I propose that art provides humans with an evolutionary advantage by allowing them to externalize and collectivize both the memory of the past as well as enabling us to plan for the future.
Individuals perish, and with them their memories. If, however, the individual experience is externalized and codified in art, the collective organism retains the information even though the individual expires. Language is communication in the present. Art is communication over time. When writing was invented, about 3,000 BC, symbolic language and art merged.
Even more significant than retaining the past, art concerns itself with the future. I propose that art is the next step in human cerebral evolution beyond Rapid Eye Movement (REM) dreaming in that it takes advantage of language in a way that dreams do not (I will discuss this at length below). Because it is an external (i.e., it takes place outside of the brain), collective event, art is not dependent upon the processing abilities of a single individual. It "networks" a large number of brains to address alternate future realities, thereby preparing the collective as well as the individual for events that have not yet occurred. Art is practice for the real thing.
Why Art? or, Solving the Big Head Problem" was published in abbreviated form in Communication Arts Magazine, January/February, 1996 (pages 24 - 29)
David Lance Goines