Skip to main content
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
. 1975 Sep;72(9):3638–3641. doi: 10.1073/pnas.72.9.3638

Analysis of incipient reproductive isolation within a species of Drosophila.

T Dobzhansky
PMCID: PMC433051  PMID: 1059154

Abstract

Drosophila willistoni and its subspecies quechua are morphologically indistinguishable, but differ in relative frequencies of certain allozyme genes. The cross quechua female X willistoni male produces nearly or completely sterile males, while the reciprocal cross gives fertile males. Hybrid females are fertile. Analysis of the sterility with the aid of chromosomes marked with mutant genes shows that the second and X-chromosomes have major and third chromosomes minor effects. Backcross males of the same chromosomal constitution may be either fertile or sterile; the threshold effect may be due to environmental variations or to gene variants present in the strains crossed. Only a trace of ethological isolation between the subspecies is present. In contrast to a narrowly localized and geographically isolated subspecies bogotana of D. pseudoobscura, the subspecies quechua of D. willistoni is fairly widespread, although its geographic area is not accurately known. Neither with bogotana nor with quechua are there valid reasons to suppose that these subspecies are of very recent origin.

Full text

PDF
3638

Selected References

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

  1. Ahearn J. N., Carson H. L., Dobzhansky T., Kaneshiro K. Y. Ethological isolation among three species of the planitibia subgroup of Hawaiian Drosophila. Proc Natl Acad Sci U S A. 1974 Mar;71(3):901–903. doi: 10.1073/pnas.71.3.901. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Ayala F. J., Powell J. R., Dobzhansky T. Polymorphisms in continental and island populations of Drosophila willistoni. Proc Natl Acad Sci U S A. 1971 Oct;68(10):2480–2483. doi: 10.1073/pnas.68.10.2480. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Carson H. L., Clayton F. E., Stalker H. D. Karyotypic stability and speciation in Hawaiian Drosophila. Proc Natl Acad Sci U S A. 1967 May;57(5):1280–1285. doi: 10.1073/pnas.57.5.1280. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. 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]
  5. Dobzhansky T. Genetic analysis of hybrid sterility within the species Drosophila pseudoobscura. Hereditas. 1974;77(1):81–88. doi: 10.1111/j.1601-5223.1974.tb01356.x. [DOI] [PubMed] [Google Scholar]
  6. Prakash S. Origin of reproductive isolation in the absence of apparent genic differentiation in a geographic isolate of Drosophila pseudoobscura. Genetics. 1972 Sep;72(1):143–155. doi: 10.1093/genetics/72.1.143. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. de Toledo Cardoso de Mello J. Estudo da esterilidade entre diferentes linhagens de Drosophila willistoni. Rev Bras Biol. 1971 Jun;31(2):145–151. [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