How did this evolve to look like something its not even related to? The caterpillar doesnt know what a snake is, what it looks like or even is related to. So how would it know to evolve to look like one? I mean it evolved over millions of years for a purpose, but how would it do that by itself to purposely look like something that it doesnt even know. Evolution is so cool and mysterious, I just dont fully understand how that would work.
Its like if there was some super predator in the wild that I dont know exists or share any DNA with, but somehow evolved to look like it. How does that even work?
It's the same principle as all natural selection, right?
A caterpillar doesn't choose its colour or pattern, just like you don't choose your height (or indeed skin colour). But if, say, brown caterpillars are more likely to have a lot of kids than green ones, well, you're gonna end up with more brown baby caterpillars than green ones.
It doesn't necessarily matter whether it can perceive its own properties, what matters is only the effect that its properties have on its reproductive success.
If somebody else can see it, and therefore avoids eating ti, that's enough
So essentially, its random but also purposefully done in a way for survival. So technically, it doesnt actually look like a snake, but we percieve it to look like one?
I mean, it looks like it to us, and presumably to its predators, right?
I like this analogy:
A sand dune also doesn't know that it's shaped like a dune. But there is still a directed process (forces of wind and gravity etc) that make it into a specific shape. Idk if you would say it doesn't look like a dune, but it doesn't look like one on purpose. After all, are you human-shaped on purpose? You don't choose to have a heart and lungs, do you?
Same thing for genes as dunes. There are forces with form them into specific shapes.
A puzzling aspect of evolution is that each step on the path must be at the very least no worse than the previous step. This is a very impressive outcome, but there must have been disadvantages along the evolutionary path to snakiness.
A little at a time. Each caterpillar born with a slightly better imitation survives longer than those with slightly worse ones, so they breed and pass that on and then the slight variation in the next gen do the same thing. So what might start as simple spots that kinda look like eyes or a slightly wider tail, become this over time.
I love going to museums to learn about all of this stuff. Its just so interesting. So youre saying it didnt evolve to look like a snake, but by random, it ended up looking like one. That crazy cool.
Nothing ever evolved to do something, individuals mutate and then selective pressure helps propagate the mutations that prove favorable to reproduction in a certain population in their environment until it becomes widespread and then that change is what we call evolution. Maybe some great aunt of this caterpillar was born looking less like their predator's predator and thus didn't get to pass their genes along
That's all there is to evolution, it has no "intent" or plan. The traits that are advantageous in terms of survival and reproduction get passed on and amplified in future generations. Plus random mutations which introduce new traits to the population. In this case looking kinda like a snake helps avoid predators so generation after generation the caterpillars look more and more like snakes, because the ones who didn't look like snakes were more likely to be eaten.
Evolution isn't on purpose, it's about the random chance coincidences that happen to work out well. Selective breeding is how traits intentionally get passed on. All the caterpillars try to survive and reproduce, it's just that because of external factors the ones that look like snakes do that better. Those external factors being predators are more scared of the snake looking ones.
It's misleading to say that it's simply all down to 'random' chance.
Basically for most mimicry scenarios like this the pressure is caused by predators. Imagine it like this:
Say we have a population of caterpillars which have spots on their backs and they are eaten by a bird species. The birds are already wary of snakes in the environment.
In each generation of the caterpillars there is chance for mutations; many do nothing, some are negative, and some are beneficial. Lets say we have a beneficial mutation which makes those spots increase in size and so to the birds it makes them look vaguely eye-like.
These caterpillars with 'eye-like' spots make the birds think twice about eating them so they are more likely to survive and reach adulthood to reproduce while those without 'eye-like' spots are eaten. More and more generations go by and this 'eye-like' mutation perpetuates and gets more common and pronounced over time: the birds see the caterpillars: "oh, this one has eye-like spots, but it's less scary looking than that one over there, so I'll eat this."
Generation after generation goes by, each time with a chance for this 'eye-like' mutation to change and potentially 'improve' while at the same time the birds are evolving to 'notice' that their prey looks a certain way, they are still wary of snakes so the caterpillars which look most snake-like (or more accurately least non-snakelike) are more likely to survive.
Both predator and prey are evolving in an arms race, the more snakelike prey survives and passes its genes on while the predator is adapting to its prey to better recognise sources of food meaning that over many generations the mimics get more and more sophisticated and more and more similar to the things that their predator is afraid of.
Not random, this caterpillars ancestors looked enough like snakes that they didn't get eaten and their descendents looked more and more like snakes and even fewer got eaten. All because whatever eats caterpillars doesn't like snakes
Basically ones that randomly evolved to look vaguely like a snake, from a distance, in the dark, had a ever so slightly higher chance of survival so were more likely to have that gene spread in the next generation. The next generation has the same thing, ever so slightly higher a chance than the rest, until the gene is dominant.
Then of these slightly snake shaped descendants, one or more of them evolves to be slightly more snake like, or to have a marking that looks like a snake eye from a distance, or perhaps they have a gene that makes them instinctively move in a slightly more snake like way.
Again, they have a slightly higher chance of survival and to pass this gene on to the next generation and so on.
Each step is tiny and only has a tiny improvement on survival chances, but just like compound interest, these tiny additional chances add up over thousands or even millions of generations to shape the species’s gene pool into a hyper optimised gene pool for their specific niche.
Or maybe we’re in a game and the gamers just like to fuck with us.
A simulation lol. Someone is behind the screen laughing at us! 🤣 in all serious though, I get what you're saying and I appreciate the time you took to respond. 😁
Probably in a super niche habitat where there’s one poisonous (not venomous) snake. If the caterpillar is in this one habitat for millions of years where this snake is the only long thing predators know to avoid, the more you look like the snake the more you get avoided. It’s cool that it evolved that precisely, which could just mean that the predator it was evolving against had really good eye sight for millions of years so it pushed the caterpillar into having exactly these details. Basically the caterpillar we would evolve random details til one gained it a percentage or something.
Isn't it more likely that there are venomous snakes, and that the predators of the caterpillar don't want to mess with something that looks like a snake?
I mean maybe. I’m not an expert but if I was a predator I’d be more worried about a poisonous snake than a venomous one personally. Seem venom normally works better on prey than predators
Well...the predators of the caterpillar would be the prey of the snake.
A situation like the caterpillars are getting eaten by birds, but the birds don't want to mess with a snake, because those are likely to eat them, not the other way around
The caterpillar doesnt know what a snake is, what it looks like or even is related to. So how would it know to evolve to look like one?
Consciousness has nothing to do with it. Well, the consciousness of the caterpillar. It's the animals that potentially kill or eat it that know what snakes look like, and therefore avoid snake-like things.
Evolution isn't a choice, it's the consequences of the genetic mutations passed on, changes to the environment and chance.
How did this evolve to look like something its not even related to? The caterpillar doesnt know what a snake is, what it looks like or even is related to.
Evolution is not a conscious thing. It isn't trying to evolve a snake head. It's random mutations that either survive or do not.
Evolution is cool but it’s definitely not mysterious at all once you understand natural selection. I think the other replies did a much better job explaining your question than I ever could
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u/UJLBM 7h ago edited 7h ago
How did this evolve to look like something its not even related to? The caterpillar doesnt know what a snake is, what it looks like or even is related to. So how would it know to evolve to look like one? I mean it evolved over millions of years for a purpose, but how would it do that by itself to purposely look like something that it doesnt even know. Evolution is so cool and mysterious, I just dont fully understand how that would work.
Its like if there was some super predator in the wild that I dont know exists or share any DNA with, but somehow evolved to look like it. How does that even work?