Living the Scientific Life has a great summary of this recent paper which suggested that islands can serve as sources for biological diversity via back-migration to continental sources. Am I the the only one to think of the Shifting Balance Theory? To be succinct, Sewall Wright and R.A. Fisher spent several decades disputing (PDF link) the importance of population substructure and random genetic drift as salient forces in evolutionary genetic dynamics (Wright tended to emphasize their importance to a far greater extent than Fisher). In this scenario, where there was diversification of the original colonizers on islands, it seems plausible that the rate of migration1 might have been low enough for substructure to become a significant parameter. Of course islands are special cases which are not ubiquitous, so the biggest take home message might be that evolutionary genetic dynamics needs to considered in context.

1 – Fst, which is a reflection of interpopulation vs. intrapopulation genetic variation, can be related to the # of migrations per generation via 1/(4Nm + 1), where N ~ number and m ~ proportion of migrants per generation, so that Nm is the # of number migrants per generation. 1 migrant per generation is usually sufficient to serve as a break on interpopulational differences. Random genetic drift’s power is inversely proportional to N, so when the population is large there isn’t much sampling variance which the 1 migrant has to work against, while in a small population 1 individual is a much larger proportion of the population. More here.

Just a reminder everyone, I am NOT a Muslim. Just saw a reference to me as a “Muslim guy” on a comment board in regards to evolution vs. creation (pointing to this site as a good read on the topic). I do not regard Islam as an ethno-religion like Judaism or Hinduism. Unlike the latter religions, creed, profession of belief, is a hallmark of Islam. I reject the creed, ergo, I reject the religion and do not identify as Muslim. Over at Sepia Munity I specifically changed my handle to “razib_the_atheist” because I got tired of people assuming I was Muslim from my name (thinking I am a Muslim was not the problem, the problem was that people addressed me as if I held beliefs common to Muslims, which resulted in some bizarre questions , i.e., “As a Muslim, don’t you think you should speak up about the problems with Islam?”). Part of the problem I think with regards Sepia is that many of the people come from a Hindu tradition where there isn’t such a close coupling of creed to religious identity, so my origin as a Muslim is given greater weight than I myself give it. In fact, I have noted that on the internet, where people don’t know me in day-to-day interactions, there is far more emphasis given to my Muslim origin than in my regular life (where people assume I am of Hindu background from what I can tell in reference to consideration for my presumed vegetarianism). For example, several people have assumed that I might identify with civil rights issues in relation to Muslims because of my background, but the reality is that I don’t (above and beyond my general libertarianish concern with such issues). I am not even averse to a legal name change if that is what is necessary to decouple myself from any Muslim identity (as I said, most people assume I’m Hindu despite my name, so I don’t think it is necessary at this point). Also, unlike several acquaintances who are atheists of Muslim background, I do not identify as a cultural Muslim in any way, shape, or form (given Islam’s traditional hostility toward unbelievers who was “born” into the religion, I see no reason that I should evince warm feelings toward the cultures in which it is embedded).

To readers of this weblog this is all likely superfluous, but I wanted this on the record, this isn’t the first time that I have seen a reference to me as a Muslim on a message board. The fact is that on the personal level I am as irritated and offended by people associating me with Islam as a believer as a Muslim would be by an evangelical Christian telling them that they are “idol worshippers” (this happens!). This is an issue where in fact I feel comfortable being in agreement with evangelical Christians, because unlike more “cultural” religious traditions like Judaism, Hinduism or Roman Catholicism, they place primacy on belief and don’t regard personal origin as particularly determinative (“born again” Christians of course must go through an experience of becoming “Christians” as adults, and Baptists reject infant baptism because of their emphasis on the primacy of personal choice).

PS: On my name, “Razib,” it is actually simply a slight tweak on the name “Rajib,” which is a conventional Bengali variant of the name “Rajiv.”

Update: On my name, in kindergarten, my teacher, a naturalized American citizen of Dutch origin, had difficulty enunciating the “j” in my name and switched it to a “z.” My parents call me “Rajib,” as do the rest of my relatives and Bengali acquaintances from my parental generation. Everyone else knows me as “Razib,” though truncation is a common tendency. Occassionally I run into someone who is “in the know” and they can’t help but call me “Rajib,” because that is the variant they are familiar with (if they knew someone named Rajib they invariably can’t help but use that form).

RMP over at EvolGen is starting a series called Detecting Natural Selection. I know a substantial subset of readers don’t come out of a science background, so I think some might find it of interest. The first entry is up, if anything is a surprise, read the whole thing (eventually).

Something new

“A collection of public affairs lectures, panels and events from academic institutions all over the world — for you to view, listen to, stream or download.”

… not to be confused with the ResearchChannel

This is a short post which I will elaborate on later in a broader biological context, but Richard Sharpe’s comment is something I want to respond to real quick: “If Greeks are Caucasian, then…Just how do you designate yourself….”

First, I’m not white, my ass is a rich brown, ergo, I’m not “Caucasian.” The nerdy amongst us though might be familiar with the term “Caucasoid,” which shares a relationship with Caucasian (there were very few non-white Caucasian/Caucasoids in the country when these terms became common). Well, operationally I don’t think South Asians should really be considered Caucasoid (though Middle Easterners should, Middle Easterners-Europeans are a monophyletic clade in relation to Brownoids). On a phylogenetic tree, if I had to make one, I would make Caucasoids and Brownoids (my term) a monophyletic clade in relation to other races of man.

But there’s a serious problem with this in my opinion. In The Real Eve Stephen Oppenheimer spun a grand genetic-historical narrative which culminated during the Last Glacial Maximum, about 30,000 years ago. It is from this point that Oppenheimer traces the origins of modern races. He states flat out that admixture has been minimal. Perhaps. Perhaps not. The problem with Oppenheimer’s story is that it is rooted in mtDNA, which is passed only through the female line. This is neat, because it eliminates recombination between lineages, so you get a clean cladistic tree all the way back to a common ancestor with all the putative ancestral character states. But the vast majority of our DNA is recombinant, and not passed uniparentally. You look at many Latin Americans, and the mtDNA will tell you they are cousins to East Asians, while the NRY (passed through fathers) will tell you they are Iberians. This is the most extreme case, but I doubt it is the only one.

So back to Richard’s question. The problem I have with answering stuff like this is that I’m a melange, as all people are. I can say that I suspect it is likely that vast majority of my ancestry can probably be traced to the South Asian subcontinent around 10,000 years ago, but my NRY and mtDNA might say something different. Our full ancestral complement does not decompose itself into a bushy cladistic tree, it a reticulated mish-mash, like a ball of spaghetti. I mean, we’re not asexual, right? We’re one species across which genes can flow in a sweeps. Well, tell that to the authors that are making tidy advances based on books that pedal neutral lineage markers as the family-tree writ large. Genealogy is big bucks, even in quasi-scientific garb.

And who forgot selection? (Natural and social)

P.S. I have to say, about 2/3 of my scientific posts probably are derived from a question from the comment boards. A lot of the time it is even a 2nd or 3rd order idea, not a direct response. So thanks.

I didn’t know this article in The Wall Street Journal was free, but it is, so I’ll link to it: The New White Flight: In Silicon Valley, two high schools with outstanding academic reputations are losing white students as Asian students move in. Why? To some the article might be revelatory. This quote is very interesting to me:

Cathy Gatley, co-president of Monta Vista High School’s parent-teacher association, recently dissuaded a family with a young child from moving to Cupertino because there are so few young white kids left in the public schools. “This may not sound good,” she confides, “but their child may be the only Caucasian kid in the class.”

Why should this matter? I don’t know, I was the only non-Caucasian kid in most of my classes between the age of 6 and 18, and I wasn’t traumatized, but perhaps whites aren’t as ethnocentric and exclusionary as the Asian Americans which dominate this Cupertino High School (you know how well South Asians and East Asians cooperate! Hindi, Chini, Bhai Bhai!). From reading the article it seems to me that some Asian American parents, usually first generation immigrants, are bringing the “cram school” mentality to these shores. I’m all one for scholarship and academic competition, but to some extent I suspect that for the majority of kids this simply becomes a self-perpetuating cycle, like high stakes standardized testing.1 If I had a normal child, a kid below 3 standard deviations above the mean in IQ and without any specific drive and passion that could be optimized by attending these sorts of schools, I might also be hesitant to allow them to become ensconced in the kind of ends driven atmosphere sketched out above. I am skeptical that much value would be added to their cognitive toolkit over the long term in relation to the marginalization of normal avenues of socializing and the participation in common rites of passage which confer a sense of full citizenship. Nevertheless, I will be convinced at white terror of Asian American hegemony when I read about flight from Cal Tech, MIT and Berkeley, as Cal Poly, RPI and the Cal State schools start receiving Caucasian applicants who reject the former institutions because of their yellow cast.

But note throughout the article the transposition of subtle talking points and background assumptions normally utilized in articulation of the need for ethnic sensitivity toward members of underrepresented minorities in the context of whites. Over the last few years the cultural center has been tacitly cheerleading the transformation of this nation into a minority white polity where racial awareness is acceptable for minorities. It seems possible that a byproduct of these the two phenomena indicated above might be the organization of whites as a racial interest group. Society isn’t a linear system, so who knows.

1 – Or the devaluation of a bachelor’s degree in the United States because of widespread access to university educations, and the pressure from society for all children to at least make a go at it.

There is a common belief that in Britain the different ethnic groups are becoming increasingly concentrated into different geographical districts, as ‘white flight’ reduces the proportion of whites in inner city areas, while ethnic minorities cluster together. The Chairman of the Commission for Racial Equality, Trevor Phillips, recently expressed the fear that Britain is ‘sleepwalking to segregation’.

Recent research casts doubt on such claims. The research is by sociologists at the University of Manchester under Dr Ludi Simpson. (Google on “Ludi Simpson” and “segregation” for numerous reports.)

Simpson’s own press release summary of the findings is as follows:

Our research suggests there is a lot of good news; in fact, there is more mixing. On balance there is neither retreat nor White flight. The larger populations of Black and Asian communities that have been highlighted are there simply due to natural growth; i.e. people having children. There are no Black or Asian ghettos anywhere in the UK where families of one colour are trapped. In all parts of Britain, the children of immigrants are moving away from so-called ghettos. After a couple of generations the mixing will be far more noticeable and the population growth of these groups will have slowed and probably stopped.

In a more detailed comment on the northern city of Bradford he says:

The broad picture that can be painted from these data is one of dispersal of a growing South Asian population from the inner city. This does not result in lower segregation because the inner city South Asian population is ‘re-filled’ by natural growth (more births than deaths) and by immigration; there is some movement of South Asian families into the housing of White populations who move from inner city areas. Thus the index of segregation for Bradford as a whole has been stable, but this stability is the balance between several different trends.

He adds that recently released data from the 2001 Census supports the Bradford findings for most areas of Britain.

These findings have been widely reported in the Press, generally without criticism or analysis. For example, according to the Guardian:

The study also says that immigration is not the reason for increased numbers of non-white Britons over the past decade, and that “white flight” from inner cities is another myth… The study says the increase in the number of non-white Britons is due to demographics rather than immigration. Ethnic minority populations are younger and have fewer elderly people than white communities. The number of Asian and black people is increasing because fewer die from old age and they have more women of childbearing age relative to white people. The author of the study, Ludi Simpson, said: “The common myth is that the growth of the ethnic minority population is due to immigration. That’s not true – it is more due to the growth of [ethnic minority] people born in Britain.”

In further press notes Simpson says ‘Fertility [of ethnic minorities] has reduced rapidly from the high levels associated with immigrant families. It is the youthfulness of immigrant workers and therefore their low mortality which has caused population growth, not high fertility, and not further immigration’.

This is interesting research, and it is useful as a corrective to unsupported myths. But it may create an equally misleading counter-myth. It is necessary to distinguish between the facts and the PC spin put on them.

The facts are that in inner city areas the proportion of ethnic minorities is increasing, while ethnic minorities are also spreading out into surrounding, previously all-white, areas. This pattern is almost inevitable because the ethnic minority population is growing. But even if the ethnic minority population were not growing, it is predictable that economically successful immigrants would wish to move away from poor quality urban environments, and into previously white suburbs and rural areas.

Whether the combined effect of these factors is regarded as increasing or reducing ‘segregation’ depends in part on how segregation is measured, which is not straightforward. (For some discussion of different measures see here.) But it is evident that by Ludi Simpson’s own chosen Index of Segregation there is no overall reduction in segregation. The growth of ethnic minorities in inner city areas increases segregation, while the dispersal into surrounding areas reduces it. The two factors roughly balance each other. Simpson’s own statement ‘This does not result in lower segregation’ could hardly be clearer. So if Simpson or others choose to headline the claim that ‘integration’ is increasing, this is giving only half the story.

I don’t claim to know whether ‘integration’ in any useful sense is increasing or not, but one test of this would be to look more closely at where the ‘dispersing’ ethnic minorities are going. Are they dispersing at random into the surrounding areas, or are they concentrating in more localised districts? For example, some of the outlying areas of Leicester are far more heavily Asianised than others. Some suburban schools in Leicester are now mainly Indian, and schools are a good indicator of the extent of practical integration or segregation. A recent study by Burgess, Wilson and Lupton found that ‘Looking at both schools and neighbourhoods, we find high levels of segregation for the different groups, along with considerable variation in segregation across England. We find consistently higher segregation for South Asian pupils than for Black pupils. The data also suggest that segregation tends to be lower for Black pupils where they are relatively numerous, but that no such attenuation exists for pupils of South Asian origin. Indeed, for these groups, segregation is higher where they are relatively numerous’.

There is nothing surprising about non-random dispersal of people with distinctive cultural and religious traditions. People will want access to appropriate places of worship, shops, etc. An important factor in directing dispersal to particular areas is the prevalence of Asian estate agents (realtors) serving mainly their own communities. This is not necessarily a bad thing, but it would be nice to know the facts, and not just prattle about ‘integration’.

I was also intending to discuss the claim by Simpson that the main factor in the growth of the ethnic minorities is the age structure of their population, and not continuing immigration or higher fertility. But I will save that for another post.

For those of you who watch television, The Infidel Guy will be on ABC’s Wife Swap next week. Apparently Reggie’s wife is switching places with a pastor’s wife, should be pretty tweaky.

I just found out recently that a biography of Luca Cavalli-Sforza was published this spring, A Genetic and Cultural Odyssey. I’ll probably be reading it over the Thanksgiving weekend, but I thought I’d give people a heads up around here since I suspect I’m not the only fan. The History and Geography of Human Genes is one of those seminal works which has really shaped the intellectual path I have taken. Over the years I have become progressively more skeptical about reading history from alleles frequencies, but Cavalli-Sforza’s work is an interdisciplinary inspiration to this day. If a readable genetic monograph is your cup of tea, I also recommend Consanguinity, Inbreeding, and Genetic Drift in Italy. I picked it up a few years in Barnes & Noble in New York, and read most of it on the airplane. The frequency of aunt-nephew marriages in Sicily will make you wonder! Finally, Genetics of Human Populations is back in print, though the text isn’t updated a lot of the population genetic models are becoming extremely relevant again to deal with the swarms of data that are the norm in the post-genomic era.

As a naturalized American citizen, I point you to Michael Blowhard’s immigration post.