Ecology and Evolutionary Biology

Royal Ontario Museum

Researchers at the Royal Ontario Museum (ROM) and the ��Ƶ have discovered evidence of the oldest swimming jellyfish in the fossil record, CNN reports.

A study, published in Proceedings of the Royal Society B, documented the finding of 182 fossils in the Burgess Shale, a deposit in B.C.’s Rocky Mountains known for its rich preservation of the explosion of life during the Cambrian period.

Researchers found that the fossils belong to a newly identified species of jellyfish that swam in the Earth’s oceans 505 million years ago, CNN reported. Given that jellyfish are 95 per cent water, it is a remarkable and rare fossil find.

“Although jellyfish and their relatives are thought to be one of the earliest animal groups to have evolved, they have been remarkably hard to pin down in the Cambrian fossil record,” Joe Moysiuk, a PhD candidate in the Faculty of Arts & Science’s department of ecology and evolutionary biology, who is based at the ROM, said in a statement quoted by CNN. “This discovery leaves no doubt they were swimming about at that time.”

Co-author Jean-Bernard Caron, an associate professor in ecology and evolutionary biology and the ROM’s Richard Ivey Curator of Invertebrate Palaeontology, adds that the discovery the new species – called the Burgessomedusa phasmiformis – enriches our understanding of the complexity of Cambrian food webs, noting that these jellyfish were efficient swimming predators.

The discovery was covered by outlets around the world, including the Guardian, CBC News and New Scientist. Visitors can see fossils of Burgessomedusa phasmiformis at the ROM’s Willner Madge Gallery, Dawn of Life.

The trash clogging Toronto's harbour has been turned into art: CTV News

Christopher.Sorensen — Fri, 21 Jul 2023 15:26:20 +0000

The trash clogging Toronto's harbour has been turned into art: CTV News

Christopher.Sorensen Fri, 07/21/2023 - 11:26

Cutline

(photo by Jack McCombe)

Topic

Sustainability

Waste collected from the city's waterfront by the ��Ƶ’s Trash Team has been turned into a floating art installation intended to remind people about the pervasiveness of pollution.

The sculpture, called “Tangle,” is made of refuse ranging from polypropylene bags to microplastic particles and discarded toys – all wrapped in willow branches and invasive plants found in Lake Ontario. It can be viewed in the Harbourfront neighbourhood’s Peter Street Basin until September.

Created by Trash Team artist-in-residence Emily Chudnovsky, the work is designed to raise awareness of the waste we routinely see in our waterways.

“We produce so much waste as a global society,” Chudnovsky told CTV News. “How can we use less material and how can we learn from the natural world, which has many different systems for filtering waste, repurposing waste and not producing waste?”

The U of T Trash Team is made up of undergraduate and graduate students, post-doctoral researchers, local volunteers and staff working in collaboration with Chelsea Rochman, an assistant professor in the Faculty of Arts & Science’s department of ecology and evolutionary biology.

Read the story at CTV News

Beyond Wordle: U of T students, staff and faculty share their pandemic hobbies

geoff.vendeville — Mon, 24 Jan 2022 19:08:43 +0000

Beyond Wordle: U of T students, staff and faculty share their pandemic hobbies

geoff.vendeville Mon, 01/24/2022 - 14:08

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Divya Dey, an undergraduate student at U of T Scarborough, used the pandemic as an opportunity to take up outdoor hobbies – from camping and caving to tree-top trekking (photo courtesy of Divya Dey)

Geoffrey Vendeville

Topic

Undergraduate Students

Solving Wordle’s daily mystery word has emerged as the latest in a long line of pandemic-era pastimes – beginning with the sourdough-baking craze of 2020.

Yet, while the online puzzle has quickly racked up millions of devotees, it's not the only thing helping people cope with a frigid winter amid the latest – and hopefully last – wave of COVID-19 transmission.

U of T News asked ��Ƶ students, staff and faculty what's bringing them joy these days.

Divya Dey

Bachelor of science student at U of T Scarborough

(Photo courtesy of Divya Dey)

As a fourth-year student at U of T Scarborough studying environment sciences, I love being immersed in the great outdoors! But being a student, it can be hard to find time to do the things I love, so, since the start of the pandemic, I made it a mission to try new things in outdoor settings.

I have gone cliff jumping, caving, tree-top trekking, camping, visited farms, gardening and countless hikes across Ontario. This has allowed me to push my personal boundaries, try new things and bond with my family (especially my dog) while doing so!

Charlie Keil

Principal of Innis College and professor in the department of history in the Faculty of Arts & Science

When the pandemic caused my local gym to close, I started running every day – always early in the morning. There is only so much techno music one can listen to, which led me to podcasts. I’ve now become a devotee, particularly to those that offer political analysis or cultural commentary.

The one caveat: They must last close to one hour, so that I don’t have to switch my selection midway through my run. COVID-19 is thoroughly pernicious, but it has provided an opportunity for sustained edification. A regular dose of Ezra Klein is good for the brain. And now I can’t get by without my weekly instalments of the Slate Political Gabfest and Culture Gabfest.

Lisa Erdle

PhD candidate in the department of ecology and evolutionary biology in the Faculty of Arts & Science

One thing that is getting me through the latest phase of the pandemic is spending time outside.

This time of year, the waterways around the Toronto Islands typically freeze. This year, in the thick of our cold weather, we’ve had perfect conditions for skating.

We’ve also gotten a bit creative – my husband and I built an “ice sail” by repurposing items we found in the trash, including a broken paddle and a ripped sail.

Going out on the ice (with safety gear, of course) and trying something new reminds me that we can have adventures in our own backyard.

@outsidebrendan Ice skate sailing pt. 1! #wintermagic #wildice #getoutside #iceskating #olympicscountdown ♬ Rasputin (Single Version) - Boney M.

Nick Iwanyshyn

Photographer and video producer at U of T Mississauga

(Photos courtesy of Nick Iwanyshyn)

My fiancé and I moved to Hamilton from Toronto in the spring of 2020.

Over the summer, we made a habit of riding our bikes to a coffee shop every Saturday – never the same one twice – to explore our new surroundings. Some of our favourite cafés so far are Smalls Coffee, Durand Coffee and Synonym Shop.

With the temperature occasionally dropping to -20 Celsius, it can be hard to find motivation to go outside. But even in the depths of winter, I never regret leaving the house for an oat cappuccino.

Jaco Lokker

Director of culinary operations and executive chef

Like many, I rediscovered the joy of cooking at home. I started the pandemic by scrambling around, trying to find yeast and flour so I could bake bread. I quickly realized that bread was just not my thing.

After that, I spent my summer barbecuing, having a friendly competition with my neighbour to see who would master the almighty brisket.

As fall arrived, I finally found my true passion: making incredible, rich and flavorful homemade stocks. Or some would prefer to refer to them as bone broth. To me, they're the same. They bring an immense amount of flavour to meals. I use them as a base for all my soups and stews. I've also used them for dishes like risotto or when making rice pilaf or paella.

I have added a recipe for my favourite: leek and potato soup. For those still baking bread, I bow to you!

(Photos courtesy of Jaco Lokker)

Jaco Lokker's leek and potato soup

Servings: 8
Prep Time: 20 Minutes
Cook Time: 40 Minutes
Total Time: 1 Hour

Ingredients:
30 grams — Butter
700 grams — (3 large) Leeks roughly chopped, white and light green only
700 grams — (8 medium) Yellow fleshed potatoes, peeled and roughly chopped into 1/2-inch pieces
2 litres — Chicken broth or vegetable broth
2 — Bay leaves
250 millilitres — 35 per cent cream
To taste — Himalayan sea salt
To taste — Fresh ground black pepper

Chopped chives for garnish

Instructions:

Melt the butter over medium heat in a large soup pot. Add the leeks and sauté, stirring regularly, until soft. Adjust the heat if necessary, to avoid the leek from browning.
Add the potatoes, your choice of chicken or vegetable broth and bay leaves. Let the pot come to a boil and reduce heat to a simmer. Simmer for 15-20 minutes, or until the potatoes are soft. Add the 35 per cent cream and season.
Remove the bay leaves, then purée the soup with a hand-held immersion blender or a regular blender until smooth.
Serve in a bowl and top with chives or parsley.

U of T study shows winter road salt poses year-round threat to aquatic life in Toronto’s rivers

Christopher.Sorensen — Tue, 16 Mar 2021 15:23:46 +0000

U of T study shows winter road salt poses year-round threat to aquatic life in Toronto’s rivers

Christopher.Sorensen Tue, 03/16/2021 - 11:23

Cutline

(photo by Lubo Ivanko/Getty Images)

Chris Sasaki

Topic

Sustainability

As spring nears, two ��Ƶ researchers have found that the salt spread on roads and sidewalks in the Greater Toronto Area during the wintertime remains a threat to aquatic life in the city’s rivers during the warmer months.

PhD student Lauren Lawson and Donald Jackson, a professor of aquatic ecology in the department of ecology and evolutionary biology, in the Faculty of Arts & Science, say heavy salting – including by businesses and private citizens, who the researchers say tend to salt excessively – is having a year-round impact on aquatic life.

They reported their findings in a paper published recently in the journal FACETS.

“Our research shows that chloride pollution from road salt is a year-round threat to our urban freshwater ecosystems,” says Jackson. “Of the samples we took from four GTA rivers and creeks during the summer, we found that nearly 90 per cent exceeded federal guidelines for long-term exposure of aquatic life to chloride.”

In northern temperate regions like North America, the primary non-natural or anthropogenic source of salinization is road de-icing and anti-icing agents applied to highways, streets and sidewalks. In cities – where road density is highest – this results in high concentrations of chloride in runoff flowing into urban waterways.

Lawson and Jackson estimate that more than one-third of the sites sampled had concentrations that would be lethal, according to government guidelines, to two-thirds of aquatic species – and possibly more given species’ greater sensitivity while in early stages of development during the summer. The concentrations discovered may also negatively affect reproduction and spawning.

“Increased chloride concentrations in freshwater can be toxic and lead to changes in an organism’s behavior and ability to withstand other stressors,” says Lawson. “It can increase lethality, alter food webs and lead to biotic homogenization where only hardier species survive.”

The researchers measured the concentration at 214 sites along four GTA waterways: the Humber and Don rivers, as well as Mimico and Etobicoke creeks. The sites ranged from the headwaters north and northwest of the city to where they enter Lake Ontario in Toronto.

A location on Mimico Creek where U of T researchers sampled water to measure chloride from road salt (photo by Donald Jackson)

Samples were collected in July and the first two weeks of August when chloride concentrations are typically at their lowest level. Concentrations are expected to be higher during the preceding winter months when road salt is actively applied to roadways and sidewalks.

The U.S. and Canada annually use roughly 24.5 and seven million tonnes of road salt respectively in both commercial and industrial applications, as well as to de-ice sidewalks of small businesses and homes. Toronto alone uses 130 thousand tonnes of road salt each year – an amount equal to the weight of the CN Tower.

As the co-authors point out, Toronto has a salt management plan that includes the use of more effective brine instead of salt, as well as technology designed to optimize spreading and reduce use.

But, Lawson and Jackson say, there is more work to be done.

For example, the researchers say private citizens often use excessive amounts of salt and spread it in an inefficient manner. Also, salt use at transit stops is unregulated, which can result in less than optimal application.

“We need private citizen education – including for businesses – on the proper amount and application of road salt,” says Jackson. “A little salt goes a long way when applied correctly.”

Given their findings, the authors recommend research to better inform revisions to current federal guidelines. In particular, they suggest a focus on site-specific biological communities and increased attention to the year-long impact road salt has on urban ecosystems.

“Ultimately, it is critical to track changing environmental quality as the constant urbanization of Toronto changes land-cover,” says Lawson.

“Tracking environmental change will provide evidence for the need for sustainable management and city-development in an increasingly concrete world.”

The research was supported by the Natural Sciences and Engineering Research Council of Canada.

Meet five U of T researchers awarded 2021 RBC Post-Doctoral & Graduate Fellowships

Christopher.Sorensen — Thu, 11 Mar 2021 16:01:15 +0000

Meet five U of T researchers awarded 2021 RBC Post-Doctoral & Graduate Fellowships

Christopher.Sorensen Thu, 03/11/2021 - 11:01

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From left to right: Amlan Kar, Roshni Thawani, Harris Chan, Maxwell Farrell and Ilya Yakavets (photos courtesy of RBC)

Topic

Entrepreneurship

Faculty of Information

Startups

ThisIsThePlace

Vector Institute

Five ��Ƶ researchers – working on artificial intelligence, anti-cancer therapies, pandemic prevention and international learning – were awarded RBC Post-Doctoral & Graduate Fellowships at this week’s virtual Entrepreneurship Week.

The fellowships, offered through a partnership between U of T, RBC and Borealis AI, recognize emerging U of T leaders who are establishing a record of research, scholarship and making an impact .

“RBC and Borealis AI have supported ��Ƶ students and trainees and helped foster the next generation of tech innovators and entrepreneurs in Canada,” said Derek Newton, U of T’s assistant vice-president of innovations, partnerships and entrepreneurship. “Organizations like RBC and Borealis AI provide more than financial aid – they also help our researchers with industry mentorship and guide them to access key capabilities, as they work to explore their field of research.”

The 2021 RBC Post-Doctoral & Graduate Fellowship winners are focused on applying a range of innovative technologies and techniques to help address key societal and health issues.

“With a focus on creating new computational models to help address key societal and financial services problems, the winners of the 2021 RBC Post-Doctoral & Graduate Fellowships are helping policy-makers, educators, service providers and entrepreneurs forge a more innovative future,” said U of T alumna Eirene Seiradaki, director of research partnerships at Borealis AI. “As the AI research centre backed by RBC, Borealis AI is excited to see how this esteemed group will influence innovation and entrepreneurship at UofT and around the world.”

“Innovation is a critical component of RBC’s tech strategy, and we’re thrilled to partner with the ��Ƶ to support these researchers,” added Bruce Ross, RBC’s group head, technology and operations. “The RBC Post-Doctoral & Graduate Fellows are working on cutting-edge projects that will elevate and enrich the tech industry in Canada and around the world.”

Here are this year’s winners:

2021 RBC Graduate Fellows

Harris Chan: PhD candidate in computer science n U of T’s Faculty of Arts & Science and the Vector Institute

Research topic: Goal-Agnostic Exploration for Multi-Goal Reinforcement Learning

Research interests: The intersection of deep reinforcement learning and natural language processing for developing efficient and generalizable learning systems with applications to robotics

“Current reinforcement learning systems are encouraged to collect their own data through an AI agent that maximizes some cumulative reward – just like a human might train a pet by offering tasty treats. However, most reinforcement learning systems are capable of only completing a single task or game at a time. And they require billions of interactions with the environment in order to learn. Multi-goal reinforcement learning, on the other hand, trains an agent to achieve many potential goals, thereby allowing a single agent to achieve competency at several tasks and – potentially – generalize to novel situations.

“I am very honoured to have been awarded the RBC Graduate Fellowship and am excited to see how our research in Multi-Goal Reinforcement Learning can allow us to make an impact in academia and beyond.”

Amlan Kar: PhD candidate in computer science in U of T’s Faculty of Arts & Science and the Vector Institute

Research topic: Machine Learning for Machine Learning Data

Research interests: Creating automated 3D content and human-in-the-loop interactive annotation techniques to help create data for machine learning

“As the world of artificial intelligence becomes increasingly dominated by large scale data-driven techniques, my research focuses on making annotated machine learning data more easily available to researchers and practitioners. We are seeking to develop algorithms that support efficient human-in-the-loop annotation and automatic data generation with simulated 3D content creation. That, in turn, should allow us to extend beyond synthetic data generation to a wide range of applications including indoor and outdoor environment design, architecture and simulation for algorithm testing.

“The RBC Graduate Fellowship award should allow me to expand the research within real human environments while, at the same time, creating opportunities for commercial value to be created.”

Roshni Thawani: Master’s candidate in U of T’s Faculty of Information

Research topic: Creating a digital application prototype to support international learning experiences

Research interests: Building a universal digital hub for international learning through human-computer interaction, user experience design and ethnographic research.

“UNESCO estimates that in 2017 there were more than 5.3 million international students studying abroad. My research aims to make that a more seamless and valuable experience for the students, academic institutions and other stakeholders. Based on pain points gathered from secondary and primary ethnographic research, the application would pool information from various online sources such as internship organizations, abroad universities, bursaries, loans, scholarships and other university funding forms in order to generate a customized plan of action to help the user reach their goal destination.

“With the support of the RBC Graduate Fellowship award, I hope to create a seamless international experience that encourages more students to learn overseas and creates a more inclusive and higher-quality level of education for all.”

2021 RBC Post-Doctoral Fellows

Maxwell Farrell: PhD, ecology and evolutionary biology in U of T’s Faculty of Arts & Science

Research topic: Predicting the severity of cross-species infectious diseases

Research interests: Identifying the forces that shape, host and parasite biodiversity and building tools to prioritize research for diseases that are likely to become public health threats in the future.

“Many infectious organisms have the ability to infect more than one host species. Yet, there is currently limited information to predict the outcome of infection across host-parasite combinations. A major limitation has been the lack of comparable data for a large diversity of hosts and parasites. Using machine learning and text analysis of scientific literature, I will build a novel global database of infection-induced diseases for all known parasites of mammals.

“This RBC Post-Doctoral Fellowship will help create a greater understanding of the evolution of infectious diseases which, in turn, will form the basis for predicting the impacts of emerging infectious diseases before they jump to infect humans, domesticated animals and wildlife."

Ilya Yakavets: PhD, chemistry in U of T’s Faculty of Arts & Science

Research topic: Deep learning framework for self-driven development of combination cancer chemotherapies in a microfluidic spheroid-on-a-chip platform
Research interests: Applying deep learning to the development of new anticancer therapies, including multi-drug combinations and nanomedicine

“Breast cancer is the most commonly diagnosed cancer in females in Canada, accounting for one in four of new cases. And combination chemotherapies offer the potential for the improvement of therapeutic responses of breast cancer patients by utilizing multi-drug cancer treatment. To help medical professionals and patients make a decision about the best drug combination in a time-effective manner, we will integrate frontier artificial intelligence with a ‘spheroid-on-a-chip’ microfluidic device in a way that would allow simultaneous high-throughput screening of multiple drug combinations.

“This RBC Post-Doctoral Fellowship has the real potential of augmenting physician decision-making with AI in order to provide innovative cancer treatments. It makes a big dream more reachable.”

From longer holidays to compassion in the classroom: Supporting U of T students during COVID-19

Christopher.Sorensen — Fri, 18 Dec 2020 21:28:01 +0000

From longer holidays to compassion in the classroom: Supporting U of T students during COVID-19

Christopher.Sorensen Fri, 12/18/2020 - 16:28

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(photo by David Lee)

Geoffrey Vendeville

Topic

UTogether

Geography and Planning

Undergraduate Students

Urban Studies

Earning a university degree isn’t easy – and this year the challenge is made more difficult by a global pandemic that has forced students to dramatically alter the way they live, study and socialize.

That’s why ��Ƶ President Meric Gertler recently extended the winter break by one week to Jan. 11. for students in first-entry undergraduate divisions and some graduate and professional programs.

“It’s prompted by the fact that we’ve all been under an extraordinary amount of stress for months now, because of the burdens imposed by the COVID-19 pandemic,” he said in a letter to the U of T community.

“The entire leadership team across our three campuses cares deeply about the wellness of each and every one of you. We want to make sure that you’re able to rest and recharge, and to make the most of the upcoming holiday break.”

In light of the added pressure COVID-19 has placed on students, Micah Stickel, acting vice-provost, students, is also calling on faculty to double down on kindness and compassion.

“This is a unique time for everybody,” he told U of T News, adding that the university has been listening closely to students through consultation sessions and surveys.

“The message that we shared with everybody is to focus on care, compassion and flexibility.”

In practical terms, Stickel says that means opening up a pathway for honest communication between students and professors while paying close attention to the demands that students are facing in their lives.

He recommends a healthy balance of large and small assignments so students don’t have to juggle too many bite-size assignments – or worry about a single, large assignment that could make up the bulk of their grade.

Overall, the time spent in class and on work outside a class should be in the ballpark of 10 hours per week, per course, he says.

“That’s our ask, but obviously there’s some flexibility there,” he said. “Generally, the message is to think about students’ experience not just in your own course, but in all the courses that they’re taking.”

Professors across Canada can get tips for supporting student mental health from the Centre for Innovation in Campus Mental Health. And, to ensure that faculty, staff and librarians who support students also take care of their own mental health, U of T offers a wide range of resources and supports.

Since the pandemic began, professors across U of T’s three campuses have also been sharing their experiences with each other online and in webinars organized by the Centre for Teaching and Learning, offering advice on how to re-think assessments and assignments and examples of how to lower stress and improve learning for students.

“The biggest thing that I’m doing differently this year is having a “radical generosity” policy for extensions,” Kathy Liddle, assistant professor, teaching stream, in sociology at U of T Scarborough, told the Centre for Teaching and Learning. “Students can get extensions on anything for any reason, without any documentation and without penalty.

“My decision was based on the fact that my priority is for them to learn the material, but I don’t want to tie the assessment to their ability to turn in something by a particular time. Especially this year. They don’t have to ask for the weekly quiz or the weekly discussion post – I just leave them open and then they catch up as necessary. For assignments, I have them contact their TAs to ask for a specific amount of time so that they are making a specific plan for themselves. But we accept every request.”

Liddle says “the outpouring of gratitude and appreciation from the students has honestly been overwhelming.”

Fiona Rawle, a professor of biology and the associate dean, undergraduate at U of T Mississauga, coined the phrase “the pedagogy of kindness” to describe her teaching method, which also emphasizes communication, compassion and flexibility.

In her biology course of more than 1,000 students, she aims to foster connections within the class and bridge the “divide” between student and teacher.

Today was our last class. Students surprised me by making posters & holding them up at the same time

Was a great ending, highlighting the importance of connection to learning@UTM @UofT @AcademicChatter #WomenInSTEM

(you can see me in the upper corner crying a bit...) pic.twitter.com/mY2wEsMnGI
— Dr Fiona Rawle (@FiRawle) December 8, 2020

“We know that the more connected our students feel, then the better they learn,” she said in a guest-hosted episode of the U of T podcast, The New Normal.

“We want students to know that they are more than a number.”

In the last class of the semester, Rawle’s students showed her some kindness in return, surprising her on Zoom by holding up posters expressing their thanks. Rawle tweeted a screenshot of the class, adding: “You can see me in the upper corner crying a bit…”

Fabian Parsch, an assistant professor, teaching stream, in the department of mathematics in the Faculty of Arts & Science, says the experience of teaching remotely during the pandemic has taught him the value of giving students more time to complete tests.

In one of his classes he gave his students 24 hours to write an exam, providing them with some leeway if their computer crashes or in the case of another unforeseen calamity.

“All these things contribute to students being able to focus on the course content instead of being stressed out by their surrounding conditions during an already stressful time,” he says.

David Roberts, director of the urban studies program at Innis College and an assistant professor, teaching stream, in the department of geography and planning, says he agrees that teaching during a pandemic “requires greater compassion and care for our students and a heightened recognition of the struggles they are facing during this time.”

Whether in his first-year introductory course on urban studies and his fourth-year seminar on cities and mega-events, he says he prioritizes patience and understanding.

“While the pandemic has definitely exacerbated many situations, a lot of our students were struggling with various things prior to the pandemic,” he says.

“Recognizing this, I try to keep abreast of the various support programs available to students and encourage my students to make use of them. I try to be understanding and accommodating, while also being fair to my TAs and others.

“These practices have become more central to my teaching approach as more of my students have confided their struggles to me.”

While COVID-19 has brought student mental health into even sharper focus, the well-being of students was already a top priority for the university, Stickel says.

As part of its response to recommendations by the Presidential and Provostial Task Force on Student Mental Health, the university recently launched a new mental health website for students, where they can access a toolkit of resources for building resilience, find health-focused events across the three campuses and book a counselling appointment online.

Stickel also urges faculty to demonstrate a personal commitment to supporting student mental health by including a statement on their syllabus and using it as an opportunity to discuss mental health with students and periodically check in with them.

Megan Frederickson, an associate professor of ecology and evolutionary biology, made a point of checking in with her students – all 1,933 of them – in the final class of BIO 120 last week.

“I always tell my students their grades are not a measure of their worth as a human being,” Frederickson told U of T News. “They’re so focused on getting high grades and there are so many wonderful students who are not going to be high-achieving in terms of marks, but that doesn’t mean they’re not going to go on to do amazing things with their lives.”

To help keep students engaged this term, Frederickson delivered lectures from locations across the city, including ravines, museums and the zoo, in a series of pre-recorded videos that could be viewed asynchronously. In her last video, sitting at her kitchen table, she thanked them for their patience and good humour and spoke about how tough the year has been for everyone and how much she hopes to eventually meet them in person.

“I really do hope that you’re taking good care of yourself and your loved ones and your communities – and I really genuinely think that is more important at this moment in time than getting a high grade in BIO 120,” Frederickson says. “So I wish you good luck on your final test. But remember it is just a test.

“It’s not the most important thing in life – or even in your university career.”

U of T Mississauga grad discovers little-known parasitic fly is killing local crickets

Christopher.Sorensen — Thu, 25 Jun 2020 13:40:54 +0000

U of T Mississauga grad discovers little-known parasitic fly is killing local crickets

Christopher.Sorensen Thu, 06/25/2020 - 09:40

Cutline

Erik Etzler stumbled upon Stylogaster neglecta, first described in 1890, while cleaning the lab. He says few had studied it over the past century (photo courtesy Eric Etzler)

Patricia Lonergan

Topic

Biology

Graduate Students

U of T Mississauga

A new ��Ƶ Mississauga study reveals a dramatic, gruesome and deadly battle for survival quietly playing out on the campus fields.

Erik Etzler, who recently graduated with a master’s degree in ecology and evolutionary biology, has found that the common tree cricket – best known for its soft, buzzing musical notes during long, warm summer evenings – is an unwilling host to a lethal parasitic fly.

A native fly known as Stylogaster neglecta, which is part of the parasitoid family Conopidae, is roughly the size of a mosquito, with a similar body shape, Etzler says. Researchers knew the fly was parasitic, but it was Etzler who recently uncovered which insect the fly is using as a host.

Using a tube-like organ, the fly stabs a nymphal cricket, embedding eggs into what Etzler describes as teenage crickets in their third or fourth molt. He says the young crickets look fine after the eggs have been embedded into them.

But inside is a larva that, over time, feeds on the viscera of the immature cricket. Then, like a gruesome scene from a science fiction film, a fly maggot emerges from the abdomen of the cricket, killing its host in the process.

And it’s not just a few crickets that find themselves an unwilling carrier to a parasitic fly. Etzler found that 40 per cent of the crickets he netted at U of T Mississauga’s old field had eggs embedded in them, meaning there is a 40 per cent mortality rate among the campus’s young cricket population.

Curious if the phenomenon was localized, Etzler expanded his study to include three other sites. He netted crickets at sites in Cambridge, Ont., King City, Ont., and Albany, NY. He found young crickets carrying the fly larva at each of those sites as well.

Only one cricket, he says, made it to adulthood before dying. He suspects it’s because it was “stabbed late.”

Etzler’s study, published in The Canadian Entomologist, is the first to reveal that this fly parasitizes tree crickets.

Etzler says that he finds it bizarre how little was known about this fly. It was first described in 1890, he notes, yet no one learned much more about it in 100 years.

“It’s shocking how poorly we understand it,” says Etzler, who first stumbled across the fly while cleaning up the lab.

He explains that he found dozens of flies that had come out of crickets collected by graduate students decades earlier. The flies were identified and left in a box.

Almost 20 years later, Etzler, who had been looking for a master’s project, decided to tackle the packed-away mystery.

His research has shed new light on an environment where “bizarre things” happen.

“It’s a dramatic world out there,” he says.

Road salt is taking its toll on insects in Toronto area, U of T researchers find

Christopher.Sorensen — Tue, 03 Dec 2019 13:44:45 +0000

Road salt is taking its toll on insects in Toronto area, U of T researchers find

Christopher.Sorensen Tue, 12/03/2019 - 08:44

Cutline

Researchers at U of T Mississauga found that long-term exposure to high levels of salinity due to winter road salting suppress the immune response of aquatic insects (photo by Paul Bruch via Getty Images)

Blake Eligh

Topic

Biology

Sustainability

U of T Mississauga

Undergraduate Students

It may help keep your car on the road in the winter, but research from the ��Ƶ suggests that road salt is creating problems for wildlife.

Researchers from the lab of Shannon McCauley, an associate professor of biology at U of T Mississauga, investigated the impact of road salt exposure on larvae of Anax junius dragonflies. The results, published in the journal Frontiers of Ecology and Evolution, show that long-term exposure to high levels of salinity suppress the immune response of aquatic insects, negatively impacting their ability to fight infections and recover from injuries.

Known as “green darners,” Anax junius dragonflies are one of the most common and abundant species in North America. Long and thin, they can grow to a length of 76 mm and are fierce and voracious predators.

“They eat everything, including each other, other dragonflies, mosquitos and zooplankton,” says Rosalind Murray, a post-doctoral researcher in the McCauley Lab who co-authored the study with McCauley and undergraduate biology student Racquelle Mangahas. “In a fishless pond, Anax junius are top predators that shape the aquatic ecosystem.

“We don’t know much about how macro invertebrates – larger insects – respond to salinity, and no one has ever looked at this particular species.”

Post-doctoral researcher Rosalind Murray with Associate Professor Shannon McCauley of U of T Mississauga’s department of biology.

Murray notes that 2017 was a boom year for the insects, which were collected at U of T’s Koffler Scientific Reserve north of Toronto for the study. “It was a good opportunity to ask questions about what is happening to these top predators,” she says.

Salt enters aquatic environments in a number of ways. In colder climates, salt is spread liberally for traction on icy roads, parking lots and walking paths, where it can be washed into ponds, rivers and streams when the snow melts. In warmer locales, salt also enters the watershed through road gravel, agricultural applications and runoff from saltwater residential pools.

Previous research measured how much road salt might be lethal to aquatic populations, but Murray notes that many creatures may experience non-lethal salinity levels over different periods of time.

“Stagnant ponds might contain little pockets with higher salinity, and insects can move in and out of them so they may experience quick acute exposure,” she says. “They may not be experiencing salinity at a rate that is sustained enough to kill them. We wondered how salinity might be affecting animals in a non-lethal way.”

The researchers theorized that salinity might have an effect on the insects’ immune systems. To observe the potential effects of road salt on larval immune response, the researchers turned to melanin, a chemical that plays a role in wound healing. “When an insect has a wound, it sends melanin to encapsulate the foreign object or wound,” Murray says.

Four variants of Anax junius at different stages of development (photo by Rosemary Martin)

Dragonfly larvae were injected with a monofilament to mimic injury that might be caused by a parasite or other wound. The larvae were then placed into water with various levels of commercial road salt ranging from standard tap water with no salt added to solutions of one and three grams of salt per litre. The larvae were left in the solutions for periods ranging from one to 96 hours (four days), after which the researchers measured the amount of melanin deposited on the monofilaments.

“We found that the highest level salt treatment in longest-term exposure resulted in a significantly decreased immune response,” Murray says.

“Dragonflies are pretty robust, but at the longest period of the highest concentration, we saw that they are being affected by high concentrations of salt,” she says. “Our study exposed the insects for just four days, but animals may live for years in the same pond. A chronically salty environment, it could – and likely would – have a much stronger effect.”

Chronic exposure to salination could have other long-term implications for the insects and also for other creatures on the food chain. Additional research from the McCauley Lab indicates that exposure to road salt appears to negatively impact the appetite of adult dragonflies. “Our research shows a decrease in the number of mosquitos that they are eating, which could impact how many mosquitos are in our environment.”

“It’s a global problem that’s not specific to cold climates,” Murray says. “It is important to be aware of how much salt we are adding to the environment, and that it is having an effect.”

The research was supported the Natural Sciences and Engineering Research Council of Canada.

U of T-led team text mines over 89,000 scientific papers, revealing new evolutionary insights into ants and plants

noreen.rasbach — Thu, 03 Oct 2019 04:00:00 +0000

U of T-led team text mines over 89,000 scientific papers, revealing new evolutionary insights into ants and plants

noreen.rasbach Thu, 10/03/2019 - 00:00

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The Amazonian ant Allomerus octoarticulatus protects its host plant Cordia nodosa against the plant’s enemies (photo by Chris Reid)

Sean Bettam

Topic

Graduate Students

Subheadline

New research led by ecologists at the ��Ƶ shows that mutually beneficial partnerships between ants and plants that arise from the rapid diversification of both organisms do not in turn promote further diversification in ants as they do in plants.

In such co-operative relationships – known as mutualisms – plants provide ants with food or shelter, while ants protect plants against herbivores or disperse their seeds. Previous research has shown that plants with ant partners diversify faster, showing a bigger difference between extinction rates and the rise of new plant species than do other plants not involved in similar relationships.

“We wondered if plants similarly affect ant evolution and found that is not the case,” says Megan Frederickson, associate professor in the department of ecology and evolutionary biology (EEB) in the Faculty of Arts & Science and senior author of a study published in PLOS Computational Biology.

The researchers hypothesized that ants would first evolve mutualism with plants and then further diversify as plants do. But a computer-generated model based on data extracted from more than 89,000 previous research studies suggests ants that are already rapidly diversifying are more likely to slow the process once they evolve a plant partnership.

“To our surprise, the intimate and often beneficial relationships that ants have with plants apparently did not help to generate the over 14,000 ant species on Earth today,” says Katrina Kaur, lead author of the study and a recent graduate of EEB’s Master of Science program. “Mutualism may put the brakes on the rise of new species or increase the threat of extinction because an ant’s fate becomes linked to its plant partner’s.”

Kaur, currently a PhD candidate at the University of British Columbia, and her colleagues collaborated with specialists at U of T’s SciNet high-performance supercomputer facility in order to address their query.

The researchers knew the data they needed was buried in thousands of scientific papers each discussing just one or a few ant species, so they wrote a computer program to “read” and extract data from the over 89,000 paper abstracts. They successfully assembled a large database of ant ecological interactions, mapped the data onto an ant evolutionary tree, then modelled how partnering with plants has affected ant diversification.

“To be able to comb through so much literature so quickly and with such accuracy was astounding,” said Frederickson. “The model could easily be adapted for use by researchers in other areas of biology as well as other disciplines altogether.”

The researchers plan to use their “text-mining” computer program to assemble an even larger database from thousands of additional papers in order to understand why ant-plant partnerships have different effects on ant versus plant evolution. A similar approach could also reveal insights about other species in mutualistic relationships, such as seed-dispersing birds or human-gut microbes.

Support for the research was provided by the Natural Sciences and Engineering Research Council of Canada.

With a file from Public Library of Science (PLOS)

U of T ecologists find strong evidence of ‘fishing down the food web’ in freshwater lake

noreen.rasbach — Mon, 30 Sep 2019 20:59:54 +0000

U of T ecologists find strong evidence of ‘fishing down the food web’ in freshwater lake

noreen.rasbach Mon, 09/30/2019 - 16:59

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(photo by smiltena/iStock)

Sean Bettam

Topic