I enjoy collaborating and welcome inquiries from other labs interested in similar questions or systems!
Phylogeographic history and the structuring of species' ranges
The history of populations matters to their evolutionary fate. Patterns of colonization shape the distribution and amount of genetic diversity available for selection across species' ranges; prolonged periods of separation can leads to population divergence and can send populations down different evolutionary trajectories; and subsequent contact between divergent populations can have dramatic consequences for the fitness of individuals resulting from hybridization. We use molecular data and phylogeographic methods to study the biogeographic history of species in temperate regions of North America and the implications of this history for the structure and dynamics of species' ranges.
Questions that we are interested in include:
Work on these questions is continuing in wood frogs and long-toed salamanders and will soon expand to include other temperate amphibians.
The history of populations matters to their evolutionary fate. Patterns of colonization shape the distribution and amount of genetic diversity available for selection across species' ranges; prolonged periods of separation can leads to population divergence and can send populations down different evolutionary trajectories; and subsequent contact between divergent populations can have dramatic consequences for the fitness of individuals resulting from hybridization. We use molecular data and phylogeographic methods to study the biogeographic history of species in temperate regions of North America and the implications of this history for the structure and dynamics of species' ranges.
Questions that we are interested in include:
- Where did species persist during glacial periods during the Pleistocene?
- What routes did species take to colonize their present ranges?
- To what extent do species' ranges represent the patching together of distinct genetic groups and what are the implications for biodiversity?
Work on these questions is continuing in wood frogs and long-toed salamanders and will soon expand to include other temperate amphibians.
Evolutionary ecology of range limits
Explaining why species' have geographic range limits is a long-standing goal in evolutionary ecology and bears upon our fundamental understanding of the distribution of biodiversity. Yet despite much theoretical attention, we lack even a basic understanding of the causes of most species' range limits. Much of our work aims to determine how dispersal limitation, abiotic factors, and species interactions shape the contemporary range limits of species. Beyond that, we are interested in knowing why species fail to evolve trait values that would allow them to overcome ecological constraints on range expansion. We tackle these questions using a variety of methods, including ecological niche modeling and population genetic analyses.
Questions that we are interested in include:
We work on these questions in both plants and animals, with upcoming plans to specifically expand this work to amphibian range limits in Alberta.
Explaining why species' have geographic range limits is a long-standing goal in evolutionary ecology and bears upon our fundamental understanding of the distribution of biodiversity. Yet despite much theoretical attention, we lack even a basic understanding of the causes of most species' range limits. Much of our work aims to determine how dispersal limitation, abiotic factors, and species interactions shape the contemporary range limits of species. Beyond that, we are interested in knowing why species fail to evolve trait values that would allow them to overcome ecological constraints on range expansion. We tackle these questions using a variety of methods, including ecological niche modeling and population genetic analyses.
Questions that we are interested in include:
- What is the relative importance of niche versus dispersal limitation for range limits in northern areas?
- How does the interplay between species interactions and abiotic conditions affect populations at the edge of the range?
- How do genetic drift and gene flow influence the adaptive potential of peripheral populations?
We work on these questions in both plants and animals, with upcoming plans to specifically expand this work to amphibian range limits in Alberta.
Parapatric range limits and hybridization
The meeting of species following range expansion often results in the formation of parapatric (geographically abutting) range limits. What prevents either species from expanding into the range of the other in these cases? When ecologically similar species come into contact, range expansion may be limited by competition, shared enemies, and/or reproductive interference. For species that also hybridize, range limits are thought to reflect a tension between dispersal by parental forms into the zone and selection again hybrids. We study the causes of parapatric range limits and the potential role of abiotic conditions in shaping the formation of these limits. We are particularly interested in parapatric range limits that involve hybridization. In these cases, different genes may paint a different picture with respect to the range limits between groups. For instance, mitochondrial and chloroplast genes often defy species borders based on nuclear genes. We are interested in the relative importance of genetic drift, gene flow, and selection in shaping these patterns, and the consequences of the breakdown of coevolved cyto-nuclear gene interactions in hybrid individuals.
Questions that we are interested in include:
The meeting of species following range expansion often results in the formation of parapatric (geographically abutting) range limits. What prevents either species from expanding into the range of the other in these cases? When ecologically similar species come into contact, range expansion may be limited by competition, shared enemies, and/or reproductive interference. For species that also hybridize, range limits are thought to reflect a tension between dispersal by parental forms into the zone and selection again hybrids. We study the causes of parapatric range limits and the potential role of abiotic conditions in shaping the formation of these limits. We are particularly interested in parapatric range limits that involve hybridization. In these cases, different genes may paint a different picture with respect to the range limits between groups. For instance, mitochondrial and chloroplast genes often defy species borders based on nuclear genes. We are interested in the relative importance of genetic drift, gene flow, and selection in shaping these patterns, and the consequences of the breakdown of coevolved cyto-nuclear gene interactions in hybrid individuals.
Questions that we are interested in include:
- To what extent are parapatric range limits attracted to dispersal barriers or areas where abiotic conditions are stressful?
- What is the relative importance of extrinsic versus intrinsic barriers to gene flow at parapatric range limits?
- What are the causes and consequences of cytonuclear discordance at parapatric range limits?
Our changing world and species' distributions
Around the world species are contending with the direct and indirect effects of climate change. We are broadly interested in answering questions about when and where species fail to track changing conditions. We are also interested in understanding the acute effects of climate-mediated disturbance events on populations and range limits. We are currently studying on the effects of a severe wildfire on peripheral populations of the long-toed salamander in Alberta. See here for more details.
Around the world species are contending with the direct and indirect effects of climate change. We are broadly interested in answering questions about when and where species fail to track changing conditions. We are also interested in understanding the acute effects of climate-mediated disturbance events on populations and range limits. We are currently studying on the effects of a severe wildfire on peripheral populations of the long-toed salamander in Alberta. See here for more details.