Cultural practices seem to have been mostly shared within geographical zones. However, unrelated peoples might adopt similar technologies and social organizations. An example of such a cultural area could be Mesoamerica, where millennia of coexistence and shared development between the peoples of the region produced a fairly homogeneous culture with complex agricultural and social patterns. Another well-known example could be the North American plains area where, until the 19th century, several different peoples shared traits of nomadic hunter-gatherers primarily based on buffalo hunting. Within the Americas, dozens of larger and hundreds of smaller culture areas can be identified.