Of course it should. The theory of evolution is a very sold theory with an incredibly large amount of scientific evidence to back it up.
I won't go into a lot of detail here, (I've already given the detailed version somewhere on this site) but it's time to bring up the general population's misuse of the term "theory." A theory is not a guess, or some random idea that someone came up with off of the top of their head. If I said, there are unicorns living in the Amazon rainforests, that would not be a theory, because there isn't enough thought or evidence to back it up. The theory of evolution, the theory of gravitation, etc. are theories. They've been studied, and there is ample evidence to back them up. Technically, if you insist on going in that direction, they aren't facts, because if someone did enough research with enough good evidence to back their claims that such theories were false, the scientific community would, with time and ample study, renounce them. But for all practical purposes, many theories may as well be considered facts.
