In The Storyteller by Llosa, why is keeping a culture pure beneficial for the tribes, and how did it become polluted?
This story describes the history of the Machiguengas and in particular it charts their movment from being a culture that exists in diaspora to being a culture that has its very identity as an itinerant group of people stripped from it by rampant Western development. Whilst the culture existed in diaspora, it became essential to find some way of maintaining a distinct cultural identity that separated them from other tribes and cultures and allowed them to carry on existing as a distinct group. This was why the storyteller was such an important person in Machiguenga society: it was his job to maintain the cultural purity of the Machiguengas, which given how dispersed they were, allowed them to survive. Note how the narrator describes the function of the storytellers, who:
...using the simplest, most time-hallowed of expedients, the telling of stories, were the living sap that circulated and made the Machiguengas into a society, a people of interconnected and interdependent beings.
The metaphor describing the storytellers as "the living sap" of the Machiguenga culture is particularly telling as it highlights their importance in maintaining cultural purity. However, as the story develops, the impact of development and Westernisation on the machiguengas is clear, and they begin to lose their distinctiveness and their culture, which is so closely bound in their identity as a diaspora people. With the impact of the oil trade, terrorism and drugs, the story predicts a sad future for the Machiguengas, and one where their cultural purity has become sullied and tainted, to the loss of both them and the world as a whole.