Literaturdatenbank
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Rödder, D., Lawing, M. A., Flecks, M., Ahmadzadeh, F., Dambach, J., & Engler, J. O., et al. (2013). Evaluating the significance of paleophylogeographic species distribution models in reconstructing quaternary range-shifts of nearctic chelonians. PLoS ONE, 8(10), e72855.
Added by: Admin (06 Jan 2014 18:25:16 UTC) |
| Resource type: Journal Article DOI: 10.1371/journal.pone.0072855 BibTeX citation key: Rdder2013a View all bibliographic details  |
Categories: General Keywords: Emydidae, Kinosternidae, Schildkröten - turtles + tortoises, Sternotherus depressus, Systematik - taxonomy, Trachemys nebulosa Creators: Ahmadzadeh, Dambach, Engler, Flecks, Habel, Hartmann, Hörnes, Ihlow, Lawing, Polly, Rödder, Schidelko, Stiels Collection: PLoS ONE |
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| Abstract |
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The climatic cycles of the Quaternary, during which global mean annual temperatures have regularly changed by 5–10°C, provide a special opportunity for studying the rate, magnitude, and effects of geographic responses to changing climates. During the Quaternary, high- and mid-latitude species were extirpated from regions that were covered by ice or otherwise became unsuitable, persisting in refugial retreats where the environment was compatible with their tolerances. In this study we combine modern geographic range data, phylogeny, Pleistocene paleoclimatic models, and isotopic records of changes in global mean annual temperature, to produce a temporally continuous model of geographic changes in potential habitat for 59 species of North American turtles over the past 320 Ka (three full glacial-interglacial cycles). These paleophylogeographic models indicate the areas where past climates were compatible with the modern ranges of the species and serve as hypotheses for how their geographic ranges would have changed in response to Quaternary climate cycles. We test these hypotheses against physiological, genetic, taxonomic and fossil evidence, and we then use them to measure the effects of Quaternary climate cycles on species distributions. Patterns of range expansion, contraction, and fragmentation in the models are strongly congruent with (i) phylogeographic differentiation; (ii) morphological variation; (iii) physiological tolerances; and (iv) intraspecific genetic variability. Modern species with significant interspecific differentiation have geographic ranges that strongly fluctuated and repeatedly fragmented throughout the Quaternary. Modern species with low genetic diversity have geographic distributions that were highly variable and at times exceedingly small in the past. Our results reveal the potential for paleophylogeographic models to (i) reconstruct past geographic range modifications, (ii) identify geographic processes that result in genetic bottlenecks; and (iii) predict threats due to anthropogenic climate change in the future. Our phylogenetic tree is largely congruent with previous phylogenetic work (for a synopsis see Iverson et al. ). Most discrepancies were found within the Kinosternidae and some genera of the Deirochelinae. Regarding the first, the position of Sternotherus depressus leads to a paraphyly of Sternotherus in respect to Kinosternon. This might be an artifact of the sparse and often nonhomologous data available for the members of these two genera and is also reflected by generally low support values in this clade. However, there is currently no comprehensive molecular phylogeny of this group available for verification. Although intrageneric relationships of Graptemys and Pseudemys in our results slightly differ to previous hypotheses, the posterior probabilities strongly support our topology (Appendix S6 in Material S1). The major ambiguity is the polyphyly of Trachemys due to T. nebulosa, which is the sister species of Malaclemys according to our results, yet this has poor support.
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