Natural selection increases female fitness

• Theory shows how sexual selection can exaggerate male traits beyond naturally selected optima and also how natural selection can ultimately halt trait elaboration.

• Empirical evidence supports this theory, but to our knowledge, there have been no experimental evolution studies directly testing this logic, and little examination of possible associated effects on female fitness.

• Here researchers used experimental evolution of replicate populations of broad-horned flour beetles to test for effects of sex-specific predation on an exaggerated sexually selected male trait (the mandibles), while also testing for effects on female lifetime reproductive success.

• They found that populations subjected to male-specific predation evolve smaller sexually selected mandibles and this indirectly increases female fitness, seemingly through intersexual genetic correlations we document. Predation solely on females has no effects.

• Our findings support the fundamental theory, but also reveal unforeseen outcomes—the indirect effect on females—when natural selection targets sex-limited sexually selected characters.

Published: 08 June 2021

source:

https://www.nature.com/articles/s41467-021-23804-7

https://doi.org/10.1038/s41467-021-23804-7