Patterns and Strength of Selection in Wild Fish Populations

Selection is the engine of adaptive evolutionary change. Over the past three decades, there has been an explosion of studies using multiple regressions of fitness components on traits to estimate selection in wild populations. Recent syntheses of the resulting partial regression (i.e., selection) coefficients have been used to examine the strength of selection in the wild (Kingsolver et al. 2001 Am Nat, range of taxa), the temporal dynamics of selection (Siepielski et al. 2009 Ecol Lett, range of taxa), and selection on size of juvenile fishes (Perez and Munch 2010 Evolution). Using data from these syntheses, I will review what we do and do not know about selection acting on wild fish populations. This will include a summary of the published data with regard to fish families that are represented, life history (e.g., semelparous vs. iteroparous), life stage, trait type (e.g. morphological vs. behavioural vs. life history vs. physiological), and whether the focal species is principally a freshwater resident, marine resident, estuarine, or diadromous. I will then provide an overview of the strength, direction, and form of selection acting on wild fishes, including a focus on the temporal dynamics of selection for studies including temporal-replicates. Finally, I will discuss how these patterns might differ in harvested populations.