There are so many theories floating around us. One of them says aliens created humans - and the entity God is actually an extra-terrestrial. Another says the world is going to come to an end on the thirtieth day of January.
The now-fact 'The earth is round' was a theory once. The fact at that time was that the earth is flat.
The theories become facts as time passes and new theories come in. The fact is, 'facts' aren't facts after all. They are just beliefs of humans.
The humans that love to believe they are intelligent. That's another belief on their part.
It's these beliefs that keep changing. And that makes the humans believe that they are growing intelligent.
What is the ultimate fact then? Or is there any fact at all?