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Associate Professor Aneil Agrawal of the Faculty of Arts & Science is one of the world’s most promising evolutionary biologists.

A Canada Research Chair and the winner of the faculty’s Outstanding Teaching Award in 2011, investigates how genetic mutations enter populations and may be removed by different forms of selection.His work adds to our understanding of the evolutionary consequences of the flow of harmful mutations through populations and could have practical benefits for medicine.

Agrawal is one of three U of T faculty members awarded an E.W.R. Steacie Memorial Fellowship this year by the Natural Sciences and Engineering Research Council. The fellowships were created to enhance the career development of outstanding and highly promising engineers and scientists who are faculty members of Canadian universities.

U of T News asked Agrawal about his research and the impact it may have for future generations.

Tell us about your research.

My research focuses on two issues:
(1)  Most plants and animals reproduce by sexual reproduction, a process which involves shuffling the genetic diversity in parents and re-distributing it among offspring. Many aspects of physiology, morphology, and behaviour have evolved to facilitate sexual reproduction but why bother with sex at all? Why not reproduce asexually? My work involves developing theoretical models to understand the possible advantages of sexual reproduction in a quantitative framework. Recently, we have been using rotifers (a small aquatic animal capable of both sexual and asexual reproduction) to test some of the theory. In a recent experiment, we provided some of the best evidence to date for the old idea that sex can be favoured because it accelerates the rate of adaptation to environmental changes.

(2)  New mutations happen every generation and the vast majority of those that affect fitness are deleterious. This constant input of harmful mutations means that there will always be variation within populations even if selection is constantly trying to eliminate it. We use theoretical models to understand how much the presence of these bad genes reduces fitness on average and contributes to variation in fitness.  We also use fruit flies as a model organism to understand general properties of mutation. For example, for a set of mutations, what is the range of fitness effects and how much does this depend on whether they are assessed in an environment to which they are adapted to or not?

What kind of impact could this research have for society?

With respect to (1):
We know that sex is common across a wide variety of organisms living in diverse set of ecological circumstances. Whatever is the force providing the advantage to sex must be of general importance to biological systems. Understanding this force is important for understanding biological life and thereby improves our ability to conserve it or manage it and manipulate it (e.g., agriculture, forestry, etc).

With respect to (2):
Deleterious mutations are common in humans (though most have very minor effects). A significant challenge to public health is how to assess and manage problems that arise from many mutations of very small effect; this is different from dealing with mutations of relatively large effects, which is what medical geneticists typically deal with.  Our work will help us to think about the challenges of dealing with many small effect mutations, both in human populations as well as populations of other organisms. We have also performed a series of experiments in fruit flies examining how different genetic and nutritional conditions affect mutation rates. This may eventually influence policy when we begin to think about the long-term and distributed effects of environmental contaminants.

What sort of changes/developments have you witnessed over the course of your career?

The increasing capacity to collect DNA sequence data is making it possible to ask questions about mutation and adaptation that weren't possible 10 or 15 years ago. 

What drew you to this field – and to this particular focus?

I am drawn to these areas because they combine elements of mathematical theory and genetics to understand fundamental aspects of biology.

Why U of T?

U of T has a long-standing tradition of scientific excellence in general. Moreover, I am really thrilled to be in Canada's only Department of Ecology & Evolution where I am surrounded by a number of outstanding colleagues, who are also nice people!
 
What advice would you give to a student just starting out in this field?

(1) Work hard and follow your passion.  (2) Quantitative skills never go out of style!