As with so very many things, it all comes down to a question of definitions. First, let's talk some about what evolution is. There are certainly some good definitions in a nearby dictionary, but those are generally immaterial to the point at hand. What's more interesting to me is what people tend to mean when they say "evolution". The first is the most entirely logical. If you accept as fact that organisms inherit traits from their parents, then it follows naturally that if an organism is unable to procreate, its traits will not flow into the next generation. Thus, the average traits of that organism have a tendency to migrate towards a configuration that is capable of reproduction before death. I believe that this is generally accepted. (So, perhaps nearly everyone believes in evolution. I'm sure there's some disagreement there too.)
So, what do people mean when they say they don't believe in evolution? They may mean that they don't believe that all life evolved from archean prokaryotes. That is certainly a tough pill to swallow, but I think the biggest barrier is the ability to conceptualize a billion years, let alone four. For many, it may mean a disagreement on the genesis of life which, interestingly, has little or nothing to do with evolution. In order for evolution to exist, life must precede it. There are plenty of theories about where life came from, be it random chance, panspermia, or the hand of God, but evolution talks about what happened after that. For most, it seems to mean that they don't believe that man evolved from the lesser primates. Some believe that God created man. While this doesn't preclude a belief in evolution, those who hold this belief generally claim that they don't believe in evolution. (Personally, I have difficulty believing in the possibility of a non-omnipotent God. An omnipotent God could have created the universe 14 billion years ago. He could have created the Earth 4 billion years ago. He could have created everything on Sunday, October 23, 4004 BC. He could have created everything 4 minutes ago, including you, me, and all of our memories. But I digress...)
So, let us consider the people who claim that they believe in evolution. For many, their attitudes do not bear that out. You will note that among those who claim a belief in evolution, there is a very strong tendency to make a distinction between that which is natural, and that which is man-made. If you actually do believe in evolution, then that which is man-made is a subset of that which is natural. Also, this begs the question(1), exactly when did the works of man break off as no longer a work of nature? Was it the advent of H. Erectus? The beginnings of civilization? Last Tuesday?
Moving on from that, we come to our next definition, that being the word "believe". There are two distinct definitions of this word. The sense that I have used in the preceding paragraphs is that of accepting the existence of a thing. The other sense is that of accepting as beneficial. Most notably among those who believe in the existence of evolution, one finds a notable lack of a belief that it's a good idea. Consider gopherus agassizii, a turtle which, when picked up by a helpful person trying to move it out of the road, will become so frightened that it will empty its bladder, thus losing so much water that it becomes dehydrated and dies. If your reaction to the perception of a threat is effectively suicide, there may well be an entirely valid reason that you are becoming extinct. And yet, those who say this animal should be protected are often those same ones who claim to believe in evolution.
Even better, try an experiment (please note that I do not accept any liability for damages you may incur as a result). Find a person who meets these three criteria:
- They claim to believe in evolution.
- They are concerned about the extinction of species from our planet.
- They are concerned about the dangers of nuclear waste.
Note 1: For all of you pedantic grammarians out there, yes, I'm well aware that I am misusing that phrase. Irregardless(2) of what you think I will continue to use it as I see fit.
Note 2: OK, yeah, I'm just screwing with you on that one.