Females frequently mate with several males, whose sperm then compete to fertilize
available ova. Sperm competition represents a potent selective force that is expected to …

Multiple mating or group spawning leads to post‐copulatory sexual selection, which
generally favours ejaculates that are more competitive under sperm competition. In four …

Sexual and asexual reproduction are found throughout the plant and animal kingdoms.
Asexual reproduction has its advantages, chief among which is that it does not require the …

Publisher Summary This chapter reviews the current knowledge of variation in sperm
morphology over several levels of biological organization: variation within males (both within …

Sperm experience intense and varied selection that dramatically impacts the evolution of
sperm quality. Selection acts to ensure that sperm are fertilization-competent and able to …

In contrast to early predictions, it is now widely accepted that males incur substantive costs
from ejaculate production. Hence, males are predicted to allocate their reproductive …

Confronting another individual or group motivated by the same goal is a very frequent
situation in human communities that occurs in many other species. Competitive interactions …

Reproduction is a critically important event in every animals' life and in all vertebrates is
controlled by the brain via the hypothalamic-pituitary-gonadal (HPG) axis. In many species …

The ability of females to adaptively influence offspring phenotype via maternal effects is
widely acknowledged, but corresponding nongenetic paternal effects remain unexplored …

There are two reasons why researchers are interested in the phenotypic relationship
between the expression of male secondary sexual characters (SSCs) and 'ejaculate …