Complexity, Evolvability, and the Process of Adaptation

There is a widespread view that the process of adaptation in complex systems is made difficult due to an evolutionary cost of complexity that is reflected in lower evolvability. This line of reasoning suggests that organisms must have special properties to overcome this cost, such as integration, modularity, and robustness, and that the reduction in the rate of evolution and variational constraints could help explain why organisms might not respond to selection. Here, we discuss the issues that arise from this conviction and highlight an alternative view where complexity represents an opportunity by increasing the evolutionary potential of a population. We highlight the lack of evidence supporting the influence of complexity on evolvability. Empirical data on the patterns of contemporary selection are critical for understanding this relationship. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 53 is November 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.