Why a Phylogeny for C. elegans?
As a “model system”, we would like to think of C. elegans as being representative of biological systems in general and of animals in particular. However, along with Drosophila, this “model” has a derived mode of development quite different from other species, probably as an adaptation for rapid life cycles in response to ephemerality of resources (Hodgkin and Barnes, 1991). To determine what features are primitive and shared ancestrally with other species, and which features are derived (e.g., convergent or novel), a model needs a phylogenetic context. An accurate phylogeny for nematodes including their relationship to other animals has major consequences for our understanding of how diversity has evolved in morphology, genes, developmental mechanisms, behavior, and life history, but also for studies of comparative functional genomics. We need species phylogenies to allow discrimination between orthologues and paralogues in gene phylogenies.Discriminating orthologues from paralogues en
