race/history/evolution notes: September 2010

Charlemagne was very tall, but not robust

Paper mentioned by John Hawks: "Reconstructed stature of 1.84 m falls at about 99% of Medieval heights [. . .] Thus, tall stature indeed could have contributed to the success of “Charles the Great” as a king emperor and soldier."

Below, a couple other papers that appeared in Hawks's citeulike feed.

The biological standard of living in Europe during the last two millennia: "We find that heights stagnated in Central, Western and Southern Europe during the Roman imperial period, while astonishingly increasing in the fifth and sixth centuries."

New Light on the "Dark Ages": The Remarkably Tall Stature of Northern European Men during the Medieval Era: "Based on a modest sample of skeletons from northern Europe, average heights fell from 173.4 centimeters in the early Middle Ages to a low of roughly 167 centimeters during the seventeenth and eighteenth centuries. [. . .] It is plausible to link the decline in average height to climate deterioration; growing inequality; urbanization and the expansion of trade and commerce, which facilitated the spread of diseases; fluctuations in population size that impinged on nutritional status; the global spread of diseases associated with European expansion and colonization; and conflicts or wars over state building or religion."

Preferred and actual mate characteristics

From Preferred to Actual Mate Characteristics: The Case of Human Body Shape

The way individuals pair to produce reproductive units is a major factor determining evolution. This process is complex because it is determined not only by individual mating preferences, but also by numerous other factors such as competition between mates. Consequently, preferred and actual characteristics of mates obtained should differ, but this has rarely been addressed. We simultaneously measured mating preferences for stature, body mass, and body mass index, and recorded corresponding actual partner's characteristics for 116 human couples from France. Results show that preferred and actual partner's characteristics differ for male judges, but not for females. In addition, while the correlation between all preferred and actual partner's characteristics appeared to be weak for female judges, it was strong for males: while men prefer women slimmer than their actual partner, those who prefer the slimmest women also have partners who are slimmer than average. This study therefore suggests that the influences of preferences on pair formation can be sex-specific. It also illustrates that this process can lead to unexpected results on the real influences of mating preferences: traits considered as highly influencing attractiveness do not necessarily have a strong influence on the actual pairing, the reverse being also possible.

2010 Forbes 400 by ancestry: more statistics

See preceding post for complete list.

		Net Worth					No. of child- ren
	n	Total billions	Pct of total	Mean	Median	Age	No. of child- ren
NW Euro	203	764.45	55.84	3.77	2	67.24	3.19
Jewish	143	486.5	35.54	3.4	1.8	63.44	3.06
Italian	17	34.9	2.55	2.05	1.6	61.76	2.71
E Asian	8	22.4	1.64	2.8	2.6	60.63	2.25
Mid East	8	22.1	1.61	2.76	1.95	72	3.13
E Euro	7	16.2	1.18	2.31	2.5	68.86	3.43
Greek	7	11.5	0.84	1.64	1.7	77.57	4
S Asian	4	5.75	0.42	1.44	1.43	57	2.25
Hispanic	2	2.4	0.18	1.2	1.2	68.5	2.5
Black	1	2.7	0.2	2.7	2.7	56	0
Overall	400	1368.9	100	3.42	2	65.7	3.1

2010 Forbes 400 by ethnic origins

[Related: 2012 Forbes 400 by ethnic origins; more statistics on 2010 Forbes 400 by ancestry.]

[Correction: Moved Frost to Jewish section; updated statistics accordingly.]

Forbes has published its list of the 400 richest Americans for this year. My current estimate of the ethnic breakdown of the list is shown in the far right column below:

	1987 (%)	2009 (%)	2010 (%)
Northwestern European	72	52.25	51
Jewish	23	35	35
Italian	2.25	3.5	4.25
East Asian	0.25	2.0	2.0
Middle Eastern	1.5	2.25	2.5
Greek	0.5	1.5	1.75
Eastern European	0.25	1.5	1.75
South Asian	0.0	1.25	1.0
Hispanic	0.25	0.5	0.5
Black	0.0	0.25	0.25

The 2009 estimate is also mine, and I have used the same methodology as before. The 1987 estimate is Nathaniel Weyl's. The first thing I notice is that the Northwestern European proportion of the list continues to decline.

Full list below. Feel free to post corrections.

"Thousands" of genes influence intelligence

A commenter writes: "Robert Plomin and colleagues have apparently found some IQ genes". From the story:

SCIENTISTS have identified more than 200 genes potentially associated with academic performance in schoolchildren. [. . .]

The finding emerged from a study of more than 4000 British children to pinpoint the genes and genetic combinations that influence reasoning skills and general intelligence.

One of its main conclusions is that intelligence is controlled by a network of thousands of genes with each making just a small contribution to overall intelligence, rather than the handful of powerful genes that scientists once predicted.

So much for the fantasies of certain technorapturist HBDers that genetic engineering will erase racial differences in intelligence within a few decades.

Open thread (4)

For links, comments, suggestions, etc. Previous open threads: 1 2 3

Population structure math: two recent papers

Analysis of Population Structure: A Unifying Framework and Novel Methods Based on Sparse Factor Analysis

Two different approaches have become widely used in the analysis of population structure: admixture-based models and principal components analysis (PCA). In admixture-based models each individual is assumed to have inherited some proportion of its ancestry from one of several distinct populations. PCA projects the individuals into a low-dimensional subspace. On the face of it, these methods seem to have little in common. Here we show how in fact both of these methods can be viewed within a single unifying framework. This viewpoint should help practitioners to better interpret and contrast the results from these methods in real data applications. It also provides a springboard to the development of novel approaches to this problem. We introduce one such novel approach, based on sparse factor analysis, which has elements in common with both admixture-based models and PCA. As we illustrate here, in some settings sparse factor analysis may provide more interpretable results than either admixture-based models or PCA.

Theoretical Formulation of Principal Components Analysis to Detect and Correct for Population Stratification

The Eigenstrat method, based on principal components analysis (PCA), is commonly used both to quantify population relationships in population genetics and to correct for population stratification in genome-wide association studies. However, it can be difficult to make appropriate inference about population relationships from the principal component (PC) scatter plot. Here, to better understand the working mechanism of the Eigenstrat method, we consider its theoretical or “population” formulation. The eigen-equation for samples from an arbitrary number () of populations is reduced to that of a matrix of dimension , the elements of which are determined by the variance-covariance matrix for the random vector of the allele frequencies. Solving the reduced eigen-equation is numerically trivial and yields eigenvectors that are the axes of variation required for differentiating the populations. Using the reduced eigen-equation, we investigate the within-population fluctuations around the axes of variation on the PC scatter plot for simulated datasets. Specifically, we show that there exists an asymptotically stable pattern of the PC plot for large sample size. Our results provide theoretical guidance for interpreting the pattern of PC plot in terms of population relationships. For applications in genetic association tests, we demonstrate that, as a method of correcting for population stratification, regressing out the theoretical PCs corresponding to the axes of variation is equivalent to simply removing the population mean of allele counts and works as well as or better than the Eigenstrat method.

Assortative mating by ancestry among American whites

Testing for non-random mating: evidence for ancestry-related assortative mating in the Framingham heart study.

Population stratification leads to a predictable phenomenon-a reduction in the number of heterozygotes compared to that calculated assuming Hardy-Weinberg Equilibrium (HWE). We show that population stratification results in another phenomenon-an excess in the proportion of spouse-pairs with the same genotypes at all ancestrally informative markers, resulting in ancestrally related positive assortative mating. We use principal components analysis to show that there is evidence of population stratification within the Framingham Heart Study, and show that the first principal component correlates with a North-South European cline. We then show that the first principal component is highly correlated between spouses (r = 0.58, p = 0.0013), demonstrating that there is ancestrally related positive assortative mating among the Framingham Caucasian population. We also show that the single nucleotide polymorphisms loading most heavily on the first principal component show an excess of homozygotes within the spouses, consistent with similar ancestry-related assortative mating in the previous generation. This nonrandom mating likely affects genetic structure seen more generally in the North American population of European descent today, and decreases the rate of decay of linkage disequilibrium for ancestrally informative markers. Genet. Epidemiol. 2010.

Sub-Saharan mtDNA and malaria in Portugal

Genetic characterization of uniparental lineages in populations from Southwest Iberia with past malaria endemicity:

Malaria endemicity in Southwest Iberia afforded conditions for an increase of sickle cell disease (SCD), which in the region follows a clinal pattern toward the south, where foci of high prevalence were found. SCD distribution is associated with specific geographical areas, and therefore, its introduction into Iberia may be related to the migration of different populations. We have analyzed the variation of uniparental markers in Portuguese populations with high frequency of SCD-Coruche, Pias, and Alcacer do Sal-to evaluate if their present-day pattern of neutral diversity could provide evidence about people inhabiting the area over different time periods. Two hundred and eighty-five individuals were sampled in Coruche, Pias, and Alcacer do Sal. All were analyzed for the control region of mitochondrial DNA (mtDNA); males were additionally examined for Y-chromosome markers. Results were then compared with data from other Portuguese and non-Portuguese populations. In Coruche, the genetic profile was similar to the profile usually found in Portugal. In Alcacer do Sal, the frequency of sub-Saharan mtDNA L lineages was the highest ever reported (22%) in Europe. In Pias, mtDNA diversity revealed higher frequencies of Mediterranean haplogroups I, J, and T than usually found in surrounding populations. The presence of Sub-Saharan maternal lineages in Alcacer do Sal is likely associated with the influx of African slaves between the 15th and 19th centuries, whereas in Pias, the Mediterranean influence might be traced to ancient contacts with Greeks, Phoenicians, and Carthaginians, who established important trading networks in southern Iberia. Am. J. Hum. Biol. 22:588-595, 2010.

Women selling seafood in Alcácer do Sal.

"WASP" decline: NYG&B edition

3 Years After a Windfall, an Unexpected Reality for the Genealogical Society:

Since 1869, the New York Genealogical and Biographical Society has made its name helping New Yorkers understand their roots. But the more the society pondered its future, the more the people at its helm became convinced that it needed to break with its past.

Making what they called a “forward-looking decision,” the trustees hung a for-sale sign on the society’s longtime home at 122 East 58th Street several years ago. Then — to the shock of the society’s own members, who were still reeling from the sale — the trustees gave the society’s vast collection of scholarly books and historic papers to the New York Public Library.

The radical downsizing may have been as pragmatic as it was bold, but the timing could have been better.

The building was sold in 2007, and one-fourth of the $24 million that the society raised from the sale washed away as the stock market eroded. That, together with high administrative costs, led the society to make large staff reductions in early 2009, just as the new owners of its old headquarters sold them again — this time for $28.5 million.

The new owners: a synagogue. In a comment, the new NYGBS president insists:

there is no doubt whatever that the choices were carefully, thoroughly, and thoughtfully considered by dedicated trustees and by the consultants who advised them over an extended period of time.

I don't doubt most of the trustees were doing what they thought was best. But I'd be curious to know the names of the consultants involved.