While there are still "holes" in the theory of evolution its still the best bet we got going right now. There is just too much evidence pointing to the fact the life mutates and evolves. Look at the Galapagos Islands or Madagascar (excuse the spelling), where we have species of animals that have evolved into new animals to cope with the living enviroments. You see this everywhere in nature, animals adpapting to there suroundings to make them better hunters, gatherers, builders, etc...
We even see this in humans, take the Inuit people. They have evolved to cope better with the cold weather.
MSNBC News Story.
So I think there is plenty of evidence supporting evolution, but we still have a lot to learn about the origins of life.