Fluctuating selection and dynamic adaptive landscapes

One of the central assumptions in Wright's original conception of the adaptive landscape, was that fitness remained constant through time. Decades of study have since shown that this assumption is invalid. This chapter explores how spatial and temporal variability in selection lead to dynamic shifts in adaptive landscapes. After considering a number of empirical examples of variable selection, it concludes that traits that are particularly important in biotic interactions are more likely to result in shifting landscapes. As such the chapter considers the various roles of frequency- and density dependence, sexual selection, predation, competition, phenotypic plasticity, and genetic polymorphism in affecting the strength and forms of selection. The review here supports a view of adaptive landscapes as highly dynamic and fluctuating