Abstract
The existence of so great a diversity of species on Earth remainsa mystery, the solution to which may also explain why and how biodiversityinfluences the functioning of ecosystems. The answer may lie in quantifyingthe trade-offs that organisms face in dealing with the constraints of theirenvironment. Societal responses to the loss of biodiversity also involve trade-offs,and the elaboration of these will be essential in developing wiser environmentalethics and policy.