Research Interests

Many problems in evolutionary ecology can be understood as dilemmas. When foraging, for instance, an individual faces a choice between (i) remaining committed to a resource of ever-diminishing quality, and (ii) leaving that same resource in search of a new, hopefully unexploited one. Here, the decision to remain or leave presumably has consequences for the fitness of the given individual only. Of course, this will not always be the case. In fact, we generally expect that decisions made by an individual have consequences for his/her neighbours as well.

A dilemma whose resolution simultaneously influences the fitness of a number of individuals is, what I call, a “social dilemma”; and the choice of one option over another is, what I call, a “social behaviour.”

 

Some of the social behaviours that have interested me recently include:

 

Sex Allocation

Here an individual (usually a parent) has to choose between investing in sons, or investing in daughters. In many cases, selection favours increased investment in one sex at the expense of investment in the other, and can confer an advantage to parents that produce broods with uneven (i.e. biased) sex ratios. My research in this area tries to understand how various features of an organism’s life history can contribute to the evolution of sex-ratio bias.

Wild, G., West, S. A., 2007. A sex allocation theory for vertebrates: combining local resource competition and condition-dependent allocation. American Naturalist, 170:E112–E128. [pdf]

Wild, G., 2006. Sex ratios when helpers stay at the nest. Evolution, 60:2012–2022.

Wild, G., Taylor, P. D., 2004. Kin selection models for the co-evolution of the sex ratio and sex-specific dispersal. Evolutionary Ecology Research, 6:481–502. [pdf]

 

Cooperation and Altruism

Cooperation and altruism are sometimes called “evolutionary puzzles,” because, at first glance, the evolution of these behaviours seems so improbable. Why should an individual do something that reduces its own fitness, while increasing the fitness of a potential competitor? Is it not better to choose to be selfish instead?

It turns out that there are many reasons why cooperative or altruistic behaviours can be considered to be adaptive. In particular, my research in this area looks at the ways in which spatial structure promotes the spread of cooperation and altruism.

Taylor, P. D., Day, T., Wild, G., 2007. The evolution of cooperation on a finite homogeneous graph. Nature, 447:469–472.

 

Pathogen Virulence

Why do some pathogens make you sicker than others? The answer lies in the tradeoff that exists between virulence and transmissibility. Effective transmission between hosts comes at the expense of host health. If the impact on the host is too great, then the host dies; if the impact is too small, then the pathogen can’t find new hosts to infect.

Clearly, a pathogen must strike a balance between “too sick” and “not sick enough.” Exactly how that balance is struck is likely to be pathogen-specific and could be responsible for the wide range of disease symptoms confronted by medical science.

My research tries to understand how biological features of host-pathogen interactions influence the tradeoffs faced by pathogens, and ultimately, the evolution of pathogen virulence.

Wild, G., Gardner, A., West, S. A., 2009. Adaptation and the evolution of parasite virulence in a connected world. Nature, 459:983-986.

Wild, G., Costain, G., Day, T., 2007. An epidemiological context for the consequences of plasticity in host-pathogen interactions. Evolutionary Ecology Research, 9:221-238. [pdf]

 

Other research themes include:

 

Social Conflicts

What happens when different individuals or different genes are forced to solve a social dilemma together? Do they ever come into conflict? Can selection resolve a conflict? If so, how? My research in this area addresses such questions.

Wild, G., West, S. A., 2009. Genomic imprinting and sex allocation. American Naturalist, 173: E1-E14. [pdf]

Wild, G., Taylor, P. D., 2005. A kin-selection approach to the resolution of a sex-ratio conflict between mates. Journal of Theoretical Biology, 236:126–136.

 

Underpinnings of Evolutionary Theory

My research in this area tries to get “under the hood” of the mathematical tools used by evolutionary biologists to see how they work and how they relate to one another.

Wild G., 2008. Toward evolutionary graphs with two sexes: a kin selection analysis of a sex allocation problem. Journal of Evolutionary Biology, 21: 1428-1437.

Taylor, P. D., Day, T., Wild, G., 2007. From inclusive fitness to fixation probability in finite homogeneous populations. Journal of Theoretical Biology, 249 (2007) 101-110.

Wild, G., Traulsen, A., 2007. The different limits of weak selection and the evolutionary dynamics of finite populations. Journal of Theoretical Biology, 247:382-390.

Taylor, P. D., Wild, G., Gardner, A., 2007. Direct or inclusive fitness: how shall we model kin selection? Journal of Evolutionary Biology, 20:301-309.[pdf]

Wild, G., Taylor, P. D., 2004. Fitness and evolutionary stability in game theoretic models of finite populations. Proceedings of the Royal Society of London, Series B, 271:2345-2349. [pdf]