Conclusions change continuously, but they change towards refinement and not in any random direction. The earth going around the sun in an circle is still wrong, but more right than the sun going around the earth. (It goes around in an ellipse.) First, we recognized light and magnetism as separate forces, but then we refined that view as a unified electro-magnetic force. Science is a method of refining knowledge. Sure, it changes, but in bettering increments.

Evolution is a fact, and I urge you to look up and better understand it.