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Evidence for ecology's role in speciation.
Jeffrey S McKinnon1, Seiichi Mori, Benjamin K Blackman
1Biological Sciences, University of Wisconsin-Whitewater, Whitewater, Wisconsin 53190, USA. mckinnoj@uww.edu
Nature
|May 21, 2004
Summary
Body size drives reproductive isolation in parallel speciation of stickleback fish. This suggests speciation can be a byproduct of ecological divergence and selection on key traits.
Area of Science:
- Evolutionary Biology
- Speciation Research
- Ecology and Behavior
Background:
- Connecting natural selection's role in speciation to reproductive isolation and ecologically important traits remains a challenge.
- Parallel speciation links ecology and isolation, but the specific phenotypic traits involved are often unconfirmed.
Purpose of the Study:
- To investigate the phenotypic traits mediating reproductive isolation in parallel speciation.
- To determine if body size evolution in stickleback populations accounts for observed mating incompatibilities.
Main Methods:
- Documented the influence of body size on reproductive isolation in Northern Hemisphere stickleback populations.
- Conducted experimental manipulations to confirm the role of body size in mediating assortative mating and reproductive isolation.
Main Results:
- Parallel increases in mating incompatibilities between stickleback populations were largely explained by assortative mating based on body size.
- Body size evolves predictably with environmental changes, influencing reproductive isolation.
Conclusions:
- Body size is a key phenotypic trait mediating reproductive isolation in stickleback speciation.
- Speciation may frequently arise as a byproduct of ecological divergence and divergent selection on a limited set of traits.
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