemisphere species exhibits far less genetic variation (surprise!). A relatively recent paper concluded that the…
razib | September 2, 2006In a few posts below I mentioned long term effective population. The effective population is basically the breeding population as opposed to the census size. Depending on the species this can vary quite a bit. One important point to consider (and this is obviously relevant to inbreeding and genetic diversity) is that the breeding generation alive must be placed in its historical context, how many ancestors does this population have?
For non-overlapping generations long term effective population size is the harmonic mean of the effective population sizes of each generation. It is defined by…