Sexual selection often leads to sexual conflict via pre-copulatory (harassment) and/or copulatory (traumatic insemination) male harm to females, impacting population growth, adaptation and evolutionary rescue. Male harm mechanisms are diverse and taxonomically widespread, but we largely ignore what ecological factors modulate their diversification. Here, we conducted experimental evolution under low- (20±4ºC), moderate- (24±4ºC) and high-temperature (28±4ºC) regimes in Drosophila melanogaster, a species with male harm via harassment and seminal fluid proteins (SFPs), to show that temperature drives the divergent evolution of sexual conflict. At the low-temperature regime, evolution resulted in reduced and less plastic harassment (i.e. pre-copulatory harm) while, at the high-temperature regime, it was characterized by responses in the seminal proteome driven by differential expression of SFPs. Our results suggest that temperature can be key to understand the past diversification and future (global warming) evolution of sexual conflict, and the maintenance of genetic variation in male harm traits.

Funding provided by: Ministerio de Educación Cultura y DeporteROR ID: https://ror.org/03nc27g21Award Number: FJC2018-037058-I Funding provided by: Ministerio de Ciencia, Innovación y UniversidadesROR ID: https://ror.org/05r0vyz12Award Number: PRE2018-084009 Funding provided by: Generalitat ValencianaROR ID: https://ror.org/0097mvx21Award Number: AICO/2021/113 Funding provided by: Marie Curie AssociationROR ID: https://ror.org/03syqx014Award Number: 101061275—Ref. 2022-1244816 Funding provided by: Ministerio de Ciencia, Innovación y UniversidadesROR ID: https://ror.org/05r0vyz12Award Number: PID2020-118027GB-I00