Abstract
The species are endemic to the newest island in the archipelago and are broadly sympatric. They are easily distinguished morphologically in both sexes. Using standard electrophoretic procedures, we have examined 25 loci encoding for structural proteins from 539 silvestris and 325 heteroneura collected at three widely-separated localities where the two species are sympatric. Pairwise comparisons within and between the species show the following coefficients of genetic identity (Nei's I): within silvestris, 0.961 ± 0.01; within heteroneura, 0.949 ± 0.02; between silvestris and heteroneura, 0.939 ± 0.01. Neither the differences within nor between the species are significant. There are no fixed allelic differences either within or between the species. At the three areas of sympatry, the species show gene frequency differences (P < 0.05) at 9, 11 and 13 loci respectively. This is not much different from the variation within either one of the species across the three localities. The two species have similar heterozygosity ( H) levels (silvestris, 0.083; heteroneura, 0.089) and percent of polymorphic loci (both 0.37). It is suggested that despite their morphological divergence, these species are much more newly formed than classical sibling species. Significant allozymic differences may not have had time to accumulate.
Full Text
The Full Text of this article is available as a PDF (751.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- 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]
- Ayala F. J., Powell J. R., Tracey M. L., Mourão C. A., Pérez-Salas S. Enzyme variability in the Drosophila willistoni group. IV. Genic variation in natural populations of Drosophila willistoni. Genetics. 1972 Jan;70(1):113–139. doi: 10.1093/genetics/70.1.113. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carson H. L., Nair P. S., Sene F. M. Drosophila hybrids in nature: proof of gene exchange between sympatric species. Science. 1975 Sep 5;189(4205):806–807. doi: 10.1126/science.1162353. [DOI] [PubMed] [Google Scholar]
- Coyne J. A. Lack of genic similarity between two sibling species of drosophila as revealed by varied techniques. Genetics. 1976 Nov;84(3):593–607. doi: 10.1093/genetics/84.3.593. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lewontin R. C., Hubby J. L. A molecular approach to the study of genic heterozygosity in natural populations. II. Amount of variation and degree of heterozygosity in natural populations of Drosophila pseudoobscura. Genetics. 1966 Aug;54(2):595–609. doi: 10.1093/genetics/54.2.595. [DOI] [PMC free article] [PubMed] [Google Scholar]