Gryphon Cast Episode 13 Transcript

Speakers: Amanda Reside, Mackenzie Charter and Michael Lim

Amanda Reside

Many people, myself included, can get a bit stressed out when thinking about the realities of climate change. But we aren't the only ones experiencing climate related stress. Unsurprisingly, climate change is driving animals to adapt in all kinds of ways, and they may even have mechanisms to prepare the next generation to deal with similar stressors that they deal with. Open your ears and your mind and let's chat about that. Welcome to Gryphon Cast, a podcast where we casually chat about science coming out of the College of Biological Science at the University of Guelph and how that work can affect lives around the world. I'm your host, Amanda. Reside with me today is co-host Mackenzie Charter. Hello everybody and extra special guest, founder of Gryphon Cast and recent Guelph alumnus Dr. Michael Lim. Welcome back, Michael.

Michael Lim

Thank you for having me, guys.

Amanda Reside

It's so great to be able to come full circle. Michael completed his Ph.D. in Dr. Nick Bernier’s lab, and today we'll be chatting about their recently published study, which examines the ability of mother fish to deposit certain biological molecules into their offspring as a result of environmental stressors. We'll be recording this one week after Mother's Day, so we almost got perfect timing. So, Michael, you've been on one side of this interview process before, and the audience is just dying to know more about your own research. So how would you describe your Ph.D. research?

Michael Lim

So, I would broadly describe it as we're trying to uncover how you could transfer stress across generations and what that would mean in terms of how it affects your offspring. And then of course, we sprinkled in a little bit of that climate change angle in terms of if we are exposing you to stress related with climate change, can your offspring be better adapted or not?

Mackenzie Charter

Very cool. Very cool. So, when you were when you were in your undergrad or I don't know if you did a Masters, but when you were doing your Masters, did you expect to be looking at sort of transferring stress across generations? Or how did you end up with that kind of a topic?

Michael Lim

So, I guess I kind of comes down to grow up in a time where climate change was kind of top of mind. And so, you have this thing where like all your professors and your teachers are going through like, you know, elementary school all the way up through university. You're talking about, “Oh, climate change is it's big, it's impacting everyone”.

It's going to be terrible. It's going to be up to you to figure out how to fix this problem that we've laid on your shoulders and like, good luck.

Mackenzie Charter

I certainly feel the responsibility. Yep.

Michael Lim

It's like work is always kind of top of mind where you where I want to understand more about the potential impacts that all these, you know, educators growing up have hinted at and kind of warns you about. And so that in combination with kind of the work, I’ve been leading up to this point. So, for my undergrad and my Masters, I did research projects looking at the impact of anthropogenic activities. So, things like mining and like effluent coming off from nuclear power plants. So, it's kind of almost like a natural progression to go through. Okay, now we studied one specific life stage and I looked at eggs and that kind of impact for my master’s is like, why not? We just combine those ideas together with the impacts of climate change into my own study, which is the whole benefit of having your Ph.D. being able to you kind of have more of a say in what you want to study.

Amanda Reside

Cool. Yeah. I mean, was there any particular moment throughout that, you know, educational onslaught of climate change related warnings that really inspired you to, like, go on and take on the responsibility of grad school and a Ph.D.?

Michael Lim

I think I'm not sure if I can speak for most people who did grad school. I wasn't doing it for the sake of researching a specific thing. It was more about kind of getting those broader skills in terms of research and analysis and just so happened that I ended up being in a stress lab and I could kind of mix my interests along with the expertise that was provided through Nick and all the other graduate students at that time. So, it's one of the things, are you living in the moment? You don't think about it, but looking back, it's almost like, oh, it's a clear progression of all the things I've been doing through my academic career that got to me this point.

Mackenzie Charter

Hindsight is always 20/20.

Michael Lim

Yes.

Mackenzie Charter

You and Dr. Bernier recently published a study titled “Zebrafish Parental Progeny Investment in response to Cycling's Thermal Stress and Hypoxia Deposition of heat shock Proteins but not Cortisol”. To translate that a bit for our audience, let's talk about some of the overarching topics you covered. In a broad sense you were studying how organisms can adapt to environmental stressors related to climate change. Specifically, you focused on fish and how they can adapt between generations to fluctuations in water, temperature and oxygen content. Would you be able to explain how climate change affects temperature, oxygen and any other aspects of the environment in aquatic ecosystems?

Michael Lim

Sure, so when we say climate change, for most people listening, you might immediately think of climate change as global warming, period. And so you have that increased temperature. So, it's kind of a more easy, okay, if the general planet is warming, of course, water temperature is also going to increase. And what's perhaps not so obvious is the impacts on oxygen.

So, there are, for example, the direct impacts of temperature on water chemistry. So just by the fact of the properties of water at a higher temperature, you have less oxygen dissolved in the same amount of water. But the bigger factor here, more than just that is the amount of oxygen demand. So that kind of comes back to energy rates and rates of reaction. So, to simplify that, let's say if you're looking at a certain thing, like, say, like a lizard and under what conditions, you might expect them to move around more and be a little more active versus that and colder temperatures might slow down. So you have these certainly reduced activity and oxygen consumption at college because you're not doing quite as much, of course, is not as impactful to humans or other mammals because we're warm blooded. But that's a whole other thing. So, under high temperatures, you are having less oxygen being dissolved in the water and you're also going to have a higher oxygen demand because you are having more activity required to keep up with your increased reaction rates in your body. So, it is kind of stress that comes from not only reducing oxygen but increasing what you need. As for other aspects of the environment. So, climate also impacts a lot of things I didn't study in the study, such as, for example, impacts on acidity. So like carbon dioxide is that big greenhouse gas that you hear about all the time in the news when we talk about climate change. And so, with increased carbon dioxide, you can have that more dissolved into water and create carbonic acid which can dissociate into carbonate and hydrogen ions so that we have that increased acidity. So that can also impact things like, you know, coral reefs and bleaching. But yes, there is a lot of multifaceted things are working together impacting environmental systems.

Amanda Reside

Right. So, you focus in your study specifically on temperature and oxygen content. And you also mentioned eutrophication as an environmental stressor. Can you just define for us what eutrophication is and how it's related to temperature and oxygen?

Michael Lim

Sure, so eutrophication might be better known as an algal bloom. So it's what happens when you have a lot of extra nutrients. This is usually temporarily in an aquatic body and so you increase the algae that grows in that environment. The problem comes is that with this increased number of algae and can also have increased amounts, other microorganisms, they consume more oxygen and also when they die and decompose also consume a lot more oxygen. So, this creates these low oxygen environments and this kind of positive feedback almost, where you're creating a more severe environmental living as more and more things die and becomes more and more severe and create these like hypoxia or dead zones, literally, where anything that requires aerobic function would struggle to survive.

Mackenzie Charter

So, your research is based on something known as the maternal match hypothesis. So, would you be able to explain the maternal match hypothesis to us and how you used it to design your study?

Michael Lim

Sure. So maternal match hypothesis is just kind of one of many names this phenomenon is given. And in fact, I would argue that the use of the word maternal is perhaps a little limiting and should perhaps be in environmental, for example, or parental, but beside the point. It essentially involves the transfer of information from one generation to the next to help prepare them for future stressors. So, in terms of designing my experiment, I was kind of interpreting the idea of, sure, we might see an effect, but what is causing it? What is the actual information being transferred?

Mackenzie Charter

Interesting and interesting how language is always changing and evolving, right?

Michael Lim

Yes, especially in science.

Mackenzie Charter

So, is this a phenomenon that is observed in more than just like outside of aquatic ecosystems, like in mammals or in humans?

Michael Lim

Yeah, it's been seen across a lot of different species, especially those raised in lab activity, like in mice, for example. Probably the most famous one in humans is one that comprises survivors of the Dutch famine, where they had children and grandchildren with babies of higher incidences of cardiovascular disease, obesity and those kind of like diet related things. And so, research does suggest that perhaps this is due to having offspring who are predicted to be exposed to low food environments. And so, in contrast, when you’re living in environments that have higher amounts of food and or especially in the more modern age like fast food and everything, it's not as great for the body which are expecting this kind of more, I don't know, nutrient deficient environment. Of course, you know, there's like a little extrapolation there, but it really comes down to that whole matching idea where it's really only beneficial if it's a good preparation in terms of matching of what the parents are seeing, what your offspring are seeing. So, you can't have that mismatch when you start seeing little issues.

Amanda Reside

Right. That's so cool. I, I know you've mentioned that. I'm sure in the last two years of working with you, but it's such a such a good example, even if, you know, examples are never perfect in science, it's a really a really good way to kind of hit the point home.

Michael Lim

So, with lots of other factors, but the thought is it could be related to that.

Amanda Reside

So, to answer your particular research question, you subjected parent fish to cycling temperature and hypoxia stressors, so hypoxia being low oxygen, and then you measured certain biological molecules in both the mothers and their offspring. Why did you choose cycling stressors in particular? And what makes that set up different than previous studies?

Michael Lim

So previous studies typically use statics, which is that be holding conditions steady throughout the entire exposure period. So, everything is either temperature, hypoxia or some kind of combination of to be relatively rare, but it does happen. And while I don't knock those because they're very important for establishing what the kind of effects you might see when you start manipulating things like the length of exposure and if you want to cycle or not like I did, I think we're at that stage where we need to step beyond that and try to represent what seen in natural environments more accurately, I would suppose. And it kind of ties back into another answer I had earlier, where it's almost like a natural progression, but I was doing. So, in my master’s we were looking at the impacts of incubation temperature on lake and white fish embryos impact them across time. So previously they've been studied at constant temperatures. But I was thinking, well, clearly, they're responding in the Fall and temperatures drop and then they maintain temperature and they increase. So why don't we replicate that? And so by doing that, I was seeing different changes in the vulnerable time and hatching and survival. So it was almost a natural progression to, well, if I did that on a long timescale across like six months, why don't we do this at a shorter time scale and see the change across every day?

Amanda Reside

Okay. So, for the audience, the cycles mimicked how temperature and oxygen fluctuate throughout the day, like with sun versus when the sun sets. Interesting. So, the fish that you used in your study are zebrafish. Can you tell us a bit about these fish in particular and why you chose them for your study? I know that people in zebrafish work will be like, Oh, well, of course. But for those outside of the field, what makes them particularly suited to what you're looking at?

Michael Lim

So, zebrafish have quite a long history when it comes to being used as a research model. Well, relatively young. They are shallow tropical water fish native to India and like other southern areas like Myanmar and Bangladesh, that kind of region. And they typically experience high temperatures and possibly low dissolved oxygen levels throughout the day, depending on what time of day you're sampling them. So, they're particularly well used for study in that kind of almost like a positive happenstance because they were essentially just a fun little zebrafish like aquarium kind of fish you could get at a pet shop. And so they were used for study like decades and decades ago and was known because of the continued study on them for different things like behavior and neurogenesis and that kind of thing, that they really kind of took off and are being used in not just what I'm doing for environmental stress, but also for like human research, because they have a lot of similar responses as humans do and a lot of similar genes.

Amanda Reside

So, you mentioned that zebrafish experience a wide range of temperatures natively. Could this mean that temperature fluctuation would actually be less of a stressor for the species?

Michael Lim

So, this kind of comes down to what you want to call a stressor. Mm hmm. So is something stressful because you have the triggering of certain hormones related to stress, like, say, producing glucocorticoids or using heat shock proteins or something stressful because you actually have like cellular DNA damage, in which case you didn't have the repair. And so, it's more really because of requiring it, just because those are tricky in that regard, because anything that deviates from homeostasis. So, homeostasis for the audience maybe I'm feeling with the term essentially is when you're maintaining this kind of like set range where you want to hover around, which is ideal for you. So, think of its kind of like your thermostat, that kind of thing, where you set a temperature you want to maintain around there. So, if you deviate too far, say like a really hot day and temperature was really high, then it might be stressful that you're far outside of where you want to be and you have to kind of rein yourself back in. So even though they might experience it natively it doesn't mean they won't be stressed per se, I guess is what I'm trying to get at.

Mackenzie Charter

Yeah, that's really interesting. That makes a lot of sense.

Michael Lim

It's an area of concern in the field of stress of how you want to define stress. So, I don't want to I don't want to say that they are or not stressed. It just it comes down to how you want to define.

Amanda Reside

Once again, running into language. Yes, trickiness in science.

Mackenzie Charter

So, in these zebrafish, you measured glucocorticoids, which are stress hormones and heat stress proteins. So how did you choose to focus on those when thinking about temperature regulation and hypoxia or low oxygen?

Michael Lim

So, I chose to study glucocorticoid. So those involve things like cortisol. So, they got incoming the nickname or the moniker like stress hormone, just because they are produced when you're stressed, because they have a bunch of roles, they're related to helping you deal with that stress. So, for example, cortisol can help mobilize energy storage is like having more glucose. So, you can consume fuel more, more readily versus other forms. You also stop your energy being shunted towards, you know, nonessential processes like if in the middle of a fight you may not necessarily want to think about, oh, I really got to grow or oh, I really got to prepare to reproduce later on. Your focus is more about do I have the energy to fight or escape this particularly stressful scenario? And likewise, heat shock proteins are also produced very commonly following a stressor. It's not just heat like the name implies, but a wide variety of things, including hypoxia or low oxygen and like radiation and high salt and drought. All those kinds of stressors can also increase heat shock protein levels. So, keeping those two kinds of groups of compounds that are typically increased following stress, I figured, okay, so we have these stressors. Let's compare things that are commonly seen in climate change, freshwater environments, so high temperature and dissolved oxygen, which are also ...not just climate change, but also known to increase both cortisol as a glucocorticoids and heat shock protein. So, it's kind of a scouring the literature and seeing what fit and made sense for my model.

Amanda Reside

So, you found differences in how glucocorticoids are metabolized, which basically means broken down and you were able to find some differences in how they're metabolized in the whole body of the zebrafish compared with just the ovary. Which was interesting to you because of the, you know, reproduction angle. So why would you think that something like cortisol metabolism would be different between ovaries and the whole body?

Michael Lim

So, I didn't actually didn't measure the metabolites or other metabolism enzymes in the whole body just at the gills. So, the girls are coming with water to the water, which are having the high temperature and the lows of oxygen literally being exposed to them versus the ovaries are kind of more central and they have different kind of proportions of different types of cells and macronutrients. So that could also impact of how much is stored in each one. And then another thing to keep in mind is that for these metabolites I was looking at or not metabolites ... these metabolizing enzymes. I was only looking at gene expression. So gene expression for those listening, it's a kind of not only a quick way, but an easy way to compare different levels of certain targets you are looking for. When you're doing these kinds of studies, they don’t necessarily translate to what you see in real life. So, imagine it being like a recipe card. So, you might see a lot of recipe cards in an area, but have no one takes the recipe cards, actually makes food with them, then it doesn't mean anything. You just have a bunch of cards lying around that don't do anything. So usually it's not quite, you know, you have a ..., there's nothing happened. It's more of a 1 to 1 or at least a proportional ratio, but just a caution that we're not necessarily seeing impacts. So, like when I was measuring 20 beta-hydrocortisone, which is a breakdown product from cortisone and cortisone from cortisol, we didn't see any differences, even though we did see differences in the enzymes responsible for converting cortisol.

Amanda Reside

Interesting, right? So, for the listener, I really love your recipe card analogy. Basically, cells will make gene transcripts, which are the recipe cards in response to, you know, some stimulus and then those transcripts are turned into proteins or the food in Michael's analogy. So, there are different things that you can measure when doing a study like this.

Michael Lim

And then even one step further, it's you can have the protein, but it didn't stop there. It depends whether you actually use them or not. So, it's kind of eating the food, but the it's a good thing.

Amanda Reside

Yeah, it does get it does get quite muddy when you talk about subcellular processes like this. So very, very interesting thing to keep in mind about, you know, what does all this mean for the actual fish?

So, thinking about your results, did you find notable differences in how glucocorticoids were passed down compared to how heat stress proteins were passed down? Did you see differences or no differences that you expected?

Michael Lim

So, I got to tackle the proteins first and that was something more what you would expect where there are increased levels of heat shock proteins in stressed parents, particularly those exposed to my high temperature cycling regime that with or without hypoxia and then you saw increased levels of heat shock proteins and in the embryos. So, you can get dust your hands off “Look, we did it! We have that collection right there, increased levels inf the mother, increased levels in the offspring. We did it. Here's the information”. So, when we looked at glucocorticoids, so in terms of cortisol, contrary to a lot of work and not fish species, which is typically seen in an increased amount of cortisol increased by acquiring deposited, we saw increments of cortisol in the mothers, but then we saw a decreased levels in the offspring. So, the complete opposite. So that was really surprising. But in later studies in my thesis, which we're not talking about today obviously, but it showed that was very consistent, that this is not just a one-off thing, but they were consistently having lower cortisol levels. So clearly this is something that not only hides potential differences between species, it's just not even just fish and humans, but you know, it's good to have an open mind, I guess. But taking unexpected results.

Mackenzie Charter

If it's yeah, if it's not predictable, at least it's consistent.

Michael Lim

Yeah. In hindsight to the research, a little more varied in terms of if you see increased cortisol or not in fish. But at the time a lot of work had really been pushing would see an increase.

Amanda Reside

So, you found that hypoxia causes a decrease in reproductive success which seems fairly intuitive. But you also saw that elevated temperatures, saw some aspects of reproductive success go up and others go down. So, what did you measure in terms of like your end points there?

Michael Lim

Yeah, so reproduction, I was measuring just literally the amount of eggs per female and then we also measured viability. So, the percent surviving at one hour. So, we yes we did have lower quality in terms of the actual amount of survival. And in another study, I'm just like dropping all these things for future studies and another study coming out soon. We also measured size, and we see differences in size of embryos as well. So, this is a clearly potentially a thing going on here in terms of reproductive impacts. But that's for another podcast, I guess?

Amanda Reside

You observed an increase in egg number, but a decrease in egg viability.

Michael Lim

Yes, just in the second temperature compared to I think second hypoxia? But there's actually no difference compared to the controls.

Mackenzie Charter

So, thinking about your conclusions and moving forward, it's interesting to think about how mothers can pass on information about their environment to their offspring at a subcellular level. But we all know it takes two to tango, as you said earlier, maybe the like parental hypothesis. So, could you speculate on what the father’s contribution may be in this scenario of environmental stress?

Michael Lim

Sure, so for better or worse, as you can probably imagine, people are usually more interested in studying what it means for humans. And so and so for a human context and an animal. So, you have the mother literally carrying the child that entire developmental period. So, what the mother's passing on is more, I guess, important and impactful across time versus other species that are oviparous so in other words, egg laying species like fish may not necessarily have any impact on development and care after being laid. So, all that information is all deposited at that moment of fertilization. And so, work on oviparous species has suggested that the impact of ... sorry father’s is actually more important than you might expect. So, one end goal is in terms of epigenetic modifications.mSo that's for those who are unsure what I'm talking about, epigenetic modifications, are essentially changes to how your genes express themselves without actually changing your genome itself. So, a common thing we might see is like DNA methylation, which can impact how much your genes are actually expressed. So, this can be inherited both from your mother and through your father. But more recent work in fish is shown that, for example, in zebrafish, I believe the maternal DNA methylation pattern that can be just scrubbed out and they keep the paternal. And so, we have the instances across the paternal line in different fish species across generations where this is just an impact seen through that line. So not to say that one gender is more important the other, but rather they probably have different contributions and should be able to be studied.

Amanda Reside

Yeah, that's a really cool distinction that I think we're so biased as mammals towards like the mother contribution.

Michael Lim

I mean, like I get your funder, you're like, “Oh, humans, I understand that. I'm going to fund that”. And so that's, that's how it works.

Amanda Reside

But yeah, and, and even in other egg laying species like you think of birds, oftentimes the mother does have more, you know, contribution to the care post laying like you picture, you know, a chicken sitting on her eggs. But that's not the case for fish, certainly. So very cool.

Michael Lim

While crazily in fish like birds eventually do nothing but some other fish species like the mother leaves. Good luck. And the father's own stickers of the eggs, like, you know, fanning and dancing, all kind of thing. So, it all depends on your species. But yes, it's highly variable out there in nature.

Amanda Reside

Yeah. So, on that note a little bit, do you think that this research is applicable to other fish or other types of animals, given all this diversity?

Michael Lim

I kind of feel like I'm contradicting myself. But although there is a huge amount of diversity, there's also a lot of conservation for certain things. So, like the cortisol stress response and heat shock protein stress response there quite well preserved because there are so that I would not be surprised to see if we saw similar stress patterns being inherited across different species. Of course, it could differ depending on the type of stress you're using and how I guess going back to that idea of how stress an animal is by your stressor could change the levels that are actually increased or not in your parents. But in general, yes, I think we can be looking at these two different pathways as something to look forward for stress transfer across generations.

Mackenzie Charter

So to touch on more of, I would say, a human aspect of it. What was your favorite part of the research project?

Michael Lim

This always a tough question, and whenever I ask the people to when I was like, I was like, it’s always fun to see what they come up with. But being in the hot seat now, it's really hard to pick something. I always kind of I was like, Oh, I always got that answer. But it's really, it's true because there's so many different things that you think about. Like knowing when you get your first paper out, for example. When you did your first major finding or like when you get to present in a conference, all the things are really great and they're fun. And I think I'll go back to an answer I've heard before. I feel kind of bad. I can remember their name right now, but I remember asking them what they really, really enjoyed about their work. And it was really in that first moment when you are running an assay or you are running that statistical testing, you see that difference and you're the only person in the world in that moment that knows something that's like pretty like mind blowing, it's like that moment. You're the only person that has that kind of knowledge. That's like seeing a new thing for the first time.

Amanda Reside

Yeah, that's a really good answer. I mean, yeah, running, seeing the output of a test and seeing that P value. And so, a little mini firework goes off like, that's so exciting.

Michael Lim

So, the best things you do like a color metric test or something. So you can literally see the impact right away, look I did it. Something happened. Yeah.

Amanda Reside

You see that color change and it's so much more tangible than my example.

Michael Lim

Just another zero, like. Oh, yeah, well, you've been in science enough. No, no, no, no. Don't let me knock that. Which, incidentally, if you get that extra zero in there like, oh yeah, yeah.

Amanda Reside

Did you have any surprising moments? And if you did, did you have like a most surprising part of the research?

Michael Lim

So, I guess we kind of talked about before, but I think the most surprising thing was seeing the complete flip in terms of the cortisol being transferred. Just because I've been so focused on the other literature in the kind of realm before that in terms of mammals and looking at birds and seeing increased GC transfer or glucocorticoid transfer that was pretty shocking. I think that, I think that was probably the biggest surprise for me in having to figure out why literally.

Amanda Reside

Yeah, that's probably a combination of those two moments of the first time that you found that out, being excited and so surprised at the same time.

Michael Lim

I think my first thought wasn't happiness. It was, Oh God, did I do wrong right?

Amanda Reside

And then and then it turned out to be consistent.

Michael Lim

Yep, it turned out to be consistent. So, it definitely wasn't. I messed up like the labels of the different treatments. It was definitely a very consistent effect. Yeah.

Mackenzie Charter

So, if you could have if we could get you to travel through time and go back and you could change one thing about this study, what, what would you change and why?

Michael Lim

So, I don't want to throw the Mass Spec facility under the bus, but I really wish that we had just used professional services or just like giving it all to a technician just to do instead of trying to like, do like half of it around and then trying to run into the Mass Spec Facility downstairs. I literally wasted years trying to get that to work, just like putting samples in and then things together break down or someone occupy it for some time, and you come back and tell me the exact same thing as usual. I don't work anymore. It was limited to that for years. And then the pandemic has it. So, it's just it just kept going on and on. It was like, oh, we came back from the pandemic. Like, now this is it. Forget it, we're done. We're just going to give it to professional service. They'll do it the whole thing from the end. And that's how we got that data. It yes, I would go back in time and say, Michael, just forget it. It's not going to happen.

Amanda Reside

So last but not least, what do you hope this work will do for the field or the general public?

Michael Lim

So, for the field, I hope it just kind of the strength of that notion that keep your mind open in terms of studying not just the beaten path, in terms of just cortisol for example, and expecting a certain outcome. Most other things like for heat shock proteins, there haven't really been super well tied in to looking at stress across generations. And I'm seeing a pretty consistent effect across my studies. So, showing the importance of that and also, of course looking at more naturally relevant conditions. Yeah, we're at that stage where we can do that. We can kind of mix things, have different stressors, change across time and mix them all together a little bit kind of thing I think is the way of the future that's for the general public. I would say the jury is out. On if animals can cope with climate change or not and that but we might may not be quite so deep in gloom as we initially thought in terms of being much more rapid. That can happen with natural selection and that perhaps we shouldn't knock Lamarck so harshly or his idea that there could be influences across generations for those who may be less familiar, hopefully you talk about the same example like in your maybe high school biology, where Lamarck was a famous biologist, or I guess evolutionary biologist. We talked about how giraffes grew really long necks because their ancestors had stretched out and had long necks and this kind of like proliferated across time. And so perhaps is not quite so cut and dry as that there's probably more influence about natural selection and those kinds of ideas. But perhaps he was on to something, after all, with this field of epigenetics.

Amanda Reside

Use it or lose it. That was his that was his motto I remember from school. Well, thank you so much, Michael, for coming back after, you know, graduating and moving on to exciting things. You're still giving us your time. So, I really appreciate it.

Michael Lim

I remember back on SCRIBE fondly, so I'm happy to come back and do something.

Mackenzie Charter

So that brings us to the end of today's podcast. A big thanks again to our guest, Dr. Michael Lim, for joining us today. Gryphon Cast is brought to you by your hosts, Amanda Reside and me Mackenzie Charter. If you're hungry to learn about more science topics, check out SCRIBE Research Highlights that’s S-C-R-I-B-E Research Highlights on the University of Guelph website at uoguelph.ca. Or you can follow us on social media @UofGCBS. Find us on Instagram, Twitter and Facebook. Music in the podcast comes from upbeat details are in our show notes. And until next time, stay curious.