What On Earth is Evolution?!

Evolution is everywhere in science and almost nowhere in popular culture is it explained clearly. In this episode of What On Earth?!, we dive into some of the biggest misconceptions about evolution and separate the science from the myths.

Is evolution “just a theory”? Did humans really evolve from monkeys? Is evolution completely random? And does evolution explain how life first began? These are questions many people have heard, but the answers are often far more interesting than the misconceptions themselves.

We break down what evolution actually means in biology, explain how natural selection works, and explore what scientists really mean when they use the word theory. Along the way, we talk about fossils, common ancestry, adaptation, and why evolution is one of the best-supported ideas in all of science.

This episode is not a debate. It’s a guide to understanding the science in a clear, accessible way. Whether you’re completely new to evolution or just want a better grasp of what the theory actually says, this episode is for you.

If you’ve ever heard conflicting claims about evolution and wondered what the science really is, this episode of What On Earth?! is the perfect place to start.

Transcript

SPEAKER_01 0:20

Hello everyone. Welcome back to What on Earth? The podcast that breaks down science into clear, concise, hopefully accessible conversations. And today we're tackling a topic that many people have heard of, and it's one of my favorite subjects, but few fully understand it, which is evolution. Specifically the myths and misconceptions surrounding it. There's a lot of those around. You may have heard people say things like evolution is just a theory or it's random or humans evolve from monkeys. Um and I'm curious, Veronica, do you have any of these pre-conceptions in your mind right now?

SPEAKER_00 0:58

I mean, I definitely will not say evolution is just a theory, because we know that the theory is very scientifically proven form of science, like very heavily evidence-based science. And if you don't, please go back to our episode when we talk about flat Earth, because we definitely told you what theory is and how scientists prove theories. But I but I do you know I'm I'm a space in rock girly. So in my head, we do come from monkeys. Tell me I'm wrong.

SPEAKER_01 1:33

Well, we'll talk all about it in this episode. And we're gonna figure out what all these statements actually mean and where they go wrong. And we'll also define evolution clearly first. Um explain again what a scientific theory really is, and we'll also dive into some of the most common misunderstandings about evolutionary biology. But we'll start with the basics, what I already mentioned, what is evolution? How do we describe it? How do we define it? So when scientists talk about evolution, they mean something very specific actually. And in biology, it refers to changes in the genetic characteristics of a population over generations. So over time, if certain traits help organisms survive and reproduce more successfully than others, those traits may become more common in a population, which is called descent with modification. So the central idea of evolutionary biology is you have this trait in your individual that is very advantageous in the group you live in or in your population. So population is a group of individuals that is confined to either geography or type of species, and that trait is more successful, so the individuals that have that trait can reproduce more, so they get more kids that also have this trait, and therefore it becomes more established in the population. So that's an important thing. Evolution acts on populations, not on individual organisms, and individuals don't evolve during their lifetime because these genetic traits don't change much or enough in one's lifetime.

SPEAKER_00 3:04

So what you're saying is that you as an individual will not change, but your offsprings might because of certain conditions?

SPEAKER_01 3:14

That's a good point. So you might be born as an individual with a genetic mutation, we call them, and that creates an advantage for you to survive or to mostly mostly to reproduce. So you get more kids because of this trait, and all those kids get those traits as well, and then you get a genetic shift in the population over generations.

SPEAKER_00 3:33

So it's like a longer process. Individuals might inhabit those changes, but generally the big picture we get over generations, right?

SPEAKER_01 3:42

Yes. Yes, you get evolutionary change over generations over time. Yes. So evolution isn't just about change, it's about heritable change. So anything that can be passed down from parents to offspring that are different from other individuals. So evolution explains how life diversifies and why we see patterns of similarity and difference among living things. Therefore, we now know what evolution is. So we'll talk about what a scientific theory is because we talk about the theory of evolution usually, right? So in everyday language, the word theory means a guess or a hunch. But in science, this term is very much stronger and more precise because a scientific theory is a well-supported explanation for a set of observations about the natural world. And it's built from a large body of evidence, which can be used to make predictions that also can be tested. So when people say evolution is just a theory, that always grinds my gears a lot. Because I have so much to say about it, I don't know where to start. It's a misunderstanding that stems from mixing up everyday and scientific meaning of the word theory.

SPEAKER_00 4:47

And remember, scientific language is not everyday language, so go back to our fast episode.

SPEAKER_01 4:52

We started off strong.

SPEAKER_00 4:53

We we started there. We literally told you guys that scientists communicate differently.

SPEAKER_01 4:59

Yeah, yeah. So the theory of evolution, like other theories such as gravity or platectonics, has stood up to more than, well like, well for evolution, 150 years of rigorous testing, evidence gathering, rechecking, trying to disprove it, and then, well, not being able to disprove it, it's pretty set in stone at this point. I mean, you have to have a very big discovery to be able to disprove it. So theory and science means the truth for as long as we can not disprove it, basically. I'll start with the first misconception, and that is that evolution is just random. We cannot direct it in a way, which is a common misconception because these genetic changes are random, but then the ones that survive are not random. So it's a little bit of both. It's said in some kind of truth. There's a little bit of nuance to it. So some components of the evolutionary process involve this randomness, as I just said. Genetic mutations occur without direction or purpose. So evolution does not have direction in that way. But natural selection, so the process that filters this genetic variation, is not random. Certain traits increase the frequency of offspring surviving, which improves survival. For example, sometimes it doesn't, which is also interesting, but we'll talk about it later. It's a little bit of a caveat. But reproductive success is given as the main factor for evolutionary direction. This mix of random and non-random processes is a very complicated structure, but it's the defining trait, the defining feature of modern evolutionary theory. So not the one Darwin started, but the one we evolved to think of being true.

SPEAKER_00 6:38

A lot of people, yes. So you just said that not the one that Darwin came up with. Do we have different theory? So the one that Darwin came up with is not the current one. Did we diverge from the views of Darwin? Can you can you elaborate on that a little?

SPEAKER_01 6:54

Yeah. It's been a while since I looked into that. I should have done that maybe for this one. I think well we're gonna do a full episode on Darwin's life and how his theory shaped the world because it was very controversial. He had a lot of struggles with it. But I think Darwin's first version of the theory was um a good starting point, but there were a lot of things he got wrong as well. So we shaved and changed the theory into what it is today. Also with the like scientific discoveries we got since then, like the microscope, the DNA sampling, the tinier things we can now research.

SPEAKER_00 7:30

I guess also carbon dating and fossil record we have better ones than they was accessible when Darwin was alive, I guess.

SPEAKER_01 7:38

Yeah, yeah. And also better like equipment to get it out to date it to yeah, research it, basically. So he started off very strong. Well, we made it a little bit better since then. Another thing you hear a lot when people talk about evolution is that they say it explains the origin of life somehow, how the very first living things came into existence and how life began. But it does not seek to explain life's origin, that's a very different part of science. It only explains how life changed after it already existed. So the questions about how the first cells formed are the domain of more origin of life research. But that's not the same as evolutionary theory. Evolution only begins when life already exists and then describes how that life diversifies.

SPEAKER_00 8:22

So we cannot trace back, you cannot like take back these traits to kind of go back to the primordial life. It doesn't work like this.

SPEAKER_01 8:33

No. No, because it explains how life came to be so complex as we know it now. So we have the bacteria, different bacteria types that I already explained in a previous episode, where they merged and then got this whole new trait level that they could exploit, the whole new thing. But not how these bacteria, these instant first living things were created. Gotcha. So sometimes you've heard also people say, evolution means progress, and humans are like superior or at the top of this evolutionary process. Like you've seen these diagrams that look like ladders, the simple organisms at the bottom, humans at the top, making it look like evolution works toward a goal. But evolution doesn't have a direction, it's not a sentient being thinking we're gonna create like ubermensch or something. It doesn't strive for complexity or intelligence or perfection. It simply reflects the changes that help organisms deal with their current environments.

SPEAKER_00 9:26

And this is also why So is it also that's why we have some ancient beings like creatures in the in the oceans which were there for like centuries or and millions of years and they didn't evolve because they didn't have a necessity to evolve? So they are exactly the same as they were in Permian?

SPEAKER_01 9:44

Yes, but no, because the necessity to to change is also a bit of a difficult wording you use. Because the the um evolution doesn't feel necessity. Like the randomness of the mutation just happens to have an advantage and therefore it changes. So I mean we have the same now, right? The climate change being super fast. We have a necessity to adapt to this warm climate, but unless this mutation happens naturally, perchance, in one individual that is better able to reproduce because of that trait, and that trait has to be heritable as well, then it gives an advantage, and then you see it more. But it's purely Yeah.

SPEAKER_00 10:24

That's that's super interesting because in my head evolution was like, oh, there was just like signal from environment, and then you have to adapt or die, but you explain it more random, right? Like, okay, it's not random again, it's misconception, but like there were just this mutation, and if the mutation helped you to procreate, then we are talking about evolution, right? It's not necessarily influence from external factors.

SPEAKER_01 10:49

Yeah, yeah, it's not just random and it's not just directional, it's a a weird mix of both, which is misleading sometimes, yeah. Yeah.

SPEAKER_00 10:58

Isn't it because humans just like to have you know like we like to think that everything has its purpose and everything has its direction, so it's like human interior inheritance biased. Um, that you know, we have a creator and then there's a purpose of our life, and then it has to have a purpose of everything living on Earth, and we kind of cannot understand randomness in our head.

SPEAKER_01 11:22

Yeah, yeah. It's it's very hard to to grasp this. That's why yeah, we're discussing it right now because it's fundamental to how we understand evolution and fossils and all these kinds of things. Evolution doesn't aim to be better, it just aims well it doesn't even aim. It it just means that this evolution that happened is better suited for what the environment that is happening now. So instead of thinking of evolution as progress, it's better to think of it as an adaptation to change in conditions, and also non-directional adaptation to change in conditions, it's in that case it's chance for it to turn out better. Then we're gonna continue to the next misconception, which is humans evolved from monkeys, which you'd already talked about, and which is a very common misunderstanding, so no worries about that.

SPEAKER_00 12:08

I think it comes because you know in my head when you talk about it, I have this diagram which I know it's very uh politically incorrect in our current climate, that you have monkeys and then you have you know this like uh slowly standing up monkeys, and then you have a human Indian, right? So it came in my head when I think about evolution, I just think about this picture. So I guess this is the source of this misconception that humans came from monkeys.

SPEAKER_01 12:33

Yeah, yeah, it's a apparently that picture, it's funny you mentioned it, is very controversial. I didn't know, but I was writing my thesis, I did two theses on human evolution and subjects we'll discuss later, but I put this one at the front of my paper or my thing, and then his reviewer went was very mad at me. It was like, you know that's a Nazi symbol. I was like, no, no, would I know that? I'm just trying to write about human evolution. I'm just a girl. Yes, yeah, so I'm just a girl liking humans. I've removed that for the final function.

SPEAKER_00 13:07

Yeah, but like I also didn't know it's uh it was related to like Nazi ideology of uber human until much later in my life, and I was very interested in Second War War when I was uh high school girl, so it's very very interesting.

SPEAKER_01 13:24

Yeah, yeah, painful moment for me, but yeah. So the it it isn't accurate, it's not an accurate depiction of evolution. Humans and modern monkeys share a common ancestor, an ancestral species that lived millions of years ago, and from that ancestry different lineages branched off. So one branch led to modern monkeys, and another eventually led to humans and other apes. So we are cousins, basically, on a tree of life and not direct descendants of the modern monkey. Okay, yeah, okay, makes sense. Yeah, interesting. Okay. Then there's another misconception, and that is that incomplete fossil records disprove evolution somehow, because it's often said that the gaps in the fossil records disprove evolution. But in fact, we expect these gaps because fossilization is rare. The conditions needed to preserve remains don't happen everywhere. We already talked about this in episode three about fossils. If you don't remember, please listen to it or if you're interested. Please look back to that episode. We expect gaps because not every environment or every species is going to fossilize and we're not gonna find them anymore. But importantly, m many of these transitional forms have been found. Fossils with features that bridge ancient species and more recent species. So, for example, we know Archaeopteryx, that's this bird-like type of thing. It's a very famous fossil, you see it everywhere. Um, and it is a combination between birds and reptiles. It has these bird features but also reptile features. So therefore we know that birds are probably very closely rated, or at least like somehow diverged from reptiles.

SPEAKER_00 14:58

So chickens are dinosaurs?

SPEAKER_01 15:00

Yes.

SPEAKER_00 15:02

That explains that explains why I'm afraid of them, because I they are terrifying.

SPEAKER_01 15:07

Really? I'm afraid of chickens. I mean I mean, modern research thinks that dinosaurs have feathers as well, and they sound more like chickens than the roars you hear in Jurassic Park. We'll have to talk to Tom about this, my partner, because he knows a lot about these misconceptions from Jurassic Park, whole different subjects. But we do find these bridge species, these like transitional forms combining species. So the fossil record is incomplete, but it is consistent with the patterns evolution uh evolutionary theory predicts. So actually, yes, an incomplete fossil record does not necessarily disprove evolution. Okay, so we've tackled the biggest ones. How do you feel?

SPEAKER_00 15:48

There that's a lot to process, to be fair. I would not be surprised if our listeners will have to like re re listen to this episode and maybe do some, I don't know, their own research to kind of glue it together because it's a it's a lot of information. So we covered so far that yeah, humans did not come from monkeys, that the evolution is not like it doesn't it's not directional, that it's very it doesn't have a purpose, besides maybe survival, or not even not, because like this is something I also want to ask you because they are the species which went extinct, not necessarily during the mass extinction, they just like faded out, right? Is it also evolution?

SPEAKER_01 16:30

Yeah, it could be. It could also be uh wrong place, wrong time sometimes, but that's a very interesting like sidestep we could take for now. Um sometimes evolution process response to something that actually does not help survival, but it does help we call it virility, I think, creating more offspring, more more kids, basically. Which is for example, there's this bird species that got a very long tail, and the longer the tail, the more attracted females were to this male, so the more offspring this male could get, but at the same time it made the male less able to flee from predators because the long tail was just simply in the way. It got caught more, but it also reproduced more. So how do you explain that? It doesn't improve survival. So like peacocks. Yeah, yeah, for example, yeah, you can imagine a peacock. Yeah.

SPEAKER_00 17:17

Because like it has beautiful tail with no other purpose than attracting female, but then it also makes you very resistant for flying. I actually practical. I actually never saw a peacock, like male peacock flying, so I don't know if they even fly.

SPEAKER_01 17:33

No, but they do mate more. So they get more children that also get this big tail or even bigger tail, and then like more females like mate with that one, and then yeah, you have this this loop, and at some point it's unsustainable, of course. So then these big ones die off before they can reproduce, and that that limits the extent of how long a tail can get a bit.

SPEAKER_00 17:52

So this would be the moment when we could talk about like this fading out of a species because they focus on this one specific trait that it actually became prevented them from from mating or survival, like they were more susceptible for predators or stuff like this? Yeah.

SPEAKER_01 18:09

It really depends on how how fast or how big the population is, I think. Um because if you have this one male that has a very long tail, for example, that only mates with other females, then the long tail is the only preserving factor. If then the tails become too long and the so that these ad uh these males don't even reach adulthood, to be able to mate, to be able to make all these kids, then it can go very fast. Yes. But usually because evolution is gradual and overpopulations, it doesn't go that fast. But then you need just one event of like, I don't know, think about something, bears that find this population and kill them all, and you're done. Because there's so little males or so little left.

SPEAKER_00 18:53

Another question, because this is something you you just mentioned and it made me think, uh is evolution moving faster in short-lived species? I don't know, flies which live one day and the generational overturn is much faster compared to like humans who live around 80 years old?

SPEAKER_01 19:12

Yes. So I would not say evolution is faster, but the species just changes faster because you have more population in the same span of time as humans live. So we did these tests, I think, in the in high school with the I don't know what they're called in English, but the Latin name is Drosophila melanogaster. These like tiny fruit fly kind of things. You had the red ones and then one white one, and the one of the genes was recessive and the other was dominant.

SPEAKER_00 19:40

Dominant?

SPEAKER_01 19:41

Yes. The other one was recessive, the other one was dominant, and then you had to see how m how much time or how many flies it took for them to become split even or even take over one of the two. We couldn't do that with cats, for example. Because I mean, how would you breed enough cats in like one semester? Sure. You cannot see it then, even though the same thing probably happens.

SPEAKER_00 20:02

Yeah. I guess it happens because we have all the breeds of cats, right? So you kind of breed them for specific traits. But I don't know again if it's evolution because at this point humans just put their fingers on it, right?

SPEAKER_01 20:14

Yeah. Um it is a type of natural selection, but it's not natural.

SPEAKER_00 20:19

So it's not an evolution then.

SPEAKER_01 20:21

Yeah, I think you would get a different answer any scientist you ask, but I would say it's not.

SPEAKER_00 20:25

I have another question for you. Because I know uh that certain environments create opportunity for different evolution to happen, like you have Australia, right? And then you have those species which evolve totally differently from let's say any other part of the world. So we have you know kangaroos with the pockets and stuff like this. Is it evolution?

SPEAKER_01 20:51

Yes, definitely. It's just a different kind of opportunity, and I wanted to do a separate episode about specific types of evolution, how how they work. But basically, if you split a population and take like a small genetic pool of this population and separate it, like by land, for example, which has happened in Australia, it creates a whole different gene pool to pick from, and therefore the course of evolution could be different than on other continents. But uh yeah, I'm very excited to talk about this in a separate episode where I have better examples than I can get now.

SPEAKER_00 21:24

Yeah, okay, yeah, that sounds super interesting because it seems that there are so many factors. Like there is, you know, environment, and then there is the genetic mutation, and then there is a you know like reproducibility, and then that the offspring has to inherit it and it has to be dominant, it cannot be recessive. It's so complex that it's actually impressive that we can study this because you know when I did my experimental work, our basis was always just to limit your experiment to one variability. So we either vary temperature, pressure, composition, right? But here. Here it seems like you vary so many different things that it's just uh very hard to understand because it we the picture becomes very messy. So maybe that's the reason of this common misconceptions.

SPEAKER_01 22:12

Yeah, yeah, it it's easy to misunderstand, but also that's also the reason why evolution is highly debated in science. And not like why whether evolution theory is true or exists, but everyone has their own opinion on how it happened or what happened in the past. So for example, if you take human evolution, it's like a minefield of people that think they're right and that have their own opinion and their own decisions on how different species are and where to like separate species, like when it's one or the other. Um it's a lot of discussion there, which is also very interesting because we keep each other sharp on these misconceptions and on how it works, or um finding new theories, new explanations, which is very fun because you take the whole environment into account when thinking about this uh evolutionary direction. But yeah, it's not always as objective as maybe uh experiments could be.

SPEAKER_00 23:04

So it's like between social science and data science, because they yeah, the the data is very scarce, right? We only have fossils record, and then we have to recreate it what happened, like we only see the final product produce, right? Which is the species we we know of.

SPEAKER_01 23:23

Yeah. Please never say that to a scientist, like a paleontologist, that they're a social sciences because they will not be happy with you. But I would I would say it's more qualitative data than quantitative data. So you take one species or a few that you find, or fossils that you find, and try to decipher what happened to that individual, instead of finding like twenty or f a hundred individuals and then seeing a common denominator. Sometimes you can do that, obviously with ammonites, they you find them everywhere. They're easy to preserve, so you can do these quantitative measures. But often more often than not you will have to do with one or part even of a species or of an individual.

SPEAKER_00 24:01

Yeah, don't get me wrong, I have a huge respect for paleontologists because it's like, yeah, it's being a detective but like blindfolded, you know? It's not even being a detective like you're a geochemist and you have all the chemical compositions which are your evidence. It's more like you're you're detective blindfolded in a fog with one object in your hand and try to find a killer.

SPEAKER_01 24:23

Yeah, but that's the fun. That's the fun part to me.

SPEAKER_00 24:25

Yeah, that's why I like to listen to you now when you talk about it. Because it sounds so fun.

SPEAKER_01 24:29

Yeah. Okay, so I hope understanding these clarifications will help you see evolution as a powerful and evidence-based scientific framework, and one that continues to inform us on everything from medicine to ecology to the world around us. I want to thank you for listening to What on Earth. Um, if you have any questions about the topic, please send them our way, either on Instagram, on YouTube, on Facebook, uh, Spotify, anywhere you can find us, uh please send them and uh we'll hope to see you soon.

SPEAKER_00 24:59

Yes. And remember to stay curious and always ask yourself what on earth.