No evidence for parallel sympatric speciation in cichlid species of the genus Pseudotropheus from north-western Lake Malawi

Publication Type:Journal Article
Year of Publication:2003
Authors:P. Bouteillon, Rico, C. , Van Oppen, M. J. H. , Knight, M. E. , Hewitt, G. M. , Turner, G. F.
Journal:Journal of Evolutionary Biology
Date Published:Jan
Accession Number:5576058
Keywords:Article Geographic Terms: Africa, Nyasa L., Article Subject Terms: Allopatric populations, Article Taxonomic Terms: Cichlidae, Biological speciation, cichlids, D 04668 Fish, Freshwater fish, G 07290 Population genetics, G 07371 Fish, gene flow, genetic distance, Genetic drift, genetics, Lake Malawi, Lakes, Microsatellites, population genetics, Pseudotropheus, Q1 01443 Population, sexual selection, speciation, Sympatric populations

To test the hypothesis of parallel speciation by sexual selection, we examined length variation at six microsatellite loci of samples from four sites of four to six putative species belonging to two subgenera of rocky shore mbuna cichlids from Lake Malawi. Almost all fixation indices were significantly different from zero, suggesting that there is presently little or no gene flow among allopatric populations or sympatric species. Analysis of variance indicated that genetic distances among allopatric populations of putative conspecifics were significantly lower than among sympatric populations of heterospecifics. The topology of trees based on distance matrices was also largely consistent with the hypothesis that the putative species are monophyletic and have thus not evolved in parallel in their present locations. If parallel speciation does occur in Malawi cichlids, it may be on a larger spatial scale than investigated in our study.

Alternate Journal:J. Evol. Biol.

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