Do Genes Code for Traits?

Abstract

The orthodox view in evolutionary biology is that genes code for phenotypic traits. Thus an organism’s genotype is standardly characterised as coding for that organism’s phenotype. A code is a species of representation; so, on the received view, genes can be said to represent traits, and genotypes to represent phenotypes. This theory of genetic activity does not imply that genes somehow act alone to produce phenotypic traits. Every biologist knows that development is a complex and distributed process, involving a vast array of causal factors, many of which are located in the wider metabolic and environmental contexts within which genes make their contributions (much more on this below). However, two crucial features of the standard approach in biology are (i) that genes are understood as doing something special in development, and (ii) that the concept of coding helps us to understand what that “something special” is. Thus any adequate account of genetic coding must have the consequence that, of the many causal factors which combine causally during development to produce a fully grown organism, it is the genetic factors alone which end up counting as being representational in character.