In species with separate sexes, females and males often differ in their morphology,
physiology and behaviour. Such sex‐specific traits are functionally linked to variation in …

Converging lines of inquiry from across the social and biological sciences target the adult
sex ratio (ASR; the proportion of males in the adult population) as a fundamental population …

Males and females often have different roles in reproduction, although the origin of these
differences has remained controversial. Explaining the enigmatic reversed sex roles where …

The year 2021 marks the 150th anniversary of the publication of Charles Darwin's
extraordinary book The Descent of Man and Selection in Relation to Sex. Here, we review …

Rising global temperatures threaten to disrupt population sex ratios, which can in turn cause
mate shortages, reduce population growth and adaptive potential, and increase extinction …

Males and females often exhibit different behaviours during mate acquisition, pair‐bonding
and parenting, and a convenient label to characterize these behaviours is sex role. The …

Size differences between males and females are common across the tree of life (termed
sexual size dimorphism; SSD), and have fundamental implications for ecology, life history …

Most vertebrates, including all mammals and birds, are sexually reproducing organisms. The
implication of sexual reproduction is that an adult bird exists because a male transferred …

Abstract We developed a Hidden Markov mark–recapture model (R package marked) to
examine sex‐specific demography in Magellanic Penguins (Spheniscus magellanicus). Our …

Altruism is favored by natural selection provided that it delivers sufficient benefits to relatives.
An altruist's valuation of her relatives depends upon the extent to which they carry copies of …