Ancestral proportions and admixture dynamics in geographically defined African Americans living in South Carolina.

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.

Admixture and relationships of the population of Jacobina, Bahia, Brazil.

As part of the Cornell-Bahia project on leishmaniasis, the people of Jacobina in the state of Bahia in northeastern Brazil were studied for five genetic polymorphisms: ABO blood groups, hemoglobin variants, PGM1, 6PGD, and adenylate kinase. A maximum likelihood method of calculation of frequency of genes for these traits indicates that the ancestry of the people is 45% African, 43% Portuguese, and 12% Brazilian Indian. This estimate is similar to previous estimates of admixture in the people of northeastern Brazil, except for more African and less Caucasian ancestry.

Ethnicity and human biology.

Stanley Garn's book, Human Races (1965), captured the essence of the new genetic concept of ethnic groups as populations which share the same gene pool, shaped by natural selection. Since then new genetic traits, especially DNA polymorphisms, have been employed to build upon his vision. They have proven useful in the forensic sciences, medicine, and the human biology of adaptation, migration, evolution, and phylogeny.

Hypervariable polymorphism of APO(a) in blacks and whites as reflected by phenotyping.

Genetic polymorphism at the apolipoprotein(a) structural locus was investigated in 203 American blacks using a high-resolution SDS-agarose electrophoresis method followed by immunoblotting, and the gene frequency data were compared with a previously screened American white sample using the same method. Between the two samples, a total of 27 discrete APO(a) allelic isoforms have been documented; of these, 24 were common to both groups. Of the 203 blacks screened, APO(a) immunoreactive isoforms were detected in 201, with a total of 101 distinct phenotypes (67 (33%) single-banded and 134 (67%) double-banded).

Ethnic and genetic differences in susceptibility to osteoporotic fractures.

A plethora of investigations in recent years has demonstrated the occurrence of ethnic differences in bone mineral content, bone density and fracture rates. These findings indicate that genetic determinants exist both for bone development during growth and for bone loss during aging. Twin and parent-offspring studies have corroborated the existence of a hereditary component.

Skin color and mortality.

The relation of skin color and mortality from all causes, coronary heart disease, and all cardiovascular diseases was explored in 787 black men and women of the Charleston Heart Study Cohort. Associations were studied by examining rates of mortality during the period 1960-1990 by tertiles of skin color, as measured by reflectometer. Across the tertiles of reflectance there were no significant differences in mortality rates, except for sex differences.

Molecular basis of a unique African variant (A-IV 5) of human apolipoprotein A-IV and its significance in lipid metabolism.

Human apolipoprotein A-IV (apoA-IV) exhibits a genetically determined structural polymorphism amenable to analysis by isoelectric focusing and immunoblotting techniques. We have determined the allele frequency and molecular basis of a unique ApoA-IV*5 allele which is widely distributed among blacks but is absent in other populations. The frequency of the ApoA-IV*5 allele in blacks (N = 308) was estimated to be 3.

Ethnic and genetic differences in bone mass: a review with a hereditary vs environmental perspective.

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.

Taxonomic note: Bunopithecus: A genus-level taxon for the hoolock gibbon (Hylobates hoolock).

The recent discovery that the hoolock gibbon (Hylobates hoolock [Harlan, 1834]) 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.

The Cajuns of Southern Alabama: morphology and serology.

A survey was conducted of 324 members of the Cajun isolate of Southern Alabama. Tradition and appearance suggest that this population of about 3,000 are not entirely White, Black, or Indian but constitute a triracial community somewhat reproductively isolated and inbred. The earliest American settlement in the area, along the banks of the Mobile and Tombigbee Rivers, lay between Spaniards to the South and Indian tribes on the other sides: Creek, Choctaw, and Cherokee.

Multivariate analyses of anthropometric and psychometric variables in probands with affective disorders and their families.

Data on 121 subjects, probands with affective disorders, their spouses and first degree relatives, are analyzed by multivariate methods to determine the relationships between physical types and propensity to illness. 56 variables are used: 39 anthropometric measures, age, sex, and 15 psychometric scales. In a canonical analysis between the anthropometric measures and the psychiatric scales, each canonical variable is found to be largely identified with a single psychometric component, as found in a principal components analysis of the psychometric scales.