a response to MarkSWerner We may only speculate about the earliest proto-man's inclinations; we know from discovered relics that they were hunters and possibly fishers. However, I will submit that (even though this time was prehistoric) vanity could not have been a motivator. Any record of a particularly grueling hunt (of any sort of dangerous other predator) would have most likely been depicting a number of hunters in a life-threatening situation. There may have been (in a crudely analogous expression) an heroic individual at some particular moment (similar to the game-saving catch or a game-saving sack); the hunt would have been the all to capture.
Theatre vs. Visual Art While there are some instances of graphic expression from prehistory, one other thing to keep in mind is that a tribal or cultural history would have been passed down more by fireside filibusters by the individual with the best (or perhaps most expressive) memory, rather than by visual depiction. The bulk of graphic expression that is extant is that of larger civilizations which had governments with the resources and the power to chisel a record of their wills in stone; even if prehistoric individuals wished to, their ability for visual records was limited to resources at hand.
Histories of smaller social groups, if they existed at all, were most likely handed down by word of mouth. And there were people, no doubt, who were gifted, perhaps not has hunters, or even fishers, but as memorizers of the words of their elders. They were the first historians, the first storytellers, the first thespians. I can well imagine that, after the sun went away, and the day's food had been cooked and consumed, that the group's members were sitting, sated by food and warmth, to listen to someone relate a segment of that group's past, embellished by dance and gesture, depicting some significant event of that group.
Yes, these are total imaginings of some possible event of some theoretical cluster of comrades; but the progression of historical thought, at some level, had to be by word rather than graphic depiction, given where many of these groups lived in earliest proto-human time. Graphic art, if it existed, most likely would have been rendered on bark using prey blood; those people would not necessarily have rendered their images on exposed rock - they would have learned that rain and snow and sun would obliterate any images on exposed surfaces. Those pieces of bark might have lasted two or three generations as talismans, to be replaced by other bark talismans. Only graphic arts which could be concealed from the elements would endure past a handful of generations. Sounds and words (intonations, to use Artaud's word) would have been the most permanent (in the fixed sense) and the most dramatic (in the mutable sense) expression and containment of a clan's past and individuality.