Ecology, Evolution, and Behaviour in a Changing World
My research lies at the intersection of ecology, evolution, and behaviour. I focus on two questions asking about the origins, evolution, and maintenance of biodiversity: (i) What are the characteristics of selection? (ii) Can we predict how organisms will adapt and evolve? A fundamental challenge addressed by biology is to explain why we have the biodiversity we observe today. In other words, what are the origins of biodiversity, how did it evolve, and importantly, how is it maintained? Selection and adaptation are two key processes that underlie biological diversity, and yet we often consider selection and adaptation from a static viewpoint – considering evolution at one point in time and space. While informative, this approach often cannot explain what we observe in nature. By considering evolution as a dynamic process that varies in space and time, we can deepen our understanding of selection and adaptation and the role they play in the origins and maintenance of biodiversity.
Humans are dramatically changing the world both directly (e.g. artificial selection or domestication) and indirectly (e.g. cascading effects from urbanization), altering the dynamics of natural selection. Organisms must rapidly adapt and evolve to these different selection pressures if they are to cope, persist, and survive. My research goal is to determine the importance and efficacy of this process of rapid adaptation to human made changes and use this information to reduce the unwanted consequences of human-caused selection changes, as well as to facilitate adaptive responses that could allow continued persistence of populations.
Darwin's Finches on The Galapagos Islands
Humans are now recognized as a major selective force that is changing and shaping evolution by altering the patterns of spatiotemporal variation in selection. Human impacts are amplified on oceanic islands, where small population sizes and geographic isolation make species more susceptible to disturbance and more vulnerable to extinction. On isolated islands, such as the Galápagos Islands, human imposed threats are exacerbated by the evolutionary naïveté of island animals who have evolved over millions of years in the absence of humans. Human impacts on organismal populations can be both direct and indirect, the sum of which can lead to high extinction rates, especially on islands. Currently, I focus on two human influences known to impose strong selection on adaptive traits: (1) invasive predators and (2) urbanization.
(1) Introduced feral cats are particularly problematic for many bird species, and have been known to decimate native bird populations on islands; introduced snakes have had similar effects on islands such as Guam. The often-devastating effects of invasive predators are driven in large measure by the ecological naïveté of island animals to predators. Thus, one mechanism by which island species might be able to persist in the face of anthropogenic influences is through the evolution of adaptive antipredator behavioral responses. I am currently exploring this by quantifying antipredator behavior in birds occupying islands with various levels of predation.
(2) On the Galápagos Islands, four of the islands now have permanent human settlements that vary in their degree of urbanization (e.g. population size and density, town area, and light pollution). Currently, I am studying how urbanization affects antipredator behaviour in Darwin’s finches, and together with my colleagues, I am also studying the link between microbiomes and immune function in urban and non-urban populations of Darwin’s finches
Domestication and Feralization in Trinidadian Guppies
The Trinidadian guppy is an iconic example of rapid evolution where male guppy colour responds to certain selective pressures (e.g. predation) very strongly, but multiple other factors are also shaping male guppy colour variation such as the underlying genetic architecture and stochastic processes such as drift. One strong human influence on guppies is domestication via artificial selection for colour for the aquarium trade. This type of artificial selection can result in domestication syndromes, where other phenotypic traits can evolve, even though they are not being directly selected for. Furthermore, both wild guppies and domesticated guppies have been introduced world-wide and are now found on all continents except Antarctica. I will ask three questions focusing on the evolution and ecology of domesticated vs. wild guppies.
(1) What are the domestication syndromes in guppies? Beyond colour, little is known about what other traits might differ between domesticated and wild guppies. This can be assessed through laboratory-based experiments comparing a suite of phenotypic traits (e.g. morphology, behaviour, or physiology) between domesticated and wild guppies.
(2) What are the ecological impacts of introduced guppies and does this differ between domesticated and wild guppies? I will use experimental introductions in mesocosms and track changes through time in abiotic variables and biotic community assemblages to determine ecological impacts of introductions.
(3) How do guppies adapt post-introduction and become feralized? Will domesticated guppies “de-evolve” the traits they were selected for? Answering these questions will offer insight into not only evolutionary questions about domestication syndromes and feralization, but also into applied aspects concerning introduced species.
Human Influences on Ecology and Evolution in Southern Ontario
Southern Ontario consists of dense, urban areas such as Hamilton, semi-urban areas such as the vineyards of the Niagara Region, as well as more undisturbed areas. Thus, Southern Ontario has a human-disturbance gradient that allows for the study of adaptive and evolutionary processes among urban, semi-urban, and undisturbed populations of organisms. Such communities provide an opportunity to quantify spatial variation in selection due to abiotic and biotic variation among populations and to study local adaptation. By quantifying selection and adaptation among populations that vary in disturbance, I aim to explore the effects of human influences on ecology and evolution. I plan on conducting a series of field-based observations and experiments (e.g. reciprocal transplants and then monitoring survival and reproduction), as well as common garden experiments to quantify local adaptation and to tease apart the plastic and genetic components of such adaptations. This part of my research program is in development and if you are interested in working on this with me as a collaborator or student, I would be happy to discuss this further. Please contact me or consider joining the lab!
Alaskan Three-Spine Sticklebacks
My research outcomes on characterizing selection and predicting adaptation can have a strong, applied aspect for conservation, especially the conservation of biodiversity. However, the efficacy of using behaviour, evolution, and ecology in conservation efforts is a broad and wide-ranging area and can even produce conflicting results. Systematic evidence syntheses (e.g. systematic reviews and systematic maps) are tools that can overcome this problem by conducting thorough and transparent reviews that utilize both peer reviewed literature and grey literature, and also incorporate the involvement of stakeholders (e.g. policy makers, NGOs, and government). I am currently developing a review on conservation translocations and hybridization, which is of growing concern in the efforts to preserve and maintain biodiversity.