Here's a beautiful 9 minute video on butterfly anatomy which will give you a deeper appreciation for these lovely insects that we see everywhere in our world and usually take for granted.
Whether you agree with the conclusion of the filmmakers that butterflies are intentionally and intelligently designed or you believe that they came about through purely blind, random mechanisms like natural selection, the sheer beauty of the engineering and design of these creatures is breath-taking.
The intuition that what we see in the natural world was purposefully designed is so powerful, however, that Nobel Prize-winning biologist Francis Crick felt compelled to remind us that, "Biologists must constantly keep in mind that what they see was not designed, but rather evolved."
In other words, those who observe the realm of nature must, through an exertion of will, convince themselves that it's all an accident, the result of an astonishingly improbable string of coincidences.
Here's the vid:
If you enjoy the butterfly video you'll also enjoy this one on birds:
In his 1996 book The Blind Watchmaker biologist Richard Dawkins stated that “Biology is the study of complicated things that give the appearance of having been designed for a purpose.” (italics mine)
Both Crick and Dawkins believe that the appearance of design and purpose in the realm of living things is an illusion. In order to avoid succumbing to the illusion we have to persuade ourselves that the compound eye, tongue and scales of the butterfly are not for anything. They serve a function but have no actual purpose.
These and every other structure in living things evolved step by step by blind, mindless undirected processes and found themselves at each stage put to particular uses until they finally reached their present form which happens to have a useful function.
Well, maybe so, but it takes a lot of faith, a lot of blind faith, in the efficacy of dumb luck to believe that it could produce a butterfly or a bird.