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 …

The outcome of sperm competition is mediated largely by the relative numbers of sperm from
competing males. However, substantial variation in features of sperm morphology and …

Females of many species mate with multiple males, thereby inciting competition among
ejaculates from rival males for fertilization. In response to increasing sperm competition …

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 …

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

Interest in how often female social insects mate is particularly intense because of its impact
on sociality and because of the well-known extreme multiple mating in honeybees. With …

Sexually antagonistic coevolution may be an important force in the evolution of sexual
dimorphism. We undertake a comparative study of correlated evolution of male and female …

Evolutionary biologists have endeavoured to explain the extraordinary diversity of sperm
morphology across animals for more than a century. One hypothesis to explain sperm …

While both sperm number and quality are now recognized to be important in determining the
outcome of sperm competition, very few studies have experimentally assessed the influence …

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