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Frequency-dependent selection predicts patterns of radiations and biodiversity
Carlos J Melián1, David Alonso, Diego P Vázquez
1National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara, Santa Barbara, California, United States of America. melian@nceas.ucsb.edu
Plos Computational Biology
|September 25, 2010
Summary
Frequency-dependent selection explains speciation rate trends, offering a new perspective on global biodiversity. This model accurately predicts diversity patterns in cichlid fish and Darwin's finches without invoking pre-existing niches.
Area of Science:
- Evolutionary Biology
- Speciation Research
- Biodiversity Science
Background:
- Empirical studies show mixed evidence for speciation rate trends, with declining rates attributed to pre-existing niches and constant rates to non-adaptive processes.
- Understanding speciation rate drivers is crucial for explaining global biodiversity patterns, representing a significant knowledge gap.
Purpose of the Study:
- To investigate frequency-dependent selection as an alternative explanation for speciation rate trends.
- To develop and test a DNA sequence-based model incorporating frequency-dependent selection.
- To compare model predictions with empirical data from cichlid fish and Darwin's finches.
Main Methods:
- Construction of a frequency-dependent, DNA sequence-based speciation model.
- Comparison of model outputs with empirical speciation rates and species richness data.
- Analysis of two classic model systems: cichlid fish and Darwin's finches.
Main Results:
- The frequency-dependent selection model accurately predicts declining speciation rates and high species richness in cichlid fish.
- For Darwin's finches, a model without frequency-dependent selection better explains constant speciation rates and lower diversity.
- Incipient species abundance, influenced by frequency-dependent selection, may drive differences in observed diversity.
Conclusions:
- Frequency-dependent selection and genetic distance-based speciation are sufficient to explain high biodiversity.
- The model predicts a decline in speciation rates over time, even without pre-existing niches.
- This research provides a novel framework for understanding the evolutionary processes shaping global species diversity.
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