The main focus of my research seeks to provide answers to this question: What processes cause and what patterns correlate with speciation and biodiversity? Because my training, experience, and interests are multidisciplinary, I seek answers from numerous areas of biology, including paleobiology, ecology, behavior, genetics, biochemistry, and others using different biological systems. Therefore, I can comfortably accommodate students who wish to do research with me on a wide variety of topics of mutual interest particularly, but not exclusively, arthropods and plants.
I have had the pleasure of collaborating with numerous students engaged in research projects. These projects include subjects as diverse as: plant developmental genetics, insect cytogenetics, aquatic ecology, reconstruction of ancient communities preserved in the fossil record, forensic ecology, environmental ethics, biological illustration, biology education, and many others. In collaboration with each of the students, some of them from local high schools, research initiatives are written and reviewed. Hence, competitive grant proposals may be submitted and progress reports presented at professional meetings. Some students have received funding to pursue their research projects. As a result of students’ increasing intellectual independence and long-term productivity, I have more time to pursue other research interests (as seen here). Below, I briefly summarize some of my research interests, in no particular order.
Paleobiology. The natural history, biogeography, and ecology of ancient communities. For instance, the study of two North American Jurassic assemblages preserved in lithographic limestone and seemingly dominated by insects suggests that it is ecologically and biogeographically closer to its penecontemporaneous counterparts in Asia and not those described for Meso- and South America. Also, there are great differences in the botanical composition between these two North American Jurassic paleocommunities. We have conducted similar research on ancient communities preserved in amber collected in different parts of the world.
Plant exudate chemistry. Our ultimate goal is to generate widely available databases of C-13 (carbon-13 isotope) solid state nuclear magnetic resonance spectroscopy and H-1 (proton) NMR signatures of plant exudates of the world. With a larger database, we will have greater ability to: 1) identify the botanical origin of modern and fossil exudates (e.g. amber), 2) make specific statements about the systematics and evolution of some exudate-producing plant groups (e.g. Fabaceae), and 3) understand paleoenvironments and paleoclimates entombed in fossil exudates during different intervals in Earth’s history.
Aquatic Ecology. I am especially interested in documenting stream biodiversity and ascertaining the water quality therein. In a 13 month-long study done with undergraduates, we showed a discrete gap in the relative composition of biodiversity along Snyder’s Branch Creek (Salem, VA). The nature of this gap suggested the presence of an organic pollution source. Furthermore, we documented a large biodiversity of aquatic macroinvertebrates, including over 40 species of larval chironomids.
Sexual Selection and Evolution. What makes Drosophila melanogaster females choose conspecific males? The answer to that question involves many sensory channels whereby females obtain information about the conspecificity and possibly “quality” of courting males. We have shown that while female D. melanogaster prefer fully winged over wingless males, they cannot discriminate between fully winged males and males with over one complete wing and three-quarters, or more, of another wing.
Molecular identification and phylogenetics of arthropods. Our investigations have confirmed the usefulness of molecular markers for the rapid and reliable identification of agriculturally, silviculturally, and medically important insects, including the agriculturally-beneficial parasitic wasps, Trichogramma, the cone-feeding beetles, Conophthorus, and the blood sucking sand fly Lutzomyia. For years, several colleagues and I have been working on the large Puerto Rican arboreal millipedes Anadenobolus arboreus.
Insect-plant interactions: a case of possible coevolution between species of North American Monoxia beetles (Chrysomelidae) and their host plants. Monoxia is especially interesting because most of its species groups feed on selected host plant genera placed in very divergent plant families, the Asteraceae, the daisies, and the Chenopodiaceae, the plants in the spinach family. By doing field and laboratory work, I have found congruent patterns of host plant association, cytogenetics, and morphology.
