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Surprisingly few examples of rapid evolutionary change in behavioral traits have been documented in nature, yet circumstances favoring rapid evolution in other traits apply equally well to behaviour, including animal signals. This chapter considers the role of signals in rapid evolution and the way behavior influences evolutionary change. Because communication involves interactions between individuals, changes in signal structure or production must be accompanied by change in the receiver, which means that behaviour itself can constrain evolution. Alternatively, behaviour may facilitate contemporary evolution. The chapter reviews the literature as well as work presented in this chapter with a field cricket in which pre-existing behavioural plasticity apparently facilitated spread of a mutation that silences males, simultaneously eliminating their sexual signal and protecting them from a parasitoid.

This chapter outlines three basic ways in which humans can alter evolution on adaptive landscapes: through changes in topography, changes in dimensionality, and phenotypic excursions. Changes in topography involve the numbers, positions, gradients, and elevations of surface features on the landscape, such as peaks and valleys. Changes in dimensionality involve the number of at least partially independent traits under selection. Excursions typically involve more or less abrupt changes in the phenotypic position of populations on existing adaptive landscapes, such as through plasticity, hybridization, or genetic manipulation. These different types of change can generate predictions for changes in selection and alterations in evolution — assuming the population can persist through the disturbance. Invasive species can have all of these classes of effects, either for the invasive species or for native species. Climate change will most obviously involve a shift in peak position, such as breeding times under warmer temperatures. Hunting/harvesting will also often involve a shift in peak position, particularly toward smaller and slower growing individuals, and might also decrease phenotypic variance. Habitat loss and fragmentation will influence numbers and positions of adaptive peaks, and can also influence excursions by altering patterns of gene flow in meta-populations. Finally, a decrease in habitat quality can decrease the heights of fitness peaks and cause adaptive landscapes to become smoother. It can also change dimensionality, such as through the introduction of a new contaminant. In conclusion, viewing human-induced environmental change in the framework of changes to adaptive landscapes offers new insights and new perspectives for research.

Understanding the evolutionary responses of birds to urbanization has lagged behind understanding ecological responses. I provide a conceptual framework for understanding evolutionary processes in urban environments and distill key features of birds that enable them to evolve with the novel features of urban environments. Contemporary evolution of cultural and genetic traits is well documented in urban environments. Furthermore, because of the close association between people and birds in urban environments, coevolutionary relationships are possible. These may involve genetic and cultural traits. For example, humans and corvids appear to be culturally coevolving in American, European, and Asian cities. Showing the public that evolution occurs in their backyards may provide a unique way to engage them in science.

This chapter evaluates various methods for inferring how phenotypes/genotypes influence population dynamics, including extensions of the year-by-year tracking approach used in analyzing the eco-to-evo side of eco-evolutionary dynamics. It provides a detailed outline of the various possibilities, including complexities that move beyond population dynamics. The chapter examines how maladaptation resulting from environmental change might decrease individual fitness and contribute to population declines, range contractions, and extirpations. It considers the extent to which contemporary evolution helps to recover individual fitness and population size, which might then make the difference between persistence versus extirpation and range expansion versus contraction. A final analysis asks how phenotypic variation within populations and species influences population dynamics.

This chapter explores the role of animal behaviour as a critical link between human activity and ecosystem processes. It explores the impacts of behavioural trait changes on ecosystems, and describes how these effects are often the result of changes in traits related to consumption and nutrient cycling. It enumerates two mechanisms of rapid behavioural trait change that shape ecosystem processes: phenotypic plasticity and contemporary evolution, and considers their effects. It proposes a framework to integrate the ecosystem effects of plasticity and evolution using a reaction norm approach to parse the contributions of plasticity, evolution, and the evolution of plasticity to ecosystem change. It also suggests using the framework to predict the effects of human-driven trait change on ecosystems.

As habitats vary, selection for migration varies in intensity and pattern across space and time, with the result that migratory life-history syndromes and the routes and connectivity between regions also vary. The variation may occur among and within species, and there may be major life history differences between migrants, non-migrants, and partial migrants. Examples include more vigorous activity among cane toads on an invasion front and muscle histolysis following flight to promote reproduction in insects. Variation in routes followed may occur within populations at different seasons or in the overall pattern between populations, as is the case when leapfrogging occurs. Migratory variation in distance traveled can influence reproductive traits such as clutch size in birds. Partial migration has been the subject of theoretical analysis including evolutionarily stable strategy (ESS) models. Depending on conditions, degrees of trade-off occur among migration strategies. The action of natural selection on migration has resulted in both long-term evolution and evolution in contemporary time.