Nieroshai said:
I believe in evolution. I am also a Christian. My bone to pick is the misuse of the term "evolution" to mean "the origin of life" instead of "the reason life is so diverse." Evolution explains how different species came about, and ties in with natural selection to weed out weaker mutations to aid adaptation. Where evolution fails to be more than a theory is that "scientists" use evolution as a catchall term to encompass everything conceivably biological. "How did life begin. It evolved." (nevermind that inorganic material does not evolve in the biological sense of the word) "Why did that species of insect evolve to look like a leaf? It evolved because it needed protection from predators." (nevermind that an animal can't just go "there's predators eating my species, whatever can I do? I KNOW! I'll try REAL HARD to make my kids vaguely leaf-shaped and convince them to make thheir kids more leaf-shaped until we look like our food!" Complete reversal of cause and effect) Pure and simple: there are things explained by evolution, and things that fall outside the scope of the theory. That scope is this: evolution is change over time within organic biological organisms through random mutations that are genetically inherited by their offspring. The way we use the word "evolution" today often ignores this simple definition to take the form of a scientific panacea.
Let me break this off into two pieces.
1. Evolution doesn't/shouldn't cover the origins of life. This is true. The origin of life is not covered by evolutionary theory, however once life started, everything thereafter can be explained via evolution. The theory right now that covers the origin of life is called abiogenesis.
2. Leaf shaped bug anecdote. Evolution is NOT a voluntary process where the species consciously decide to be a certain way. I don't think that you actually believe that and you were just being sarcastic, but I wanted to make that clear. Next point to make is that evolution is based upon a series of very gradual steps that take place over vast amounts of time. I don't know the actual evolutionary path of the leaf bug, but let's say that it started out as like a blue butterfly, or something. Let's also assume that this butterfly lived in an environment with lots of leaves and trees. If one of the offspring of this blue butterfly was slightly more greenish than the regular butterflies, it would blend in more with the environment, which gives it a slight edge over all the blue butterflies, and be more likely to survive to mating age and pass on this gene to its offspring. Over time, this difference in survivability would mean that more and more green butterflies would exist in the population. Another butterfly mutates again to become more green, and the cycle repeats, until it is as green as the leaves ( any greener and it becomes less fit as it cannot camouflage as well). So now we have green butterflies. Assume now that one of them mutates to that its wings look more like leaves, so it can blend in even better. the same principle applies, and natural selection selects for this trait, and it becomes more prevalent in the population, and over time the wing shape becomes more refined. Finally, let's assume that one of the species loses its ability to fly, and becomes stuck living on the branches of the trees on which it's born. This is actually good in a way, because it can go stiff and pretend its a leaf much better than a butterfly that is flying in the air. This could potentially be a speciation point, where some of the butterflies continue as they were, and a new species of flightless leaf bugs branches off from them, since both models are still quite fit for survival. so then after generations and generations of segregation and no cross group interaction between the leaf bugs and the butterflies, and they've differentiated from each other so much that they can no longer successfully breed. Ta da, you have a new species.
Keep in mind that that whole process was completely hypothetical and it probably happened differently than that, but the principles are the same.