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
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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.

Colborne_profilepic

 
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/

EEB Seminar: October 23rd

 

This upcoming Thursday, University of Waterloo’s Dr. Josh Neufeld will talk on how
 

A perfect storm of scientific serendipity implicates Thaumarchaeota in global vitamin B12 production
 

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

Vitamin B12 (cobalamin) is a complex metabolite and essential cofactor across many branches of life, including most aquatic algae. Eukaryotic algae and other cobalamin auxotrophs rely on environmental cobalamin supplied from a relatively small set of vitamin-producing prokaryotic taxa. Although several bacteria have been implicated in cobalamin biosynthesis and associated with algal symbiosis, the involvement of Archaea in cobalamin production is poorly understood; the Thaumarchaeota had not been implicated in cobalamin synthesis prior to this research. Based on the discovery of a complete thaumarchaeal cobalamin pathway in the metagenome of an aquarium biofilter, we hypothesized that Thaumarchaeota, which are ubiquitous and abundant in aquatic environments, play an important role in cobalamin biosynthesis within aquatic ecosystems. To test this hypothesis, we examined cobalamin synthesis genes across sequenced thaumarchaeal genomes and over 50 metagenomes from a diverse range of marine, freshwater, and hypersaline environments. Our analysis demonstrates that all available thaumarchaeal genomes possess cobalamin synthesis genes, predominantly from the anaerobic pathway, suggesting widespread genetic capacity for cobalamin synthesis. Furthermore, although bacterial cobalamin genes dominated most surface marine metagenomes, thaumarchaeal cobalamin genes dominated metagenomes from polar marine environments, increased with depth in the marine water column, and displayed a potential seasonality with increased winter abundance observed in time-series datasets (e.g., L4 surface water in the English Channel). Our results suggest niche partitioning between thaumarchaeal, euryarchaeal, proteobacterial, and cyanobacterial cobalamin genes across all metagenome datasets analyzed. Analyses of available soil metagenomes also implicate Thaumarchaeota as relatively abundant cobalamin producers in terrestrial habitats. These results provide strong evidence for specific biogeographical distributions of thaumarchaeal cobalamin synthesis genes, expanding our understanding of the global biogeochemical roles and keystone services provided by Thaumarchaeota.
 
josh
 
Josh Neufeld is an Associate Professor in the Department of Biology at the University of Waterloo. As a microbial ecologist, Josh combines cultivation-based and molecular approaches for studying biogeochemical cycling in aquatic, terrestrial, and host-associated environments.

His website can be found here (https://uwaterloo.ca/biology/people-profiles/josh-d-neufeld) and he communicates via Twitter (@joshdneufeld).

EEB Seminar: October 16th

This upcoming Thursday, our very own Dr. Virginia Walker will talk on
 

There may be more to nanoparticles than meets the eye
 

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

There is no doubt that engineered nanoparticles (NPs) found in a variety of consumer goods are technologically valuable. However, we need to understand their potential toxicity so that the costs and benefits of their near-ubiquitous applications can be evaluated. The chance discovery that Julie’s mum had purchased one of those NP-discharging clothes washers has given me wanderlust. I have journeyed to Paul’s arctic site for soil samples, visited the med school’s “mouse house”, paid several visits to Emma’s ‘roboguts’ in Guelph, and dusted off my own fruit fly bench. I have even inveigled Pranab, Niraj and Laura to join me in this obsession. Although the quest will continue, for now, our molecular and physiological evidence suggests that there may be more to NPs than meets the eye, and that perhaps we should exercise some caution before using them ‘frivolously’.

Walker

EEB Seminar: October 9th

Dr. Arthur E. Weis will talk on

Phenology as Habitat Choice in Plants: How and why the when of germination and flowering determines the what and who of fitness impacts, everywhere

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

Correctly timing the transitios-arven-fieldn from one life history stage to the next is key to individual survival and reproduction. The date of a transition has no intrinsic fitness impact. Rather, selection on the timing of birth, dispersal, reproduction, dormancy, etc., arises because individuals that transition at different times experience different temporal segments of the general environment. Climate, resource availability, and exposure to enemy/mutualistic/competing species can change predictably over the course of the seasons. Individuals occupying different temporal segments can have predictable fitness differences. In addition, differences in transition time also expose individuals to different segments of the social environment.

In populations that are heterogeneous for phenology, some sets of individuals are more likely to interact than others. Partitioning total selection on phenology into components caused by the general and social environment is fraught with difficulty. The temporal general and social environment are inevitably correlated. Further, phenological traits by necessity impose confounding genotype-environment correlations. I will present three experiments with Brassica rapa that manipulate these correlations to examine components of selection on germination and flowering time. One manipulates the length of the growing season to examine the fitness function for flowering time. A second contrasts selection on flowering time through female and male function by breaking the genetic correlation between mates (eliminating assortative mating). A third reveals that asymmetric competition between early and late germinants gives rise to individual and group components of selection.

 
After 19 years in southern California, Dr. Weis returned to the land of four seasons to take directorship of the Koffler Scientific Reserve at Jokers Hill. He lives at the reserve and has a research laboratory there. His main lab and greenhouse space are on the main campus of U of T, where Dr. Weis is a professor in the Department of Ecology and Evolutionary Biology.

Recently, Dr. Weis has become interesteart_weisd in the selective pressures imposed by climate change. In California, his lab used the “resurrection paradigm” to demonstrate a rapid adaptive response by field mustard, a winter annual, to an extended drought. At KSR he is continuing to work on the evolution of phenology to lengthening growing seasons.

The Weis lab website can be found here.