 Scott Gilbert’s Developmental Biology exhibits a similar pattern (Gilbert 2000 [2003, 2006, 2010]). Developmental biology is constituted by two broad questions (“How does the fertilized egg give rise to the adult body? And how does that adult body produce yet another body?”), which can then be subdivided into further categories, such as differentiation, morphogenesis, growth, reproduction, regeneration, evolution, and environmental regulation. These questions can be parsed more analytically in terms of five variables: abstraction, variety, connectivity, temporality, and spatial composition. The values given to these variables structure the constellation of research questions within the broad problem agendas corresponding to generally delineated processes. For example, research questions oriented around events in zebrafish gastrulation are structured in a way that differs from the research questions oriented around vertebrate neural crest cell migration because they involve different values for the five variables: abstraction (zebrafish vs. vertebrates), temporality (earlier vs. later), spatial composition (tissue layer interactions vs. a distinctive population of cells), variety (epiboly vs. epithelium to mesenchyme transition), and connectivity (gut formation and endoderm vs. organogenesis and ectoderm/mesoderm). These configurations can be adjusted readily in response to shifts in the values for different variables (Love  2014).[7]