A few weeks ago I noticed that the Wikipedia entry for Cape Coloureds has little fleshed out information on their genetics. As a mixed population it seems that people would be interested, but has always been hard to find anything from Google Scholar on this topic. But the recent Tishkoff paper, The Genetic Structure and History of Africans and African Americans, has some data. You can find a full post at my other weblog, but it seems that not only are the Cape Coloureds substantially European, Khoisan and Bantu, but likely they’re also substantially Indian, and there is a definite East Asian element, no doubt from slaves brought from Maritime Southeast Asia by the VOC. There’s also a lot of variance in this particular sample of Cape Coloureds. Assuming this is representative I would offer that the main reason is that the Coloured population has historically had many people entering it from other groups, and, many leaving to other groups.
Month: June 2009
Who are the Cape Coloureds of South Africa?
A little under 10% of South Africa’s population are Cape Coloureds. They speak Afrikaans and generally worship in Reformed Christian churches, but exhibit discernible non-European ancestry, in particular African ancestry. In the United States anyone who manifests African ancestry is coded as “black.” Though hypodescent started out as a tool for maintaining white racial purity against colored taint, today it is accepted within black America as the social norm. Barack Obama has obvious mixed ancestry but he is accept as fully black racially by both black and white Americans. In South Africa someone who looked like Obama obviously would not be white, but, they might be Coloured, as this group exhibits a wide range of appearance, as is the norm among very mixed populations.
In the course of research I stumbled upon the fact that the past two winners of Miss South Africa are Coloured, or at least likely Coloured as there is some ambiguity. Tansey Coetzee clearly has Coloured ancestry just by her surname, Coetzee, which is known among Afrikaners (note that Afrikaner surnames are not necessarily Dutch, as Huguenots and Germans were part of the original Cape Colony population). But Tansey Coetzee also has an Asian Indian mother (she offers this in interviews on YouTube). I assume in South Africa that someone who is Coloured + something else is most likely to self-identify as Coloured. The second Miss South Africa is Tatum Keshwar. Her identity is a bit more confused, as the surname has convinced many Indian publications that she’s Indian, while Coloureds are complaining that she is in fact a Coloured. Most people in the world who look like Tatum Keshwar are probably South Asian (there 1.3 billion South Asians, and a substantial minority of this is hundreds of millions), and her surname suggests that like Tansey Coetzee she has Indian ancestry. But listening to Tatum Keshwar on YouTube it sounds like she speaks English with an Afrikaans accent, strongly suggesting Coloured cultural background. She also refers to going on a modeling job to India (naturally, she looks like a lot of Indian models, so it would be a good fit), but she doesn’t talk about India like a “Non-resident Indian” might from what I can tell, alluding to how “exotic” it is and not mentioning any family connection. In most of the world someone who looked like Tatum Keshwar and had her name would be Indian. But not necessarily in South Africa.
I wanted to note ambiguities in Keshwar and Coetzee’s ancestry because genetics can now supplement what we know about the Cape Coloureds.
Low carb diet weblog
A friend of mine has a new weblog, Low Carb Art and Science, which some of you might be interested in (or not). I do think it is ironic since this is an individual who presumably is in favor of a diet of red beans & rice. If you want a more eclectic range of posts on diet you might want to check out FuturPundit.
FireFox 3.5 this week
A new version of FireFox is coming out today. You can already test drive the latest pre-release already. I’ve been using Chrome since last year for 95% of my browsing needs because of the speed. I miss plugins, and there are also pages that render a bit idiosyncratically and AJAX apps which get confused. Because of low market penetration naturally designers and developers don’t always make sure that their sites work appropriately for Chrome. In any case, now Farhad Manjoo has a review up of the new Firefox browser, and seems to think that it has revived the brand. His points are:
My new blog about health, nutrition, and diet
Some readers here may already follow the food-related stuff I write about at my personal blog. Well, to allow myself to write more about diet, nutrition, and food in general, I’ve started a new blog called Low Carb Art and Science. Lord knows there are already lots of blogs that deal with the topic, but this one will have lots more data and a stronger emphasis on evolution. But there will be plenty of less serious stuff and easy recipes too. Plus I’ll take an occasional interdisciplinary approach, as with an earlier post I wrote about the late Medieval shift away from carbs and toward meat.
The first post up is about the changing American diet and poorer health — except that the graphs show that the changing American diet has been one that’s rigidly adhered to what the health experts tell us to eat. The data weren’t hard to find, analyze, and present, but I’ve never seen them before, let alone in a clear-to-see visual format. If you doubted whether the anti-meat, pro-grain message was being followed or not, and if so, whether it was making us healthier — this will be a real eye-opener. Take-home lesson: eat more saturated fat and cholesterol, and less carbohydrates.
Comments closed here; comment over at Low Carb Art and Science.
Neurotypicals are irrational beasts
Arnold Kling highlights this section from a Scientific American article, The Science of Economic Bubbles and Busts:
But behavioral economics experiments routinely show that despite similar outcomes, people (and other primates) hate a loss more than they desire a gain, an evolutionary hand-me-down that encourages organisms to preserve food supplies or to weigh a situation carefully before risking encounters with predators.
One group that does not value perceived losses differently than gains are individuals with autism, a disorder characterized by problems with social interaction. When tested, autistics often demonstrate strict logic when balancing gains and losses, but this seeming rationality may itself denote abnormal behavior. “Adhering to logical, rational principles of ideal economic choice may be biologically unnatural,” says Colin F. Camerer, a professor of behavioral economics at Caltech. Better insight into human psychology gleaned by neuroscientists holds the promise of changing forever our fundamental assumptions about the way entire economies function–and our understanding of the motivations of the individual participants therein, who buy homes or stocks and who have trouble judging whether a dollar is worth as much today as it was yesterday.
The gain vs. loss dictum indicates a strong risk aversion in humanity. Why might this be? I suspect it has to do with the fact that for most of our history we’ve been an animal like any other, on the Malthusian boundary, always facing individual or group extinction. The possibility of becoming as rich as Warren Buffet, or as prolific as Genghis Khan, by taking risks or trodding the path less taken, simply did not exist. The downside was extinction, the upside might be temporary success, only to see your lineage be swept away by history due to a propensity to gamble.
Dana Milbank vs. Nico Pitney
I don’t post much on contemporary politics, mostly because I don’t have much value-add, but also because so much of it from the blogosphere is simply a critique of the mainstream press. In fact I think the mainstream press is essential and invaluable in many domains. The current crisis in print journalism is going to cause problems because these organizations serve as primary sources for many webloggers on abstruse or specialized topics. Who do you think puts bread on Carl Zimmer’s table?
But, I do believe that almost all “political analysis” and “commentary” in the mainstream media can be, and is being, easily substituted by weblogs (compare & contrast The New York Times analysis of the Democratic primaries vs. Nate Silver’s). I don’t see any comparative advantage here for the establishment. The existence of these sectors of the media seems a relic of the pre-internet era. Both the Right and Left are correct in their criticisms of the trivialities which the media often engage in to maintain the perception of objectivity. Below is an awesome face to face “exchange” between Nico Pitney and Dana Milbank.
From genome-wide association studies to molecular biology
One of the rationales advanced for the identification of common alleles that confer modest risk to a disease via genome-wide association studies is that these associations will lead to biological insight into the disease. Two papers published today represent an important first step towards this goal for a variant associated with colorectal cancer.
Like many polymorphisms associated with complex diseases, the one investigated in these studies does not fall within a gene–this particular variant falls hundreds of thousands of bases away from the nearest gene. It does, however, fall within a non-coding element that is conserved across millions of years of evolution, suggesting that it is functional. These studies show that, indeed, the SNP falls in a binding site for a transcription factor, and that the two alleles have different binding affinities for that factor. Additionally, one of the studies shows that the genomic region containing the SNP loops over and makes physical contact with the nearest gene (MYC, a known oncogene), supporting the hypothesis that the SNP affects its regulation.
These studies raise more questions than they answer, of course. None of the studies find an association between the SNP itself and steady-state MYC expression in cell lines. My guess is that, like many transcriptional enhancers, developmental-time-point-specific manner. An important direction now is to determine when that important time point is.
Science of Bubbles
Long article in Scientific American, The Science of Economic Bubbles and Busts. H/T Calculated Risk.
God & welfare
Why should government welfare mean less religion?:
This was a question that Anthony Gill and Erik Lundsgaarde tackled by in 2004. They analysed the data from a range of countries, and found that the greater proportion of GDP that was spent on government welfare, the more non-religious people there were and the lower church attendance was. This held true even after statistically adjusting for other factors, like per-capita GDP, urbanization, government regulation of religion, and religious pluralism.
The standard explanation for this relation is that religion & government provide competing services, welfare. As government expands it presumably “crowds out” civil society welfare services, of which religious institutions are generally the most prominent. The author of the blog post above is generally skeptical of this model. I personally think it’s plausible, but the “rational choice” framework which it emerges from has generally been found wanting in many circumstances (e.g., general failure to explain religious dynamics in Eastern Europe after the fall of Communism). So more exploration of the topic is needed.
But I was wondering, how about checking to see if there’s a relationship between religion & welfare in the United States? I found per capital welfare spending by state, percentage with “No Religion” from The American Religious Identification Survey, and queried how important religion was and what percentage were atheists from the Pew Religious Landscape Survey. I didn’t adjust welfare spending for background variables (cost of living, age structure, etc.), but I thought it would be instructive as a “quick & dirty” exploratory exercise. Charts below.