One of the papers I graded this semester was on the evolutionary psychology view of music. We talked about this subject in class, reading articles by David Huron and Donald Hodges. As I've thought about it more, spurred by reading the student's paper and attending a session at the Neurosciences and Music II conference, I've realized a major problem with the application of evolutionary psychology (one that most people probably already thought up). Evolution is about physical adaptations, traits that are passed from one generation to the next. These adaptations can include changes to the brain, which will affect the behavior of the particular species. But so much of evolutionary psychology is looking only at behavior, not at physical changes. In asking the question of why humans evolved to enjoy and make music, many studies focus only on the behavior, and don't distinguish between behaviors caused by physical attributes and behaviors caused by social attributes. A culture can pass along behavioral responses from one generation to the next through education and social pressure, just as much as by the formation of the brain or the sense organs.
Some more recent studies have looked at brain scans and brain physiology, comparing humans with other species and mapping these comparisons to behavioral trends. While seals are hardwired to vocalize in efforts to attract a mate, it has been shown that the actual sounds that are made are learned. (Even if the learned Mainer accent didn't help with the ladies...) Other studies on primates, birds, and rats have attempted to clarify which musical behaviors are solely human, and thus possibly an evolutionary adaptation. But defining whether a bobo's drumming is musical behavior can be difficult, if not impossible given the current definitions of music.
I still don't know what to think about music as an adaptation. Are there studies on the evolutionary aspects of other arts, such as painting or poetry? I know there is plenty on the evolution of language, as that is often cited in the music studies.