Departmental Seminar – 18 April

This week the Department welcomes Dr. Stephen Short from the Department of Biology, University of Toronto:

The Complex and Enigmatic World of Freshwater Algal Viruses


As well as being agents of infectious disease, it is now widely accepted that viruses are intimate partners in life that have shaped the evolution of cellular organisms and have played an ongoing role in Earth’s biogeochemistry. With respect to the latter, the discovery almost 30 years ago that viruses infected marine and freshwater primary producers, including species of eukaryotic algae, contributed to the emergence of virology as its own discipline within aquatic sciences. My research program is centered on freshwater algal viruses with the broad goal to understand how they influence aquatic primary production and food web processes. To that end, my students and I have explored freshwater algal virus ecology by studying their biodiversity and seasonal dynamics, persistence in the environment, and relative importance to phytoplankton mortality. We have learned that diverse algal viruses can be found in various freshwaters, but as in marine environments, freshwater algal virus communities are surprisingly dominated by a single group. We have also discovered that algal viruses can form seasonally persistent ‘seedbanks’, and some can overwinter in a frozen pond remaining infectious until their host abundances reach levels we presume are necessary for ongoing virus production. Additionally, the fact the we were able to detect diverse viruses in Lake Erie sediments suggests that sediments are an important refugium that could allow some phytoplankton virus to escape seasonal bottlenecks when they suffer high rates of destruction. With respect to our studies of virus-mediated mortality, we have developed experimental methods to examine phytoplankton mortality at a species, or taxon level. An unexpected finding from this work was the observation that in some cases, viruses appeared to counteract the effects of grazing mortality by stimulating an alga’s growth, perhaps through the liberation of resources from other lysed cells, or by reducing competition. Finally, an additional focal point of my research program is our isolation and ongoing characterization of a newly discovered algal virus. Molecular characterizations of this virus in the lab and field have revealed its complex evolutionary history as well as its puzzling ecological dynamics. Overall, my research has helped demonstrate that, despite their furtive nature and borderline status as ‘living’ microorganisms, freshwater algal viruses are critically important members of freshwater ecosystems.

This seminar will be held in Room 1102, Biosciences Complex, from 11:30-12:30pm. Free meet & greet pizza lunch after the seminar from 12:30-1:30PM in the 3rd floor lunch room (3406).

EEB Seminar – 9 February

This week EEB welcomes Dr. Ivana Schoepf from the Department of Biology, Queens University:

When to live alone and when to live in groups? A field experiment of the habitat saturation hypothesis


Animals display highly diverse social systems ranging from species that live solitarily to species that live in complex social groups, such as cooperative breeding species with helpers at the nest. Several studies have aimed to understand why social groups form and how they are maintained. Theory predicts that group-living can arise as a consequence of ecological constraints, while reproductive competition between group members should lead to increased costs of group-living, and thus promotes solitary-living. Several studies have confirmed the “ecological constraints“ model (also known as the Habitat Saturation Hypothesis), but field experimental tests of the reproductive competition hypothesis are lacking. Here I will present the results of a field manipulation experiment performed on a wild African mammal aimed at testing these hypotheses.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. Light refreshments are served starting at 12:15.

EEB Seminar – 30 March

This week EEB welcomes Dr. Kate Neville from the Department of Political Science and School of the Environment, University of Toronto, and Dr. Emily Darling from the Department of Ecology and Evolutionary Biology, University of Toronto:


What do seed pods have to do with coral reefs, climate refuges, biofuels, and anti-fracking protests? Thanks to the greenhouse at Queen’s, they launched the ecological training of Dr. Emily Darling and Dr. Kate Neville, whose work now spans global hemispheres and academic disciplines. Dr. Darling’s work focuses on coral reef resilience and evaluating tipping points of coral assemblages to climate disturbances, with emerging work on climate refuges. Along with her own research on life histories, multiple stressors, and community disassembly in tropical coral reef systems, she also engages in “big data” analyses, drawing together global datasets on coral bleaching and survival, with attention to socio-ecological concerns and participatory community research. With a focus on biofuels and hydraulic fracturing, Dr. Neville studies the intersection of global commodity markets with local communities and ecosystems, and the campaigns of resistance that emerge around them. Her work brings together strategies of activism, patterns of finance, and competing claims over land and resources, revealing the often negative consequences of new energy “solutions” for local people and places. This seminar takes an unorthodox approach to thinking about ecology, challenging ecologists to think further about science-policy communication and the intersecting questions of natural and social science scholars.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. Light refreshments are served starting at 12:15.

Departmental Seminar – 29 March

The Biology department welcomes Dr. Alan Cohen from the University of Sherbrooke:

How physiological complexity impacts our understanding of trade-offs, ecophysiology, and the aging process


The physiological regulatory networks that help cells and organisms maintain homeostasis are one of the best examples of a formally complex system, yet most treatment of physiology supposes that molecules have relatively simple, linear roles that can be easily understood by a reductionist approach. Here I present three examples of projects showing the importance of integrating complexity into different levels of analysis ranging from the mechanisms of aging to the evolution of life histories. First, I illustrate statistical approaches to integrate information across multiple biomarkers and extract signals of underlying processes. These approaches can be used to identify important new physiological processes, to measure condition, and to measure the aging process itself. They also point to a new mechanistic understanding of aging. Second, I present a theoretical model of how multiple physiological currencies underlying trade-offs may shape life history evolution in unexpected ways. Third, I integrate these perspectives to propose a new theory for how lifespan and aging evolve.

*This seminar will be held on Wednesday, in room 3110 of the BioSciences Complex,  from 1:30-2:30pm. *

EEB Seminar – 23 March

This week EEB welcomes Dylan Sora and Harley English-Dixon from the Department of Biology, Queen’s University:

Natural selection on phenology across the elevational range of an annual plant, Rhinanthus minor


A major question in evolutionary biology is why do species fail to adapt? A failure to adapt can be demonstrated at species range limit, and may be caused by a failure to achieve optimal trait values needed to expand beyond this limit. Species exist along a continuous gradient of differential seasonal pressures, where individuals at the range limit often experience the most severe effects of seasonality. Phenology, the timing of major life history events, is a target for selection, and may have associated life-history trade-offs (eg. time at reproduction versus size at reproduction) in environments with short growing seasons. The annual plant Rhinanthus minor grows in the Rocky Mountains of Alberta where it spans a continuous environmental gradient with an upper range limit of ~2300m. Over the past two summers I measured phenology, lifetime fitness, and other associated life history traits in natural populations of R. minor across its elevational range. I use multivariate selection analysis along with other associated statistical techniques to determine how phenotypic selection on flowering phenology differs across R. minor’s elevational range, and if phenology is the target for selection at high elevations reinforcing the upper range limit.

Personality and social dominance in the male zebra finch


Animals often display behaviours that are consistently different from the behaviours displayed by other members of the same population, within a single context. These consistent differences, which describe an individual’s personality, are sometimes correlated with other behaviours across contexts to create a behavioural syndrome. It is predicted that in social species, individuals that are bold, highly active, and exploratory will be dominant over individuals that are shy, less active, and avoidant. Understanding the relationship between personality and dominance is of special interest because dominance has been identified as a strong predictor of fitness in social species. However, experiments testing this relationship in birds have shown mixed results. I will discuss preliminary results from my MSc research, which focuses on the repeatability of personality traits and their association with social dominance in captive male zebra finches.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. Light refreshments are served starting at 12:15.

EEB Seminar – 16 March

This week EEB welcomes Dave Ensing from the Department of Biology, Queen’s University:

Research and management in an invasive plant species complex


Alien, invasive species are considered one of the greatest threats to biodiversity and ecosystems services worldwide. One such group of invasive plants is the Pilosella hawkweeds (formerly Hieracium, Asteraceae), which are native to central Europe and found as exotics throughout the Americas and Oceania (Australia, New Zealand). Similar morphology and complex life history have resulted in a variety of taxonomic classifications, and considerable difficulty and confusion when identifying them in their introduced ranges hindering control efforts. I will provide a brief natural history of this fascinating (IMO) group of species and their putative control agents. I will then highlight the potential for misplaced control efforts due to mis-identifications, establish how morphology and genetics agree that the invasive species are unique, and emphasize the necessity for species specific control efforts. This talk highlights work Dr. Chandra Moffat (AAFC) and I conducted on hawkweeds while we were students in (Queen’s alum) Jason Pither’s lab at UBC’s Okanagan Campus.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. Light refreshments are served starting at 12:15.

EEB Seminar – 9 March

This week EEB welcomes Dr. Bob Cox from the Department of Biology, University of Virginia:

Two phenotypes, one genome: Integrating endocrine, transcriptomic, and quantitative genetic perspectives on sexual dimorphism


The evolution of sexual dimorphism presents a puzzle – how do males and females express dramatically different phenotypes despite sharing essentially the same underlying genome? The answer to this question often depends on whom you ask. An endocrinologist might reply that the development of sexual dimorphism requires sex steroids such as testosterone and estradiol. A quantitative geneticist might say that it involves the reduction of genetic correlations between the sexes. A molecular geneticist might view the problem as one of regulating the expression of shared genes differently in each sex. These apparently disparate perspectives may often describe the same underlying phenomenon of genetic dis-integration between the sexes. For example, in the lizard Anolis sagrei, the gradual development of extreme sexual size dimorphism is accompanied by the ontogenetic breakdown of between-sex genetic correlations for body size and growth rate. This breakdown of genetic constraint is mirrored by a sharp increase in the sex-biased expression of hundreds of autosomal genes in the liver, particularly those genes that regulate growth, metabolism, and cell proliferation. Mechanistically, treatment of females with testosterone stimulates the expression of male-biased genes while inhibiting the expression of female-biased genes, thereby masculinizing phenotypes at both organismal and transcriptomic levels. Collectively, these findings suggest that hormones such as testosterone can orchestrate sex-biased gene expression to facilitate the phenotypic development of sexual dimorphism while simultaneously reducing genetic correlations that would otherwise constrain the independent evolution of the sexes. Moreover, changes in the coupling of testosterone to gene expression can facilitate rapid evolutionary shifts in sexual dimorphism at the organismal level.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. Light refreshments are served starting at 12:15.