More known unknowns

I am fascinated by the ability of certain insects and animals to possess, or even create, the colouration and markings on their skin which enables them to appear as if they are an integral part of the tree trunk or leaves on which, or against which, they have sited themselves. While I understand how evolution is said to operate, my credulity is challenged. Am I to believe that this ability reflects random (chance) mutation, followed by adaptation through survival?

Or, does this reflect a need to adapt? If so, does this implicate purpose? Indeed, is there not evidence of purpose in the way my plants and trees seek to outgrow one another in order to reach the sunlight? There is a battle going on in my backyard. Or, is there not purpose in the way our senses indicate a threat to our health, or even existence, without any visible or audible signs of an approaching threat? Or, in the way my eyelids lower themselves to protect my eyes just when some material, or even some life-form, is about to strike, or fly into, my eye? Or, in the way my brain offers me an appropriate word, while my conscious mind is still searching, for what I am writing or when I am solving a crossword puzzle? Does the human brain have life of its own?

Do we really know how the whole human being works? For instance, we have not explained how anyone could come up with a cosmology which states that the life of the universe is cyclical, with existence followed by death (or suspension) repeatedly, with a larger cycle estimated to span 3.11 trillion years (which cycle also repeats itself, presumably for ever)! While such a concept can be neither proven nor disproven, how could some humans conceive and calculate such a scheme?

In terms of how we know what we know, it seems improbable that we did not receive some outside help.