The Hour is Blue

Evolution in a Rapidly Changing World — Dr. Sally Otto

In this conversation, I speak with Dr. Sally Otto, University Killam Professor in the Department of Zoology at the University of British Columbia, Fellow of both the Royal Society of Canada and the United Kingdom's Royal Society, member of the U.S. National Academy of Sciences, and recipient of a MacArthur Fellowship. She is internationally recognized for her contributions to evolutionary biology, particularly the mathematical understanding of how evolution works.

Our conversation centres on three recent research works: “Evolution of Cross-Tolerance to Metals in Yeast,” published in 2025; a research manuscript examining how population numbers can decline where genetically different populations meet; and “The Changing Status of Imperilled Species in British Columbia,” published in 2026.

We discuss how organisms adapt to environmental pressures, what happens when genetically different populations come into contact, and the challenges facing species in a rapidly changing world. Through mathematical theory, laboratory experiments, and the study of biodiversity, our conversation explores the possibilities and limits of evolution, and what evolutionary science can tell us about the future of life on Earth.

CiTR 101.9 FM / The Blue Hour

Recorded live on October 13, 2026

Listen: CiTR | Apple Podcasts | Spotify | YouTube

The Blue Hour, hosted by Farha Guerrero, airs live every Tuesday at 2 p.m. PT on CiTR 101.9 FM at the University of British Columbia in Vancouver, Canada.

Transcript

Transcript lightly edited for clarity and readability while preserving the substance and natural rhythm of the conversation.

Farha: Hello and welcome to The Blue Hour. I'm Farha Guerrero.

Before we begin, I would like to acknowledge that we are broadcasting from UBC on the traditional, ancestral and unceded territory of the Musqueam people.

As we speak about the natural world today, I also want to recognize the Musqueam people's long stewardship of these lands and waters.

Sally, it's really a privilege to welcome you here to CiTR!

Sally: Thank you so much for having me. I'm delighted to be on the hour with you.

Farha: I had the privilege a couple of weeks ago of speaking with a woman named Jasḵwaan Bedard. They also call her the Hummingbird Doctor.

She's from Haida Gwaii, and I know that Parks Canada has called Haida Gwaii the Galápagos of Canada.

There was a moment in the interview where I just felt that I needed to honour her. I'm sorry, I'm a little emotional saying this.

The Haida language is culturally endangered. There aren't that many people in the world who speak it.

But Jasḵwaan has an attitude where she believes that the issue is not about language revitalization, it's about language strengthening, because she believes Haida has always been here with us.

And that's what she's working very hard to do.

I want to do the same with you, Sally. I want to honour you.

What I just read out at the introduction is extraordinary.

You are an exceptional scientist, and you have contributed a lot to the world.

And I want you to know, the same way that I said with Jasḵwaan, what you do is extraordinary on so many levels.

Not only have you written maybe 200 or more papers, you have thousands of citations from those papers that have been shared across this global world of scientific research, also reaching people like myself, who is not a trained scientist.

And that has enormous value.

The awards can only tell us part of the picture. What I feel with Jasḵwaan and you is that so much of the hard work you do is done in silence.

So much of it may not be witnessed.

And it's a testament to this feeling that I must have done something well in my life to be able to sit across from people like you!

Sally: Oh, that's such a beautiful sentiment and honour.

The science that we write, it never tells us about what's in our hearts.

And so that's a good chance for us to start there, what is in our hearts.

And like you were saying with Jasḵwaan, I believe that what I'm trying to speak to is just the incredible ways in which nature nurtures us, the biodiversity in the world that we see around us.

I've been studying my whole career how that has evolved and what maintains it, what places biodiversity and species at risk of extinction - so what we are likely to lose.

But maybe too, we can talk about what does that mean to me? What does that mean to your listeners when they look at the natural world around them? What is it that we value?

Farha: I was listening to a lecture of yours. I always do this last minute, and sometimes it is what I find draws me in the most.

Hearing the person before I actually meet them.

This was a lecture of yours from about six years ago, titled Evolution in a Rapidly Changing World.

You have a very beautiful image that you begin the lecture with, which is really about what you call the tree of life.

When you start the lecture, you state that our understanding of evolution has led from a single-celled organism, over three and a half billion years ago, to enormous diversity on this planet. I think you and many evolutionary biologists are still struck by something so simple...

Do you still feel that?

Sally: Oh, absolutely.

And that tree of life, we can think of it as three and a half billion years or so old.

But if you add up all of the branches, and those branches signify the different adaptations, mutations, changes that each species underwent in its survival to the present, then you're talking about, I can't remember the number, but it's so large, it's about equivalent to the number of words ever published in all published works.

And so it's just astronomical how much evolutionary change each species, and certainly the total, represent.

Farha: You said 10 to the 15.

Sally: Thank you. You have the number in front of you.

Isn't that incredible? 10 to the 15 years. And I just can't think of numbers that large. So I have to use metaphors.

Farha: But it's a great metaphor, because it says 10 to the 15 - innovations independently on each branch of that tree.

Sally: If you sum all of those branches.

Farha: That's right.

Sally: And so it's really important that we don't see it as this one linear thing.

It's really this branching, almost fractal-like complex world.

And again, when we lose a species, we're not just losing our present-day attachment to it, but we're also losing all of its record of evolutionary adaptations from when it first arose to the present.

Farha: Now, the numbers do mean something to you, because you are very much a person who likes math. I learned that even from a young age, you enjoyed it.

So much of what you've contributed, Sally, is really being able to use math to understand evolution. And it has been an enormously powerful tool for people to use.

What's very interesting about you is that you have the mathematical side of the work you do, but you also still have the laboratory. You still do experiments.

Those two things are very important to you, right?

Sally: Coming together. Yes.

Most people don't realize that math is in biology at all. And yet, it's such an important tool.

I'm going to explain why I think math is so useful.

It's actually really challenging to understand evolution. There's so many things going on, interactions with other species, interactions between genes.

And you're not just trying to figure out what's happening with one gene over time, you're trying to figure out what's happening across a genome, a set of individuals and a set of species.

My brain can't put that all together through words.

So math is this really strong tool that we can use to say, if this and this and this are happening, what do we expect to see?

And what if we change this? What do we expect to see different?

Basically, I don't think that we have the brain power to do all of that ourselves.

And so I use math really as a tool to help me think, to clarify when I'm wrong, to say, nope, you assumed this, it was wrong.

And to guide me in my new understanding of how evolution works.

Farha: I consider you quite a young woman for what you've accomplished in your lifetime.

And what I'm also struck by is that your research keeps evolving.

You keep asking questions. And that's really amazing, because I don't think you've fallen asleep yet, saying, "Oh yes, I'm done with this!"

So there's much to unpack.

Before we talk about some of these recent articles, I want to mention some of the really interesting questions you had early on, especially about evolution.

Why, as species, there's sexual as well as asexual reproduction, and how over time, things can be seen in terms of what is favoured and what isn't favoured.

And also why sexual reproduction, which is so much more work?

Sally: So risky!

Farha: Do you remember the moment those questions were something you started to ask about?

Sally: Fairly early on.

I remember even in my first project as an undergraduate, there were questions about why evolution takes this turn versus this turn.

I was working on a clam shrimp with three sexes.

It had two genetic types of hermaphrodites and males, and I was like, why that system?

It could just be selfing hermaphrodites, or it could just be the standard two sexual types, males and females, but it wasn't.

And so learning about that system and using the math to figure out under what conditions evolution will take this turn or that turn, and that is critically important to understand.

Because if evolution always went the same direction, then we'd have a very boring world.

We'd have one type of species doing one kind of thing, and that would be all, but clearly that's not the case.

And so it's that context dependence that we need to really understand about evolution.

And that context dependence is critical for understanding why some organisms reproduce asexually, some sexually, some are large and complex, and others are microscopic.

And they've all been evolving for the same amount of time.

Farha: And then you go into the genomes, right?

Even within the genomes, you get some genomes that are so packed and massive, and then some that are so small.

Sally: Exactly. And some with one chromosome and others with many.

And you'd think that the blueprint of life, the genome, would have evolved early on and then stayed fairly constant.

Not at all.

We see genes moving in, chromosomes moving around, fusing and fissioning, number of copies of genes, number of copies of chromosomes evolving over time.

So that's pretty interesting.

Why is the blueprint so malleable and flexible over evolution?

Farha: And then just to think about how we see evolution today, even compared with when we were younger.

There's the evolution that feels really old, where you just feel, wow, those ancestors are really old.

And then there's evolution that we feel, and certainly this is a very important subject today with climate change, where we're seeing evolution in a much quicker way.

It's almost like we're watching things change in real time.

Sally: Absolutely.

*Farha: And we're certainly going to get to some of your experiments, especially with baker's yeast, the yeast that I use when I bake.

Sally: That's a huge change, I would say, over my career.

When I started, evolution was thought about on a geological timescale, millions and millions of years.

And partly for a bad reason, because we're changing the environment so rapidly, organisms are having to evolve to keep up.

But also because we've done the kinds of experiments, the type of measurements to see, no, actually, evolution is happening all around us.

We can't actually stop it.

We don't want bacteria to evolve antibiotic resistance. It's impossible to stop.

We don't want viruses to evolve to be better at infecting us.

But it's something that again, tells us that evolution is constantly on the go.

So that's really a sea change, to understand evolution in the here and now, not just over geological timescales.

Farha: At the end of this lecture that I mentioned earlier, which I'm going to link to my blog, because it's such a beautiful talk, one thing you say is that never has there been another species that has changed the course of evolutionary history in a single century.

Sally: Yes, that's the impact humans have been having.

And it's so multifaceted, as I get into that talk.

We're lopping off whole branches of the tree of life. Some taxa are just gone.

Large mammals are one of those, we've lost many large mammal species from the planet.

The species that go extinct tend to be specialists, they tend to be found only in particular environments, or they're over-hunted, like the large mammals, or they're overfished.

So it's not just a little branch here, a little branch there, but whole parts of the tree of life that we're losing.

And that's only one way that we're changing evolution.

We're also imposing new and different selective pressures so that every species is now having to adapt, not just to the natural world, but to the world we've created.

Farha: Interestingly, in that lecture, you show a map of where most of the impact is.

For example, in Canada, you can clearly see it's where most of the human habitation is, the southern part of our country, the urban areas.

Another thing that came out in that lecture, which really helps us understand, especially those of us who remember maybe seeing more bird populations growing up, is that now we may not see those same birds.

In the course of a lifetime, we can say that we've seen fewer swallows, or whatever birds we might have grown up seeing.

And speaking of swallows, you've noticed that the wings of swallows have changed, right?

If they're swallows that live near roads, a shorter wingspan would be more...

Sally: That was an incredible scientific study that showed that the roadkill of these swallows on the side of the road had longer wings relative to the surviving birds in that area.

So humans, by car strikes, were basically selecting against the less manoeuvrable, large-winged individuals, favouring the short-winged, manoeuvrable birds.

And then think about, well, okay, natural selection has led to the wings that you see today.

So we're perturbing those natural selection pressures.

And who knows what that means for those birds and their survival, their ability to migrate and raise young.

Farha: So we are changing that tree of life. We are shaping, reshaping that tree of life.

That's where we'll start. I would love to talk about these recent papers because they were so interesting to me.

The experiments in your lab, especially with yeast, are something you've been doing for a while, right?

Maybe you could tell us why yeast is such a good material for you to look at.

Sally: Right. Well, it can reproduce every 90 minutes, which is why you use it to make your bread. You don't have to wait years for it to rise.

And that replication, every time it replicates, there's a chance of having a mutation. Not a lot of mutations, but some.

And so over the course of a day, we can track evolution.

And the kind of experiments we've been really interested in doing lately is when the environment has taken a turn for the worse.

So much worse that the organism can't replace itself. The population's going to go extinct.

Can evolution happen fast enough to rescue those populations before they go extinct?

And so we can do that in the lab over the course of days because we put yeast, let's say about a hundred thousand cells, into a little well of an environment that's just toxic enough that they can't grow.

And then we wait and see.

And if we don't see any growth, then that population's gone extinct.

But every once in a while, we'll find a well where, just like at the bottom of your beer bottle, there's been a little bit of yeast precipitating at the bottom.

We'll find a well like that. And then we'll take those out and sequence them.

And the other thing to point out is that this genome is so small that we can sequence the whole genome of all of those surviving populations.

So we get this snapshot of exactly how each of them has evolved.

Farha: Now, the paper that you sent me is called Evolution of Cross-Tolerance to Metals in Yeast.

Tell us about that.

Sally: So really this starts at how humans have been impacting, changing the environment in so many ways.

But a lot of our understanding is, in our experiments, we change one thing at a time. But the environment's not like that.

So for mine tailings, it's not just that we have zinc or we have high levels of cobalt or copper.

We have multiple metals at high concentrations.

And so one of the things that I think we need to do better at is understanding which environmental changes are beyond the reach, not only of the organisms as they are today, but even beyond the reach of evolution.

Evolution won't allow - there's no mutation in the genome that will allow survival in this complicated environment.

And we don't know that. We don't know those limits because we tend to do things one at a time.

And we don't understand when it is impossible because there's simply no mutation that allows adaptation to cobalt and copper together, whereas there might be tons that allow manganese and copper.

And that's important, not just for evolution, for our understanding of what lies beyond evolution and adaptation in a changing environment, but also to how we characterize environments that might be unhealthy for humans.

We tend to do that one at a time. We say this is the level of whatever zinc or mercury in our water that's tolerated.

But actually it turns out that sometimes how toxic they are, how bad they are, and how impossible they are to adapt to depends on which combination of environmental changes we see.

Farha: And so you were interested in this study to look at how yeast would interact with these metals.

For example, let's say you have a mine, and you've now got a huge change in the landscape.

How does life exist under these kinds of stresses, especially when you have metals that could become a new part of that environment?

What did you find, and what surprised you?

Sally: What we were hoping for was a little bit of a framework. So we made several predictions about what would predict cross-tolerance or not.

We took yeast, we adapted them beyond what they can tolerate in six heavy metals, and then asked, well, if they adapted to that, if they adapted to zinc, did they also adapt to copper or not?

And we tried to develop a framework and say, well, maybe if these three predictions hold up, we'll be able to say something more general.

But none of our predictions that we tried worked.

There was some rhyme and reason to the results.

Things that evolved by changing a particular phosphorus pathway seemed to be more generalist.

Evolving in cobalt seemed to lead to more generalist lines that were not only good in cobalt, but in other ones.

But by and large, I would say it is challenging.

We don't really know what makes for a combination of environments that's not only toxic to the current organism, but also out of reach for all of the mutations that that organism could undergo in the near future.

So we're still working that out.

And shout out to my graduate student, Penny Kahn, who's just recently received her PhD. Yay!

Because she then said, well, if these are the cross-tolerances that we see, is it the case they cannot adapt to this combination of metals or that combination of metals?

And so it was true.

We found that there were, she found, that there were a series of metal combinations that nothing could adapt to.

Farha: And then you have this phrase, evolutionary rescue.

Can you define that?

Sally: So the scenario we've been talking about is really about evolutionary rescue.

When a population is declining in size, and so it's petering out, it's on the way to extinction, there are mutations that can occur, genetic adaptations along the way that change the species and allow it to persist.

And that's evolutionary rescue.

Farha: And when you publish a paper like this, what do you see as the real value behind all of this laboratory work?

Sally: I think to some extent, evolutionary rescue can almost seem like a panacea.

Oh, don't worry, evolution can fix everything.

Well, evolution can't fix everything.

There's not enough time, there's not enough individuals, and sometimes there's not even the possibility of a mutation to fix the type of problems that a species faces in a changed environment.

So I think that's the real motivation, to try and figure out what are the limits.

Farha: And in your lecture, you'd mentioned an example of Chernobyl, that there was evidence of evolution in that environment, right?

If there's a toxic place on Earth, certainly there is one.

Essentially, what I feel you're doing in your lab is trying to see, in a timespan that you can control, how life, how organisms react.

Sally: Right, and what they're unable to react to.

Farha: That's right.

Sally: And it's kind of incredible, the changes that we see.

Not in this experiment, but in another one, we actually saw the beginning steps of speciation in the lab over the course of these short-term experiments.

The way that the different replicates had adapted to the environment that we were challenging them with were incompatible.

So when we crossed them, their offspring were sick.

Farha: That leads us to another paper, The Changing Status of Imperilled Species in British Columbia.

This is really interesting to me for many reasons. I'm a longtime British Columbian. I was born in Calgary, but I spent my whole life in this province, really.

And so I know some of these species that you mention in the paper. I can see them. I can imagine them.

But this is another side of you, Sally, where you feel deeply connected, not only to what you do, but also to conservation and the idea of legal rights for species.

And when we talk about that, it's a very deep conversation, because we're now talking about insects that should have rights as well, right?

So it's not just about protecting them. It's more. It's ensuring that they have a voice, what scientists can give them.

Here in our province, the government has a way of categorizing species that are at risk of extinction.

Sally: That's right.

Farha: Maybe you could tell us about that and then tell us what you found in this research.

Sally: So first of all, some context.

There is no Species at Risk Act in British Columbia that protects endangered species on provincial Crown land or private land.

There's a federal act, but that only has mandated protections on federal Crown land, which is about 1% of British Columbia.

So that's really setting the stage for, okay, so it matters that we know if business as usual is leading to the demise of species at risk, or if things are getting better for species at risk.

The BC Conservation Data Centre has an online database that keeps track of pretty much all known information about species status in British Columbia, and they use colour coding.

So red stands for threatened or endangered, blue is of special concern, and then yellow is secure.

There's also a lot of species where we just don't have enough information, even here in British Columbia.

Not far away, but right here, we don't know what's happening to all of the species in our own province.

But this database is kind of a snapshot in time.

If you look it up today, you can see what the red, blue, or yellow status is today, but you don't know how that's been changing over time.

And that's what we dove into, to understand how do we have more or fewer imperilled species than we did when it started.

We had access to data back to 2008.

Farha: And so you examined these records over a long period of time, right?

You said that the red- and blue-listed species increased by about 25%.

But you were interested not just in those numbers, you were interested in why, right?

Sally: Exactly.

Farha: Tell us about that.

Sally: One of the challenges in this was that the database is live, and it kind of uses different reasons at different points in time, and talks about it differently.

So it was very hard to get at what exactly is going on.

But recently, they've started using very specific language about whether or not the changes were due to genuine improvements, or dis-improvements in the environment, or non-genuine changes.

Let me unpack that.

If a species has gotten better because we protected the habitat, restored habitat, or released more individuals, there's a stronger population, that would be a genuine improvement.

If we discovered a population that we didn't know existed, but it was there all along, there hasn't been any genuine improvement.

We've just improved our knowledge, but not actually what's on the ground happening to that species.

So that's a non-genuine change.

What we found was that almost every case where species got better, it was for non-genuine reasons, the vast majority.

Whereas when things got worse, it often got worse for genuine reasons.

And so what that was saying was that even for the species that got better, it wasn't because we've really been helping them all that much.

Farha: And so climate change, or warming temperatures, might have given some boost in these numbers. For example, I think it was dragonflies?

Sally: Right. That was one of the cases where there was a genuine improvement.

There were more of these dragonflies observed in British Columbia, but the reason for it was climate change.

So there's more habitat for that particular species.

And it's not really something that we did to protect them ourselves.

Farha: But I guess what's important for listeners is that sometimes when we see these numbers or announcements, we want to clap for joy and go, oh great, this species has now moved to a different colour.

But it's not that simple.

Sally: No, no.

And there's many, many more that are getting more and more endangered over time, which we documented in the paper.

There are positives.

The restrictions on hunting of whales, for example, have really improved the numbers of several species, gray and humpback.

The restrictions on DDT have also massively helped raptors return to our province and the country.

So there are things that we have done that have helped.

And those particularly help when there's one thing really bad going on in their lives, in the lives of those creatures, like DDT.

So if we fix that one problem, we can really help the species.

That gets harder when it's death by a thousand cuts, because then how do we undo those thousand cuts?

Farha: There was something you said in that same lecture, which is such a good image. I literally was driving by several trees when I heard it.

Trees unfortunately can't walk and move up north when temperatures rise, right?

Some species with wings obviously can, and they can migrate north.

You mentioned salmon species as well. Pink salmon have changed when they migrate.

But trees can't, and some things just can't.

Sally: For example, colleagues here at the UBC Forestry Department have found that the climate is changing in such a way that the optimal place for a tree to grow is moving by a kilometre a year.

A kilometre a year!

And so trees aren't moving that fast.

And there's some things we can do to help.

They've changed forestry practices in British Columbia so that they are more likely to take seeds from further south now than they were before, just to try and boost and give trees a helping hand in a changing climate.

But that's only for the ones that they're reseeding, and that's not going to help all plants and animals keep up with a changing environment.

Farha: So that's where that initial question of legal status comes in.

What do you envision for that? When we say that, what does it mean to you?

Sally: Well, the fact that these species don't have legal protection in British Columbia means that they're going extinct on our watch.

And that is extraordinarily hard for me to witness, and I think many of your listeners to witness.

We simply do not do enough to prevent such dramatic loss of habitat that they're gone.

Old growth is a classic example.

Since I started at UBC, we've completely lost northern spotted owls from our province.

I think there's one remaining individual, and even that hasn't been seen in a few years.

Farha: So the last paper, let's switch quickly to that because this one is in progress. This is math. This is cool.

But you have to help me out, because what was the working title for that?

Sally: Oh, I think I maybe sent you ten of them. We haven't decided on a title.

Farha: So this is examining how population numbers can fall where genetically different populations meet. That was really interesting.

Sally: So let me motivate this project.

You know how we were talking about how evolution was originally seen as this glacially slow process over geological timescales.

Now we recognize that's not true, that it's happening here and now at the same timescale that ecological interactions are happening.

And so this is an example of a project where rather than assume that those are happening on different timescales, I'm asking, what if they're happening at the same timescale?

When hybrids form between two types, the incompatibilities actually lead to fewer babies and more deaths, and so lower density of individuals where they meet.

And that ecological feedback with evolution not only leads to places where the theory predicts fewer individuals will be present, but it can actually drive the densities down to zero.

So you can be walking along a forest and it looks perfectly fine and not see a particular species of bird present and think, what's wrong with this environment?

Well, the answer is there's nothing wrong with the environment. It's just that the incompatibilities had led to this hybrid sink in this area.

And so I find it, this is where the math is so interesting, to go, when do we see these kinds of vortices happening where environmental clines or species coming together can actually lead to gaps between where we see species?

Farha: Now, cline, that's a very cool word.

It's like a geographical transition?

Something like maybe between coastal and inland forms of a bird, like you mentioned.

Sally: That's right.

Or temperature tolerance up a mountain or along a gradient north and south.

So the clines refer to the genetic changes that are happening on those environmental gradients.

And they're all around us. Species are doing that all the time.

But understanding how does that feedback actually lead to presence or absence of a species, that's what the math that we're trying to do is trying to get at.

Farha: And so your central question with this, what are you really after?

You're working on this math and trying to understand these patterns. What are you trying to get out of it?

Sally: This is an area where the field kind of thinks about it one way.

And I think about density as being externally regulated and fixed by the environment, nothing to do with the evolution of the species itself.

And so this is when you say, well, hold on a second, that assumption might not be right.

Let's evaluate it. Let's do the math and figure out if it's reasonable or not and go, oh, whoops.

We really need to take this feedback into account because we get a different answer.

We would predict a species is here, but it's not here.

And so I think that's where math really helps, is it allows you to say, no, these assumptions aren't consistent with what you're stating is happening.

So let's reassess.

Farha: Is there anything surprising you with this current research?

Sally: Well, there's some cool twists and turns that are kind of specific.

But for example, there's a classification of things that keep species apart. And they're either premating or postmating.

So premating is, you don't like the other species, so you don't mate with them, and that keeps you apart.

And postmating are things that happen afterwards. You mate, no problem, but your offspring are either sick or infertile.

And so this theory is actually saying that postmating isolation barriers, the kind of failure to produce viable and reproducing offspring, actually leads to lower density, which means that they're mating less.

So these are actually also becoming premating barriers because they're not encountering each other in this no-go zone between them.

And that's reducing mating.

So that's a very technical kind of result, but it makes us pause and rethink even these core classification systems for species barriers.

Farha: It's fascinating.

I want to give you the floor a little bit.

I'm sure you've got more than the few papers you sent me on the go, but where are you at right now?

What's your next project? What are you envisioning? Can you give us some hints?

Sally: Well, where you catch me today is really considering Bill C-39.

So we could talk about that and its potential implications. This is the Building Canada Strong Act.

It's now past second reading in the House, and so it's at committee this month.

Why it concerns me is that, as I was saying, we don't have the best environmental laws for protecting species as it is in this country.

The federal law only has limited jurisdiction.

And we've seen tailing pond accidents. We've seen releases.

We continue to see water advisories in many First Nations because of poisoned water supplies that industry has created.

So I really, really think that it's dangerous to move forward on a building platform that weakens environmental laws.

And what I wish for is that the House and the Senate evaluate this law and push for stronger environmental regulations.

But every single aspect of the law that I've seen loosens, sidesteps, or removes environmental protections.

This isn't a Building Canada Strong While Protecting Our Environment Act.

And I think it needs to be.

Farha: And how do you feel as a scientist when sometimes it feels like a roadblock?

How does that make you feel, given what you know, and what your colleagues, researchers and collaborators know?

Sally: It's so hard because part of it is, why does it feel like we're talking to deaf ears when we talk about protecting nature and the environment?

Why doesn't that necessarily resonate?

For some people, it's a disaster, literally harming your family to harm nature.

And for others, it's just not seen that way.

It's a problem to be solved in the future by future businesses or environmental efforts.

So it's not seen in that same way.

I think it fills me with a little bit of despair when protecting nature isn't given the very highest importance in regulations and laws.

Farha: But this despair, what I feel with you, Sally, is that it's not making you give up.

At least in that lecture, you end with a positive note.

You say that you believe that especially these young people, they're going to want to protect what they have and what they love.

I can think of my sons who grew up with black bears in their backyard.

And I can see them in the future wanting to know that their kids could also see those bears.

Sally: That's right.

And that perspective of looking and protecting for seven generations hence, that is wisdom that First Nations communities are teaching us.

And that's what we need to do. Not just for the here and now, but for all generations in the future.

But back to despair.

There can be a tendency for despair to lead to paralysis.

And that's where I'm like, okay, no, let's not fall into that trap.

Because if we are stuck or in a rut or feeling like, no, we can't move and don't do anything, then these consequences will necessarily happen.

So let's each and every one of us listening, whatever it is that's making you despair now, take that on as a challenge to act in one small way, whatever that small way is.

Because that forward momentum will make you feel better about yourself, about having tried to save this world that's so important.

Farha: Just before we went on air, I was trying to get a sense of what even that despair might be in numbers.

Species that we know are on the verge of extinction.

You said we don't even know how many species are actually in the world or in the ocean, right?

So it's hard to put a number on it, but certainly the number is big.

And that has to give us reasons to take this very seriously.

Sally: At a global level, about a quarter of species of vertebrates and plants are at risk of extinction.

And for some groups like cycads and corals, it's even higher than that.

So the numbers are astronomical.

And that's not even really accounting for climate change impacts, because those climate change impacts are happening now and in the decades that are coming up.

But our assessments are looking in the past.

So it's even more dire than that.

Farha: Let's see if we can end on a positive note, because it's important.

We're here at a university, and you mentioned one of your PhD students who just got her PhD.

These are the next generation of scientists, of people who are going to do great things.

And as one Italian evolutionary biologist and philosopher, Telmo Pievani, who I've been in touch with and who I'll be speaking with in a few months in Milan, said as he was talking to the PhD students about to get their PhD, he said "Welcome to the Republic of Knowledge."

Those were his words.

And that's beautiful. We all can be in the Republic of Knowledge.

Sally: Absolutely.

Farha: Including those citizen scientists, which are so important, like bringing the birding back, right?

Those birdwatchers, they help us know the numbers every year.

What is it, the annual Christmas count?

Sally: Or actually the iNaturalist app.

If you're listening and you don't have it, download it today, because it's got this cool feature where you can point the camera at something live, and it will tell you what it is.

Sometimes it gets it wrong, but it's pretty good.

And that data actually does go into the scientific databases that are used to figure out what species are imperilled, and which ones are doing better with every passing year.

So we get a really good sense of where we are if we have a lot of data from citizen science.

But I do also want to comment on how students have played such a critical role in my intellectual life.

Without them, I wouldn't have made it.

And these successes really are our successes, of being in an environment where students are constantly asking new questions, challenging the status quo, pushing the boundaries of science.

And that is so fun to be a part of and a witness of.

So what a great job that I have had, and a privilege to have worked with so many amazing students.

But I should say, even though they give me hope, they have energy, they're wise beyond their years, and they have passion to act, I also think I can't just look to them and say, they're our solution.

Us old folks have to be a part of the solution too.

Farha: A hundred percent.

That's beautiful.

Well, thank you, Sally, for joining me. It's been a real honour.

Sally: Absolutely. Ditto. Thank you for having me. Great conversation with you.

Farha: Oh, thank you.

Further Reading and Listening