The questions, to which you need to write 2,500 words worth of answers to one of are:
- How has demographic increase affected the development of human societies?
- In the archaeological record, what has happened when cultures have met?
So its not immediately obvious why reading several pages and online articles discussing rock art will help you much with either of these.
I think I'm going to pick the 2nd of the two, as TMA-3 has already given a few examples to consider. The Human Past, for all its size, is quite light in details on some of the civilisations that might be considered. It has very little on the Persians, and not a great deal more on the Inca.