Cultures are shaped by their physical environment. Mythologies reflect the cultures that give them birth. Cultures that are widely seperated in space but share similar physical environments (e.g. the people of the Amazon, the tribes of the Equatorial African jungles, or the clans of the jungle areas of South East Asia) should in theory have the same sort of mythologies? The reason I ask the question is because I've recently been reading on of the books of Joseph Campbell, who was well known for his research on myth, and it set me thinking about the problem.