From the Past to the Future: Considering the Value and Limits of Evolutionary Prediction.

The complex interplay of the multiple genetic processes of evolution and the ecological contexts in which they proceed frustrates detailed identification of many of the states of populations, both past and future, that may be of interest. Prediction of rates of adaptation, in the sense of change in mean fitness, into the future would, however, valuably inform expectations for persistence of populations, especially in our era of rapid environmental change. Heavy investment in genomics and other molecular tools has fueled belief that those approaches can effectively predict adaptation into the future. I contest this view. Genome scans display the genomic footprints of the effects of natural selection and the other evolutionary processes over past generations, but it remains problematic to predict future change in mean fitness via genomic approaches. Here, I advocate for a direct approach to prediction of rates of ongoing adaptation. Following an overview of relevant quantitative genetic approaches, I outline the promise of the fundamental theorem of natural selection for the study of the adaptive process. Empirical implementation of this concept can productively guide efforts both to deepen scientific insight into the process of adaptation and to inform measures for conserving the biota in the face of rapid environmental change.