The evolution of arthropod nervous systems: Insights from neural development in the Onychophora and Myriapoda

Abstract

The phylogenetic positions of the Onychophora and Myriapoda are pivotal for those interested in the evolution of arthropod nervous systems: studies of neural development in these groups are likely to shed light on the ground plan for basal arthropods. This article reviews our current understanding of mechanisms for neurogenesis and the establishment of early axon pathways in the central nervous system (CNS) of Onychophora and Myriapoda. While our knowledge is limited for the Onychophora, neural development in this group shows few features in common with any of the extant arthropods. Features previously thought to be synapomorphies for the Onychophora and Myriapoda (e.g., ventral organs, spli..