ABSTRACT
The relation of economics to the biological sciences can be described as that of “second cousins, twice removed” in the extended family of the sciences. In economics the theory of the organism, or economic behavior, has two major divisions: the theory of the firm and the theory of the household. Biological ecosystems tend to be more cyclical than social ecosystems. In biology, nitrogen goes round and round, financing protein on the way. Economic processes are much more linear, going from mines and wells to commodities, garbage, and dumps. The economic concept of production, or a production function, also has counterparts in the biosphere. Every organism has inputs and outputs, and the relations of these to one another provide essential parameters for the ecosystem. A biological population with sexual reproduction cannot come down to one member, or even to a population consisting all of one sex, without dying out very rapidly.
