Genevieve von Petzinger: Why are these 32 symbols found in ancient caves all over Europe?

Genevieve von Petzinger is studying the evolution of writing by looking at cave paintings.  Before her, most researchers focused on animals in cave paintings even though most cave paintings included geometric figures.  She spent hundreds of hours crawling through caves to find these paintings, document them, and categorize them.  She found that there were only 32 different geometric symbols used across the cave paintings of Europe, indicating that they had come from a common origin and were being used intentionally rather than being used randomly.