Ejaculates are fundamental to fitness in sexually reproducing animals: males gain all their
direct fitness via the ejaculate and females require ejaculates to reproduce. Both sperm and …

Maternal effects are now universally recognised as a form of nongenetic parental influence
on offspring but, until recently, paternal effects were regarded as an anomaly. Although it is …

Recent theoretical models predict that the evolutionary diversification of the weapons and
ornaments of pre-mating sexual selection should be influenced by trade-offs with male …

The fact that sperm carry more than the paternal DNA has only been discovered just over a
decade ago. With this discovery, the idea that the paternal condition may have direct …

Sperm morphological variation has attracted considerable interest and generated a wealth
of predominantly descriptive studies over the past three centuries. Yet, apart from …

Female promiscuity can generate postcopulatory competition among males, but it also
provides the opportunity for exploitation of rival male ejaculates. For example, in many insect …

ABSTRACT A central paradigm in evolutionary biology is that the fundamental divergence in
the fitness interests of the sexes ('sexual conflict') can lead to both the evolution of sex …

Sperm production and allocation strategies have been a central concern of sperm
competition research for the past 50 years. But during the 'sexual cascade'there may be …

Theory predicts that costly sexual traits should be reduced when individuals are in poor
condition (ie traits should exhibit condition‐dependent expression). It is therefore widely …

Mounting an immune response is costly, requiring an animal to draw on its limited nutrient
pool at a cost to future growth and reproduction. A trade-off between immunity and …