I wouldn't mind faking some Rock Art, if I had the time, but, until then, here's a link to some theory about the art instinct and human development ( http://www.guardian.co.uk/books/2009/mar/08/art-instinct-brian-morton-review ). It seems as though art has survived because it has an evolutionary purpose - not mapping herds of mammoth but making the artist more attractive to a potential mate. (!)