EEB Seminar: January 15th

 

Thursday, January 15th, will be our first EEB seminar of the winter term.

Dr. Megan Frederickson will talk to us about

The ecology and evolution of mutualism

at 12:30 in the EEB lounge (BioSciences 4338)

The seminar is hosted by Dr. Shelley Arnott
cropped-myrmica1

Research in the Frederickson lab focuses on the ecology and evolution of mutualism, or cooperation between species. Mutualisms are extremely common in nature—so common, in fact, that every plant and animal on Earth may be involved in at least one mutualism. But cooperation is puzzling because it has the potential to be destabilized by selection for “cheating,” or taking the benefits of cooperation without fully reciprocating. The evolution of mutualism is especially perplexing because partners do not share genes, precluding inclusive fitness benefits. The Frederickson lab uses a variety of approaches to study mutualisms involving insects (especially ants), plants, and microbes in both temperate and tropical ecosystems, to broadly characterize the ecological and evolutionary dynamics of mutualisms. I will describe our recent research on “cheating” in mutualisms, trade-offs between investing in multiple mutualisms (e.g., pollination and protection mutualisms), and the role of mutualism in facilitating biological invasions.

Visit Dr. Frederickson’s lab by going to mutualism.ca
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Christmas EEB special: December 4th

eckert
 

This Thursday will be our last EEB seminar of the term. To celebrate accordingly, we have invited our very own

Chris Eckert

to talk to us about

PLANTS

and evolution ‘n stuff probably

 

at 12:30 in the EEB lounge (BioSciences 4338)

The seminar is hosted by your EEB committee

EEB seminar: November 27th

 

This Thursday, Dr. William R. Glass will talk about the

Northern range edge populations of Spotted Gar: local adaptation and implications for conservation

at 12:30 in the EEB lounge (BioSciences 4338)

The seminar is hosted by your EEB committee
 
bill glass photo with gar(1)

Populations at the edge of a species’ range are often small, isolated, and exposed to harsh environmental conditions compared to populations at the core of the range. These factors can lead to edge populations evolving at a faster rate than core populations, giving rise to local adaptation in edge populations. Thus, it becomes important to conserve range edge populations if the goal is to preserve the overall diversity within a species. Local adaptation can be manifest in many forms including changes to life history, altered behaviour and ecological interactions, and genetic differentiation.
 
The Spotted Gar (Lepisosteus oculatus) is a Threatened fish species in Canada. The species is at the northern edge of its range in Canada and is found in three coastal wetlands of Lake Erie: Point Pelee; Rondeau Bay; and, Rondeau Bay. Spotted Gar ranges as far south as the Gulf of Mexico, is generally common, and not considered to be at risk outside the Great Lakes region. We investigated the local adaptation of Canadian Spotted Gar populations through a radio-tracking study of the home range and critical habitat utilized by the Rondeau Bay population, along with a range-wide population genetic study using microsatellite loci. It was found that the Spotted Gar in Rondeau Bay use aquatic macrophytes as cover, and inhabit areas much further offshore than a core population of Spotted Gar in the Atchafalaya River basin in Louisiana, which typically uses sunken timber for cover. Population genetic data reveal that the northern populations of Spotted Gar are distinct from southern populations. Additional population structure within the Canadian sample sites was also uncovered. The results of these two studies were used to inform the Spotted Gar Recovery Strategy and the conservation of the Canadian populations of Spotted Gar will be important for the maintenance of the overall diversity within the species.
 
Bill completed his undergraduate degree and PhD at the University of Windsor, where he studied local adaptations of range edge populations of fish Species at Risk in Canada. He is currently working as a post-doctoral Visiting Fellow at Fisheries and Oceans Canada studying abundance, distribution and habitat use of fish Species at Risk.

EEB Seminar: November 20th

 

This Thursday, PhD students Haley Kenyon and Mike Lavender will talk about

Genes vs culture: song variation across an avian hybrid zone

and

The role of competition in community assembly

respectively, in a special grad student shared EEB seminar

at 12:30 in the EEB lounge (BioSciences 4338)

The seminar is hosted by Dr. Paul Martin and Dr. Shelley Arnott
 
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Elucidating the relationship between genetic and cultural evolution is important in understanding speciation, as learned premating barriers are often involved in maintaining species differences. I explored this relationship by examining a widely recognized premating barrier, bird song, in a narrow hybrid zone between black-throated green (Setophaga virens) and Townsend’s warblers (S. townsendi). I used song analysis, genomic techniques and playback experiments to characterize the cultural and genetic backgrounds of individuals in this region to determine whether song acts as an important reproductive barrier between these species.
Talk by Haley Kenyon.
 
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Competition between species is believed to play an important role in community assembly by affecting species co-occurrence patterns with trait-based limiting similarity and negative co-occurrence null models commonly used to assess competition’s role in community assembly. Negative co-occurrence patterns are suggestive of competitive interactions while under limiting similarity, competition is expected to drive the segregation of species that overlap in niche. A recent review indicates that these null models produce significant results less than half the time. The lack of findings that indicate competition is an important interaction in community assembly may simply represent the true state of things; however, it is also possible that this lack of support is due to the failure of the null models under certain conditions (i.e., due to poor statistical power). To test this we generated synthetic communities that varied in size and in the strength of the signal of limiting similarity or negative co-occurrence. We then explored the power of common null models to pick up this signal. The statistical power for both null models decreased rapidly as the strength of the signal decreased. Sufficient statistical power (β < 0.30) was achieved when 80% or more of species contributed to the signal of limiting similarity, and 60% or more of species contributed signal to patterns of negative co-occurrence. Common community-scale null models of limiting similarity and negative co-occurrence fail to report patterns that occur at the sub-community level. This problem will likely be relevant for most communities, given existing evidence that multiple processes contribute to the assembly of species within a community. While these models are useful for assessing the predominance of a pattern in communities, alternative approaches are needed to assess the influence of competition on species organization within communities in more detail.
Talk by Mike Lavender.
 
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Visit Haley’s and Mike’s respective labs by going to the Martin Lab or Arnott Lab.

EEB Seminar: November 13th

 

On Thursday, Dr. Jessica Forrest will talk about

Solitary bees in a warming world

at 12:30 in the EEB lounge (BioSciences 4338)

The seminar is hosted by Shelley Arnott
 

bee bee

Ectotherms in temperate regions stand to benefit from globally rising temperatures, which ought to increase development rates and foraging opportunities. However, climate change can also bring declining snowpack, altered phenology, and more variable weather, all of which may negatively affect ectotherms and other organisms. In this seminar, I will explore ways in which solitary bees—an important group of native pollinators—are affected by climate change, particularly in the Colorado Rocky Mountains, where I have focused my field work.

jessica forrestBy tracking reproductive success, rates of development and parasitism, and over-winter survival of individual bees, we are beginning to understand what factors limit population growth in bee species with different life-history strategies. The long-term goal is to be able to forecast bee population and community responses to multiple types of environmental change, including a warming climate.
 
Jessica Forrest is an Assistant Professor in the Department of Biology at the University of Ottawa. She obtained her MSc from Queen’s, studying zooplankton ecology with Shelley Arnott. She switched to terrestrial ecology when she began her PhD on plant-pollinator interactions with James Thomson at the University of Toronto. Jessica continues to investigate the evolutionary ecology of pollinators and pollination, with a focus on anticipating the responses of plants and their pollinators to various types of environmental change.

Visit Dr. Forrest’s website at http://forrestlab.wordpress.com/

EEB Seminar: November 6th

This Thursday, Dr. Scott Colbourne will talk on

Sympatric speciation: Foraging ecology and sexual selection in pumpkinseed sunfish (Lepomis gibbosus)

at 12:30 in the EEB lounge (BioSciences 4338)

The seminar is hosted by Fran Bonier
 

Pumpkinseed_mussels

Sympatric speciation is typically thought to require both disruptive natural selection and a mechanism of reproductive isolation that results in genetic differentiation. Divergent selection related to foraging has been described in many taxa, but the contribution of foraging to reproductive isolation and ultimately sympatric speciation are not yet well understood. Here I used stable isotope analysis of diet and morphological analysis of body shape to examine phenotypic divergence between littoral and pelagic foraging ecomorphs in a population of pumpkinseed sunfish (Lepomis gibbosus). I then examined reproductive isolation between ecomorphs by comparing the isotopic compositions of nesting males to eggs from their nests (a proxy for maternal diet), and used nine microsatellite loci to examine genetic divergence between ecomorphs. The data support the presence of distinct foraging ecomorphs in this population and indicated that there is significant positive assortative mating based on diet. However, there was no evidence of genetic divergence between ecomorphs, indicating that isolation is either relatively recent or is not strong enough to result in genetic divergence. Based on our findings, pumpkinseed sunfish represent an interesting system in which to further explore the mechanisms by which natural and sexual selection contribute to phenotypic and genetic divergence within a population, prior to the occurrence of sympatric speciation.

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Scott is currently a post-doctoral fellow at the Great Lakes Institute for Environmental Research in Windsor, ON working with Aaron Fisk and Dan Heath on the foraging ecology of Great Lakes fishes and the development of eDNA detection techniques for invasive species. In this seminar he will be focused on his PhD research with Bryan Neff and Fred Longstaffe at the University of Western Ontario during which he focused on the foraging ecology of sunfish in relation to reproductive tactics, sexual selection, invasive species, and sympatric speciation.

EEB Seminar: October 30th

This upcoming Thursday, Kiyoko Gotanda will talk on

Adaptation as a spatio-temporal mosaic of selection

at 12:30 in the EEB lounge (BioSciences 4338)

The seminar is hosted by Fran Bonier
Kiyoko

Adaptive divergence due to variation in selective pressures is believed to have generated much of the biodiversity observed today. Despite this, it is commonly assumed that selective pressures are consistent through space and time. In particular, studies often examine selection at a single site at a single time and take that to represent the selection to which a whole species is subject. However, recent work has demonstrated that there can be considerable spatial and/or temporal variation in selection, and this is what I will discuss. I will explore how spatiotemporal variation can affect adaptive divergence, and what some of the underlying causes of this variation might be.

Kiyoko is a former professional ballet dancer who is now a researcher in organismal biology. After dancing with ballet companies such as the Joffrey Ballet of Chicago and Les Grands Ballets Canadiens de Montreal, she hung up the pointe shoes and went to McGill University for her BSc. She is currently a PhD candidate at McGill University.

Kiyoko’s research focuses on the intersection of evolution, ecology, and behavior. Broadly, she seeks to understand how variation in selective pressures affects the origins and evolution of biological diversity. More specifically, Kiyoko focuses on adaptation and how it is affected by spatial and temporal variation in selection. Her website can be found via this link http://www.kiyokogotanda.com/