Nongenetic selection and nongenetic inheritance

摘要

According to the received view of evolution, only genes are inherited. From this view it follows that only genetically-caused phenotypic variation is selectable and, thereby, that all selection is at bottom genetic selection. This paper argues that the received view is wrong. In many species, there are intergenerationally-stable phenotypic differences due to environmental differences. Natural selection can act on these nongenetically-caused phenotypic differences in the same way it acts on genetically-caused phenotypic differences. Some selection is at bottom nongenetic selection. The argument against the received view involves a reformulation of the concepts of inheritance and heritability. Inherited factors are all those developmental factors responsible for parent-offspring similarity; some inherited factors are genetic and some are not. Heritable variation is intergenerationally-stable phenotypic variation; some such variation is genetically-caused and some is not.