Monkey Tales - Learning About Stress

Ask A Biologist Podcast, Vol 133
Podcast Interview with Noah Snyder-Mackle
Noah Snyder-Mackler with Gelada monkeys.

Dr. Biology: 0:00

This is Ask A Biologist, a program about the living world, and I'm Dr Biology. Imagine if you had your own private tropical island. It's not too big, about 37 acres, which is enough room to explore if you're one of the few people allowed to visit. As you might expect, the island has many trees and other plants. It's really a lush tropical island and, as you look around, it seems to be well. It seems to be a bit of paradise Well, monkey paradise, because the island we're going to talk about today is Cayo Santiago, also called the Island of the Monkeys, a place where scientists have been able to study a colony of rhesus macaques brought to the island in 1938. 

But the story of this island, like all good tales, maybe in this case a monkey tale has a twist. It happened in 2017 when Hurricane Maria and its destructive storm hit the island. You might remember that nearby Puerto Rico was also devastated by Maria. It was so bad it took days before scientists could get back to Cayo Santiago to find out that almost all the lush trees had been destroyed. They were just gone. This meant no food and little shade from the hot tropical sun for the monkey residents. So what happened to the 1700 or so monkeys that called Cayo Santiago home? 

Today's guest has the answer. Well, maybe we should say part of the answer and a new science mystery to solve, or several mysteries. Noah Snyder-Mackler is a faculty member and scientist in the School of Life Sciences and the Center for Evolution and Medicine at Arizona State University. Noah studies how social behavior impacts health and survival, which is really important for all of us. This means he looks at how social relationships can protect us from stressful events like, say, your entire world being wiped out by a hurricane. 

For this episode, we will see how our primate friends are doing and what we're learning from them about coping with stressful events, and perhaps, if we have time and you're willing to listen to a little bit longer episode, we can journey high into the Ethiopian mountains to learn about another group of primates who deal with a different kind of environmental stress. To start us off, Noah, welcome to Ask A Biologist.

Noah: 3:02

Thanks for having me, Dr Biology.

Dr. Biology: 3:04

All right, for those that may not know about, let's start at the beginning. Let's go back to 1938. Why are these rhesus macaques? Why are they actually on an island just off the coast of Puerto Rico?

Noah: 3:18

Well, before we get to that, I think we have to know a little bit about what are rhesus macaques.

Dr. Biology: 3:23

Ah, even better.

Noah: 3:24

Yeah, so rhesus macaques are a really widespread non-human primate, so a monkey close relatives of humans, and they have the broadest geographic distribution of any non-human primate. So humans, we live pretty much everywhere in the world, right? Rhesus macaques are spread throughout Asia and they live up at high altitude and down at low altitude, and in forests and in cities. They're pretty much everywhere. They're adaptable, they're versatile and they've actually been one of the most commonly used animal models for different sorts of research projects, including biomedical research. 

And so one of the two main reasons why these monkeys were brought to Cayo Santiago all the way from their homes in India was because the US wanted a population of rhesus macaques nearby for research purposes, and the guy who brought these over, a primatologist, Clarence Ray Carpenter, wanted to have a place where he could do some naturalistic, behavioral and environmental and ecological studies and observations of the rhesus macaque in a semi-natural environment, without having to take a ship all the way over to India.

Dr. Biology: 4:41

Brought them close to home.  Do people live on the island?

Noah: 4:47

People do not live on the island of Cayo Santiago. It’s about one kilometer, just short of a mile, half mile or so off the coast of Puerto Rico. So, you have to take a little boat out there and the only people who are allowed out there are the primate center staff who help feed and provision water for the monkeys and the researchers you can't visit, okay?

Dr. Biology: 5:04

No touristy stuff. It is truly an exclusive island for macaques. 

Noah: 5:19


Dr. Biology: 5:20

All right, so we have this island. It's up until 2017, a lush island.

Noah: 5:21

A very lush island, lots of palm trees, many species of mangrove, out on the edge of the island. It's a nice little paradise out there. 

Dr. Biology: 5:25

Then Hurricane Maria hits. 

Noah: 5:27  

Yeah, and it's not like. This is the first hurricane to come through the Caribbean and to hit Puerto Rico and to hit this island, and there's been strong hurricanes did this island before, but Mario is pretty much unprecedented in its devastation. It was coming in and hit as a category four hurricane just barely below a category five the highest category, there is and it just took a direct hit right onto the southeast coast of Puerto Rico, which is where Cayo Santiago is, and then continued on to just devastate the mainland of Puerto Rico. And what happened was combination of the wind and then the storm surge, which is just this like rise in the water level around, really, knocked down a bunch of the trees and then, with all the salt water, over time eroded and killed many of the other trees that remained and that survived the hurricane.

Dr. Biology: 6:18

Wow. So at the beginning of the show I said it took weeks to get to the island. Is that correct?

Noah: 6:26

Not quite. It took us weeks to sort of get a really full assessment of what was happening on the island. But the Caribbean Primate Research Center staff. So, the primate center, the staff that maintain and Provide food and water for the monkeys on the island, because, again, it's a small island with a lot of monkeys and they need food. There's not a lot of food for them on that island. They were able to, despite the devastation of their homes, get out to the island with food within just a couple of days, with food and water, and if they didn't do that heroic act to take care of the animals, they wouldn't have survived much longer.

Dr. Biology: 7:01

That’s food and water, but the hurricane and I'll have to check what the wind speeds are a hurricane, category four are just short of five, but well over a hundred miles well over a hundred miles

Noah: 7:14

Well over a hundred miles an hour. 

Dr. Biology: 7:15

And for even a human to survive, that would be tough.

Noah: 7:20

Very tough.

Dr. Biology: 7:21

We're talking around 1,700 Monkeys. 

Noah: 7:24

So, you're gonna ask me the question that everyone asked me is what do you think they were doing?

Dr. Biology: 7:28

Well no, I'm gonna ask you how many made it?

Noah: 7:31

You want to ask how many made it? Yeah well, much like human society, animals die on a regular basis old animals, sick animals, things like that. That happens. It's a very natural colony and this is a population that we study, where there's natural births and deaths. We call that natural mortality, and so on any given month out of the 1,700 monkeys will have about 1% that'll die. Actually, a little bit less than that in general, but that is an average and some months there's 2% and some months there's 0.1%. After the hurricane, actually it ended up being about 2%, which is a little bit higher than usual, but well within the range and not out of the expected range that we see on a monthly basis.

Dr. Biology: 8:14


Noah: 8:15

Miraculously, they survived. 

Dr. Biology: 8:18

And we'll probably never know how they did it, because that's the thing it just amazes me. It's not like they have the kind of shelter and the kind of things that we do. We'll never know what they …

Noah: 8:30

Will never know, and I think the fact that there were 1,700 monkeys on this small island and with the storm surge the island got smaller because there was water all around. Means that they had to get really close to one another and they had to find a place that was protected from the extreme winds and rain that was coming from the hurricane. So only a few places they could have gone. And we know they had to all get really really close together. And these are monkeys that don't always like each other. They've got their close friends, their close social groups, but they don't necessarily mix well with the other social groups. They have their groups territories, but for this they actually had to survive, they had to tolerate one another.

Dr. Biology: 9:11

So, we're getting into your area. 

Noah: 9:13

Yeah exactly. 

Dr. Biology: 9:15

Sounds very stressful to me 

Noah: 9:16

Very stressful. 

Dr. Biology: 9:18    

All right, it's been six years. What are we learning from it? What are they teaching us how to deal with stress? 

Noah: 9:26

Yeah, so one of the really wonderful things about studying Cayo Santiago is that we have this really beautiful hybrid or Goldilocks system between the wild and a very captive lab environment. So it allows us to combine really natural behaviors and environmental complexity, this rich social complexity, with some of the tools that we can use in the lab, like we control blood samples from these animals every year and release them back and they go back to their group and go about their days, and this allows us to pair really rich environmental data and social data with biological inferences on their health.

Dr. Biology: 10:09

Right. So how do you measure stress? Humans you can kind of see it. I suspect you can probably even see stress outwardly from the primates.

Noah: 10:19

Yeah, so they exhibit many of the same behaviors that we exhibit when we are feeling uncomfortable or stressed or in an unpredictable situation. We'll get a little bit anxious, we'll engage in what we call self-directed behavior, like itching or scratching and things like that. So, these monkeys will do that when they're anxious, and we can see them doing that in their regular day interactions with each other. They have families, they have friends, they have social hierarchies, and those who are lower down on the social hierarchy, lower down on the social ladder, might have less access to resources, might have less predictability in their environment, and I think what all of us crave and what all of us need to not be stressed out is to know what's coming next predictability.

Dr. Biology: 11:03

Right. So, we can do this through observations, but there's also physiological things we can do to see when, and this is true for us too, when we have stress. 

Noah: 11:14

Yeah. So, there's lots that we can do and so even before Hurricane Maria, we were measuring some of these physiological factors that capture different aspects of your immune system or of your stress response pathway or growth and things like that. There are some things where we can measure their stress hormone levels. Called cortisol, generally is the human analog, but we don't need to get into the details of that. But that is something that is elevated when you are stressed. It's sort of your fight or flight response, right? 

So, we're able to measure that over time in these animals. And also when your stress levels are elevated that negatively affects your immune function, your ability to sense and respond to some pathogen or infection in the environment, and so we measure these two things among others. You know your stress response pathway and your immune system in these monkeys and we were doing that for years before Hurricane Maria came. Then Hurricane Maria hit and in its sort of devastation there was actually this sliver of opportunity where we could examine how does such an extreme stressor, extreme natural disaster event affect immune function, affect the stress response pathway and affect health and survival in a population that can't escape that devastation or anything in the fallout of that. In humans we see that after Hurricane Katrina, those who are more well off were able to leave the destruction. They could afford to do that, those who weren't had to stick around and often bore the brunt of the negative consequences of that disaster, which means that we can't really pull apart how the hurricane was affecting health versus how other components of human lifestyle and environment were affecting health. 

And so, with the nonhuman primates, these macaques on Cayo Santiago, we're actually able to control for some of these in science we call them confounds, but these extra little nuances or nuisance, extra things that muddy up analyses and make it difficult for us to identify what's actually happening. But we can do that on Cayo Santiago, we can get rid of some of these and we can actually ask what's the direct effect of this hurricane on the immune function of these monkeys, which was the focus of probably one of our first studies coming out of there.

Dr. Biology: 13:36

When we think about stress and when you mentioned that the immune system one of the things that people have been taught or you learn is that if you're not watching your diet, if you're not getting enough sleep, there are things that you do that makes your body more prone to get sick, and this fits into this issue of stressors as well.

Noah: 14:01

It's actually similar to something that happens to our bodies as we get older. Same sort of thing wear and tear on your body, and then your immune system's not as up to the task.

Dr. Biology: 14:34

Right, as you get older, we use this term homeostasis. There's this nice balance. Everything has to be in sync and as you get older, it becomes more and more challenging because it needs to maintain that homeostasis. Much tighter than when you were younger, you're able to recover and do those all-nighters and study and still get a good score. [Laughter]

Noah: 15:01


Dr. Biology: 14:39

As a matter of fact, I don't know that I ever did an all-nighter and did really well the next day. 

Noah: 14:42

No, I don't think that's possible. We call that window of homeostatic range that you can be in. We call that your reserve, your physiological reserve right, and your reserve gets smaller as you get older, so you have less wiggle room to really get pushed out of bounds.

Dr. Biology: 14:57

So, we've been looking at this opportunity, which is interesting. So, it's devastation, but in this case we really are trying to make lemonade out of lemons here.

Noah: 15:08

Yes, absolutely.

Dr. Biology: 15:11

Six years later.

Noah: 15:12


Dr. Biology: 15:14

What's the big story for you?

Noah: 15:16

What's the big story? So, we have two sort of main stories that are intertwined and we're still trying to really really link them together. The first is link to what I was mentioning about they had to become more tolerant of one another to get through that storm. Well, after the storm, all the trees were destroyed, almost 90% of the vegetation, something like that the vast majority right? Puerto Rico, it gets really hot during the day. Shade is an important resource and now a very limited resource, and what we noticed is that all these monkeys became much more tolerant of one another. They increased their social networks a little bit and this meant that they were okay with other monkeys being closer to them that weren't necessarily close to them before. And what we saw is that those animals that were the most isolated before the storm, so at the fewest friends or were furthest away from everyone, actually increased their close number of partners or friends much more than others. So, we see that there's this strong effect on the social networks.

Dr. Biology: 16:14

Misery loves company.

Noah: 16:16

Yeah, exactly right. But there is a functional component to this. There is a fitness consequence in terms of natural selection, Darwinian fitness, and we have a paper that under review right now that hopefully will be coming out in the next six months, ideally sooner, showing that actually those who increased their social affiliation the most after the storm actually were less likely to die in the six years after the storm. So, increasing, responding to this event, and increasing your social support network, let's say, has a protective effect on your ability to survive. And what we found is that actually it was not just that overall effect. It was actually that your friendships or your time spent with other individuals during the hottest parts of the day because we can break that down when you're spending time with people Actually have the strongest effect on your survival. So, it's not that early in the morning you need to be really close to one other, but it's actually that you need to be close to others later in the day when it's really hot and shade is limited. So, there's that social buffering aspect of this, where social connections can help protect you from many other unexpected things and hopefully help improve your health into a lifespan which we see in humans. 

The other aspect of the story that again we're connecting to is down to those immune measures that we could look at. So we could take blood samples from these monkeys before the hurricane and we could look at how well their immune systems functioning. We use transcriptomics for this approach, which means we're measuring every single gene that's being expressed, the RNA, that’s being expressed in every single one of those cells that we've collected in your immune system, and using that we could sort of come up with this joint measure, this one measure of like how old does this monkeys immune system look? And we can do that pretty well, we can predict it pretty well. And what we found that before the hurricane, if you're an eight-year-old monkey, your immune system looks like you're an eight-year-old monkey. After the hurricane we could do these same measures on some of the same monkeys also, some new monkeys that we didn't sample before, and we could run the same prediction draw the blood, measure the transcriptome, those RNAs that are being expressed, and come up with an estimate of how old their immune systems look. 

Take a different eight-year-old monkey, sampled after the hurricane, so lived through this hurricane, and on average their immune system looks like that of a ten-year-old monkey, so looks like experience of the hurricane living through this traumatic and stressful event had accelerated the age of their immune system by about two monkey years. And if you're familiar with dog years and human years, that rough translation right. Those animals have much shorter lifespan. So, we can think that one dog year is roughly seven human years. We can do that same math with these monkeys and one monkey year is about three to four human years. So, you can think about this two-year acceleration in their age as being six to eight years in human life, which is a really big deal, and especially later in life that can really substantially impact your health negatively. 

But I told you about these two stories and I think the natural question is well, how are these social relationships impacting whether or not you do age, your immune system or not? That's what we're really looking into here the most. That's sort of what we're trying to tie together. It's gonna take a little bit more time, but I said on average there was a two-year age acceleration after the hurricane but that was on average. There's a big distribution some monkeys aged four years after the hurricane that added four years to their lives, others none at all. Others are a real monkeys that looked at immune systems of eight-year-old monkeys. Why? That's what we're trying to figure out here and we think that social connection, social environment, really plays a part here. 

Dr. Biology: 20:00 

Right and the other question is - those that their immune system age more rapidly. Since it's been six years since then, has there been any recovery? Is it lost forever?

Noah: 20:11

Yeah, hopefully not right. Hopefully you can come back. Your immune system is a couple years older than you and then eventually it comes back and you're matching, a few years later maybe. So that's the longitudinal repeated sampling that we've been doing on these monkeys and we're just generating those data right now. We got some federal funding, so some grant funding, to support that work just last year, and we have some wonderful researchers who are working on that with us here at ASU and elsewhere who are coming through those data to address that exact question, right? So do you come back to normal and if so, when? How long? If not, why? And what's the difference between those that do come back to Normal and those that don't?

Dr. Biology: 20:50 

Right and with all the behavioral studies you're doing along with this. It's critical. Why is one monkey doing better than the other? Is it purely physiological? Or is it because their social capabilities, the way they socialize. We've talked about when you get older, homeostasis becomes more challenging. Yeah, your reserves right? 

Noah: 21:11

Reserve is smaller. Yeah, resilience is weaker.

Dr. Biology: 21:14 

So, it's the same thing with age, it seems like for humans You're seeing the same sort of thing going along, that as you get older it's really important to have that friendship.

Noah: 21:23

Yeah, I think it's really important. Actually, we've published some really cool work actually looking at what happens to your social networks as you get older and people you know, as we get older, our social networks constrict, they narrow, they get smaller. It's not because they're less important. It's not because social connections don't matter for us as we get older and into our lives. Actually they might matter much, much more. It's just that we have limited time and those strong social connections are the ones that matter the most. So it's not that we're less interested. We're actually just like focusing on the relationships that we think matter and that are most important to us. Maybe it takes time to figure that out. And in these monkeys we actually see the same exact thing, which is really cool. 

We looked longitudinally again within individuals over time and saw that they were narrowing their social networks as they got older. And it wasn't that as you get older, no one wants to hang out with you. Right? You're less desirable. It's actually the case that you're equally desirable, if not more, desirable. You're just choosing not to interact with these other monkeys that you don't want to interact with, so you get to pick and choose who your friends are a little bit more. And so they're allowed to sort of narrow and focus their total social effort, or their total amount of time they can invest in their friends, on a few individuals that they really care about 

Dr. Biology: 22:39 

It just seems like every time we open one area of exploration, we get dozens, if not more, questions that come out of it.

Noah: 22:50

I mean that's why I'm in this job, right? It’s why we need more scientists to write them down. Never gonna be done, right? I hope I'm never done. I hope I never just find the answer.

Dr. Biology: 22:58 

Well, it's like the book on the shelf with all the answers doesn't exist. And we keep getting better at finding out where the holes are, fill in those holes and then also digging deeper little details. It's a really good example that the more we know, the more we need to know.

Noah: 23:15

Absolutely. The part we know, the less we thought we know. [laughter]

Dr. Biology: 23:20

Yeah, well, that's true, that's true. We can, we keep refining it, right. So I think you think you had the answer and you realize it's well. It's a little more complex than that right.

All right, what we're learning from our primate cousins as far as dealing with stress on this island is amazing. But not all stressors have to have a hurricane. And you work with another group of monkeys, yep, that have a different kind of stress, and it turns out I actually grew up in Colorado, in Colorado Springs, actually, which is at the foot of Pikes Peak. 

Noah: 23:58

All right, all right.

Dr. Biology: 24:00

And that mountain is fourteen thousand, I think, one hundred and fifteen feet high, so it's got some definite altitude. 

Noah: 24:06

Definitely does. You don't live on top of that.

Dr. Biology: 24:09 

But at the summit, because you can actually drive from the base of the mountain all the way to the summit on a paved road many people end up at that altitude and they have some problems or challenges. This is probably true most of your monkeys as well. So, let's talk about stress and altitude and other group of primates for sure.

Noah: 24:34

So for this part of the story we're gonna move from Puerto Rico all the way to the highlands of Ethiopia in the Horn of Africa. So East Northeast Africa. Ethiopia has this really beautiful landscape that was formed by many, many, many years of erosion and there are these huge clifflike plateaus that are about 3,000 meters above sea level. So I'll translate that back to our system out of metric here. That's about, I would say, where we do our research is about 11,000 feet above sea level, but it ranges from about 8,000 to probably about 14,000, maybe a little bit more than that, maybe close 15,000 at some of the highest points. And we're out there because there's this really cool and unique monkey called the gelata that lives only in Ethiopia and only up at high elevation. And when I say high elevation, we're talking about above 2,000 meters, above 8,000 feet above sea level and up to about 13,000 - 14000 feet above sea levels. Pikes Peak. 

Dr. Biology: 25:41

Right, just living high in the mountains. Besides, the fact that it can be cold, it's one thing, so you definitely have seasons  

Noah: 25:50

Close to the sun. Lots of UV 

Dr. Biology: 25:52

Lots of UV and something that's lacking, something that you get less of the higher you go in altitude, and that's oxygen, that is oxygen. 

Noah: 25:59

And it's actually not specifically that the oxygen itself is lacking in the air up there. There's the same amount of relative oxygen up there. It’s just that as we get higher, sort of the inverse is, as you go down underwater, further underwater is that the pressure changes right. So with lower atmospheric pressure up there, every breath of air that you bring in just as fewer molecules period, which means less oxygen. And we call this hypoxia, this condition where you have less oxygen coming in and your body's got to find a way to make do with less oxygen, because oxygen is what we need to make energy and for our tissues to survive. 

Dr. Biology: 26:43

Okay, I'm guessing this is going to be our stressor. 

Noah: 26:47

Yeah, this is one extreme environmental stressor, for sure, and we're looking at this stressor not over short periods. You know, in humans. You go up there and your body reacts to the stressor by finding ways that it can increase oxygen delivery to your body, to your lungs, to your brain. To do that it does a couple things. One you increase your breathing rate. You start going hah, hah, hah, a lot. Second thing, and one thing that's really important, is that you increase the amount of red blood cells that you're producing because these oxygen carrying things and that's a good thing in the short term. It's a bad thing in the long term if you were to stay up there and have chronic elevated red blood cell concentration, because that can impact blood pressure, lead to clots and things and be really devastating. So, it's good short term stress response to low oxygen. 

With these monkeys, they've been living up at high elevation here for, you know, let's say, a million and a half years. They aren't doing the short-term response that we're doing. So, we can use them as sort of a model to understand how evolution, natural selection, has pushed them to develop some traits, some phenotype. So, phenotype is a science word for trait, right. Natural selection has pushed them to develop these traits that allow them to survive and thrive at high altitude, in these low oxygen environments. That means we're not talking about sort of short-term responses to going up and down this mountain. We're talking about changes to their DNA sequence, to their development, to their bodies, that allow them to live there without the negative consequences of less oxygen with each breath of air.

Dr. Biology: 28:29

And this is something that's chronic stress.

Noah: 29:32


Dr. Biology: 29:53

So, unlike the one with the hurricane, with the stress that comes and goes. This is living in a stressful environment. What's going on?

Noah: 29:05

Yeah, what's going on? So, because they've been living for so many generations up there, generation after generation, and if you think about it from the same point of evolution, if one monkey develops a little mutation in their DNA sequence that allows them to do a little bit better than the other monkeys, say, a million years ago, and they can get just a little bit more oxygen out of each breath of air, then they're going to do better, they're going to have more offspring and that gene's going to spread in the population and that gene's going to take over. And so incrementally, we see some of these changes can happen, such that most of the monkeys have these and can live and thrive up there. So what we did is we decided to sequence the DNA of a bunch of these monkeys up there, and we can do this a number of ways. 

We can very carefully tranquilize them and draw a blood sample, but we only do that to a few monkeys and they're fine, they get back, they go to their groups. But also we can collect poop samples and we can get lots of monkey DNA out of those samples as well. And so in doing this, we sequence their DNA and then we look to see what are some of the differences in their DNA compared to their closest primate relatives that don't live at high altitude, which is all of the baboons, the six different species of baboons that live throughout Africa. And so in this work we actually found some really cool DNA sequence differences that are a smoking gun, right. Not the actual adaptation, but something that tells us something's going on here that's allowing them to survive and thrive at high altitude, because many of the DNA sequences changes that we saw were involved, were in or near, genes that encode for proteins that are involved in how we respond to hypoxia.

Dr. Biology: 30:32

So, the mystery is unfolding.

Noah: 30:33

The mystery is unfolding. Right, we're looking at a sequence of letters and comparing that sequence of letters to many other sequences, those same sequences in different species. We’ve done some biology to sequence the DNA and then we're crunching some numbers. We don't know if those differences that we are seeing in those letters actually does help them at high altitude, and so what we have to do is we have to then do a bunch of other tests. We have to take that DNA, take a monkey cell, put it in an incubator and say, if we change the oxygen level in here, does the cell with the gelato-monkey DNA do better than one with the baboon DNA? 

Noah: 31:35

So, we could do some of these really interesting comparisons. We can also compare gelato-monkeys that are living in the zoos at low elevation to those that are living in the wild at high elevation in terms of their blood composition and things like that. There's all sorts of comparisons we can do. We've done a number of studies, published one really cool paper just a couple years ago and we're digging in now and following up on this really interesting question, not only from just a evolutionary biology perspective   but also from the perspective of human health and medicine. Because if we can find new ways in which natural selection has allowed organisms to be okay in low oxygen environment, that might help people find new ways for treating COPD or these diseases where people have a tough time breathing or getting enough oxygen.

Dr. Biology: 32:00 

Right. All this with a theme of stress. 

Noah: 32:02


Dr. Biology: 32:05

Which, by the way, we have an episode of Ask a Biologist called Stressed Out, which, interestingly enough, is one of the more popular episodes, because I think people feel stressed out and they always want to learn if there's something that we're going to teach them about how to be less stressed, it's with Miles Orchinick. 

Speaking of guests. My scientists never get out of here without answering three questions.  

Noah: 32:30 

All right.

Dr. Biology: 32:32

So you're ready.

Noah: 32:32 

I'm ready.

Dr. Biology: 32:33

Okay, when did you first know you wanted to be a scientist?

Noah: 32:38

I think I first knew that I wanted to study animals and to understand and I was curious about biology. The first time I went to the zoo that I can remember, probably with my parents and my grandpa on my mom's side, and I always thought that the only thing I could do to work with animals was to be a veterinarian. I didn't realize until I was in college that there are many opportunities outside of being a veterinarian that allow you to study animals and learn things about evolution and biology and also even maybe apply them to understand. You know human and animal health.

Dr. Biology: 33:12 

So, the zoo.

Noah: 33:13

The zoo. 

Dr. Biology: 33:14

Oh well.

Noah: 33:15

Love the zoo.

Dr. Biology: 33:16

I had a series on the zoo just not long ago and I'm sure those guests would be thrilled to hear that. All right, so now you have your career set and my scientists are always passionate, and I do this next question. It's a bit evil. It's a thought question. 

Noah: 33:35


Dr. Biology: 33:37

First of all, because some of my scientists freak out a little bit because I'm going to take it all away. You don't get to do science anymore. And no more teaching, because I have learned over the years that most of the scientists love to teach. That's part of our DNA.

Noah: 33:49

So you speak right.

Dr. Biology: 33:50

If I take it all away from you. What would you do, or what would you be? 

Noah: 33:55

Oh man, if we were to take it all away, if I couldn't be a professional athlete.

Dr. Biology: 34:10

Well, you can. What sports sport would you want to do?

Noah: 35:03

You know, that's the thing. I don't know if I'm good enough at any of them to be a professional athlete, but I love athletics and playing different sports. I played them through high school, a little bit in college. But I think what I would really like to do and maybe this is too easy of an answer for me actually is wildlife photography. Wildlife photography, wildlife journalism, things like that. I really love taking really great photos of the animals that I'm studying and other animals that are around. It's very calming, relaxing and really fun for me. 

Dr. Biology: 34:16

Yeah, I'm with you, 

Noah: 34:17 

Not stressful.

Dr. Biology: 34:18

It's one of my passions too. Alright, the last question, and a very important one. What advice would you have for a young scientist, or perhaps someone maybe who is an athlete that always wanted to be the scientist? What would be your advice for them?

Noah: 34:54

Stay curious. It's really straightforward, I think. Ask questions, don't be afraid to ask questions and always be wondering what's going on with that and what's happening here. You know, I think, I'm gonna paraphrase Isaac Asimov. He was a famous scientist and science fiction writer. He used to say that it's something like it's not exciting to find what you were looking for, right? So the most exciting phrase in science is not Eureka, I found it. The most exciting phrase in science is hmm, that's funny, yeah. [laughter] So you got to stay curious, right? You have to be able to think about, you know, oh, that's interesting, right? And I've got to pull that thread a little bit more. I really want to understand it, because it's rare that you're gonna find the answer. You're always gonna have more questions and you have to be okay with that and comfortable with that and curious and excited about that discovery.

Dr. Biology: 35:32

Right. Mine was typically. I'm a microscopist so there are a lot of times we're imaging the tiny world.

Noah: 35:38


Dr. Biology: 35:39 

And my phrase was ‘that's not what I expected’.

Noah: 35:44

Same thing, right? I think it's just like huh, what's going on?

Dr. Biology: 35:45


Noah: 36:48

But that's exciting, right, it's not. It's not like oh, I didn't find what I thought, I found.

Dr. Biology: 35:52

Well, with that, Noah, I want to thank you so much for sitting down and visiting with me on Ask a Biologist. 

Noah: 35:58

Thanks so much, Dr Biology.

Dr. Biology: 36:00

You have been listening to Ask A Biologist, and my guest has been Noah Snyder Makler. He's a faculty member in the School of Life Sciences and in the Center for Evolution and Medicine at Arizona State University. Now, if you'd like to learn more about what Noah's been doing, we will put some links in the show notes, including a link to a 60 Minutes video that Noah was in. It featured the Monkey Island and we will also include a link to a story called Why Some Monkeys Live High in the Mountains that has been published in the Science Journal for Kids, which is another great place to explore science learning. 

The Ask A Biologist podcast has been produced on the campus of Arizona State University and is recorded in the Grassroots Studio housed in the School of Life Sciences, which is an academic unit of The College of Liberal Arts and Sciences. And remember, even though our program is not broadcast live, you can still send us your questions about biology using our companion website. The address is, or you can just use your favorite search tool and enter the words Ask A   Biologist. As always, I'm Dr Biology and I hope you're staying safe and healthy.

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Bibliographic details:

  • Article: Monkey Tales - Learning About Stress
  • Episode number: 133
  • Author(s): Dr. Biology
  • Publisher: ASU Ask A Biologist
  • Date published: February 16, 2024
  • Date accessed: July 15, 2024
  • Link:

APA Style

Dr. Biology. (2024, February 16). Monkey Tales - Learning About Stress (133) [Audio podcast Episode.] In Ask A Biologist Podcast. ASU Ask A Biologist.

American Psychological Association. For more info, see

Chicago Manual of Style

Dr. Biology. "Monkey Tales - Learning About Stress." Produced by ASU Ask A Biologist. Ask A Biologist Podcast. February 16, 2024. Podcast, MP3 audio.

MLA Style

"Monkey Tales - Learning About Stress." Ask A Biologist Podcast from ASU Ask A Biologist, 16 February, 2024,

Modern Language Association, 7th Ed. For more info, see
How are gelada monkeys, also called bleeding-heart monkeys, helping us learn about a particular type of stress? Image by Hulivili via Wikipedia CC BY 2.0.

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