ABSTRACT
Those who regard play as frivolous and without function will doubtless be incredulous to be told that playful play had a role in the evolution of cognition, particularly in mammals and birds. Most animals are active and, in principle, their behavior can impact on the evolution of their descendants. Charles Darwin (1871) suggested such a role with his ideas about the evolutionary process of sexual selection. His co-discoverer of the principle of natural selection, Alfred Russel Wallace, never liked Darwin’s proposal for sexual selection and, for a large part of the 20th century, little empirical work was done on how individuals’ choices could affect evolution. Sexual selection was not thought to be an important component of evolutionary processes. Nowadays more than a thousand papers on the process are published each year. The role of adaptability, which had its origins in a paper by Douglas Spalding (1873), was once again dismissed as relatively unimportant until recently, when interest in plasticity during development took firm root (West-Eberhard 2003; Bateson 2015). Though its origins were much later, Richard Lewontin’s (1983) ideas about niche construction have similarly excited a growing amount of attention (Laland et al. 2014). One aspect of the way in which animals’ activities might affect evolution is through their play. This chapter considers how this process might have come about.
