We now want to spend a little bit of time talking about some common misconceptions in evolution and natural selection, because probably more than in any other area in biology, people come in with some ideas of how this works, and there can be some wrinkles in those ideas that we just need to iron out a little bit. So we're going to go through these one by one. The first one here is going to be that evolution is just a theory. Alright, Evolution is just a theory.
You may hear people say this, perhaps suggesting that evolution doesn't have as much backing as other ideas, but this sort of misconstrues how we use the word theory in science. In everyday language, I may say something like, hey. I got this crazy theory. But in science, a theory means that it is well supported. A theory is a really big idea that's backed by a lot of data and explains a lot of different phenomena.
And we're going to say here that evolution is one of the most widely accepted and supported theories in all of science. Really, in biology, there is zero controversy as to whether evolution has happened, whether it continues to happen, and whether natural selection is the major driver for adaptations on Earth. Interestingly, people don't say this about other theories. Right? You don't often hear people say, like, ah, gravity, it's just a theory. Even though in physics, there's actually some real controversy as to how gravity actually works. Alright. Our next misconception here is that survival of the fittest means that the biggest and strongest survive. We've talked about this a bit already in the past, but this is looking at how we use that word fitness in everyday language versus in science.
Right? We want to remember fitness does not mean big, strong, fast. It could, depending on the organism, depending on the environment. Fitness is who reproduces the most. And we say survival of the fittest because if an organism survives, well, it's much more likely to reproduce.
The way I like to think of fitness to keep this straight in my head is that within a species, it's which organism best fits its environment. I kind of think of fitness kind of like how a shoe fits. Right? If a shoe fits really well, it works really well. If an organism fits in its environment, it's much more likely to survive and reproduce.
Our next misconception here is going to be that adaptations help the species survive. You may hear this when people are talking about something that an organism does really well or maybe on a nature show when something escapes due to an adaptation, and it says, ensuring that this species continues. But remember, in natural selection, competition is within the species. Adaptations evolve because it helps an organism do better than other organisms in the same species. We're not competing species against each other.
It's organisms within the same species passing on their traits. So we want to remember that natural selection selects individuals. It doesn't select groups. Alright. Our next misconception is this idea that the organism will evolve and adapt to its new environment.
Alright. That kind of sounds alright at first, but we're keying in on that word, the organism. Remember individuals well, individuals can change in their lifetime, but remember acquired traits are not inherited. That was that sort of big wrong idea from Lamarck. Right?
If you change in your lifetime, you don't pass that change on to the offspring. We want to say that individuals only survive and reproduce, or maybe they don't. And it's the traits that help them survive and reproduce that get passed on or don't. But it's the populations that evolve. Alright.
Our next misconception here is that the organism is the product of millions of years of evolution. This is another thing that people say when they see something that seems really well fit for its environment. It's the product of all this evolution. Well, that's not necessarily wrong, but I like to remind people that organisms from the past were not working to become the organisms we see today.
Organisms are evolving just because certain traits make it more likely that they survive and reproduce in their current environment. And over time, that can lead to big changes, but we can't really predict how this is going to come, how this is going to happen. And when we see things alive today, it's not the final stage of evolution because, well, environments change. Right?
Populations will be different in the future. If you come back in a million years, guaranteed, the organisms on Earth are going to be different than the organisms today because things will continue to evolve as environments change and populations adapt to those changes. Alright. Our final misconception here is that natural selection makes organisms perfectly suited for their environment. Right?
Sometimes we see organisms that are kind of bad at something, and we're like, well, if natural selection is so good, why doesn't it just make it better at doing that thing? Well, remember, you can't be good at everything. Life requires trade-offs. Right? You may see a sea turtle struggling to go across the beach to lay its eggs, and you're like, why doesn't natural selection fix that?
Well, it spends most of its life swimming in the ocean, and you can't be really good at swimming and really good at scampering across the beach to lay your eggs. Right? There's a trade-off there. Now also, we need to remember that selection only works on existing variations. So you may see some organisms say, like, hey, you know what would make this thing's life a lot easier?
But if that variation doesn't exist, that trait just can't evolve. Right? I can look at an ostrich and say, you know what would be better than vestigial wings? I bet that thing would really like some arms with hands on the end. But that variation doesn't exist, and I cannot envision an evolutionary pathway that would lead to that variation.
So they're stuck with what they got. Alright. So remember, evolution and natural selection are fairly simple ideas, but we see they have a lot of depth and a lot of nuance, and we want to be careful about how we think about them. We'll practice this more coming up. Check it out.
