ABSTRACT
The search for an explanation for variation in brain size has been a long one, fascinating philosophers and scientists alike (see Gould 1981 for review). Collaborations betzveen evolutionary biologists, ethologists and neuroscientists are beginning to provide exciting new insights into hozo and why such variation may have come about. This chapter reviezos the latest of these advances as well as providing an introduction to some of the methods, familiar to evolutionary biologists, that have made a major contribution to this progress. The chapter attempts to demonstrate the way in which behavior and its neural substrates are closely related and the fundamental role that natural selection has played in the evolution of the avian brain.
