Abstract
Second-chromosome lethals were extracted from four populations of Drosophila pseudoobscura in Southern California. Two of the populations were from desert oases and two from the classic habitat on Mt. San Jacinto, previously studied by Dobzhansky. Allelism tests were made on the lethals within and between all locations. The frequency of lethal second-chromosomes in each location was 0.18, and this was not different from the results of other workers for samples throughout the species range. Interpopulational allelism rates were about 0.005, and not different from earlier results of Dobzhansky. Intrapopulational rates in this study were, with one exception, the same as the interpopulational rates, and significantly lower than Dobzhansky found using the third chromosome. This may be due to lethals being linked with heterotic third-chromosome inversions. The allelism rate of the exceptional population (about 0.03 and equal to Dobzhansky's intrapopulational results) may be due to heterotic lethals, or a founder effect. Two lethals were found in three populations each, possibly due to migration among these populations, which are up to 334 km apart.
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Selected References
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- DOBZHANSKY T., SPASSKY B., TIDWELL T. Genetics of natural populations. 32. Inbreeding and the mutational and balanced genetic loads in natural populations of Drosophila pseudoobscura. Genetics. 1963 Mar;48:361–373. doi: 10.1093/genetics/48.3.361. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dobzhansky T, Spassky B. Genetics of Natural Populations. Xxi. Concealed Variability in Two Sympatric Species of Drosophila. Genetics. 1953 Sep;38(5):471–484. doi: 10.1093/genetics/38.5.471. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marinkovic D. Genetic loads affecting fecundity in natural populations of Drosophila pseudoobscura. Genetics. 1967 May;56(1):61–71. doi: 10.1093/genetics/56.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- 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]
- WALLACE B. Allelism of second chromosome lethals in D. melanogaster. Proc Natl Acad Sci U S A. 1950 Nov;36(11):654–657. doi: 10.1073/pnas.36.11.654. [DOI] [PMC free article] [PubMed] [Google Scholar]