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 …

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 …

Parental care is a trait that shows tremendous diversity both within and across different
animal taxa, and is an important topic in evolutionary biology and behavioural ecology …

This book presents the first unified conceptual and statistical framework for understanding
the evolution of reproductive strategies. Using the concept of the opportunity for sexual …

Adult sex ratio (ASR) exhibits immense variation in nature, although neither the causes nor
the implications of this variation are fully understood. According to theory, the ASR is …

Complex brains and behaviors have occurred repeatedly within vertebrate classes
throughout evolution. What adaptive pressures drive such changes? Both environmental …

We provide the first review of phylogenetic transitions in parental care and live bearing for a
wide variety of vertebrates. This includes new analyses of both numbers of transitions and …

Our understanding of parental care behavior can be significantly advanced through the
application of Williams's Principle, which states that reproduction has not only a benefit but …

In order to explain the huge variation in parental behaviour, evolutionary biologists have
traditionally used a cost–benefit approach, which enables them to analyse behavioural traits …

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 …