Sexual selection in earthworms: Mate choice, sperm competition, differential allocation and partner manipulation

► We review new and strong evidence that demonstrates earthworms are subject to sexual selection. ► Earthworms are phenotypically very flexible in mating decisions. ► Evaluation of partners is subject to intense selection. ► Sperm competition is important in shaping life history traits in earthworms. ► Earthworms constitute an excellent model for studying sexual selection in simultaneous hermaphrodites.