ShuiEro ... from vague up to sometimes ;) crystal clear drop by drop ...

Despite a massive research effort, our understanding of why, in most vertebrates, males compete for mates and females care
for offspring remains incomplete. Two alternative hypotheses have been proposed to explain the direction of causality between
parental care and sexual selection. Traditionally, sexual selection has been explained as a consequence of relative parental invest-ment, where the sex investing less will compete for the sex investing more. However, a more recent model suggests that parental
care patterns result from sexual selection acting on one sex favoring mating competition and lower parental investment. Using
species-level comparative analyses on Tanganyikan cichlid fishes we tested these alternative hypotheses employing a proxy of
sexual selection based on mating system, sexual dichromatism, and dimorphism data. First, while controlling for female reproduc-tive investment, we found that species with intense sexual selection were associated with female-only care whereas species with
moderate sexual selection were associated with biparental care. Second, using contingency analyses, we found that, contrary to
the traditional view, evolutionary changes in parental care type are dependent on the intensity of sexual selection. Hence, our
results support the hypothesis that sexual selection determines parental care patterns in Tanganyikan cichlid fishes.