Expected and observed effects on genetic diversity of ticks and tick-borne pathogens in a zone of invasion of Ixodes scapularis in Canada

The geographic ranges of ticks and tick-borne pathogens are changing due to global and local environmental (including climatic) changes. In this presentation we explore current knowledge of the drivers for, and mechanisms allowing, changes in the ranges of ticks and tick-borne pathogens. Using the Lyme disease system as an example we will use the expanding geographic distribution of the agent of Lyme disease to explore how the processes and mechanisms of expansion, and ecological conditions in newly-invaded regions, may affect the fitness of tick-borne pathogens as defined by their basic reproduction number (R₀). Using this basis we then investigate what could be expected of the diversity of tick-borne pathogens during the process of range expansion, and how historic processes (expansions/contractions) could be reflected in the phylogeography of ticks and tick-borne pathogens seen in recent years.