| Abstract: | To explain the menstrual cycle and menopause, human biologists during the past several decades have developed new models of the evolutionary origins and maintenance of female reproductive patterns that address both ultimate and proximate causation. Hypotheses proposed for these processes generally offer explanations for menstruation or for menopause, but not for both; ultimately, these explanations must be integrated. Reviewing current explanations, this paper offers an energetics-based evolutionary rationale compatible with past adaptations of Homo sapiens and with ecological patterns in small-scale, preindustrial social systems in which food resources vary and sometimes are scarce. This paper is an expansion of a poster paper presented at the 2002 Human Biology Association meetings in Buffalo, New York. Roberta L. Hall is professor of anthropology at Oregon State University. Her main interest is in evolutionary aspects of human biological variation. Current research involves body composition relationships with resting metabolic rate in males and females and climatic adaptions of nasal morphology. She also enjoys working with the Coquille Indian Tribe of southern Oregon on research concerning their prehistory and is studying ramifications of the coastal hypothesis of North American settlement. |
