Heather Bruce, Assistant Professor

I use arthropod appendages to ask questions about the origin and evolution of novel structures, and how genetic networks evolve over vast phylogenetic distances on the order of hundreds of millions of years.

I am interested in how genetic networks produce morphological diversity. This relates to the origin of novel structures, which are those that don’t seem to be derived from (homologous to) any structure in the ancestor (Müller and Wagner, 1991). Co-option of genetic pathways by unrelated tissues is often invoked to explain the origin of novel structures. However, my research into arthropod novel structures suggests an exciting alternative: novel structures may arise from existing structures (serial homologs) that persist cryptically in other lineages. Many unexpected structures may thus be related and far more ancient and evolvable than currently believed. This view may be informative for conceptualizing what the common ancestor of all bilaterally symmetrical animals (ur-bilaterian) looked like. My work has deep implications for how we assume genetic networks evolve, as it suggests that the wholesale swapping of networks, as assumed by co-option, may not be a common mechanism of morphological evolution, and we should instead explore models where networks are homologous but with millions of years of systems drift.

I have worked with arthropods from all four living groups: 

     Insects (beetles, etc)                       Crustaceans (shrimp, etc)

     Myriapods (millipedes, etc)           Chelicerates (spiders, etc)

I am interested in working on any arthropod ectodermal outgrowths ("sticky-outty thing") in any arthropod or near-arthropod! Let's figure out what that sticky-outty thing is :)