What I do

My work addresses fundamental questions in population, community, and evolutionary ecology. I am most interested in questions to do with system dynamics (changes over time) and the processes that drive them. Accordingly, much of my work uses a combination of mathematical modeling and experiments in tractable model systems such as laboratory microcosms. I use mathematical models because ecological and evolutionary systems are complex and nonlinear. It's hard to develop and test rigorous hypotheses without mathematical help. I use microcosms because their high control and replicability allows powerful, rigorous experiments that would not otherwise be possible. For instance, in microcosms we often can isolate the effects of a single process on system dynamics, which may well be impossible in nature.

My lab is currently funded by an NSERC Discovery Grant.

Below are the main lines of research currently going on in the lab.

Spatial synchrony

This is a collaboration with David Vasseur. The aim of this project is to explain spatial synchrony. Spatially-separated populations of the same species, and coexisting populations of different species, often fluctuate synchronously, even though they're hundreds or even thousands of km apart. That's amazing! We have theories of why that happens, but those theories are hard to test in nature because it's impossible to do experiments at the right spatial and temporal scales. You can't, say, manipulate the weather across all of Canada and then wait a century to see what happens to the synchrony of lynx-hare cycles. The solution is to scale nature down and do experiments in protist microcosms.  

Publications: Vasseur & Fox 2007 Ecol. Lett., Vasseur & Fox 2009 Nature, Fox et al. 2011 Ecol. Lett., Fox et al. 2013 PLoS One


Local adaptation in time and space

Environmental conditions vary in space, imposing contrasting selection pressures that favor different phenotypes and genotypes. That can cause local adaptation, with each environment being dominated by the organisms that are fittest locally. An analogous process can occur in ecology, with different species competitively dominating in different environments. Local adaptation is a powerful way to maintain diversity. But the environment also varies in time. Can you have local adaptation in time, with different locally-adapted genotypes or species dominating at different times and thereby coexisting? The simplest theoretical models say no: all else being equal, a trait that makes you well-adapted to today's conditions at the cost of making you poorly-adapted to tomorrow's conditions will not be favored by selection (in contrast to a spatially-varying environment). Of course, the world might be more complicated than the simplest theory assumes. I'm testing these ideas using lake bacteria. Water chemistry varies a lot among lakes, and over time. By freezing bacterial isolates and water samples at -80 C, we can  use the freezer as a 'time machine'. That is, we can reciprocally transplant bacteria back into water from the past, and forward into water from the future. Pilot data suggest geographic variation in the strength of local adaptation (and maladaptation) in space and time. I'm currently seeking a graduate student interested in expanding this work to many more sites and times.

Publications: Fox & Harder in press Evolution

Local adaptation, species interactions, and range limits in alpine plants

Alpine environments are characterized by steep environmental gradients. These gradients affect adaptive evolution (e.g., by selecting for local adaptation), species interactions (neighboring plants generally compete with one another low down, but facilitate one another up high), and elevational range limits (different species are found at different elevations). But there's been little work on the interplay of these. For instance, locally-adapted plants should find their local environment less "stressful", and so be less likely to experience facilitation by neighbors. Conversely, insofar as neighbors facilitate one another by ameliorating harsh abiotic conditions (e.g., shading one another from harsh solar insolation), they should weaken or even reverse selection for adaptation to local abiotic conditions. If neighbors facilitate one another, does that mean they extend rather than limit one another's elevational ranges? And how does the distribution of competition and facilitation along elevational gradients both affect, and reflect, the distribution of species along those gradients? I'm planning to address these questions by reciprocally transplanting species within and beyond their elevational range limits, and by combining these reciprocal transplants with neighbor removal experiments. I'm currently seeking graduate students to take the lead on this project.

Other projects

I have various other side projects and collaborative projects. I have a student using competing bean beetles as a model experimental system to look for character displacement. I'm using the Price equation to quantify species selection and other macroevolutionary forces in high-quality fossil datasets. I'm also using the Price equation to analyze effects of pollinator species on crop pollination (the Price equation is a versatile tool...). And I have other irons in the fire...