Evolutionary consequences of predation: Avoidance, escape, reproduction, and diversification

Abstract

One of the most important and obvious forces shaping organismal traits is predation. Prey have evolved diverse means of enhancing the probability of survival in the face of predation, and these means fall into two classes of antipredator strategies: (1) avoidance of predatory encounters, and (2) escaping after encountering a predator. A range of antipredator defenses-including behavioral, morphological, physiological, and chemical defenses-serve to either reduce the probability of detection by a predator or enhance the probability of surviving after detection by a predator. However, the recognition that reproductive strategies (e.g. offspring number, reproductive lifespan) are typically strongly influenced by mortality regimes induced by predators, highlights that most but not all antipredator traits fall into one of these two categories-that is, some life history traits influence only fecundity, not survival. Life history evolution has not traditionally been included in reviews of antipredator adaptations, however this chapter reveals that the conceptual link between life histories and predation broadens and refines our understanding of predation's role in phenotype evolution. While ecologists have long recognized the importance of predation in population- and community-level dynamics, a varied history exists for the study of predation's role in influencing evolutionary change. Despite the wealth of antipredator adaptations present in organisms, research investigating the significance of predation in biological evolution has received considerably less attention than other ecological factors (e.g. competition, mate attraction). However, predation can generate divergent selection among prey populations in several different ways, and is predicted to represent a major source of evolutionary change. Recent empirical work supports this claim. This chapter reviews the varied forms of evolutionary strategies prey have evolved to mitigate malicious attempts of natural predators, and the potential importance of predators in driving phenotypic divergence and speciation. © 2007 Springer-Verlag Berlin Heidelberg.