My program of NSF funded research is focused on the evolutionary relationships among neotropical rodents and marsupials and their parasite faunas. I investigate questions of mammalian and faunal biodiversity by generating and combining data on the phylogenetic, biogeographic, and ecological relationships of hosts and parasites. I am committed to integrating museum-oriented field research and modern systematic analysis of parasites and their hosts. These studies will provide assessments of extent and scope of coevolution and biodiveristy of mammals and their parasites of various biotic regions. For instance, recent results of my research show that a knowledge of both the host and parasite faunas of an area can provide much more information regarding regional biodiversity than if only the hosts were considered in this context.
To understand the phylogenetic relationships among mammals and their parasites, one must know as much of the biological characteristics of the host as of their parasites. For instance, I have generated phylogenetic hypotheses for rodents using morphological analysis and at the same time estimating phylogenetic relationships among the parasites using techniques appropriate at different levels of resolution such as allozyme analysis and morphology. I use the methods of phylogenetic systematics to test hypotheses of host-parasite coevolution and biogeography.
I also have interests in the ecology of symbiotic associations of mammalian groups from North America and have for the past several years been engaged in studies of the helminth parasites of geomyoid rodents and their relatives. Using these data I have begun to address questions concerning taxonomic and ecologic diversity of parasites in groups of rodents with both subterranean and terrestrial habits in the Neotropical vs. the Nearctic regions. Comparisons such as these hold great promise for increasing our general understanding of ecological diversity in tropical vs. temperate ecosystems. Although my current research program is focused on the helminth parasites of mammals, my investigations and collections are broad in scope and taxonomic coverage. I have published on topics as diverse as coccidia of stingrays (Urolophus), and coccidia, nematodes, and cestodes from rodents.
I plan to continue studies of the phylogeny, evolution, diversity, and genetic variation of parasites and their hosts using as tools, multivariate statistics,DNA sequencing, and other molecular techniques. An active and dynamic multifaceted approach to investigations of phylogeny and evolution will result in more lucid definitions of the processes responsible for the patterns that we see in nature. Being active in research on more than one class of organisms opens up funding opportunities that would not otherwise be available to researchers.