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Diversification under sexual selection: the relative roles of mate preference strength and the degree of divergence in mate preferences.

Rodríguez RL, Boughman JW, Gray DA, Hebets EA, Höbel G, Symes LB - Ecol. Lett. (2013)

Bottom Line: To ask how this disparity in focus may affect the conclusions of evolutionary research, we relate the amount of diversification in mating displays to quantitative descriptions of the strength and the amount of divergence in mate preferences across a diverse set of case studies of mate choice.We find that display diversification is better explained by preference divergence rather than preference strength; the effect of the latter is more subtle, and is best revealed as an interaction with the former.Adopting this view will enhance tests of the relative role of natural and sexual selection in processes such as speciation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA. rafa@uwm.edu

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Effect sizes (r) for the relationship between the amount of divergence in peak preferences (Δp) or preference strength and the amount of divergence in display traits (Δt). Data points show effect size estimates for each trait in each case study. (a) Effect sizes for Δp were greater than for preference strength. (b) Effect sizes varied with the sample size of each case study (N = # data points in case study = # traits × # taxa in case study), but remained consistently large and positive for Δp, and either small or large negative for preference strength. Fitted lines are quadratic functions that asymptote at a larger effect size for Δp than for preference strength.
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fig05: Effect sizes (r) for the relationship between the amount of divergence in peak preferences (Δp) or preference strength and the amount of divergence in display traits (Δt). Data points show effect size estimates for each trait in each case study. (a) Effect sizes for Δp were greater than for preference strength. (b) Effect sizes varied with the sample size of each case study (N = # data points in case study = # traits × # taxa in case study), but remained consistently large and positive for Δp, and either small or large negative for preference strength. Fitted lines are quadratic functions that asymptote at a larger effect size for Δp than for preference strength.

Mentions: We further compared how Δt relates to Δp and preference strength in terms of the effect size of the relationships. We found that the effect sizes for the Δt∼Δp relationship were significantly greater than for the Δt∼preference strength relationship (Welch anova allowing for unequal variances: F1,8.9314 = 53.97, P < 0.0001; Fig. 5a). This pattern remained when we used the absolute value of the effect sizes (Welch anova: F1,9.892 = 9.89, P = 0.022). We also found that these effect sizes were influenced by the sample size of each case study, with smaller N case studies likely overestimating effect sizes (Fig. 5b). Across 8 case studies (conservatively excluding the panmictic cricket population), the correlation between N and the effect size for Δp was r = −0.89, P = 0.0031; for preference strength, it was r = −0.66, P = 0.073. Nevertheless, effect sizes remained consistently stronger for Δp than for preference strength (Fig. 5b). In short, we found that the effect sizes for the Δt∼Δp relationship were always strong and positive, whereas the effect sizes for the Δt∼preference strength relationship were either weakly positive or negative (Figs 4 and 5).


Diversification under sexual selection: the relative roles of mate preference strength and the degree of divergence in mate preferences.

Rodríguez RL, Boughman JW, Gray DA, Hebets EA, Höbel G, Symes LB - Ecol. Lett. (2013)

Effect sizes (r) for the relationship between the amount of divergence in peak preferences (Δp) or preference strength and the amount of divergence in display traits (Δt). Data points show effect size estimates for each trait in each case study. (a) Effect sizes for Δp were greater than for preference strength. (b) Effect sizes varied with the sample size of each case study (N = # data points in case study = # traits × # taxa in case study), but remained consistently large and positive for Δp, and either small or large negative for preference strength. Fitted lines are quadratic functions that asymptote at a larger effect size for Δp than for preference strength.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3757319&req=5

fig05: Effect sizes (r) for the relationship between the amount of divergence in peak preferences (Δp) or preference strength and the amount of divergence in display traits (Δt). Data points show effect size estimates for each trait in each case study. (a) Effect sizes for Δp were greater than for preference strength. (b) Effect sizes varied with the sample size of each case study (N = # data points in case study = # traits × # taxa in case study), but remained consistently large and positive for Δp, and either small or large negative for preference strength. Fitted lines are quadratic functions that asymptote at a larger effect size for Δp than for preference strength.
Mentions: We further compared how Δt relates to Δp and preference strength in terms of the effect size of the relationships. We found that the effect sizes for the Δt∼Δp relationship were significantly greater than for the Δt∼preference strength relationship (Welch anova allowing for unequal variances: F1,8.9314 = 53.97, P < 0.0001; Fig. 5a). This pattern remained when we used the absolute value of the effect sizes (Welch anova: F1,9.892 = 9.89, P = 0.022). We also found that these effect sizes were influenced by the sample size of each case study, with smaller N case studies likely overestimating effect sizes (Fig. 5b). Across 8 case studies (conservatively excluding the panmictic cricket population), the correlation between N and the effect size for Δp was r = −0.89, P = 0.0031; for preference strength, it was r = −0.66, P = 0.073. Nevertheless, effect sizes remained consistently stronger for Δp than for preference strength (Fig. 5b). In short, we found that the effect sizes for the Δt∼Δp relationship were always strong and positive, whereas the effect sizes for the Δt∼preference strength relationship were either weakly positive or negative (Figs 4 and 5).

Bottom Line: To ask how this disparity in focus may affect the conclusions of evolutionary research, we relate the amount of diversification in mating displays to quantitative descriptions of the strength and the amount of divergence in mate preferences across a diverse set of case studies of mate choice.We find that display diversification is better explained by preference divergence rather than preference strength; the effect of the latter is more subtle, and is best revealed as an interaction with the former.Adopting this view will enhance tests of the relative role of natural and sexual selection in processes such as speciation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA. rafa@uwm.edu

Show MeSH