My empirical research focuses on the phylogenetic relationships of nymphalid butterflies, primarily based on data from mitochondrial and nuclear protein-coding genes. Many nymphalids are big, showy butterflies, well-known by the general public and popular with collectors. Nymphalids, and butterflies in general, are an excellent model system for investigations in a broad range of ecological and evolutionary subdisciplines, from evo-devo to community ecology, and obtaining a robust hypothesis of phylogenetic relationships will immensely enrich ongoing work in all those areas. The family contains some of the best-known examples of coevolutionary M?llerian mimicry, such as representatives of the genus Heliconius Kluk and the Ithomiini (both neotropical groups upon which I have conducted NSF-funded research).
Nymphalidae also encompasses the Satyrinae (browns, satyrs and ringlets), an extremely diverse yet poorly-known subfamily. The neotropical/south temperate Pronophilina, with rich representation in the Andean cloud forest and paramo, is a satyrine group of special interest from the perspective of studying geographical variation and speciation (how do butterflies occupying what seems to be a rather homogeneous niche undergo phylogenetic radiations?). At a deeper phylogenetic level, pronophilines also pose a number of interesting vicariant biogeographical problems, and may represent a relictual group broken up by continental drift. I am currently funded by NSF ($390K) to study Pronophilina, in collaboration with Latin American colleagues. I advised a graduate student with whom I have co-authored several papers on the higher-level relationships of skippers (Hesperiidae), and have worked collaboratively on the systematics of other groups of butterflies, moths, wasps and flies.
My theoretical research employs the cladistic approach to examine various areas, including the philosophy of systematics, the data partitioning controversy, species concepts and species delimitation, and nomenclatural issues.With first author R. T. Schuh, I have recently completed a completely revised 2 ndedition of the graduate-level textbook, Biological Systematics: principles and applications(2009). I also write occasional cladistic critiques of empirical papers by others that bear on issues of lepidopteran interest, such as mimicry and chemical defense.Most recently, I have completed a critical review of the homoploid hybrid speciation hypothesis for the Colombian species Heliconius heurippa.
Over the next ten years, I anticipate that I will continue to investigate phylogenetic relationships within and among various butterfly groups - there is at least a lifetime's work here. I am interested in developing collaborative study of deeper patterns of lepidopteran relationships. I am a leader of an international collaborative effort to establish a molecular phylogenetic framework for all the butterflies. I will also continue to build my contributions on butterfly phylogenetic relationships to the Tree of Life project ( www.tolweb.org).
Although my empirical work focuses primarily on molecular systematics of nymphalids, I am open and supportive of studies on other groups, including collection-based morphological revisionary studies. One of my former graduate students, Andrew Warren, worked on the molecular and morphological systematics of skipper butterflies, while another, Jason Leathers, studied the morphological systematics of braconine wasps.