Abstract
Four species of the Hawaiian Drosophila planitibia subgroup which are homosequential in their polytene chromosomes are resident on the islands of Molokai, Maui and Hawaii. Comparisons of DNA sequence divergence in these four have been made by hybridization of total single-copy radiolabeled tracer DNA from each of the species with excess nonlabeled DNA from each of the species, and measurement of the reduction of average melting temperature (ΔTma) was made in 2.4 m tetraethyl ammonium chloride. The mean ΔTma between either D. heteroneura or D. silvestris and either D. planitibia or D. differens was found to be 1.06°, whereas the difference between D. planitibia and D. differens in 0.65° and between D. heteroneura and D. silvestris is 0.75°. These measurements taken together with the distances calculated from isozyme studies, chromosomal relationships, as well as the island locations indicate that the ancestor of these species diverged from other planitibia subgroup flies on Molokai [age 1.8 million years before present, (My BP)]. We hypothesize that one line became the present-day D. differens and diverged probably at the time of formation of East Maui (0.8-1 My BP) to form the species D. planitibia. Flies from the other line migrated to Hawaii soon after its formation (0.7 My BP) to form the two species D. heteroneura and D. silvestris.
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Selected References
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- Britten R. J., Graham D. E., Neufeld B. R. Analysis of repeating DNA sequences by reassociation. Methods Enzymol. 1974;29:363–418. doi: 10.1016/0076-6879(74)29033-5. [DOI] [PubMed] [Google Scholar]
- Fitch W. M., Margoliash E. Construction of phylogenetic trees. Science. 1967 Jan 20;155(3760):279–284. doi: 10.1126/science.155.3760.279. [DOI] [PubMed] [Google Scholar]
- Nei M., Roychoudhury A. K. Sampling variances of heterozygosity and genetic distance. Genetics. 1974 Feb;76(2):379–390. doi: 10.1093/genetics/76.2.379. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sene F. M., Carson H. L. Genetic variation in Hawaiian Drosophila. IV. Allozymic similarity between D. silvestris and D. heteroneura from the island of Hawaii. Genetics. 1977 May;86(1):187–198. doi: 10.1093/genetics/86.1.187. [DOI] [PMC free article] [PubMed] [Google Scholar]