The Art of our Ancestors.

"Our ancestors must have also grown of just pointing and getting excited looks on their faces. They wanted to communicate in more specific ways. So next in the process was the drawing of pictures. Whether people had great artistic talent or not, the learned that they could send a precise message with a more precise meaning by sketching drawings on the ground or on the cave walls." - Taken from Positive Words, Powerful Results by Hal Urban.
OK so as usual I was reading a book for my power of words class, and I was excited to come across this sentence. All this time we were talking about art being a medium in which emotions are communicated, however the sentences above say otherwise. In the book it talks about the origin of language and that the first type of language that there was, was body language. Before verbal language our ancestors use to point and grunt at things. They use to get their messages across with facial expression and gestures. As time went on,however, they realized that things could be more sufficient by drawing. Art started so far back, however, it seems that we don't give the art our ancestors much credit and I don't know if we should. Art to them was more than sacred it was the easiest and most meaningful way to get across information. Today critics treat art as a physical thing, however to our ancestors it was a vital way of life. It was the factor between life and death, between getting food and starving etc. I saw that we shouldn't give ancestral art credit just because of the way we treat art today. We pick at it trying to decipher it not accepting it for what it is; unlike our ancestors who accepted it for what it was, a communication tool. Art is a big part of why we have language today, however we don't understand that. We don't look at road signs as a particular kind of art just because of the theories out there, however they would be considered art to our ancestors. They created art, the Egyptians expanded on it and then words and vocabulary was created. Why can't we look at art the way our ancestors looked at it as a communication device (not only emotional communication, but communication of ideas)? Why must we impose these requirements for art? Why can't anything that communicate an idea be considered art?