Linking individual fitness to the evolution of cognition.

It is well supported that the present diversity of animal cognitive abilities is the result of evolutionary processes, driven at least in part by natural selection. However, the evolutionary dynamics that link individual traits to fitness to macroevolutionary patterns of variation in cognition are much less clear. Is cognitive evolution fast or slow? Does selection tend to act on existing genetic variation or is adaptive cognitive evolution mutation limited? Is there a consistent pattern to the mode and tempo of cognitive evolution across groups or does it vary depending on different social and ecological pressures? Answering these questions will allow us to understand the connections between heritable variation in cognition in extant populations and the divergence in cognitive abilities across species. We review what is currently known about cognition and individual variation in fitness and discuss how fitness observed in current populations may be linked with patterns of natural selection. We provide a brief overview of relevant concepts from the population genomics literature and suggest a research agenda that integrates behavioural ecological approaches with comparative and population genomics data to uncover the patterns of cognition evolution.This article is part of the Theo Murphy meeting issue 'Selection shapes diverse animal minds'.