It's because in science, to call something a fact takes eons of time... but the general consensus of scientists, and I have many in my family, as well as doctors - and we have vaccines and medicines based on evolutionary evidence of how things grow and mutate over time - is as close as can get to a law right now, In 500 years, perhaps it will be law - like Newton's law. We also have theories of God - composed 2,000 years ago - give or take 600-700 years either way - from the Hebrew Bible through the Koran in 632 CE. And these are not based on facts and science. It's all faith. And that's fine. I do not wish to debate this. Politics and religion - not my thing now. Too many people have died because of those things.