Couple of points:
1- Trees don't have greyish spots so I don't see what you're referring to.
2- If the mutation was harmful, how did it spread from the individual in which it occurred to other individuals such that 'some of them' had this mutation? If it were detrimental they should have been a minority from the beginning and should have been wiped off quickly.
3- I don't understand the example, if they had mutated bigger spots and this was harmful, why would evolving two more bigger spots be beneficial?
4- This doesn't do anything to explain to me how the perfectly eye-like patterns would appear so perfectly on the wings of the butterfly and what primitive forms this pattern would have gone through during its evoliution.
1) That was an example i pulled out of my ass... it could have been any mixed-color spotted pattern that could blend in whatever environment they were
2) This is probably what you don't get about evolution: neutral and detrimental mutations are not wiped out "quickly"
Given an infinite amount of time and no environmental changes and no further mutations to change the equilibrium, they would eventually get wiped out
But their "lifespan" is not zero: a not-useful mutation can still spread. It just spreads with lesser probability.
3) Because the two bigger spots "suddenly" makes their previously useless pattern converge to the "omg two scaring eyes!" pattern that ends up being beneficial
4) Once the "omg two round things that seem eyes!" pattern appear, it would quickly become very dominant among the population... and from that natural selection would favor those tiny changes that make it seem more and more similar to real bird eyes.
Regardless of whether evolution is a hill climbing algorithm or not, you do agree that the pattern would have to go through several, or at least a few primitive stages before it would become as defined and eye-like as it appears on the butterfly? I'm asking what these primitive forms were. Since in the primitive form, this pattern would not provide any advantage over other patterns found in the butterflies, and would not be selected over them.
I cannot agree nor disagree with that.
Being partially stochastic in nature, evolution doesn't "require" many/few/any steps.
I can only say that "more steps" is more probable than "few steps".
And, given the stochastic nature of evolution, we have no idea what those steps were.
We can only guess.
About the eye pattern, I really cannot see what you find so incredible about it.
I could imagine:
1) lame butterfly with no pattern that amazes humans
2) lame butterfly with random big dots that make them a bit easier to stop -> crappy fitness
3) butterfly with two big dots that are not that amazing for humans, but that some animals with lesser vision recognizing capabilities could mistake as eyes of a predator -> kinda nice fitness
4) butterfly with little modifications in size/color/details of the two big dots that make them even more similar to bird eyes -> can fool "smarter" predators -> even better fitness
5) butterfly with pattern that totally resemble owl eyes -> can fool most predators -> very nice fitness -> humans find it an amazing miracle
Topic: Come on now!