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Speciation durations and Pleistocene effects on vertebrate phylogeography
J C Avise1, D Walker, G C Johns
1Department of Genetics, University of Georgia, Athens 30602-7223, USA. avise@arches.uga.edu
Proceedings. Biological Sciences
|October 27, 1998
Summary
Speciation durations typically exceed two million years. The Pleistocene epoch significantly influenced phylogeography in mammals and birds, while its impact on herpetofauna and fishes varied with molecular clock calibrations.
Area of Science:
- Evolutionary Biology
- Molecular Phylogenetics
- Zoology
Background:
- Phylogeographic studies often focus on avian species.
- Understanding speciation durations and Pleistocene impacts is crucial for evolutionary insights.
Purpose of the Study:
- To extend phylogeographic analysis to diverse vertebrate classes.
- To estimate speciation durations using mitochondrial DNA (mtDNA).
- To evaluate the role of the Pleistocene in shaping current vertebrate diversity.
Main Methods:
- Applied a previously established avian phylogeographic approach to other vertebrate classes.
- Utilized mitochondrial DNA (mtDNA) data from extant taxa.
- Employed provisional molecular clocks to date population divergences and estimate speciation durations.
- Inferred minimum and maximum speciation durations from genetic distances between intraspecific phylogroups and sister species.
Main Results:
- Speciation durations average at least two million years across vertebrate classes.
- Pleistocene conditions significantly influenced phylogeographic differentiation in mammals and birds.
- The role of Pleistocene biogeography in herpetofauna and fishes is contingent on mtDNA rate calibrations.
Conclusions:
- Speciation is a lengthy process, often spanning millions of years.
- The Pleistocene epoch was a key driver of diversification in birds and mammals.
- Further research is needed to refine understanding of Pleistocene influences on herpetofauna and fish evolution.
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