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Density-dependent diversification in North American wood warblers
Daniel L Rabosky1, Irby J Lovette
1Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA. dlr32@cornell.edu
Proceedings. Biological Sciences
|July 10, 2008
Summary
Species diversification rates often slow down over time. This study shows that density-dependent ecological interactions drove the rapid diversification of North American wood warblers, supporting the ecological opportunity model.
Area of Science:
- Evolutionary Biology
- Ecology
- Phylogenetics
Background:
- Species diversification rates commonly decrease over evolutionary time.
- The ecological opportunity model proposes that resource availability and competition influence diversification.
- Previous studies lacked species-level tests of density-dependent diversification.
Purpose of the Study:
- To develop a framework for distinguishing density dependence from other causes of declining diversification rates.
- To test the ecological opportunity model using a species-level radiation.
- To investigate the diversification dynamics of North American Dendroica wood warblers.
Main Methods:
- Construction of a novel phylogenetic tree for North American Dendroica wood warblers.
- Application of a new conceptual framework to analyze diversification patterns.
- Distinguishing density-dependent diversification from alternative models.
Main Results:
- Evidence suggests that diversification rates in wood warblers declined through time.
- The pattern of lineage accumulation is best explained by density-dependent diversification.
- Ecological interactions played a key role in mediating wood warbler diversification.
Conclusions:
- The ecological opportunity model provides a robust explanation for the diversification of North American wood warblers.
- Lineage diversification in this group is coupled with ecological diversification.
- Density dependence is a significant factor shaping evolutionary radiations.
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