Sperm competition, the contest among ejaculates from rival males to fertilize ova of a female,
is a common and powerful evolutionary force influencing ejaculate traits. During …

One of the common assumptions in the study of the evolution of parental care is that trade‐offs
exist between parental investment and other fitness‐related traits. In general, this body of …

Many studies have attempted to explain the evolution of cooperation, yet little attention has
been paid to what factors control the amount or kind of cooperation performed. Kin selection …

In species with internal fertilization, females can favour certain males over others, not only
before mating but also within the female’s reproductive tract after mating. Here, we ask …

In cooperatively breeding species, members of social groups will risk serious injury or even
their lives by actively codefending the communal territory and young in the territory. However…

Among taxonomically widespread cooperatively breeding vertebrates, those with non-breeding
helpers-at-the-nest provide an excellent opportunity to understand the proximate …

Fish exhibit impaired sensory function and altered behaviour at levels of ocean acidification
expected to occur owing to anthropogenic carbon dioxide emissions during this century. We …

Discrete variation in reproductive behavior and physiology is observed in diverse taxa. Although
it is known that most within‐sex alternative reproductive tactics arise as a consequence …

Polygyny is regarded as a beneficial strategy for males, whereas females mated with polygynous
males (males simultaneously paired to more than one female) often suffer a reduction …

Sexual selection arising from sperm competition has driven the evolution of immense variation
in ejaculate allocation and sperm characteristics not only among species, but also among …