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NSERC Prizes 2020: Marc Johnson

Department of Biology
University of Toronto Mississauga


Video name

NSERC Prizes 2020: Marc Johnson


NSERC Communications



Release date

February 15, 2021


Cities are unique ecosystems full of environmental challenges not found anywhere else in nature. Concrete and steel infrastructure and carbon emissions trap heat in cities, leaving them up to 10 degrees warmer than outlying rural areas.

Marc Johnson studies how organisms adapt and survive in urban environments. The University of Toronto Mississauga researcher wondered if plants growing in downtown Toronto would be genetically different from those in surrounding rural areas. Using common white clover, which exhibit pronounced genetic changes that allow them to thrive in varied climates, Johnson’s study showed that differences in temperature between urban and rural environments cause dramatic genetic changes in the plants.

Now, what began as a sampling of a few North American cities has exploded into an international survey: the Global Urban Evolution Project, or "GLUE," brings together more than 270 collaborators studying 160 cities on every inhabited continent, in what is believed to be the largest collaborative project in evolutionary biology ever attempted. Johnson’s lab has also expanded its work to study how a wide diversity of plant and animal species evolve in response to cities, pointing the way to changes for healthier cities where all life can flourish.

Marc Johnson

The plant that we actually study—one of the plants we study—is white clover. The humble clover that’s on pretty much everyone’s lawn.

They exhibit specific genetic and chemical changes that make them better adapted to colder environments or to warmer environments.

Well, we were aware of this work and thought hey, this would be a great model to understand: can plants actually adapt to urban heat islands where it’s warmer in the centre of a city than it is in the suburbs or in the outlying areas, in the rural and other non-urban areas. And so we’re trying to understand how does this influence not just the ecology, but the evolution of organisms.

One of the things that we ended up doing is we started looking at different cities. So we looked at okay, do we see the same types of adaptations we see in Toronto in New York City, in Boston, in Montreal, and sure enough what we find is not only were they adapting but this was one of the most stunning and strongest results I’ve ever seen from any of the research that we’ve done.

At this point we realize hey, we can actually scale this up very quickly; we’ve got the methods down very precisely, and so we launched this global urban evolution project, which we call GLUE, out to the community through Twitter and other social media platforms and so we ended up with 160 cities on every inhabited continent in the world and 277 collaborators.

This is I believe the largest collaboration—Collaborative project in evolutionary biology that’s ever been attempted or done.