Microevolutionary Response to Climatic Change

Abstract

Publisher Summary This chapter reviews recent empirical work that has investigated micro-evolutionary response to climate change and discusses potentials and shortcomings of different approaches. In particular, it focuses on the evolutionary response of avian migratory behavior. Birds may very rapidly respond to changing environmental conditions imposed by global climatic change. Although fossil records in other taxa suggest that the most likely response to climatic change is range shift rather than adaptive evolution, the validity of this inference for the current evolutionary response is questionable. Adaptability to temperature changes is likely to have evolved by correlational selection, as a result of environmental fluctuation during the evolutionary history of many bird populations. High levels of genetic variation, favorable genetic correlations, cogradient variation and adaptive plasticity may allow rapid responses to current environmental changes. Moreover, unidirectional gene flow from populations or species better adapted to warmer environmental conditions may further accelerate adaptive evolution. If climate change persists and is accompanied by an increase of climatic variability, then the rate of evolutionary change may be much lower than found in studies on single selection events because of oscillating selection and the erosion of genetic variation. In addition, environmental variation may not be buffered by phenotypic plasticity, or may become maladaptive, which may further accelerate the erosion of genetic variation.