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Ecological speciation in Gambusia fishes
R Brian Langerhans1, Matthew E Gifford, Everton O Joseph
1Department of Biology, Washington University, St. Louis, Missouri 63130, USA. langerhans@oeb.harvard.edu
Evolution; International Journal of Organic Evolution
|September 5, 2007
Summary
Natural selection drives speciation as a byproduct in mosquitofish. Adaptation to different predator environments creates reproductive isolation, supporting ecological speciation theory in nature.
Area of Science:
- Evolutionary Biology
- Ecology
- Speciation Research
Background:
- Demonstrating natural selection as a driver of speciation in nature is challenging.
- Ecological factors are increasingly recognized for their role in evolutionary processes.
Purpose of the Study:
- Investigate the role of ecology in incipient speciation of Bahamas mosquitofish (Gambusia hubbsi).
- Examine how adaptation to divergent predator regimes drives ecological speciation as a byproduct.
Main Methods:
- Analyzed morphological, molecular, and behavioral data from mosquitofish populations in blue holes.
- Assessed reproductive isolation between populations with different predator regimes and similar environments.
- Examined interspecific data within the Gambusia genus for historical prevalence of the speciation mechanism.
Main Results:
- Adaptation to divergent predator regimes significantly drives ecological speciation.
- Reproductive isolation is twice as strong between populations with different predator regimes compared to similar environments.
- The speciation mechanism appears historically prevalent in the Gambusia genus.
Conclusions:
- Ecological speciation can occur as a byproduct of adaptation to divergent environments.
- Divergence in ecologically important traits can lead to reproductive isolation and speciation.
- This mechanism contributes to observed interspecific patterns in nature.
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