EEB SEMINAR – 28 APRIL

This week EEB welcomes George Divoky the Founder and Director of Friends of Cooper Island who will present:

Four Decades of Change:
An Arctic seabird responds to a warming Arctic

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Mandt’s Black Guillemot (Cepphus grylle mandtii) is a true Arctic seabird, utilizing the marginal ice zone throughout the year and leaving the Arctic Basin only when ice cover is nearly complete in winter. Since 1975 the phenology, breeding success, diet and adult survival of the species has been studied annually at Cooper Island, in Arctic Alaska. Annual temperatures in the region have increased by >3°C during the study and the Cooper Island research has been able to document the response of an Arctic marine upper trophic level predator to the unprecedented changes occurring in snow and ice habitats in a warming Arctic.

HOST: Friesen

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 – 7 APRIL

This week EEB welcomes Dr. Christine Ward-Paige of Dalhousie University who will present:

Conservation beneath the waves – assessing aquatic ecosystem conservation needs and successes, and deploying a global network of citizen scientists

Ward-Paige

Many anthropogenic activities such as overfishing, climate change, pollution and habitat destruction stress aquatic ecosystems. Although conservation and management strategies are needed to protect and restore habitat, a lack of data is often cited as a reason for inaction. This is largely because aquatic ecosystems are difficult to census and contemporary ecosystem surveys often overlook a broad geographic and historical perspective. I use citizen science to survey and monitor freshwater and marine ecosystems at local and global scales. I couple those data with chemical analysis, fisheries surveys, bioindicator censuses, and remote sensing to understand the factors influencing ecosystem processes and to delineate conservation needs. These monitoring efforts are used to assess the effect of nutrient pollution on coral reefs, the need and effectiveness of restoration projects on watersheds and need for conservation strategies on marine ecosystems. These studies have been used to improve existing conservation efforts including sewage treatment, CITES listings, and marine sanctuaries.

HOST: Eckert

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 – 31 March

This week EEB welcomes Dr. Rowan Barrett of McGill University who will present:

The genomic consequences of adaptation

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Climate change and other anthropogenic disturbances are forcing many natural populations to adapt to new environmental pressures, but the role of selection in shaping genome evolution is not fully understood. What factors explain variability in how far and fast adaptation proceeds? Two fundamental challenges are identifying the molecular basis of adaptive phenotypic variation and elucidating the evolutionary processes acting on this variation. We would like to know which genes and, in particular, which alleles produce diversity, and how natural selection influences this variation. In natural populations, putatively adaptive loci often have been identified using genome scans, which detect outlier loci with variation significantly different from neutral expectations. Yet, this approach has some limitations; for example, it cannot inform us about the mechanistic basis of selection, recombination can obscure signals of past selection, and it can be difficult to distinguish between patterns created by demographic versus selective forces. Experimental studies help clarify the genetics of adaptation by documenting the mechanisms and targets of selection that drive changes in allele frequency (the process) in ways that are not possible when investigating historical signatures of selection (the outcome). Here, I will describe manipulative experiments with deer mice, threespine stickleback fish, and Anolis lizards that directly estimate how selection impacts the genome as populations adapt to new environmental conditions. The results shed light on the pace of adaptive evolution in nature and improve our understanding of the functional connections between genotype, phenotype, and fitness.

HOST: EEB

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 – 24 MARCH

This week’s EEB is a split session featuring two MSc candidates of the Queen’s University Department of Biology:

Part One – Megan Snetsinger, Lougheed Lab

Isolation of an endangered snake across a fragmented landscape

Negative impacts of human activities on natural systems are pervasive.
Human 20150609_140954development has been linked with biodiversity loss worldwide through the fragmentation of native habitats, resulting in reduced genetic diversity and small population sizes, and ultimately threatening species persistence. Understanding and mitigating these effects are important themes in conservation biology. My MSc research will focus on how anthropogenic factors have impacted the Butler’s Gartersnake, a species that in Canada is found only in southwestern Ontario, where much of the available land has been converted for agriculture. Using DNA microsatellite data, I have quantified genetic population structure in Ontario populations, with the ultimate goal of analysing how current landscape features relate to population connectivity and dispersal. I have also compared genetic patterns in this marsh/prairie habitat specialist with the more widespread Eastern Gartersnake, to better understand how different life histories shape genetic diversity and distributions. My findings will help guide conservation efforts for the Butler’s Gartersnake.

 Part Two – Dan McCarthy, Tufts Lab

Interactions between Angling and Invasive Species on Nest-Guarding Black Bass in Lake Ontario

Round Gobies were first documented in the St. Clair River in 1990, and since have spread throughout the Great Lakes faster than any other previous invasive fish. Now, Round Gobies pose a significant threat to many native species. They are a known predator of Bass eggs, and recent concern has been raised about changes in the recreational angling season and Black Bass recruitment in Lake Ontario. It is important to characterize the effect that Round Gobies have on both Largemouth and Smallmouth Bass in this region to make informed management decisions conserving the health of this recreational fishery.
Dan Wet Suit

HOST: Lougheed / Tufts 

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 – 17 March

This week EEB welcomes Dr. Mike Webster of Cornell University who will present:

Sexual Signals, Divergence, & Reproductive Isolation in Australian Fairy-wrens

Sexual selection is generally thought to promote divergence between populations and potentially also lead to reproductive isolation (i.e., speciation), but the behavioral mechanisms underlying this process generally are not well understood. We are exploring these mechanisms in populations of the red-backed fairy-wren, an Australian passerine bird, as well as other species of fairy-wren. Broad geographic sampling shows strong divergence across populations in male sexual signals, including both plumage coloration and song. Genomic approaches reveal a strong cline of genetic divergence separating eastern from western populations. This genetic cline is concordant with variation in songs, but differs significantly from the cline in plumage signals, indicating that plumage traits, but not song traits, are introgressing across populations. Field experiments that manipulated both signal types reveal that female mating preferences promote introgression of plumage traits, and also that male-male competition limits introgression of song but allows introgression of plumage. Together these results call for increased attention to the behavioral responses of conspecifics to divergent sexual signals, as these responses will determine the patterns of reproductive isolation that result.

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Mini-bio: Mike Webster’s research focuses on the social behavior of birds from an evolutionary perspective, particularly focusing on the processes and outcomes of sexual selection. Research in Webster’s lab is integrative and examines issues from both ultimate and proximate perspectives, and combines intensive fieldwork with genetic, hormonal and other lab analyses to unlock the secret lives of birds and other taxa. Most of this work focuses on New World Warblers and Australian Fairy-wrens. Webster received his B.S. degree from the University of California at San Diego, and his Ph.D. from Cornell University. After a Postdoctoral Position at the University of Chicago, Webster moved to academic appointments at SUNY Buffalo and Washington State University. Currently, he is the Robert G. Engel Professor of Ornithology in the Department of Neurobiology and Behavior at Cornell University, and also Director of the Macaulay Library at the Cornell Lab of Ornithology.

HOST: Martin

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 – 10 MARCH

This week EEB features our very own Dr. Bob Montgomerie who will lead a discussion regarding:

#HandOfGod

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Recent scandals, retractions, and evidence of fraud or misconduct in science have brought a number of important issues to the forefront that I think are worh our attention. In this session I will briefly present some examples, but mainly I would like to discuss the reasons for this flurry of interest in how science is done, and what we might consider as ways to solve the problem (if we agree that there is a problem). You can prepare for this discussion by reading some of the examples and comments on the Retraction Watch (http://retractionwatch.com/) and PubPeer (https://pubpeer.com) websites. And, of course, at the Twitter feed in the title.

HOST: EEB

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 – 3 MARCH

This week EEB features Queen’s University Department of Biology postdoc Dr. Maggie Bartkowska who will present:

Identifying causes of natural selection and assessing how asexual reproduction influences selection on genome-wide diversity.

Bartkowska

Selection is assumed to be a central process in nature. Although much effort has been made to quantify selection in nature, whether and how selection drives phenotypic and molecular evolution remains unknown for most systems. This is because the agents of selection and variation in selection (through time and space) are rarely assessed, and populations that deviate from random mating may experience selection differently than predicted by theoretical models. I address these gaps in two study systems. First, using a combination of field observations and experimental manipulations in Lobelia cardinalis (cardinal flower), I identify agents of selection on floral characters, and show that successful pollen transfer can vary with local floral density. In a species with separate male and female flower phases, such as L. cardinalis, successful pollen transfer varies with the density and ratio of surrounding male and female flowers, implying that the local floral environment may shape selection on floral traits. Second, using Next Generation Sequencing data, I infer the history of selection and reproduction in Spirodela polyrhiza (giant duckweed), a flowering plant thought to be almost exclusively asexual. Unlike other angiosperms, purifying selection appears to be reduced in S. polyrhiza and linkage disequilibrium across the genome is high, consistent with the expectation that selection will be less effective in populations with reduced levels of recombination. Understanding adaptive evolution, and how deviations from an idealized population influence adaptive evolution, is critical to explaining patterns of phenotypic and molecular diversity across all taxa.

HOST: Eckert

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.