Alternation between day and night is a predictable environmental fluctuation that organisms
use to time their activities. Since the invention of artificial lighting, this predictability has been …

Responding appropriately to changing conditions is crucial in dynamic environments.
Individual variation in the flexibility of physiological mediators of phenotype may influence …

Trade-offs and constraints are inherent to life, and studies of these phenomena play a
central role in both organismal and evolutionary biology. Trade-offs can be defined …

Fluctuations in abiotic and biotic conditions exist in almost all habitats (Dunlap, Loros, &
DeCoursey, 2004; Stevenson et al., 2015). Some fluctuations like the alternation between …

Glucocorticoids are highly conserved hormones that mediate a suite of responses to
changing conditions in vertebrates. Recent work has focused on understanding how …

Consistent individual differences in hormone levels and metabolic rates have been
proposed to be potential state variables underlying consistent individual differences in …

Glucocorticoid hormones are important regulators of metabolic processes, and of the
behavioral and physiological responses to stressors. Within-population variation in …

It has been well-established that there is variation in the strength and direction of the
relationship between circulating glucocorticoids (GCs) and fitness. When studies …

Humans present a behavioural paradox: they are peaceful in many circumstances, but they
are also violent and kill conspecifics at high rates. We describe a social evolutionary theory …

Males and females commonly differ in their life history optima and, consequently, in the
optimal expression of life history, behavioral and physiological traits involved in pace-of-life …