Journal of Molecular Evolution

, Volume 26, Issue 1, pp 157–164

Tempo and mode of sequence evolution in mitochondrial DNA of HawaiianDrosophila

  • Rob DeSalle
  • Toby Freedman
  • Ellen M. Prager
  • Alan C. Wilson

DOI: 10.1007/BF02111289

Cite this article as:
DeSalle, R., Freedman, T., Prager, E.M. et al. J Mol Evol (1987) 26: 157. doi:10.1007/BF02111289


Sequence comparisons were made for up to 667 bp of DNA cloned from 14 kinds of HawaiianDrosophila and five other dipteran species. These sequences include parts of the genes for NADH dehydrogenase (subunits 1, 2, and 5) and rRNA (from the large ribosomal subunit). Because the times of divergence among these species are known approximately, the sequence comparisons give insight into the evolutionary dynamics of this molecule. Transitions account for nearly all of the differences between sequences that have diverged by less than 2%; for these sequences the mean rate of divergence appears to be about 2%/Myr. In comparisons involving greater divergence times and greater sequence divergence, relatively more of the sequence differences are due to transversions. Specifically, the fraction of these differences that are counted as transversions rises from an initial value of less than 0.1 to a plateau value of nearly 0.6. The time required to reach half of the plateau value, about 10 Myr, is similar to that for mammalian mtDNA. The mtDNAs of flies and mammals are also alike in the shape of the curve relating the percentage of positions at which there are differences in protein-coding regions to the time of divergence. For both groups of animals, the curve has a steep initial slope ascribable to fast accumulation of synonymous substitutions and a shallow final slope resulting from the slow accumulation of substitutions causing amino acid replacements. However, the percentage of all sites that can experience a high rate of substitution appears to be only about 8% for fly mtDNA compared to about 20% for mammalian mtDNA. The low percentage of hypervariable sites may be a consequence of a functional constraint associated with the low content of guanine and cytosine in fly mtDNA.

Key words

Dideoxy sequencing Molecular clock Transitions Transversions Biased base composition NADH dehydrogenase Ribosomal RNA genes Phylogenetic tree Functional constraint Mosquito Insects 



mitochondrial DNA


base pair(s)


NADH dehydrogenase


ribosomal RNA


DNA encoding rRNA


million years

Copyright information

© Springer-Verlag New York Inc. 1987

Authors and Affiliations

  • Rob DeSalle
    • 1
  • Toby Freedman
    • 1
  • Ellen M. Prager
    • 1
  • Alan C. Wilson
    • 1
  1. 1.Department of BiochemistryUniversity of CaliforniaBerkeleyUSA
  2. 2.Department of Biology, Osborn Memorial LaboratoriesYale UniversityNew HavenUSA
  3. 3.Department of Biology, Curriculum in Genetics and Molecular BiologyUniversity of North CarolinaChapel HillUSA

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