Your article on the importance to an elephant family of having as its leader a matriarch of considerable age reminded me of the postulation that one of the reasons menopause evolved in humans was to allow some women to survive to old age. In preliterate societies, old people were the libraries. Some of the knowledge they accumulated might even have been needed for the tribe to survive in the kind of total disaster that occurs only once or twice in a lifetime. Nancy Axford
Sacramento, Calif.

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