The hypothesis that ornaments can honestly signal quality only if their expression is
condition-dependent has dominated the study of the evolution and function of colour traits …

We review and discuss the importance of correlational selection (selection for optimal
character combinations) in natural populations. If two or more traits subject to multivariate …

Recent interest has focused on immune response in an evolutionary context, with particular
attention to disease resistance as a life-history trait, subject to trade-offs against other traits …

The immunocompetence handicap hypothesis (ICHH) of Folstad and Karter has inspired a
large number of studies that have tried to understand the causal basis of parasite–mediated …

Polymorphic species, in which multiple variants coexist within a population, are often used
as model systems in evolutionary biology. Recent research has been dominated by the …

Summary 1 Phenotypic plasticity may allow an organism to respond to temporally variable
opportunities for growth and risks of mortality. However, life‐history theory assumes that …

A central tenet of life‐history theory is that investment in reproduction compromises survival.
However, the underlying physiological mechanisms that link reproduction to survival are …

Rapid evolutionary change over a few generations has been documented in natural
populations. Such changes are observed as organisms invade new environments, and they …

Individual animals from the same population, sex, age and reproductive status often respond
differently and consistently to predators. One important dimension of this behavioural …

Activity budgets influence the expression of life history traits as well as population dynamics.
For ectotherms, a major constraint on activity is environmental temperature. Nonetheless, we …