subcategory of Developmental Modularity consists of papers that engage with the
study of development as consisting of discrete units (modules) and the extent
to which these modules are integrated (see Developmental Systems Theory for a contrasting
position). The specific developmental phenomena that are studied include heterochrony
and allometry, duplication and divergence of modules (as seen in segmentation),
and the co-option of modules (often called exaptation).
The unifying philosophical theme is ontological; the landscape consists
of differing views on how a
developing organism is divided into functional or structural subunits. The internal
disagreements are over what the basic units are, and how they are identified
and organized. However, all papers in
this section examine the extent to which an organism’s development can be explained
in terms of interactions between (reasonably) autonomous morphogenetic (developmental) modules.