Quantifying male harm and its divergence.

Area of Science:

• Evolutionary Biology
• Sexual Conflict
• Animal Behavior

Background:

• Male harm arises from traits enhancing male reproductive success, potentially harming females as a byproduct.
• Divergence in male harm between populations can occur due to differing male and female phenotypes.
• Quantifying male harm typically involves inferring it from reduced female fitness with increased male exposure within a population.

Purpose of the Study:

• To quantify male harm in Drosophila serrata populations.
• To compare the magnitude of male harm between two distinct populations.
• To investigate the divergence of male harm and its underlying causes in sexually reproducing species.

Main Methods:

• Utilized two laboratory populations of Drosophila serrata, established from a common ancestor 7 years prior.
• Employed a factorial design to manipulate female exposure to males from both populations.
• Quantified female fitness across all four combinations of males and females from the two populations.

Main Results:

• Demonstrated substantial harm to females across the tested populations.
• Provided strong evidence for divergence in male harm between the two populations.
• Observed greater divergence in male harm compared to female harm.

Conclusions:

• Male harm is a significant factor influencing female fitness and can diverge between populations.
• Direct manipulation of male exposure provides crucial insights into the evolution of sexual conflict.
• Understanding divergence in male harm requires careful consideration of how harm is quantified and compared across populations.