I examine fundamental ecological and evolutionary questions in parasite systems and consider my research to be at the interface of ecology, evolution, and genetics. Parasitology provides a rich subject area for studies of ecology and evolutionary biology. Numerous topics such as ecosystem dynamics, mating systems, or coevolution can be addressed because parasites are extremely diverse. By diversity, I include not only the myriad of taxa that have independently evolved a parasitic lifestyle, but also the diversity in life cycles, modes of reproduction, host species, and ecosystems utilized by parasites. This diversity also allows for comparative studies to address theories or unifying principles that span ecosystems or taxonomic groups. Furthermore, there are many practical applications such as studying the evolution of drug resistance, or using parasite community structure to assess “ecosystem health”. My research interests address both basic and applied questions, and span three overlapping subject areas: 1) Genetics and Ecological Genomics, 2) Evolution: Population Genetics, Mating Systems, and Molecular Epidemiology, and 3) Ecology: Biodiversity, Conservation, and Natural History.
We use a population genetics approach to research the underlying principles that govern the ecology and evolution of metazoan parasites of animals (e.g., nematodes, platyhelminths). A central theme in our research is to ask what parasite ecological and life history traits influence evolutionary mechanisms and hence, resultant patterns of genetic variation within and among parasite populations. Moreover, the direct observation of many parasite population processes such as mating behaviors or dispersal is impeded due to their small sizes, infection sites within hosts, and complex life cycles. Thus, our research uses population genetics theory and molecular methods to elucidate the often hidden and elusive biology of parasites. In addition, our lab has advocated and demonstrated the application of evolutionary genetics to the field of epidemiology in order to better understand the transmission and evolutionary potential of human or economically important parasites. In particular, the use of population genetics methods to identify foci of transmission in human parasites (i.e., molecular epidemiology). We are interested in several evolutionary and molecular ecological based topics including how life cycle patterns influence local scale transmission processes (as inferred from genetic markers), the elucidation of parasite mating systems (e.g., selfing versus outcrossing), and factors that affect inbreeding in natural populations of parasites.
The biodiversity and natural history of parasites in many systems remain uncharacterized. This is unfortunate because parasites can constitute a significant proportion of the biomass in an ecosystem, regulate host populations, alter individual host behaviors, and be an important component in food-web chains. Our lab conducts parasite biodiversity research from the discovery of new species to the elucidation of complex life cycles. For the latter research, we largely use molecular markers from field collected specimens to identify new species and to match specimens between intermediate and final hosts. Other ecological based projects include the conservation genetics of a recently delisted water snake, invasion biology, and interactions between introduced parasites and native or exotic hosts.
||Jenna Hulke joined the lab as a new PhD student this Fall. Welcome Jenna!|
||Our molecular phylogeny of the trematode Genus Alloglossidium was accepted in Molecular Phylogenetics and Evolution. This genus is a fascinating group of trematodes as there is life cycle variation among species in the genus. Our phylogeny was used to reconstruct the evolution of these different life cycle patterns. Check out Emily Kasl’s (former PhD student in Criscione lab) paper (September 2018 issue) under Publications.|
|Feb. 2018||Check out our new publication on the rat lungworm Angiostrongylus cantonensis in Evolutionary Applications (September 2018 issue) under Publications. By collectively analyzing available sequence data, this paper corrects some prior mistakes in the literature dealing with the global molecular epidemiology of this parasite. The paper also links data from prior isolated studies into a framework that can be used for future studies. Lastly, the paper highlights the importance cryptic lineages within the presumed single species Angiostrongylus cantonensis. This study was done in collaboration with a visiting PhD student and now, Dr. Sirilak Dusitsittipon from Thailand.|