chapter  4
Pages 44

Darwin’s admonition seems to be no less applicable to assessing the prospects of modern civilization than it was to tracing the past development of the biosphere: life’s adaptation to environmental changes continues to be seen as the very essence of evolution. Adaptive processes do one of two things: they either improve an organism’s fit with its environment, or they improve the efficiency or responsiveness (or both) of its internal functions. In plants and animals they are realized through natural selection and mutation, as well as through correlational selection and aggregation of two or more traits (Endler and McLellan 1988). These processes require usually very long periods of time and their effects are far beyond the changes achievable by human societies within just one to two generations considered in this assessment.