Table of Contents

Geoffrey Legault
Postdoctoral Fellow, Wolkovich Group
Forest and Conservation Science, University of British Columbia
geoffrey.legault@ubc.ca

Hello! I am interested in a variety of topics in the fields of ecology and evolutionary biology, including: range expansion, phenology, coexistence, synchrony, and life history. To answer questions in these areas, I use or derive mathematical models to make predictions about what is possible. I also try to link the possible with the actual by fitting models to data.

I am particularly interested in applications of stochastic models, as they can account for unknown or unmeasured sources of variation, both of which are common in biological systems.

You can read more about my research by scrolling down or clicking here.

News

Curriculum vitae

Google scholar profile | ORCID profile

You can download my CV here (updated 2020-09-09)

Research

Range expansion

The geographic ranges of many species are shifting as a result of climate change and human introductions. Theoretical models show that competitive interactions have the potential to affect the speed and shape of these expansions. However, experimental evidence of these effects is lacking.

I combine experimental microcosms of flour beetles (Tribolium castaneum and Tribolium confusum) with stochastic spatiotemporal models to more clearly link theory with nature.

expansion_experiment.png

Figure 1: Experimental data illustrating the impact of interspecific competition on range expansion across 8 generations. Lines are mean abundances across 16 patch landscapes (15 replicates). Shaded areas are 95% confidence intervals for generation 8.

Winegrape phenology

Phenology, the timing of biological events, is a key determinant of lifetime fitness, species interactions, and ecosystem functioning. Using winegrapes as a model system, I am developing stochastic models of phenology that can be applied to a variety of systems and spatial scales.

      winegrape.jpg vines_heatwave.jpg      

Life history trade-offs

Life history traits (e.g., maturation time, mass at maturity) frequently co-vary and exhibit important trade-offs. Characterizing such trade-offs is necessary for predicting lifetime fitness and optimal evolutionary strategies. I develop stochastic models of life history traits and validate them with data, in order to better understand how these trade-offs manifest in natural systems.

During my postdoc with Joel Kingsolver, I created a continuous-time stochastic model describing the joint distribution of an insect's age and mass at maturity. The model is based on the developmental biology of Manduca sexta, and predicts novel trade-offs between age and mass at maturity. You can read about the model here.

I am currently working to validate this model with data from laboratory experiments.

      devmass_model.png devmass_sensitivity.png      

Publications

2020

  1. Legault, G, Bitters, M. E., Hastings, A., Melbourne, B. A. (2020) Interspecific competition slows range expansion and shapes range boundaries. Proceedings of the National Academy of Sciences of the United States of America. Accepted.
  1. Legault, G., Kingsolver, J. (2020) A stochastic model for predicting age and mass at maturity of insects. The American Naturalist. 196: 227-240 link data
  1. Bullock, M., Legault, G., Melbourne, B. A. (2020) Interspecific chemical competition between Tribolium castaneum and Tribolium confusum reduces fecundity and hastens development time. Annals of the Entomological Society of America 113(3): 216-222 link

2019

  1. Legault, G., Fox, J., Melbourne, B. A. (2019) Demographic stochasticity alters expected outcomes in experimental and simulated non‚Äźneutral communities. Oikos 128(12): 1704-1715 link data
  1. Legault, G., Melbourne, B. A. (2019) Accounting for environmental change in continuous-time stochastic population models. Theoretical Ecology 12(1): 31-48 link
    • Recommended ("Very Good") by Faculty of 1000 Prime Access the recommendation on F1000Prime

2018 and before

  1. Contributing author (2018) "Direct and indirect drivers of land degradation and restoration" in Assessment Report on Land Degradation and Restoration. Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) link
  1. Legault, G., Cusa, M. (2015) Temperature and delayed snowmelt jointly affect the vegetative and reproductive phenologies of four sub-Arctic plants. Polar Biology 38: 1701-1711 link
  1. Fox, J., Legault, G., Vasseur, D., Einarson, J. (2013) Nonlinear effect of dispersal rate on spatial synchrony of predator-prey cycles. PLoS ONE 8(11): e379527 link
  1. Legault, G., Weis, A. (2013) The impact of snow accumulation on a heath spider community in a sub-Arctic landscape. Polar Biology 36: 885-894 link

In revision

  • Legault, G., Bitters, M. E., Hastings, A., Melbourne, B. A. Interspecific competition slows range expansion and shapes range boundaries.

In preparation

  • Dallas, T., Legault, G., Melbourne, B. A., Hastings, A. Context-dependent dispersal in two species communities.

Resources

Data

Emacs

I do many of my tasks (e.g., R coding, writing, tracking RSS feeds, this website) within the venerable text editor Emacs. If you're interested in learning about it, here's a basic introduction.