Abstract: Biology and ethnology interact and impel one another.Ethnology,which introduces evolutionism from biology,is not complete.Two concepts,cultural selection and cultural selection divergence,are to be introduced besides natural selection and artificial selection to realize the theoretical compatibility of biology and anthropology,and meet the demand of theoretical analysis of ethnology.Only in this way can cultural cause of ecological disaster that ethnology is faced be understood.

Key words: cultural selection, natural selection, cultural selection divergence