Peak shifts and extinction under sex-specific selection

Area of Science:

• Evolutionary biology
• Quantitative genetics
• Sexual selection

Background:

• Sexual selection and cross-sex genetic correlation (r_mf) can facilitate adaptive landscape peak shifts.
• Sexual antagonism can constrain these diversifying effects, influencing the macroevolution of sexual dimorphism.

Purpose of the Study:

• To extend quantitative genetic models to explore how sexual selection and r_mf interact with sexual antagonism.
• To investigate their combined effects on the macroevolution of sexual dimorphism.

Main Methods:

• Extension of existing quantitative genetic models.
• Analysis of evolution on complex adaptive landscapes.
• Inclusion of demographic factors and varying strengths of sexual selection and r_mf.

Main Results:

• Moderate to strong r_mf requires only weak sexual selection for a male-only peak shift.
• Stronger sexual selection leads to a sexually concordant peak shift.
• Sex-specific peak shifts are more resilient to extinction than concordant shifts, especially under strong natural selection.

Conclusions:

• Macroevolutionary rates of sexual dimorphism may be decoupled from within-population sexual selection strength.
• Within-population selection or constraint alone may not explain macroevolutionary patterns of sexual dimorphism.
• Demographic factors significantly influence the success of peak shifts in macroevolution.