OSTRACODA IN EVOLUTIONARY STUDIES OF LIGHT AND VISION: MOLECULAR AND PHYLOGENETIC PERSPECTIVES

Evolutionists often use phylogeny to examine independent evolutionary events in search of generality. Therefore, groups of organisms rich in such independent character transitions are particularly valuable for the study of evolution. With respect to eyes, vision, and light-related characters, one such group is Ostracoda (Crustacea). Here I present phylogenies of ostracods derived from DNA sequence data and morphological characters. Based on methods of character reconstruction using these inferred relationships, different groups of ostracods probably evolved both bioluminescence and extreme sexual dimorphism (females lack eyes, males have large eyes) multiple times. Furthermore, myodocopid ostracods may have evolved compound eyes independently of other arthropods. For these and other reasons, I propose the Ostracoda are an exceptionally important group for studying the evolution of vision and light-related characters.