On evolution statistics
This basic evolution theory question has been haunting me since childhood and I'm kind of embarrassed that I can't explain it yet:
Consider a butterfly. It's wings have evolved to look like the eyes of an owl, so to prevent it's predators who are themselves preys of the owl to attack it.
From what I've learned (and feel free to indulge me in the very basics if I get this wrong), natural selection suggests that the butterflies that didn't have the owl's eyes in their wings would be eaten, leaving the ones with the eyes to survive, right?
But that implies that this useful trait appeared in the butterfly's wings by chance. Now, I know trillions of butterflies have been born before this, but trying to figure out the possibility of this to happen by chance doesn't look like it's plausible. Let's go through the things that have to work right before this trait is passed over:
1. For a butterfly to be born in a different wing colour, it should be a genetic mutation which doesn't happen this often, for what I know.
2. The wings are composed of micro-scales. For every scale to compose an image so similar that confuses even us, the margin of error is very slim. It could be anything. 429
It could be a picture of <PERSON> for all we know. The scales must be in the correct spectrum of colour by a small margin of error. So that is already a very unlikely thing to happen.
3. Then, this butterfly cannot be eaten out of bad luck (mind you, the wings don't guarantee it will not be eaten, just enlarge her chances).
4. It has to mate, which also is not a guarantee to happen, since nature deals with competition. If this butterfly we are considering is a male, the female must find the wings hot, instead of being afraid of those creepy eyes.
5. The genes of this mutations must also be dominant, so when it mates and generates offspring, at least part of the new butterflies inherit this trait.
And this is a simple example. There are animals that evolved so smartly I can't even start to think of the possibilities.
My question is, more precisely, how likely is it for a species to evolve into complex solutions? 429