To say that evolution and gravity are theories is to say that they are not known to exist factually.
Gravity exists. People use it all the time everyday.
Evolution doesn't exist that we know of.

What does exist factually, badecker?
Just for you, I'll repeat it again. What factually exists is adaptation, simple change, and like-begets-like.
Evolution theory evolution has not been proven.The funny thing is that loads of evolution thinkers who talk about evolution come right out and admit that there isn't any real evidence for evolution. Of course, they hide these kinds of statements... like at the end of their books.
This is the thing that makes evolution into the hoax that it is... not that a bunch of evolutionists are trying to find some proof of it.

Evolution process has been proven beyond a reasonable doubt.
Your education system has failed you. The evidence of this is in this thread.