The hypothesis that females prefer older males because they have higher mean fitness than younger males has been the centre of recent controversy. These discussions have focused on the success of a female who prefers males of a particular age class when age cues, but not quality cues, are available. Thus, if the distribution of male quality changes with age, such that older males have on averag...

-We present a theoretical framework in order to understand how the relationship between male parental care and paternity is dependent on the relationship between male parental care and offspring recruitment. When there is an S-shaped relationship between offspring recruitment and the parental care of a single male, we predict a threshold relationship between male parental care and paternity. Tr...

Males and females often have different requirements during early development, leading to sex-specific interactions between developing offspring. In polytocous mammals, competition for limited resources in utero may be asymmetrical between the sexes, and androgens produced by male foetuses could have adverse effects on the development of females, with potentially long-lasting consequences. We sh...

Background. Parental absences in childhood are often associated with accelerated reproductive maturity in humans. These results are counterintuitive for evolutionary social scientists because reductions in parental investment should be detrimental for offspring, but earlier reproduction is generally associated with higher fitness. In this paper we discuss a neglected hypothesis that early repro...

In a wide variety of species, a female's age of first reproduction influences offspring size and survival, suggesting that there exists an optimal timing of reproduction. Mothers in many species also influence offspring size and survival after birth through variation in parental care. We experimentally separated these effects in the burying beetle Nicrophorus vespilloides to test for coadaptati...

The typical pattern in hymenopteran species is that females are produced from fertilized eggs but that males arise parthenogenetically from unfertilized eggs (arrhenotoky). In some species, however, unfertilized eggs can yield diploid female offspring through the process of thelytokous parthenogenesis. Indeed, it is puzzling why such asexual mutants have not outreproduced their sexual counterpa...

REPRODUCTION INVOLVES TRADE-OFFS between mating and parenting (Trivers, 1972; Williams, 1966), and attendant conflicts between males and females and parents and offspring (Hager & Johnstone, 2003; Trivers, 1974). Conflicts arise because the ways in which each sex and each parent distribute limited reproductive resources is not always in the best interest of the other sex or offspring. Still, ma...

Radical declines in fertility and postponement of first reproduction during the recent human demographic transitions have posed a challenge to interpreting human behaviour in evolutionary terms. This challenge has stemmed from insufficient evolutionary insight into individual reproductive decision-making and the rarity of datasets recording individual long-term reproductive success throughout t...

Abstract A father’s lifetime experience is a major risk factor for range of diseases in an individual. The influences exposure can also be transmitted to offspring. Previous studies demonstrated that plasticisers damage the male offspring reproductive system, but link between mammalian research and human non-obstructive azoospermia remains underexplored. Here, we analysed reproduction-related g...