The time at which we humans began to produce art marks an important step in our evolution. Art represents the use of symbolic communication. Symbolic communication in turn indicates a significant change in the way we think. Other markers for this change in our brains include language, music, dance, and religion. Anatomically modern humans (Homo Sapiens) did not always exhibit these traits, thus we may infer they lacked the underlying neurobiology to support them. Our current way of interpreting and interacting with the world is something that happened on the fly as our brains changed, perhaps even suddently.
This new issue of Science contains an article describing the discovery at Blombos Cave in South Africa of tools and supplies for making red ochre, one of the oldest pigments used for cave art and body painting. Human art has been found in caves as much as 30,000 years old, but what makes this discovery important is that archaeologists date the Blombos find to 100,000 years old. Blombos suggests we have been fully human three times longer than previously thought.
Here's the citation:
Henshilwood, C.S., F. d’Errico, K.L. van Niekerk, Y. Coquinot, Z. Jacobs, S.-E. Lauritzen, M. Menu and R. García-Moreno. 2011. A 100,000-year-old ochre-processing workshop at Blombos Cave, South Africa. Science 334:219-222.
On a very cool related note: In the Rouffignac cave system in France archeologists have found evidence that some 13,000 year old finger flutes - parallel lines drawn on soft cave walls with ones fingers - were drawn by children of both genders, some as young as toddlers. What's more the lines were too straight for kids to have done themselves suggesting adults guided their efforts. Some markings were too high for children to have reached; they would have been lifted to let them make their mark. Cave art is thought to have held tremendous religious significance so the idea that children were taught to cave paint by caring adults has something interesting to say about paleolithic society.