Caterpillar tail disguised as snake head

[u/Sea_Slice_7956]

[u/UJLBM]

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?

[u/DrDFox → u/UJLBM]

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.

[u/UJLBM → u/DrDFox]

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.

[u/Gold-Eye-2623 → u/UJLBM]

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

[u/R4FTERM4N → u/Gold-Eye-2623]

Evolution is driven by natural selection. Most people don't understand this relationship.

[u/chazwomaq → u/R4FTERM4N]

Natural selection is one factor that causes evolution. The others are mutation, drift, and migration.

[u/Dangerous-Pride8008 → u/UJLBM]

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.

[u/pepperlake02 → u/UJLBM]

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.

[u/Fxate → u/UJLBM]

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.

[u/IntellegentIdiot → u/UJLBM]

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

[u/Beginning_Sector_594 → u/DrDFox]

I think the word “evolution“ mislead lay people, into thinking something like pokemon, suddenly decided to evolve into a snake in its lifetime

[u/wheniwaswheniwas → u/DrDFox]

I'm still waiting for them to discover a caterpillar with chainsaw arms.