Segments and Body Regions

Abstract

AbstractThere are limits to the current understanding of arthropod segment formation, in large part linked with the superabundance of information from one particular model system, that of Drosophila, and a paucity of work on other arthropods. Segmentation exhibits multiple levels of genetic control. Various types of genes that control segment formation have been identified. Conceptual models or evolutionary scenarios have tried to make sense of this critical process: the naupliar/post-naupliar/merosegmental model, the arthropod pattern theory, the tagmosis model, and the idiosyncratic periodic table of articulata. These models are not hypotheses suitable for testing; rather, they form scenarios (stories) of evolution. None of these processes are effective toward generating explanatory scenarios, so the focus on producing testable hypotheses will continue.