In our concern about the pollution of the biosphere we are overlooking what may be, in human terms, an even more serious problem. Man has a more indirect relation to nature than most other animals because his environmental tie is normally mediated by a cultural system. Since human adaptation has been largely cultural rather than biological, human sub-species are rather the product of shifts in learned culture patterns than in genetically inherited traits. It is the flexibility of these culture patterns- composed of technique, social organization, and communication- that has enabled the human species to flourish in every zone of the planet.

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