Condition-dependence, genotype-by-environment interactions and the lek paradox

Area of Science:

• Evolutionary Biology
• Population Genetics
• Behavioral Ecology

Background:

• The lek paradox highlights the difficulty in maintaining genetic variation for indirect benefit models of female choice.
• Proposed solutions include 'genic capture' (condition-dependence) and genotype-by-environment interactions (GEIs).
• Previous research treated these mechanisms separately, overlooking their combined effects.

Purpose of the Study:

• To integrate condition-dependence and GEIs in a population genetic model.
• To investigate how the timing of dispersal influences the evolution of female preferences.
• To assess the dual impact of GEIs on genetic variation and the male display-offspring fitness association.

Main Methods:

• Developed a population genetic model incorporating condition-dependence and GEIs.
• Analyzed the effects of varying dispersal timing relative to the life cycle.
• Examined the influence of selection and mutation rates.

Main Results:

• The timing of dispersal significantly alters the magnitude and direction of predictions regarding GEIs.
• GEIs can enhance the evolution of costly female preferences but may also impede it under specific dispersal scenarios.
• High selection or mutation rates can also negatively impact the effectiveness of GEIs.

Conclusions:

• Evaluating mechanisms resolving the lek paradox requires assessing both their effect on genetic variation and their impact on the male attractiveness-offspring fitness link.
• The net effect of GEIs is context-dependent, influenced by dispersal timing, environmental variation, and life-history stages.
• A comprehensive evaluation is crucial, as GEIs can either promote or hinder the evolution of female preferences.