Haemosporidian parasites are remarkably diverse, with the global number of species potentially exceeding that of their hosts. Understanding the drivers of this diversity are important for understanding the evolution of vector-borne diseases, as well as for the implications of infection for host individuals, which seems to vary between parasite species. However, different methods of identifying and classifying parasites differ markedly in their estimations of parasite species diversity, and so the assignation of parasite genetic lineages or morphotypes to species remains unresolved.
Molecular techniques using PCR protocols targeting a cytochrome b barcode have dramatically increased the accessibility of the study of haemosporidians to a wide range of research groups globally, but morphological study is still essential for our understanding of parasite ecology. Marrying molecular and morphological techniques is key to our understanding of parasite ecology because we know that cryptic genetic diversity is present within parasite morphospecies, but the extent to which this genetic diversity is ecologically important is unknown.
This project will firstly collate existing data on parasites from the genus Haemoproteus (Haemosporida, Haemoproteidae), where morphological and molecular data are available. Second, additional morphological analyses will be conducted on infections that have been characterised molecularly but not morphologically. Third, the project will determine the levels of cryptic molecular diversity within morphotypes and, using phylogenetic analysis, confirm whether molecular lineages within the same morphotype cluster phylogenetically. Using this information, it may be possible to test additional molecular markers to determine whether cytochrome b is the most appropriate marker to delineate Haemoproteus species, or to test whether ecological inferences obtained from molecular lineage data (e.g. host range, host relatedness) correlate with those obtained from morphological species definitions.
This study will contribute new knowledge about possible mechanisms of speciation in Haemoproteus pathogens and might ultimately contribute to improvement of bird health and wildlife conservation policies.