Heritability, evolvability, phenotypic plasticity and temporal variation in sperm-competition success of Drosophila melanogaster.

Sperm-competition success (SCS) is seen as centrally important for evolutionary change: superior fathers sire superior sons and thereby inherit the traits that make them superior. Additional hypotheses, that phenotypic plasticity in SCS and sperm ageing explain variation in paternity, are less considered. Even though various alleles have individually been shown to be correlated with variation in SCS, few studies have addressed the heritability, or evolvability, of overall SCS. Those studies that have addressed found low or no heritability and have not examined evolvability. They have further not excluded phenotypic plasticity, and temporal effects on SCS, despite their known dramatic effects on sperm function. In Drosophila melanogaster, we found that both standard components of sperm competition, sperm defence and sperm offence, showed nonsignificant heritability across several offspring cohorts. Instead, our analysis revealed, for the first time, the existence of phenotypic plasticity in SCS across an extreme environment (5% CO2 ), and an influence of sperm ageing. Evolvability of SCS was substantial for sperm defence but weak for sperm offence. Our results suggest that the paradigm of explaining evolution by sperm competition is more complex and will benefit from further experimental work on the heritability or evolvability of SCS, measuring phenotypic plasticity, and separating the effects of sperm competition and sperm ageing.

Critérios de escolha de parceria amorosa em mulheres climatéricas e menopausadas / Choice criteria of mate in climateric and menopausal women

A Teoria das Estratégias Sexuais (T.E.S) prevê que as mulheres em suas escolhas amorosas buscariam por parceiros amorosos com elevado nível social, mais velhos que elas e com qualidades de provedor e de pai. Estudos mostram que após o fim do período reprodutivo mulheres tendem a escolher parcerias de longa duração. Selecionamos 91 mulheres nas fases do climatério e menopausa, com ensino médio completo e possuindo renda média elevada, para investigarmos como elas escolhem parceiros. Como resultado, obtivemos que boa parte das mulheres se comportaram segundo a T.E.S, escolhendo parceiros mais velhos, com elevado nível de renda e instrução. Grande parte deles apresentava as características idealizadas por elas. Foi clara uma preferência por parcerias fixas, em detrimento das eventuais. Parte dos resultados permitiu a confirmação das previsões da T.E.S entre mulheres que escolhem seus parceiros durante ou após o fim do período reprodutivo.(AU)

According to the Sexual Strategies Theory (SST) women choose partners that are older, have higher social status, higher income and qualities of good provider and father. Studies show that even after their reproductive period, in which there's no need for reproduction, women tend to choose long-term relationships. We selected 91 women in Climacteric and Menopausal phases with high school level and high income to investigate their mate choice. The results showed a half of women chose older partners with high educational level and income. Most of the men had the characteristics the women idealized for a partner. Preferably women have kept fixed relationships than eventual relationships. Parts of results allow us to do the predictions in the SST for both women in and out of their reproductive period.(AU)