The adaptive potential of material stress

Background/Question/Methods

Biomedical researchers have long appreciated that maternal stressors can induce preparative and adaptive programming in offspring via exposure to maternally-derived stress, namely maternaly-derived Glucocorticoids (GCs). However, few ecologists are aware of the capacity for maternal GC exposure to translate ecological and environmental stressors into preparative and adaptive programmed offspring responses in free-living systems. We will review an emerging body of experimental field work indicating that circulating maternal GCs link ecological stressors to adaptive offspring plasticity. We attempt to emphasize that natural and human-induced ecological stressors can play a fundamental role in altering the capacity of individuals and therefore populations to respond to both predictable and unpredictable ecological change via translating maternal adversity into responsive phenotypic plasticity in a number of vertebrate models.

Results/Conclusions

Results from a number of free-living vertebrate systems reveals that although maternally-derived stress induces seemingly negative investment trade-offs in offspring, these phenotypic adjustments can be adaptive if they better match the offspring to future environments; however, responses can indeed prove maladaptive if they unreliably predict (i.e., are mismatched to) future environments. Furthermore, these same stress-induced adjustments that may indeed prove maladaptive for individual offspring can actually provide adaptive benefits to mothers by reducing current reproductive investment and benefitting lifetime reproductive success. Overall, our reccomendation to ecologists is that to properly determine the adaptive potential of maternally-derived stress, researchers must take a broader integrated life-history perspective, appreciate immediate and longer term environmental context of the stress, and examine lifetime offspring and maternal fitness.