Archives for the month of: February, 2012

uh … what was the question again?

from the world values survey, 2005-2008:

“Many things may be desirable, but not all of them are essential characteristics of democracy. Please tell me for each of the following things how essential you think it is as a characteristic of democracy. Use this scale where 1 means *not at all an essential characteristic of democracy* and 10 means it definitely is *an essential characteristic of democracy*: People choose their leaders in free elections.”

percentage of those people in each country who answered 10 – free elections are definitely an essential characteristic of democracy:

jesus h. christ – we scored lower than burkina faso. *facepalm*

i got to thinking about what people(s) think ‘democracy’ is after hail wondered what libyans think ‘democracy’ means (’cause only 29% of libyans recently surveyed want to live in a democracy).
_____

update: here’s an ethnic breakdown for the u.s. on who responded what to the take me to your vote for leader question. 61.5% of white americans think that that’s an essential part of democracy, only 33.2% of black americans think so (click on image for LARGER view – should open in new tab/window):

(note: comments do not require an email. not gonna happen.)

the christian science monitor has a little quiz up: Sunni and Shiite Islam: Do you know the difference?

i sorta do. i got 3 wrong out of 19 — 84%. eh. =/

the three questions i didn’t know the answers to were:

12. The title Sayyid is used by members of which sect?
13. The name for which sect comes from the Arabic word for follower?
15. Which sect considers members of the other to be apostates?

you try! no cheating! (~_^)

(note: comments do not require an email. sunni or shia?)

yay!

michael wade (the beetle guy) and felix breden worked up some mathematical models of the possible frequencies of “genes for altruism” in several different types of inbreeding populations.

they took different degrees of inbreeding/outbreeding …

- mating with oneself or a clone (100% related)
– mating with a sibling (50% related)
– mating with a more distant relative (20% related, i.e. not quite half-siblings)
– no inbreeding at all (0% related)

… and via wizardry (i.e. advanced algebra) they worked out how “genes for altruism” would fare in each of these populations over the course of many generations. in other words, would altruism genes become more frequent or not in these various populations?

they factored in different parameters such as whether the gene(s) (alleles) in question were dominant or recessive, and whether the selection pressures on the alleles were weak or strong. weak selection apparently refers to those cases in which one “phenotype is slightly advantageous over another.” presumably strong selection means the opposite.

here’s what wade and breden found:

under weak selection — instances in which the altruism alleles only confer slight advantages to those who have them (top two graphs) — the altruism alleles really only increase in any significant way when the individuals self-mate (or mate with clones) or mate with their full-siblings. there’s some increase in altruism alleles in populations where mating occurs between individuals who are almost half-siblings and the alleles are dominant, but that increase really doesn’t become apparent until after several hundred generations of inbreeding.

under strong selection (lower two graphs), again the altruism alleles increase in frequency the most when the individuals self-mate or mate with full-sibs. however, there is also a marked increase in populations where mating occurs between individuals who are almost half-sibs AND the alleles are dominant. in fact, the slope really takes off after just fifty generations or so (solid line, bottom graph).

the authors conclude that: “Increasing the level of inbreeding can greatly increase the rate of change of gene frequency of the altruistic allele.”

i’m interested in the evolution of altruism in humans, though, and not many humans mate with themselves (yet) or even their full-siblings. what’s more common, as we all know by now, is cousin marriage.

mating with your first-cousin in a population where inbreeding doesn’t normally occur means your relatedness to your cousin is probably around 12.5%, much lower than the lowest inbreeding rate that wade and breden looked at (20%). however, in populations where inbreeding is frequent and regular, the coefficients of relatedness are much higher — for instance, some (many?) pakistani and saudi cousins have a coefficient of relatedness of around 22% (11% coefficient of inbreeding x 2). that’s pretty much the same as the lowest degree of inbreeding that wade and breden looked at.

i think it’s apparent by looking at human behavior that inbreeding affects the frequencies of altruism alleles in different human populations, but since we don’t even know what those alleles are yet, this hasn’t been proven one hundred percent. if wade and breden did their sums right, then my guess is that (at least some) altruism alleles in humans must be dominant and must confer a good deal of advantage to those who have them. in other words, if we could graph the frequencies of altruism alleles in humans who marry their cousins regularly over time, i think they would look something like the bottom graph above, although perhaps with a trajectory that wasn’t quite so sharp (since in no population does cousin marriage happen one hundred percent of the time in every generation).

the arabs, for example, have been marrying their first-cousins (often double-first-cousins) since at least mohammed’s days, or something like 1400 years ago. if we take a very conservative generation length as twenty-five years, that’s roughly 56 generations of inbreeding up to the present. at least. plenty of time, according to wade and breden, for altruism alleles to increase in that population — provided the alleles are dominant and the selection is strong.

a couple of other things to keep in mind: 1) like genes for height or intelligence, there are probably many genes for altruism, so we have to imagine some sort of cumulative effect of many genes on human behavior, i.e. we’d have to draw many charts to map the frequencies of many genes; 2) individuals in a population might share lots of alleles for reasons other than recent inbreeding, such as a population’s ancestors having gone through a bottleneck at some point in the past. you’d think that that could also contribute to the number of shared altruism alleles in a population.

update 04/30: see also more on inbreeding and the evolution of altruistic behavior

update 05/30: see also inbreeding and the evolution of altruistic behavior ii

previously: technical stuff and which altruism genes?

(note: comments do not require an email. citizens against altruism!)

back in the 70s, michael wade ran an altruism experiment with some confused flour beetles.

confused flour beetle larvae have a tendency to cannibalize nearby eggs (’cause they’re confused? (~_^) ). wade wanted to find out if there were any differences in the cannibalization rates between more closely related versus not so closely related hatches. so, he outbred some groups of beetles and inbred other groups to see what would happen.

i don’t have access to the paper related to this research, but here’s a summary of what he found from another one of his papers [pgs. 844-45]:

“In experimental studies of kin selection, using laboratory populations of the flour beetle, Tribolium confusum, Wade (1980a) investigated the effects of discontinuities in population breeding structure on the predictions of kin selection theory. The experiment consisted of synthesizing a strain of T. confusum with genetic variability for the tendency of larvae to cannibalize eggs. Beetles randomly chosen from this strain were then placed in six different treatments, each representing a different population structure, and the evolution of the cannibalism behavior was followed for several generations….

“The population structure was varied by varying both the degree of genetic relatedness between the larval cannibals and their egg victims and the degree of random mating. Depending on the treatment, the genetic relationship between the larvae and eggs was .50 (full-sibs), .25 (half-sibs), or .00 (no relationship). These ‘interaction treatments’ were factorially combined with two different breeding structures, representing the extremes of (1) random mating and (2) within-group mating. Wade (1980a) observed that the egg cannibalism rates, which were initially equal, diverged significantly from one another only in the within-group mating treatments. Specifically, in that treatment where the larvae and eggs were full-sibs, cannibalism rates declined relative to the treatment where the larvae and eggs were unrelated. Cannibalism rates in the half-sib treatment were intermediate. In those treatments with random mating, however, no differences in cannibalism rates were observed regardless of the larval-egg relationship….

“On the basis of this comparison of two extreme mating systems, Wade (1980a) concluded that inbreeding should accelerate the rate of evolution of social behaviors.”

so, inbreeding makes the evolution of altruism (and other social behaviors) easier.
_____

digression. this research with bugs reminded of an amusing story from bill hamilton about doing research at the univ. of michigan and some other bugs [pg. 51]:

“I mathematized them [some models] as far as I could and then used simulation on the Michigan main computer, accessing it either from a huge cave-like room called NUBS in the basement of the herbarium (our nearest-neighbour building) or, later, from a smaller terminal room in my own floor of the Museum of Zoology. NUBS had firebrats plus a spectrum of dazed, earnest, and sometimes frighteningly expert freshmen. Freshmen are first-year university students; firebrats, not arsonists but primitive insects. Smartly striped like football players, the latter dashed swiftly about on the floor under the piles of unwanted output paper, especially favouring that mounded against walls. I think their name’s origin lies in their being commonly found near bakery ovens. The nature of their food there is obvious; but what it was under the paper in NUBS is hard to imagine unless perhaps there were mummified students, dead of their sorrow at their unco-operating programs.”

(^_^)

previously: technical stuff and even plants do it! and more plants playing favorites and even ROBOTS do it! and even monkeys do it and even slime molds do it!

(note: comments do not require an email. the beetles!)

In the genes, but which ones?“‘As is the case with other traits, like height, there are probably thousands of genes and their variants that are associated with intelligence…. And there may be other genetic effects beyond the single gene effects – there could be interactions between genes, there could be interactions between genes and the environment.'”

Drinking Alcohol Shrinks Critical Brain Regions in Genetically Vulnerable Mice“[D]opamine receptors, known as DRD2, may play a protective role against alcohol-induced brain damage.”

Racial differences in childhood myopia – from the inductivist.

Lactase Persistence and Understanding History – from henry harpending.

Rethinking the social structure of ancient Eurasian nomads: Current Anthropology research“[E]arly pastoral nomads grew distinct economies across the steppes and mountains of Eurasia and triggered the formation of some the earliest and most extensive networks of interaction in prehistory.”

The emoticon on your face“[R]esearchers are suggesting that happy and sad expressions are not basic, evolutionary responses that take the same form all over the world, but cultural categories that we create from a much more complex emotional reservoir.”

A Sip for the Ancestors: The True Story of Civilization’s Stumbling Debt to Beer and Fungus – great series! i recommend reading them all (links at the top of the article i linked to here). (^_^)

Zoologger: The bird that cares for its rival’s chicks

bonus: NASA Will Pay You to Eat Astronaut Food for 4 Months

bonus bonus: The Bruce effect – why some pregnant monkeys abort when new males arrive

bonus bonus bonus: Dead for 32,000 Years, an Arctic Plant Is Revived

(note: comments do not require an email. pukeko?)

and what’s the tardis doing there? and mr. spock?! (click on image for LARGER … you know the routine! (^_^) )


_____

Follow

Get every new post delivered to your Inbox.

Join 311 other followers