Evolutionary History of Arctic Biomes

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Biodiversity provides invaluable ecosystem services, such as clean water, pollination, and foods, yet it is facing unprecedented threats from climate change, pollution, habitat loss, and invasive species. The goals of my research program are to understand the evolutionary history, current diversity and distributions, and future of biodiversity in the context of global change. Due to the multiple glacial cycles the Arctic has experienced over the past two million years, the Arctic biome represents an outstanding opportunity to study the influence of dramatic environmental change on biodiversity. A key gap in our understanding of Arctic biodiversity is the role of both dispersal and evolution in biome formation. The current paradigm is that, following the retreat of the glacial ice sheets covering most of northern North America, the Arctic was recolonized by organisms living in ice-free areas (refugia) to the south and in the Northwest (Alaska and Yukon). However, recent research informed by DNA sequence data suggests that this view, mainly based on studies of plants and vertebrates, may be too simple. Our research in the central Canadian high Arctic has instead found unique species of invertebrates and high genetic diversity within some species. These patterns suggest that there may have been sustained occupancy of the North by some populations in high-Arctic refugia, mixing of populations from multiple refugia, and the evolution of unique Arctic life forms. This research program will investigate the relative roles of dispersal from refugia, biological traits, and evolution in the North. We will conduct field work in the Western Canadian Arctic, an understudied region for molecular biodiversity, and will focus upon freshwater invertebrates. We will generate new knowledge of species diversity, genetic and genomic diversity, evolutionary relationships, habitat occupancy, and ecological traits such as trophic level. We will then combine these new data with publicly available information from other geographic regions to quantify the importance of dispersal from southern areas, mixture of populations, and Arctic evolution and diversification, potentially transforming our understanding of the origins of Arctic biodiversity. Applications of this work include predicting geographic range shifts of species due to climate change to inform management efforts, biomonitoring for ecosystem health to mitigate environmental risks associated with natural resource industries (e.g. mining), and developing rapid DNA-based detection systems for potentially invasive or pathogenic species. This research program will train 3 MSc (thesis), 3 Master of Bioinformatics (coursework plus major research project), 3 PhD, 5 undergraduate, and 3 Northern students. This program will help to address the need for employees with training in biological sciences, data analysis, and working in the North for the benefit of Canada's economy and environment.