Skip to main content
PMC home page
Genetics logoLink to Genetics
. 1981 May;98(1):157–178. doi: 10.1093/genetics/98.1.157

Gene Flow and the Geographical Distribution of a Molecular Polymorphism in DROSOPHILA PSEUDOOBSCURA

J S Jones, S H Bryant, R C Lewontin, J A Moore, T Prout
PMCID: PMC1214426  PMID: 7338302

Abstract

This paper discusses the relation between the geographical distribution of an enzyme polymorphism and population structure in Drosophila pseudoobscura. California populations of this species living in very different montane and lowland habitats separated by several kilometers are similar to each other in the frequency of an esterase allele. Previous estimates suggest that gene flow is too limited to account for this homogeneity of genetic structure, so that it must reflect some balancing force of natural selection. We show, however, that dispersal over unfavorable habitats is much greater than earlier supposed. Isolated populations of D. pseudoobscura separated by 15 km from other populations are subject to large amounts of immigration. This is shown by changes in the seasonal abundance of this species and in the annual pattern of lethal alleles in such populations. The genetic structure of an experimentally perturbed isolated population in an oasis returned to normal within a single year, suggesting that such populations are ephemeral and that the oasis is subject to annual recolonization by distant migrants. Direct assessment of marked flies shows that they can move at least 10 km in 24 hours over a desert. Such extensive gene flow may help explain the distribution of the esterase allele, and is relevant to the high level of molecular polymorphism and its general lack of geographic differentiation throughout the range of D. pseudoobscura.

Full Text

The Full Text of this article is available as a PDF (1.6 MB).

Selected References

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

  1. Ayala F. J., Tracey M. L., Barr L. G., McDonald J. F., Pérez-Salas S. Genetic variation in natural populations of five Drosophila species and the hypothesis of the selective neutrality of protein polymorphisms. Genetics. 1974 Jun;77(2):343–384. doi: 10.1093/genetics/77.2.343. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Brown A. J., Langley C. H. Reevaluation of level of genic heterozygosity in natural population of Drosophila melanogaster by two-dimensional electrophoresis. Proc Natl Acad Sci U S A. 1979 May;76(5):2381–2384. doi: 10.1073/pnas.76.5.2381. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bryant S. H. The frequency and allelism of lethal chromosomes in isolated desert populations of Drosophila pseudoobscura. Genetics. 1976 Dec;84(4):777–786. doi: 10.1093/genetics/84.4.777. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Coyne J. A., Felton A. A. Genic Heterogeneity at Two Alcohol Dehydrogenase Loci in DROSOPHILA PSEUDOOBSCURA and DROSOPHILA PERSIMILIS. Genetics. 1977 Oct;87(2):285–304. doi: 10.1093/genetics/87.2.285. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. DOBZHANSKY T., HUNTER A. S., PAVLOVSKY O., SPASSKY B., WALLACE B. Genetics of natural populations. XXXI. Genetics of an isolated marginal population of Drosophila pseudoobscura. Genetics. 1963 Jan;48:91–103. doi: 10.1093/genetics/48.1.91. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Dobzhansky T, Queal M L. Genetics of Natural Populations. II. Genic Variation in Populations of Drosophila Pseudoobscura Inhabiting Isolated Mountain Ranges. Genetics. 1938 Sep;23(5):463–484. doi: 10.1093/genetics/23.5.463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Jones J. S., Yamazaki T. Genetic background and the fitness of allozymes. Genetics. 1974 Dec;78(4):1185–1189. doi: 10.1093/genetics/78.4.1185. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kimura M. Model of effectively neutral mutations in which selective constraint is incorporated. Proc Natl Acad Sci U S A. 1979 Jul;76(7):3440–3444. doi: 10.1073/pnas.76.7.3440. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Kimura M., Ohta T. Protein polymorphism as a phase of molecular evolution. Nature. 1971 Feb 12;229(5285):467–469. doi: 10.1038/229467a0. [DOI] [PubMed] [Google Scholar]
  10. Lewontin R. C., Ginzburg L. R., Tuljapurkar S. D. Heterosis as an explanation for large amounts of genic polymorphism. Genetics. 1978 Jan;88(1):149–169. doi: 10.1093/genetics/88.1.149. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Maruyama T., Kimura M. Geographical unifromity of selectively neutral polymorphisms. Nature. 1974 May 3;249(452):30–32. doi: 10.1038/249030a0. [DOI] [PubMed] [Google Scholar]
  12. Ohta T. Role of very slightly deleterious mutations in molecular evolution and polymorphism. Theor Popul Biol. 1976 Dec;10(3):254–275. doi: 10.1016/0040-5809(76)90019-8. [DOI] [PubMed] [Google Scholar]
  13. Roberts R. M., Jones J. S. Improved apparatus for vertical gel electrophoresis. Anal Biochem. 1972 Oct;49(2):592–597. doi: 10.1016/0003-2697(72)90469-1. [DOI] [PubMed] [Google Scholar]
  14. Robertson A., Narain P. The survival of recessive lethals in finite populations. Theor Popul Biol. 1971 Mar;2(1):24–50. doi: 10.1016/0040-5809(71)90003-7. [DOI] [PubMed] [Google Scholar]
  15. Sved J. A., Ayala F. J. A population cage test for heterosis in Drosophila pseudoobscura. Genetics. 1970 Sep;66(1):97–113. doi: 10.1093/genetics/66.1.97. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Wright S. Evolution in Mendelian Populations. Genetics. 1931 Mar;16(2):97–159. doi: 10.1093/genetics/16.2.97. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Yamazaki T. Measurement of fitness at the esterase-5 locus in Drosophila pseudoobscura. Genetics. 1971 Apr;67(4):579–603. doi: 10.1093/genetics/67.4.579. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Genetics are provided here courtesy of Oxford University Press

RESOURCES