Gene flow and natural selection in the origin of Drosophila pseudoobscura and close relatives.
The divergence of Drosophila pseudoobscura and close relatives D. persimilis and D. pseudoobscura bogotana has been studied using comparative DNA sequence data from multiple nuclear loci. New data from the Hsp82 and Adh regions, in conjunction with existing data from Adh and the Period locus, are examined in the light of various models of speciation. The principal finding is that the three loci present very different histories, with Adh indicating large amounts of recent gene flow among the taxa, while little or no gene flow is apparent in the data from the other loci. The data were compared with predictions from several isolation models of divergence. These models include no gene flow, and they were found to be incompatible with the data. Instead the DNA data, taken together with other evidence, seem consistent with divergence models in which natural selection acts against gene flow at some loci more than at others. This family of models includes some sympatric and parapatric speciation models, as well as models of secondary contact and subsequent reinforcement of sexual isolation.
Wang
R L
RL
Biological Sciences, Rutgers University, Nelson Labs, Piscataway, New Jersey 08855-1059, USA.
Wakeley
J
J
Hey
J
J
D000426:Alcohol Dehydrogenase; D000429:Alcohol Oxidoreductases / Q000145:classification / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D004247:DNA; D004330:Drosophila / Q000145:classification / Q000235:genetics*; D029721:Drosophila Proteins; D017344:Genes, Insect; D006360:Heat-Shock Proteins / Q000145:classification / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000145:classification / Q000235:genetics; D056950:Period Circadian Proteins; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012641:Selection, Genetic; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D013997:Time Factors
D029721:Drosophila Proteins; D006360:Heat-Shock Proteins; C089272:Hsp83 protein, Drosophila; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; D004247:DNA; D000429:Alcohol Oxidoreductases; C073796:ADH protein, Drosophila; D000426:Alcohol Dehydrogenase