Skip to main content
PMC home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1971 Oct;68(10):2554–2558. doi: 10.1073/pnas.68.10.2554

Loci Differentially Affected by Selection in Two American Black Populations*

Baruch S Blumberg 1,2, Jana E Hesser 1,2
PMCID: PMC389467  PMID: 5289889

Abstract

The hypothesis that loci differentially affected by selection can be identified was tested by a comparison of two American black populations.

The hypothesis had previously been studied in Evans County, Georgia and the data from that study were compared with data obtained from the population of Sapelo Island, Georgia.

In both, gene frequencies for 21 polymorphic systems were determined. Estimates were made for 14 of these traits of the gene migration (m) from whites into these black populations, by use of the equation: m = (qn - qAf)/(qw - qAf), where qw, qn, and qAf are the frequencies of an allele in the white, black, and West African populations, respectively. In this calculation, it is assumed that the differences in gene frequencies between American blacks and Africans are due entirely to gene mixture. On this assumption, if only gene mixture were operating, the values of “m” determined for each locus would be about the same. If “m” has a different value at some loci than it has at others, then selection for traits controlled by genes segregating at these loci could account for this difference.

Values of “m” in both populations were scattered. These values were ranked for each population and the rank orders compared. There was a highly significant association between the rank order of loci in the two populations. This finding supports the hypothesis that loci differentially affected by selection can be identified, and that the selective forces have operated on the same loci in both populations.

Keywords: Sapelo Island, Evans County, Georgia, Geeche, Gullah

Full text

PDF
2556

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BLUMBERG B. S., RIDDELL N. M. Inherited antigenic differences in human serum beta lipoproteins. A second antiserum. J Clin Invest. 1963 Jun;42:867–875. doi: 10.1172/JCI104779. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. COOPER A. J., BLUMBERG B. S., WORKMAN P. L., MCDONOUGH J. R. BIOCHEMICAL POLYMORPHIC TRAITS IN A U. S. WHITE AND NEGRO POPULATION. Am J Hum Genet. 1963 Dec;15:420–428. [PMC free article] [PubMed] [Google Scholar]
  3. GLASS B. On the unlikelihood of significant admixture of genes from the North American Indians in the present composition of the Negroes of the United States. Am J Hum Genet. 1955 Dec;7(4):368–385. [PMC free article] [PubMed] [Google Scholar]
  4. HARRIS H., KALMUS H. The measurement of taste sensitivity to phenylthiourea. Ann Eugen. 1949 Oct;15(1):24–31. doi: 10.1111/j.1469-1809.1949.tb02419.x. [DOI] [PubMed] [Google Scholar]
  5. HARRIS H., ROBSON E. B. FRACTIONATION OF HUMAN SERUM CHOLINESTERASE COMPONENTS BY GEL FILTRATION. Biochim Biophys Acta. 1963 Aug 6;73:649–652. doi: 10.1016/0006-3002(63)90337-8. [DOI] [PubMed] [Google Scholar]
  6. KIMURA M. Stochastic processes and distribution of gene frequencies under natural selection. Cold Spring Harb Symp Quant Biol. 1955;20:33–53. doi: 10.1101/sqb.1955.020.01.006. [DOI] [PubMed] [Google Scholar]
  7. NEEL J. V., SALZANO F. M., JUNQUEIRA P. C., KEITER F., MAYBURY-LEWIS D. STUDIES ON THE XAVANTE INDIANS OF THE BRAZILIAN MATO GROSSO. Am J Hum Genet. 1964 Mar;16:52–140. [PMC free article] [PubMed] [Google Scholar]
  8. POULIK M. D. Starch gel electrophoresis in a discontinous system of buffers. Nature. 1957 Dec 28;180(4600):1477–1479. doi: 10.1038/1801477a0. [DOI] [PubMed] [Google Scholar]
  9. ROBINSON A. R., ROBSON M., HARRISON A. P., ZUELZER W. W. A new technique for differentiation of hemoglobin. J Lab Clin Med. 1957 Nov;50(5):745–752. [PubMed] [Google Scholar]
  10. SINGER K., CHERNOFF A. I., SINGER L. Studies on abnormal hemoglobins. I. Their demonstration in sickle cell anemia and other hematologic disorders by means of alkali denaturation. Blood. 1951 May;6(5):413–428. [PubMed] [Google Scholar]
  11. SMITHIES O. Zone electrophoresis in starch gels: group variations in the serum proteins of normal human adults. Biochem J. 1955 Dec;61(4):629–641. doi: 10.1042/bj0610629. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. WORKMAN P. L., BLUMBERG B. S., COOPER A. J. SELECTION, GENE MIGRATION AND POLYMORPHIC STABILITY IN A U. S. WHITE AND NEGRO POPULATION. Am J Hum Genet. 1963 Dec;15:429–437. [PMC free article] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES