Developmental Mechanisms
Developmental biologists investigate both molecular genetic mechanisms and cellular-physical mechanisms. Although these two types of mechanism can be interpreted within the framework of standard philosophical discussions, they also raise distinct issues. One is the conservation or stable identity of molecular genetic mechanisms across phylogenetically disparate taxa alongside the non-conservation of cellular-physical mechanisms. Another is the explanatory generality of molecular genetic mechanisms compared with the explanatory completeness obtained by integrating these with cellular-physical mechanisms to comprehend complex interactions and morphological outcomes of ontogeny. An investigation of the former yields an analysis of conserved molecular genetic mechanisms as a special type of homology claim that licenses much of model organism research. An examination of the latter exposes a fault line between generality and completeness as distinct standards that operate in developmental biological explanations, as well as providing new resources for integrating different types of mechanisms in scientific inquiry.