Literaturdatenbank
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Mitchell, S., Pappas, M., & Freedberg, S. , Niche specialization and reduced mitochondrial introgression in a hybridizing complex of map turtles - abstract. Unpublished paper presented at Program and Abstracts of the Tenth Annual Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles.
Added by: Sarina Wunderlich (06 Jul 2014 16:11:55 UTC) |
| Resource type: Conference Paper BibTeX citation key: Mitchell2013c View all bibliographic details  |
Categories: General Keywords: Actinemys marmorata, Emydidae, Genetik - genetics, Habitat - habitat, Kinosternidae, Kinosternon subrubrum, Nordamerika - North America, Schildkröten - turtles + tortoises Creators: Freedberg, Mitchell, Pappas Collection: Program and Abstracts of the Tenth Annual Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles |
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| Abstract |
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Because reproductive isolation is a key component of speciation, hybridization between evolutionarily distinct species is a valuable tool to study the origin and maintenance of new species in nature. Previous studies have emphasized genetic and behavioral causes of reproductive speciation. Theory predicts that ecological forces such as feeding niche specialization may also lead to reproductive isolation between species. Specifically, if hybrid offspring exhibit a phenotype intermediate between that of their parents, they may be less effective at exploiting either parental niche, preventing gene flow and promoting reproductive isolation. Despite this strong theoretical prediction, it has been difficult to isolate ecological specialization as a factor driving reproductive isolation because it often co-occurs with genetic and behavioral divergence. A complex of interbreeding map turtles (Graptemys geographica and G. pseudogeographica) in the Mississippi River provides a unique opportunity to study ecological speciation. Genetic evidence of introgression has shown that behavioral and genetic barriers to gene flow are absent between the species; however, these sympatric species have remained evolutionarily distinct. Furthermore, if dietary specialization is sexually dimorphic, differential rates of introgression should be expected between mitochondrial and nuclear markers. By pairing stable isotope with genetic analyses, it is possible to determine how ecological factors can affect the maintenance of reproductive isolation in these species. In particular, stable isotope analysis can elucidate differences between species and between sexes, while genetic analyses are capable of determining if those differences are correlated to differing rates of introgression in the mitochondrial and nuclear genome.
Added by: Sarina Wunderlich |