We analyzed admixture in samples of six different African-American populations from South Carolina: Gullah-speaking Sea Islanders in coastal South Carolina, residents of four counties in the "Low Country" (Berkeley, Charleston, Colleton, and Dorchester), and persons living in the city of Columbia, located in central South Carolina. We used a battery of highly informative autosomal, mtDNA, and Y-chromosome markers. Two of the autosomal markers (FY and AT3) are linked and lie 22 cM apart on chromosome 1. The results of this study indicate, in accordance with previous historical, cultural, and anthropological evidence, a very low level of European admixture in the Gullah Sea Islanders (m = 3.5 +/- 0.9%). The proportion of European admixture is higher in the Low Country (m ranging between 9. 9 +/- 1.8% and 14.0 +/- 1.9%), and is highest in Columbia (m = 17.7 +/- 3.1%). A sex-biased European gene flow and a small Native American contribution to the African-American gene pool are also evident in these data. We studied the pattern of pairwise allelic associations between the FY locus and the nine other autosomal markers in our samples. In the combined sample from the Low Country (N = 548), a high level of linkage disequilibrium was observed between the linked markers, FY and AT3. Additionally, significant associations were also detected between FY and 4 of the 8 unlinked markers, suggesting the existence of significant genetic structure in this population. A continuous gene flow model of admixture could explain the observed pattern of genetic structure. A test conditioning on the overall admixture of each individual showed association of ancestry between the two linked markers (FY and AT3), but not between any of the unlinked markers, as theory predicts. Thus, even in the presence of genetic structure due to continuous gene flow or some other factor, it is possible to differentiate associations due to linkage from spurious associations due to genetic structure.

Based on a review of the literature, ethnic and genetic factors are significant determinants of bone mass, along with such environmental factors as diet and exercise. Differences in bone density between blacks and whites remain even after adjustment for body mass. Black-white differences in bone mass appear to be related to ethnicity because blacks have not only greater skeletal calcium content, but also greater total body potassium and muscle mass. Genetic studies of twins and parent-offspring pairs reflect strong constitutional associations of both bone mineral content and bone density at commonly measured skeletal sites. At least for females, bone mass accumulation by age 20 y is highly associated with maternal bone mass; up to menopause it is enhanced by child-bearing and lactation; beyond menopause environmental factors seem to dominate. Dietary calcium and physical activity are significant in the control of bone mass. These findings are important for osteoporosis and fractures, especially in elderly people.

No abstract

The gibbon Hylobates hoolock has been found to possess a karyotype different in diploid number and banding pattern from that of any other hylobatid. We propose that the hoolock gibbon occupy its own subgenus in the genus Hylobates.

No abstract

No abstract

The recent discovery that the hoolock gibbon (Hylobates hoolock [Harlan, 18343) has a karyotype distinct from all other hylobatids provides a new and strong motive for revising gibbon taxonomy and establishing hoolocks in a separate, higher taxon. Revising Groves's taxonomy of 1972, we propose that hoolock, along with the fossil species sericus, occupy a subgenus, Bunopithecus. With the newly added taxon, the genus Hylobates would thus contain four subgenera: Bunopithecus, Hylobates, Nomascus, and Symphalangus. Carolina, Chapel Hill, INTRODUCTIONThe complexity of resemblances among hylobatid species is reflected in the variety of groupings of these animals in modern classifications. Above the species level, the long-recognized differences between the siamang and other hylobatids have supported classifications containing two genera, Symphalangus and Hylobates [Schultz, 1933; Napier & Napier, 19671. Other taxonomists have emphasized continuity in major traits among hylobatids and have grouped all species into the single genus Hylobates [Kloss, 1929;Miller, 1933; Simonetta, 19571. Groves [1968, 19721 found the concolor as divergent from the lar-group as the siamang, and following Ellerman and Morrison-Scott [ 19511, has provided a genus Hylobates with three subgenera: Symphalangus, Nomascus for the concolor, and Hylobates for the rest [Groves, 19721. This classification is the most nearly comprehensive to date. On the basis of new and old information, we propose revising the classification by splitting the species hoolock from the subgenus Hylobates and placing it in a fourth subgenus with a fossil species resembling hoolock. Received December 13, 1982; accepted March 18,1983 [Groves, 19721. Data on vocalizations further distinguish the hoolock from the subgenus Hylobates and ally it variously with the siamang and the concolor gibbon. For example, in the great call sequences of the siamang and hoolock, male and female parts are interspersed, with moments of simultaneous vocalization. In all other species, either the male's part is concentrated at the end, or the great call is a solo [Marshall & Marshall, 1976; Haimoff et al, 19821.The hoolock gibbon differs from all other hylobatids in its body weight, which is greater than any gibbon species except the siamang [Schultz, 19731. Its third molars are unreduced relative to those of the other hylobatids, although it expresses the cingulum less [Frisch, 19731. A multivariate study of the cranial features of hylobatid has shown the hoolock to be one of five distinct morphological entities, the other four being the siamang and the concolor, Kloss, and lar-group gibbons [Creel & Preuschoft, 1976; cf. Corruccini, 19811. In addition to its distinguishing anatomical and vocal traits, the hoolock gibbon has a karyotype of unique form [Prouty et al, 19831. Three animals from the Greater Los Angeles Zoological Gardens on breeding loan to the Gibbon and Gallinaceous Bird Center, Saugus, California, were identified as hoolocks by pelage, dental morphology, and outer bod...

Dermatoglyphics, as defined by finger ridge count, is considered a classic example of polygenic inheritance in man. A set of data containing samples from both Caucasian and Japanese populations are analyzed by fitting a mixture of normal distributions, utilizing maximum likelihood estimation. The results are homogeneous over all subsets of the data and suggest that a single major autosomal locus with two additive alleles may account for over half the variation of the quantitative phenotype absolute finger ridge count. Existence of this locus awaits confirmation by pedigree or linkage analyses.