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Paleodemographic studies have seldom been attempted in sub-Saharan Africa. The Mapungubwe complex of sites in northern Transvaal (A.D. 970-1200) has yielded enough skeletal material to warrant such an investigation. The skeletal collection consists of 109 individuals (97 from K2 and 12 from Mapungubwe itself). Because the sites are extensive and their complete excavation impractical, only reconstruction of the population dynamics, not the population size, was possible. There were 81 child and juvenile skeletons (below 15 years of age) and 7 male, 5 female, 4 possible male, and 4 possible female adult skeletons. Eight adult skeletons were too fragmentary to warrant even tentative sex diagnoses. Either age-specific burial practices resulting in the surplus of child skeletons, unusual child mortality, or a state of substantial natural increase must be the explanation for this age distribution. The hypothesis of the natural increase can be partly tested by using an appropriate correction to the life table. The life table corrected for r = 2.5% has a newborn life expectancy of 18.93 |+ or -~ 1.79 years and a survivorship to 15 years of 41.66% |+ or -~ 3.91. The population pyramid derived from this life table compares well with data on some third world populations observed earlier this century. The fertility rate required to maintain the natural increase under such mortality conditions is high but comparable to that of some historical populations. High positive natural increase would indicate an economically successful population., The use of age distributions of deceased in archeologically derived skeletal series for paleodemographic reconstructions of mortality profiles, however useful for generalizations (Angel 1969; Acsadi and Nemeskeri 1970), is fraught [...]

Pooled DNA samples have been used in association studies of Mendelian disease genes. This method involves combining equal quantities of DNA from patients and control subjects into separate pools and comparing the pools for distributions of genetic markers. In this study identical quantities of DNA from 300 individuals representing 6 populations were pooled and amplified for 296 loci using the touchdown polymerase chain reaction (PCR) method. The purpose of this study is to test the efficacy of pooled DNA markers in the reconstruction of the genetic structure of human populations. The populations sampled included Chuvash, Buryats, Kizhi, Native Americans, South Africans, and New York City whites. To test the accuracy of the allele-frequency distributions, we genotyped the Buryats and New York samples individually for six microsatellite markers and compared their frequencies to the allele frequencies derived from the electropherogram peak heights for the pooled DNA, producing a correlation of 0.9811 with a variance of less than 0.04. Two-dimensional scaling of genetic distances among the six populations produced clusters that reflected known historical relationships. A distance matrix was created using all 296 loci, and matrices based on individual chromosomes were correlated against the total matrix. As expected, the largest chromosomes had the highest correlations with the total matrix, whereas one of the smallest chromosomes, chromosome 22, had the lowest correlation and differed most from the combined STR distance matrix. [ABSTRACT FROM AUTHOR]

In cross-sectional epidemiological studies, blood pressure (BP) is often found to be positively correlated with fatness. Usually sphygmomanometers with only one cuff size for adults are used to measure BP while arm circumference (AC) influences BP readings. We have studied cross-sectional anthropometric and BP data of adult men and women from three populations: Cook Islanders (n = 259), Papua New Guinean: Purari (n = 295), and Ok Tedi (n = 274). These were selected because of their diverse socio-economic, anthropometric, and BP characteristics. Partial correlations and regressions were used to analyze these data. Systolic and diastolic pressures (SBP, DBP) showed dependence on AC, body mass index (BMI), and skinfold thickness. Stature had some effect on SBP and DBP, independent of BMI and AC. When effects of AC and stature were statistically controlled, BMI did not correlate with either SBP or DBP. People of larger body mass have greater AC, and this biases BP readings. Average values of SBP and DBP in groups of underweight, normal, overweight, and obese people predicted by AC (sex, age, and BMI being statistically controlled) closely matched observed SBP and DBP averages in those groups. Out of 24 pairwise comparisons (3 samples from different populations × 4 groups of BMI × 2 pressure readings) of predicted and actual BP, only two produced statistically significant differences while 21 of the differences were 5 mm Hg or less. Correlations between BP and obesity found in epidemiological studies may be severely biased by effects of variation in AC. Sphygmomanometric measurements of BP should be corrected for continuous variation in AC.

This study utilizes the GM/KM immunoglobulin allotype system to elucidate the phylogenetic relationships of sub-Saharan Africans. The importance of understanding the relatedness of these peoples stems from the sub-Saharan region being the possible birthplace of humans. Haplotype distributions were determined for 19 populations and compared using chi-square analysis. Published data of other sub-Saharan Africans and representative populations worldwide were also added for comparison. Genetic distances between populations were calculated based on haplotype frequencies, and genetic relationships were observed through principal components analysis. Data from the GM/KM system showed a genetic homogeneity of the Bantu populations, with some exceptions, supporting the possibility of a common origin of these peoples. The Malagasy appeared as a divergent population, most likely due to Southeast Asian/Austronesian admixture, as indicated by the presence of the GM*AF B haplotype. The Cape Coloured also showed a divergence, with their genetic structures containing Caucasoid and Khoisan contributions. Finally, the Mbuti Pygmies appeared genetically isolated and had the highest frequency of the GM*A B haplotype out of all studied populations.