Function, Homology, and Character Individuation

Many philosophers believe that 1) most uses of functional language in biology make implicit reference to natural selection and 2) the fundamental way in which biologists identify parts and processes in organisms is by their selected function(s). Both these claims are mistaken. Much functional language in biology refers to actual causal roles. The extensive biological literature on the ‘character concept’ focuses on another principle of biological identity, namely homology. This work is outlined and used to refute philosophical arguments for the importance and ubiquity of classification by adaptive function.