Shawn, my use of the word "reason" has ABSOLUTELY NOTHING to do with creationism or any other so-called alternative to modern science. What I am saying is that there is a REASON that fish are colorful, that has nothing to do with any supreme being or whatever. The REASON is that it helps fish survive! If it didn't, colorful fish would be killed off at a young age and, like I said, all fish would be some subdued color to hide from predators (and ambush prey).
So, why is the sky blue? Well, there's a REASON for that too - it's because the combination of gasses that make up our atmosphere happen to scatter "blue" photons (defined by wavelength) and absorb those of other colors (i.e., wavelengths). Blue wavelengths just happen to fall within our visual range, so that's why the sky is blue, at least to us humans.
So, why do humans happen to see a blue sky? Perhaps the color assignment is random - other creatures can see either farther into the infrared or the ultraviolet. Hey, it's whatever has worked in the long run that has helped survival. Perhaps humans can see blue skies because, in the long run, it helped them to predict when bad weather was coming (e.g., the sky isn't blue but dark grey, there's bad weather coming) and therefore survive.
Shawn, you may be confusing reason with purpose. Evolutionary biology has ABSOLUTELY NOTHING to do with purpose. I've had people ask me, "What is the purpose of mosquitos?" In evolutionary biology, there IS NO purpose. However, there is opportunity, and that's how evolution works. Hey, if mosquitos can make a living sucking blood from mammals and other vertebrates, by golly, they're gonna do it! Why? Not out of any purpose, but here is a set of resources - nice, protein-rich blood - that's pretty much open for exploitation, and, given that, SOMETHING is going to find a way to take advantage of that. Some ancestor of the mosquito was born with a different set of mouthparts than the species it's "supposed" to be, due to a random mutation (they happen all the time, but only about 0.00001 percent are advantageous for survival, the rest will kill you). Well, said insect discovers that it can pierce mammalian skin and extract a fluid that is loaded with protein, and the increased nutrition allows this insect to create more offspring than the other members of its species. A few generations of this and the new insect is proliferating at a faster rate than its parent species, and pretty soon you have the makings of the modern mosquito. Is there a purpose in there somewhere? I don't see it. Is there an opportunity in there? HELL YES!!!!!!
Please, no more arguments about evolution vs. religion, folks! I'm getting tired of this. Can't we just talk about fishing???
Jonathon
No matter how big the one you just caught is, there's always a bigger one out there somewhere...