Successful conservation strategies require a sound understanding of the ecological and evolutionary mechanisms that govern species persistence. To this end, I have been fortunate to address a variety of related questions in my undergraduate and graduate research. Of particular interest is a project I am currently completing under the supervision of Dr. Felix Sperling and Dr. Julian Dupuis, quantifying rates and the spatial extent of gene flow within swallowtail butterflies. In southern Alberta, populations of Old World Swallowtail butterflies, Papilio machaon dodi, are restricted to the south-facing banks of major rivers where their larval food plant, Artemisia dracunculus, occurs. The eroding banks of these rivers comprise a dendritic ecological network of linear, isolated habitat corridors situated in a matrix of unsuitable prairie and agricultural habitat. This network presents a unique opportunity to test how habitat composition, configuration, and connectivity affect microevolutionary processes that govern species persistence; namely, gene flow.
Using single nucleotide polymorphism (SNP) data obtained from genotyping by sequencing (GBS), our primary objective is to quantify patterns of genetic differentiation between populations of P. m. dodi along major rivers in southern Alberta. If P. m. dodi are capable of long-range dispersal over the matrix of unsuitable prairie/agricultural habitat between rivers, patterns of genetic differentiation will be best-explained by geographic distance separating populations. Conversely, if P. m. dodi are not able to disperse between adjacent rivers and gene flow follows riverine corridors, patterns of genetic differentiation across populations will be best-explained by “river distance” separating populations. While the former result would suggest that habitat fragmentation has little effect on microevolutionary processes within Swallowtail butterflies, the latter would suggest that decreasing habitat patch size and increasing patch isolation may significantly reduce gene flow. Reductions in gene flow have been linked to local extinctions within butterfly metapopulations, and are therefore of great conservation concern. This research will give valuable insight into how Swallowtail butterflies respond habitat fragmentation, aiding in their effective conservation.
For other research projects and publications, please visit http://www.ace-lab.org/index.php.
The Sperling Lab 