Dr. Lynne Isbell's snake detection theory suggests that predation by snakes contributed to the evolution of our early hominid ancestor’s visual system, endowing us with forward-facing eyes and enlarged visual centers deep in our brains that are specialized for picking out specific features in the world around us, such as the general shape of a snake's body camouflaged among leaves. Predation by snakes may also have led to the evolution of human language by learning to point at snakes, a form of directed social attention and gestural language.

Snake Detection Theory was a tongue-in-cheek attempt to help monkeys to evolve by teaching them to point at snakes.The site-responsive intervention, carried out during a residency at the Tiputini Research Station in the Ecuadorian Amazon, consists of me demonstrating the nuances of pointing to howler monkeys in an enormous fig tree, using a range of "tools" and "signs": prosthetic hands, photographic aids, and popular cinema.