Examining phenological variation of an invasive plant using a developmental model
My research examines the basis for variation in flowering time in an invasive wetland plant, Lythrum salicaria, using a model of stem development. I present time series data from an ongoing common garden experiment at Queen’s University Biological Station, with families representing populations from across a 1000 km transect of eastern North America. I will also discuss the underlying data science challenges I encountered while analyzing repeated and multifaceted observations of nearly 3600 individuals and solutions with broad utility for other researchers.
The Impacts of Plastic Debris on Aquatic Ecosystems
Plastic pollution is reported in freshwater and marine habitats globally. Hundreds of species, across multiple trophic levels, are contaminated with plastic and effects have been demonstrated across several levels of biological organization. Using recent insights, this presentation will discuss the sources, fate and impacts of plastic in aquatic ecosystems.
Chelsea Rochman is a trained Ecologist with emphases in Marine Ecology, Ecotoxicology and Environmental Chemistry. She is interested in the side-effects of industrialization on the environment and its inhabitants. Her broader research interests regard the ecological effects of anthropogenic contaminants on wildlife and human resources (e.g. water, seafood). More specifically, her current focus is the implications of the infiltration of plastic debris into aquatic habitats. In addition to her academic research, Chelsea participates in policy meetings and working groups to translate scientific research beyond academia.
This week we welcome the Friesen lab for an open discussion.
For the love of the planet
The International Panel on Climate Change tells us we have less than 12 years to reduce greenhouse gas (GHG) emissions by 45% below 2010 levels to avoid “climate catastrophe”. We are making some baby-steps in this direction, but change is slow. What can we, as time-crunched biologists, do to help generate this magnitude of change, in so little time? The global community has been able to mitigate environmental crises in the past – how did we do it? What makes a successful social revolution? Who are the main generators of greenhouse gases: individuals or industry? And how do we motivate them to change? The Friesen lab will guide a general discussion, with insights from various professionals from academia, government, and nonprofit organizations, with the goal of generating concrete ideas.
Anthropocene determinants of diversity in island anole lizards
The central aim of my research is to understand how ecological and evolutionary factors combine to determine biodiversity patterns over large spatial and temporal scales. To do this, I use radiations of Anolis lizards on Caribbean islands as a natural experiment to test hypotheses about macroevolution, biogeography, and community ecology. In this seminar, I will ask how biogeographic patterns and community structure, both of which bear strong signatures of macroevolutionary history, are being reshaped by human activities in the Anthropocene. Specifically, I will ask how classic biogeographic factors (e.g., island area and isolation) and economic trade combine to predict species richness in invaded island faunas, and how natural climate gradients and recent land use patterns jointly predict the assembly of local communities within islands.
How changing biodiversity in the Canadian Arctic is affecting seabirds: from pathogens to predators, bacteria to bears
We often view the Arctic as a pristine wilderness largely free of environmental threats. Times are changing. I’ll provide a few examples of changing conditions currently affecting eider duck populations in Arctic Canada: harvest, emerging diseases, and changing predatory regimes. Infectious disease is a potentially important driver of wildlife population dynamics although the demographic effects of disease in free-ranging hosts have proven difficult to quantify. Avian cholera is a highly virulent disease of birds that has circulated among common eider populations in Europe and North America for several decades. The disease has recently appeared in the Canadian Arctic where high annual mortality, coupled with near total reproductive failure on affected colonies, has raised fears over local extirpation and severe population decline. In this study, our group used data from a marked population of northern common eiders (S. m. borealis) to estimate vital rates before and during a multi-year cholera outbreak. Nesting success remains below replacement level and there has been no evidence for population recovery. Climate change can also influence species directly by modifying their physical environment or indirectly by altering interactions among organisms. Changes affecting the ecology of top predators are a particular concern because variation in predator behaviour has the potential to restructure food webs and lead to cascading ecological impacts on prey populations. Polar bears (Ursus maritimus) are a top predator in the circumpolar Arctic and are adapted to use sea ice as a platform to hunt seals. Advancement in the timing of sea ice break-up in the spring has recently reduced the access of seals to bears, and has been associated with increased bear predation of eider eggs on islands in summer. The proportion of days on which bears are present on eider duck colonies before their median annual laying date has more than doubled during the past two decades. Nest success has also declined raising concern about the long-term viability of ground-nesting bird populations such as eiders that are unaccustomed to such intensive depredation by bears.
The evolutionary ecology of alternative reproductive tactics in Chinook Salmon
Until recently, sexual selection theory assumed most taxa were monogamous and selection was thought to operate mainly via processes prior to copulation, namely mate choice (typically females choosing amongst males) and competition for mates (typically among males). However, genetic and behavioural studies have shown that sexual promiscuity is common among most taxa. Multiple mating by females creates the potential for sexual selection to continue post-copulation via; (i) the competition between sperm of different males for the fertilization of ova (sperm competition) and (ii) the differential use of sperm from one male over another, with a presumed genetic benefit to offspring fitness (cryptic female choice). As a result, reproductive fitness is now understood to be determined by the complex interactions of male and female traits (at the phenotypic/genotypic level) during episodes of selection pre- and post-copulation. In this seminar I will outline some of the recent research our lab has conducted to better understand pre- and post-spawning sexual selection among alternative male reproductive tactics of Chinook salmon and outline areas where we are pursuing new research using behavioural, physiological, proteomic and transcriptomic approaches to better understand sexual selection and the evolutionary ecology of alternative reproductive tactics.
Eco-evolutionary impacts of land use on freshwater communities
My work focuses on eco-evolutionary dynamics in human-altered environments, asking whether changes in intraspecific variation and contemporary evolution caused by anthropogenic stressors can influence population, community, and ecosystem-level processes. This talk will describe two projects in which we (tried to!) link human-induced phenotypic change to ecological processes. Both projects focus on aquatic communities impacted by land use intensification: the first project asks if stream invertebrates and fishes can adapt to watershed deforestation in an African biodiversity hotspot, while the second project tests the theory of ‘evolutionary rescue’ in pond mesocosms facing pesticide pollution.