evolution (what I call little-e evolution or microevolution) is the tiny pieces of evolution that we can see. A popular example of this is the spotted moth, where when the trees were black with soot the black moths became more predominate because they were more fit for their environment. As well, with the examples mentioned about we can see that mutations cause for variations in the genome that can lead to predominate traits in humans. (btw.. side note, mutation isn't a bad word.. anyone with blue eyes has a mutation) This is proven, we can physically see this occur.
The controversial term is Evolution (big-E evolution or Macroevolution). This is that from different species can evolve from a single source. While this is a viable theory and fits all evidence that can be found it is impossible to prove. Why? Because we cannot actually observe an event that takes millions of years. As well, when looking at the fossil evidence we see no evidence of what are called "transition fossils." These are the fossils that would link species to species. In fact, interesting enough, approx. 6 billion years after the earth's creation an explosion of life occured in which all the basic body types can be found in fossil record within a time span of only a few thousand years (give or take, dating is inaccurate past about 8 thousand years).
Anyway (I think I'm rambling here), Evolution is a topic that, just like God, can be argued for eternity and still we will never have the answer. I personally believe in Evolution and find no reason Biblically or the other for how it contradicts the existence of God. Why? For the simple reason that a literal translation of the Genesis 1 is like taking a copy of Pinnochio and calling it reality, when in fact Pinnochio shows through an artistic method a view of Ethics and Morality, not that if you lie your nose will grow. Just so, Genesis 1 shows poetically that God is the creator, not that that was how He created it... of course, if you don't believe in the Bible, then it simply is Evolution without the presence of a creator. Either way, Evolution still works.