Archive for August, 2008

Genetic map of Europe; genes vary as a function of distance

By Razib Khan | August 31, 2008 9:29 pm

My post The Genetic Map of Europe drew a lot of interest, but there’s even a cooler paper on the same topic out, Genes mirror geography within Europe:

…Despite low average levels of genetic differentiation among Europeans, we find a close correspondence between genetic and geographic distances; indeed, a geographical map of Europe arises naturally as an efficient two-dimensional summary of genetic variation in Europeans. The results emphasize that when mapping the genetic basis of a disease phenotype, spurious associations can arise if genetic structure is not properly accounted for. In addition, the results are relevant to the prospects of genetic ancestry testing; an individual’s DNA can be used to infer their geographic origin with surprising accuracy–often to within a few hundred kilometres.

Again, great maps. First, check out this plotting of the two largest independent dimensions of genetic variation. Note the rough correspondence to the geography of Europe in terms of spatial relations. This should be no surprise considering that for all practical purposes marriage networks move across two dimensions and drop off in likelihood as a function of distance. In other words, it is common sense that relatedness between groups would drop as a function of distance. Do note the small sample sizes for some groups, the N for Denmark, Finland, Latvia, Slovakia and Ukraine is 1, while Italy and the United Kingdom have N’s of 200 or more .
genmap1.jpgClick here for full sized figure
No big surprise, but it greats really cool when you zoom in as they do in B of Figure 1 for Switzerland.

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CATEGORIZED UNDER: Genetics

Barack Obama's answers to the top 14 science questions facing America

By Razib Khan | August 30, 2008 4:03 pm

Sciencedebate 2008 got some answers from Barack Obama. Props to Chris and Sheril who put some labor hours into this….

CATEGORIZED UNDER: Politics

Sarah Palin, 14% chance of Presidency 2009-2013?

By Razib Khan | August 30, 2008 1:48 am

Seems like there’s a 14% chance that if the Republicans keep the White House this year that Sarah Palin will be President of the United States in the interval 2009-2013. Of course, you could modulate the probability up or down based on plugging in more priors into the model, but I think it gives a rough qualitative sense.

CATEGORIZED UNDER: Politics

War and the evolution of belligerence and bravery

By Razib Khan | August 29, 2008 7:29 pm

War and the evolution of belligerence and bravery:

Tribal war occurs when a coalition of individuals use force to seize reproduction-enhancing resources, and it may have affected human evolution. Here, we develop a population-genetic model for the coevolution of costly male belligerence and bravery when war occurs between groups of individuals in a spatially subdivided population. Belligerence is assumed to increase an actor’s group probability of trying to conquer another group. An actor’s bravery is assumed to increase his group’s ability to conquer an attacked group. We show that the selective pressure on these two traits can be substantial even in groups of large size, and that they may be driven by two independent reproduction-enhancing resources: additional mates for males and additional territory (or material resources) for females. This has consequences for our understanding of the evolution of intertribal interactions, as hunter-gatherer societies are well known to have frequently raided neighbouring groups from whom they appropriated territory, goods and women.

No time to read it right now, but a follow up to my post War, rape and group selection.

CATEGORIZED UNDER: Genetics

Women care more about abortion rights

By Razib Khan | August 29, 2008 3:28 pm

In my post below I pointed out that there was no sex difference in terms of attitudes toward the legality of abortion on demand. But the question remains: is there a difference of intensity? Yes. Women care more. Specifically, pro-choice women care a great deal more than pro-choice men. There is a slight sex difference between men and women in the pro-life camp, but far less. I wonder if this difference might explain why many liberals seem to assume that abortion is a “woman’s issue” and that women would by their nature support abortions rights; in their own social circle avowed apathy is a feature of men to a far greater extent. In contrast, among the pro-life this difference is greatly attenuated, so it would not be seen as a specifically woman’s issue. Data below the fold.

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CATEGORIZED UNDER: Culture

Who supports abortion on demand?

By Razib Khan | August 29, 2008 2:09 pm

Those with more education, wealth and intelligence. Those with less pigment in the skin and more liberal politics. There is no sex difference. Charts below.

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CATEGORIZED UNDER: Culture

Atheist vs. Attend Religious Services Once a Week

By Razib Khan | August 29, 2008 12:55 pm

A comment:

In Canada, places in the far west like Alberta and British Columbia contain a higher percentage of atheists and other non-religious, but also a higher percentage of evangelical Christians.

This is true in the USA to some extent…but I didn’t want to compare to “evangelical Christians” because the relatively low proportions of evangelicals in the Mountain West and the Northeast are historical artifacts due to their particular religious demography. So I used the same methodology as earlier and plotted the proportion of atheists vs. those who attend religious services at least once a week.
attendence.jpg

CATEGORIZED UNDER: Culture

McCain is a maverick

By Razib Khan | August 29, 2008 12:03 pm

palin-miss-alaska-b.jpgAt least when it comes to choosing his VP candidate. Joe Biden as a “safe” choice; Sarah Palin is not.

CATEGORIZED UNDER: Culture

Where are the seculars?

By Razib Khan | August 29, 2008 3:28 am

Over at Island of Doubt James Hrynyshyn says:

As far as I can tell, North Carolina’s no different from the rest of America when it comes to religion. About a tenth of the population is free of religious conviction….

Well, I was pretty sure that there is a statistically significant difference between most Southern states and the rest of the country in regards to these things, so I decided to check out the data in detail. The US Religious Landscape Survey allows me to see what proportion of each state’s population are atheists; that is, they don’t believe in God. Unfortunately the margin of errors are relatively big because of small sample sizes from the unbelievers for most states, so I wanted an outside “check,” and luckily the American Religious Identification Survey has state-by-state breakdowns as well. But, their breakdowns are for those with “No Religion,” a category where the rule of thumb is only 1/3-1/2 are atheists. Out of curiosity I plotted the number of atheists on the X axis vs. the nonreligious on the Y axis.
atheistvsnoreligion.jpg
The geographic patterns are interesting. Note that the West has many nonreligious, or those who are not affiliated. In contrast, parts of the Northeast have a great number of atheists, but lack of affiliation is relatively rare in comparison to someplace like Washington or Wyoming. The American South is a relatively distinctive cluster as well, with low levels of atheism and high rates of affiliation. The Midwest is a bit more diverse, but you can also see a discernible cluster there, with similar rates of affiliation as much of the Northeast but lower rates of atheism. The raw data is below the fold….

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CATEGORIZED UNDER: Culture

Amazon was not always "pristine"

By Razib Khan | August 28, 2008 6:11 pm

‘Pristine’ Amazonian Region Hosted Large, Urban Civilization:

The paper also argues that the size and scale of the settlements in the southern Amazon in North Central Brazil means that what many scientists have considered virgin tropical forests are in fact heavily influenced by historic human activity. Not only that, but the settlements – consisting of networks of walled towns and smaller villages, each organized around a central plaza – suggest future solutions for supporting the indigenous population in Brazil’s state of Mato Grosso and other regions of the Amazon, the paper says.

Preliminary interpretations of these data were reported several years ago in 1491: New Revelations of the Americas Before Columbus. Mann’s argument is simple: demographic collapse in the face of Eurasian pathogens wiped away 90% of the inhabitants of the New World within about one century of “First Contact.” And thus ensued a process of the “re-wilding” of vast swaths of the New World. So the woodlands of the North Central United States which the white settlers cut down as they moved west of the Appalachians, or the virgin forests of the Willamette Valley which the pioneers encountered, were relatively recent ecosystems which arose in the vacuum of the collapse of local native populations due to epidemics introduced originally by Spaniards and other Europeans. An important point to remember here is that these epidemics preceded the white settlement in many areas by decades or centuries, so the European experience of the native populations was only in the wake of the massive social chaos unleashed by plague. Imagine if the Chinese encountered Europe first during the Black Death; but on orders of magnitude greater scale (the Black Death killed a large minority of Europeans, Eurasian pathogens likely exterminated whole peoples in the New World).
Secondarily, the possibility that many regions of the Amazon were de-humanized recently should remind us that H. sapiens are part of nature. The heuristic whereby humanity is perceived to be above, beyond and distinct from the natural world may be useful in some contexts, but in the broad historical sense we are just another animal. I am one who suspects that H. sapiens were responsible for many megafaunal extinctions as a necessary if not sufficient cause, but after these initial contacts obviously the local ecology entered into a dynamic symbiosis with human populations. It is false to say that Mother Nature is wiser than humanity, because we are subsets of Mother Nature!

CATEGORIZED UNDER: Science

War, rape and group selection

By Razib Khan | August 28, 2008 2:41 pm

Fortune favours the brave; but the brave are motivated by favours of another kind:

If courage makes it significantly more likely that small bands of tribes-men will win military confrontations with their neighbours, its overall advantages can easily outweigh its risks, a mathematical model has shown.
Some men who carry genetic variants that promote bravery might perish because of them, but the ones who survive may win more battles through their greater daring. The resulting opportunities for rape and pillage can create a net evolutionary benefit.

The study is published in The Proceedings of the Royal Society, but it doesn’t look like it’s online yet. So I’ll have to wait on the details, but it what they’re describing seems like group-level selective events which might be vulnerable to “cheaters” who attempt to hold back and allow others to “bite the bullet,” so to speak, and reap the glory that goes to victorious tribes. Multi-level selection theorists such as David Sloan Wilson would make the argument that the way humans work against these “cheats” is through complex cognitive adaptations which allow for the policing of these anti-social traits, as well as the conventional rise and fall of groups who go through a life cycle of vigor, decline and dissipation.
I am still skeptical of higher than individual level selection in general, but, I am becoming less and less skeptical in terms of humans. I think in many ways our complex sociality is atypical enough to warrant the explanations of higher level selection and dynamics. Peter Turchin, Robert Boyd, James F. Crow and L. L. Cavalli-Sforza have also convinced me that we need to take these ideas more seriously for humans.
Related: Cooperation and multilevel selection, W. D. Hamilton & group selection & ideology and Selection on many levels…..

CATEGORIZED UNDER: Genetics

Genetics ∩ Sociology ∩ Evolution = Genomic Imprinting

By Razib Khan | August 27, 2008 7:43 pm

praderwillikid.jpgAs I have said before biology is quite often the science of exceptions, of variation. Evolutionary biologists spend a great deal of time wondering about the origin of sex, but across vast swaths of the tree of life sex is simply not a consideration. W. D. Hamilton made his name with models of inclusive fitness, but complex social structures are constrained and fully elaborated to only a few branches of the tree of life. Like economics then what interests us in biology often has normative priors; we are a homocentric species. On a fundamental level we understand that we do not exist at the apex of a great chain of being, but most of us can not help but wonder as to the human relevance of a particular biological phenomenon.
I believe genomic imprinting is one of those biological phenomena that has an interest for humans because of its theoretical peculiarities and pragmatic relevance. Diseases such as Praer-Willi syndrome are the byproducts of the peculiar nature of genomic imprinting, or at least the malfunctioning of the phenomenon. Simultaneously the dynamic which gives rise to these diseases in our species confounds general Mendelian expectations. In the case of imprinted genes the specific parental origin of the allele has direct bearing on the phenotypic outcome. It may be that the copy of the gene inherited from the father expresses while that from the mother is silent, or, it may be the inverse. Why and how genomic imprinting is a question of evolutionary and molecular genetics. A new paper in PLoS Biology, Evolution of Genomic Imprinting with Biparental Care: Implications for Prader-Willi and Angelman Syndromes, extends David Haig’s kinship theory of genomic imprinting which I’ve reviewed before. The paper is very homocentric, as evidenced by the author summary:

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CATEGORIZED UNDER: Genetics

Earthquakes → progress?

By Razib Khan | August 27, 2008 3:22 pm

Tectonic environments of ancient civilizations in the eastern hemisphere:

The map distribution of ancient civilizations shows a remarkable correspondence with tectonic boundaries related to the southern margin of the Eurasian plate. Quantification of this observation shows that the association is indeed significant, and both historical records and archaeoseismological work show that these civilizations commonly suffered earthquake damage. Close association of ancient civilizations with tectonic activity seems to be a pattern of some kind. In the hope that dividing the civilizations into subsets might clarify the meaning of this relation, primary and derivative civilizations were compared. Derivative civilizations prove to be far more closely related to the tectonic boundaries. Similarly, the civilizations that endured the longest (and that have been described as most static) are systematically the farthest from plate boundaries. It is still unclear how the relation actually worked in ancient cultures, i.e., what aspects of tectonism promoted complexity. Linkages to water and other resources, trade (broadly construed), and societal response seem likely. Volcanism appears not to be involved.

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CATEGORIZED UNDER: History

Refuting evolutionary materialism

By Razib Khan | August 26, 2008 3:22 am

Update: Please read Sandman’s response after you look over this post….
New Evidence Debunks ‘Stupid’ Neanderthal Myth:

Blades were first produced by Homo sapiens during their colonization of Europe from Africa approximately 40,000 years ago. This has traditionally been thought to be a dramatic technological advance, helping Homo sapiens out-compete, and eventually eradicate, their Stone Age cousins. Yet when the research team analysed their data there was no statistical difference between the efficiency of the two technologies. In fact, their findings showed that in some respects the flakes favoured by Neanderthals were more efficient than the blades adopted by Homo sapiens.

Now that it is established that there is no technical advantage to blades, why did Homo sapiens adopt this technology during their colonization of Europe? The researchers suggest that the reason for this shift may be more cultural or symbolic. Eren explains: “Colonizing a continent isn’t easy. Colonizing a continent during the Ice Age is even harder. So, for early Homo sapiens colonizing Ice Age Europe, a new shared and flashy-looking technology might serve as one form of social glue by which larger social networks were bonded. Thus, during hard times and resource droughts these larger social networks might act like a type of ‘life insurance,’ ensuring exchange and trade among members on the same ‘team.’”

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CATEGORIZED UNDER: Evolution

How I view religion

By Razib Khan | August 25, 2008 2:08 pm

A lot of comments have revolved around whether I am a Post-Modernist when it comes to the definition of religion. This post is to make explicit and clarify my own position so I don’t have to waste so much time in the comments. Most readers can therefore ignore this and wait until I go back to posting on genetics or something more interesting! :-)

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CATEGORIZED UNDER: Religion

Democrat and Republican, by the numbers

By Razib Khan | August 25, 2008 2:25 am

Pew has a nice survey up right now, A Closer Look at the Parties in 2008. Here are three questions, and the Republican – Democrat difference on the responses:
Do you think the US made the right or wrong decision in using military force against Iraq?, a 50 point difference on both “yes” and “no.” I’ll let you guess the signs!
Do you think abortion should be…
Legal in all cases -13 difference
Legal in most cases -10 difference
Illegal in most cases +19 difference
Illegal in all cases +6 difference
Books that contain dangerous ideas should be banned from public school libraries
Agree +4 difference
Disagree -2 difference
Check out the other responses. I’m struck how long-standing “Culture War” issues are actually far less stark in their dichotomy than proximate, almost epiphenomenal, policies such as the Iraq War. And when it comes to “core” values such as free speech there isn’t much of a difference between the parties (though a shockingly high proportion of both Democrats and Republicans believe that books with “dangerous” ideas should be banned).

CATEGORIZED UNDER: Politics

Who believes in astrology?

By Razib Khan | August 24, 2008 3:05 pm

John Hawks points me to a “He said, she said,” piece which wonders whether there is an inverse relationship between belief in the paranormal and religion. The basic thesis is that the mind abhors a vacuum so without institutionally guided supernatural beliefs people simply revert to “default” intuitions. The article doesn’t come to any conclusion, citing contradictory results. So of course I decided to look at the GSS. Specifically, two variables, ASTROSCI and SCITEST3, which query how scientific individuals believe astrology to be. I paired them up with belief in God, GOD, highest degree attained, DEGREE, and correct number of vocabulary words, WORDSUM. Since people complain about the GSS’s ghetto graphs I just reformatted them into an HTML table. You can see the raw proportions below. After the fact I was curious about political orientation, POLVIEWS, and noted that liberals were more likely to accept astrology as scientific than conservatives. In any case, I found
1) Only a mild correlation between lack of god belief and skepticism of astrology
2) Stronger correlation between intelligence (vocabulary) and degree attainment and skepticism

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CATEGORIZED UNDER: Culture

Youth Politics

By Razib Khan | August 24, 2008 12:42 pm

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CATEGORIZED UNDER: Blog

20% of American atheists are religious

By Razib Khan | August 24, 2008 12:59 am

A rather pontifical commenter promoted me to do a little digging on the demographics of American atheists, as I was pretty sure that it would reinforce my point about the subjectivity of definitions. The product is a post at my other weblog, Large minority of atheists are religious:

…20% of atheists in the United States self-identify as a member of a religion. By atheist, I mean someone who states that they “Do not believe in God.” 19% of Buddhists are atheists. 10% of Jews. 5% of Muslims and Hindus. 9% of “Other Faiths.” And of course, 22% of the Unaffiliated (those without a religious identification). To get to my 20% number I just went to the Pew US Religious Landscape Survey, checked belief in God by religion and cross-referenced with the proportion within the sample of each religion. I think it’s a rather peculiar situation that the same proportion of atheists are religious as non-religious are atheists! Chart and data below the fold….

CATEGORIZED UNDER: Religion

"Death to apostates!" 1 out of 33 Muslim university students say

By Razib Khan | August 23, 2008 4:11 pm

Islam on Campus: A survey of UK student opinions. N = 632 for Muslims. Remember that this is an elite sample of the youth insofar as they’re polling university students.
apostateislamsurvey.jpg
You might wonder what exactly Sharia law is in regarding to apostasy. Perhaps these students have a different interpretation than the majority consensus that apostates should be killed. Well….
deathtoapostates.jpg
In other words, 1 out of 33 Muslim British university students believe that apostates should be killed. Little wonder that many Europeans feel a little Islamophobia….
Additionally,
* Muslims have far less respect for atheists than non-Muslims
* Muslims have far less respect for homosexuals than non-Muslims
* Muslims are much more likely to think that it is acceptable to kill in the name of religion than non-Muslims
Details below….

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CATEGORIZED UNDER: Religion
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