Conventional sex roles imply caring females and competitive males. The evolution of sex
role divergence is widely attributed to anisogamy initiating a self‐reinforcing process. The …

Sexual reproduction is associated with the evolution of anisogamy and sperm-producing
males and egg-laying females. The ensuing competition for mates has led to sexual …

The past decade has seen a profound change in the scientific understanding of
reproduction. The traditional view of reproduction as a joint venture undertaken by two …

Sex-role evolution theory attempts to explain the origin and direction of male–female
differences. A fundamental question is why anisogamy, the difference in gamete size that …

Sex roles are typically thought of as being fixed for a given species. In most animals males
compete for females, whereas the females are more reluctant to mate. Therefore sexual …

Among primates, intense paternal care is manifested in only a few distantly related species,
including humans. Thus, neither purely phylogenetic nor socioecological hypotheses can …

Characterizations of coy females and ardent males are rooted in models of sexual selection
that are increasingly outdated. Evolutionary feedbacks can strongly influence the sex roles …

Whatever the reasons for the evolution of sexual reproduction, it leads to a situation in which
there are two individuals who may have no genetic interest in each other's future, the …

Male birds frequently face a trade-off between acquiring mates and caring for offspring.
Hormone manipulation studies indicate that testosterone often mediates this trade-off …

There is a strong intuitive expectation in both popular lore and conventional evolutionary
thinking that more males lead to more violence. Here, we untangle the logic behind this …