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08:02
Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton
Published on: May 7, 2016
Condition-dependent expression of red colour differs between stickleback species
1Department of Zoology, University of Wisconsin-Madison, Madison, WI 53706, USA. jboughman@wisc.edu
Journal of Evolutionary Biology
|June 23, 2007
Summary
Sexual selection drives sexual isolation in three-spined sticklebacks. Differences in condition-dependent nuptial coloration between limnetic and benthic males reveal distinct sexual selection pressures, leading to reproductive isolation.
Area of Science:
- Evolutionary biology
- Behavioral ecology
- Speciation research
Background:
- Sexual isolation is crucial for speciation, often arising from divergent male mating traits and female preferences.
- Differences in sexual selection strength or targets can drive these trait divergences.
Purpose of the Study:
- To investigate how sexual selection contributes to sexual isolation by comparing mating traits and female preferences in closely related species.
- To use condition dependence as a signature of sexual selection acting on nuptial coloration in three-spined sticklebacks.
Main Methods:
- Assessed condition dependence of red nuptial color in limnetic, benthic, and anadromous three-spined stickleback males.
- Compared the strength of the color-condition relationship and variance in color to other traits.
- Examined the relationship between female preference for red and the extent of condition dependence.
Main Results:
- Limnetic males exhibit strong condition-dependent expression of red nuptial color; benthic males show weak or no condition dependence.
- Ancestral anadromous males display no condition dependence for this trait.
- Female preference for red color correlates with the degree of condition dependence and its role in mate recognition.
Conclusions:
- Strong directional sexual selection on red nuptial color is a derived trait in limnetic sticklebacks, contributing to sexual isolation.
- Divergent sexual selection acting on condition-dependent coloration plays a key role in the speciation of three-spined sticklebacks.
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