BABBITT, Courtney C.; PATEL, Nipam H.; University of Chicago; University of California, Berkeley: Developmental Systematics: ontogeny and phylogeny in the Malacostraca (Crustacea).

Within the wealth of comparative embryological and developmental data being produced by the evodevo community there may be a large source of untapped phylogenetic information. The central aim of this study is to assess the potential of using individual developmental events for use in phylogeny reconstruction. This approach will a) reveal at which taxonomic levels these developmental characters contain phylogenetic signal; and b) give predictions about what changes in developmental processes occurred during evolution. To accomplish this, we are focusing on defining characters from developmental events in the highly morphologically and developmentally diverse Malacostraca (Crustacea) for subsequent use in phylogenetic analysis. Using the rich embryological literature and recent developmental genetic data for this group as a starting point, we are examining development through antibody staining and cell lineage experiments. Events such as early cell divisions, the onset of segmentation, and other ontogenetic morphological events are currently being tested as characters for phylogeny reconstruction. These character hypotheses are then tested by congruence with our 18S and 28S molecular phylogenetic data sets. By translating development into the language of systematics we can decipher the details of the evolution of development in malacostracans, and illustrate how to define developmental characters to examine the evolution of development in other systems.