6533b830fe1ef96bd1297ba6
RESEARCH PRODUCT
A hierarchical analysis of genetic structure and variability in patchily distributed coexisting Chiastocheta species (Diptera:Anthomyiidae)
Jes JohannesenJes JohannesenVolker Loeschckesubject
Geneticseducation.field_of_studyPopulationPopulation geneticsBiologyIntraspecific competitionGenetic distanceGenetic markerEvolutionary biologyGenetic variationGenetic structureGeneticsGenetic variabilityeducationGenetics (clinical)description
The pattern of genetic variation in four coexisting fly species of the genus Chiastocheta was studied by allozyme electrophoresis. The fly species are confined to patches of one plant, Trollius europaeus, and thus experience very similar habitat fluctuations. Collection sites were chosen in a hierarchical fashion and F-statistics were estimated at three levels: intraregion, inter-region and total population. Population characteristic genetic parameters were compared within and among species and were related to the hierarchical level. The species were used as replicate experiments for inference of habitat history, and the hierarchical levels were used as inference for specific gene flow patterns. Genetic variability was related to relative species abundance but not to local population size. The species divided into two heterogeneity classes, C. dentifera/C. trollii, and C. inermella/C. abruptiventris, where the former pair had more genetic variation than the latter. However, among all species no differences in the average number of alleles per locus were found. The amount of variability was not related to interspecific phylogeny, and the species could thus be analysed independently for genetic structure. Species-specific genetic patterns were found, but for all species the amount of genetic differentiation was related to regional geography. For three species, differentiation within regions was often higher than at the total population level whereas the differentiation among regions was negligible. Differentiation of the fourth species, C. inermella, increased with geographical scale indicating an isolation-by-distance genetic structure. We suggest that within species the amount of genetic differentiation need not be related to intraspecific ancestry, as high differentiation was not necessarily associated with low expected geographical structure.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1996-05-01 |