For those thinking evolution may not be a fact because for some topics contradicting explanations exist, please consider the following analogy:
A dead body is found. There is a hole in it's skull, and a bullet inside the brain. Lots of blood everywhere. A gun found 50ft from the body matches the bullet in the brain. Fingerprints on the gun match the victim, but no gunshot residue on his hands. Also, there are 32 stab wounds in the body, but no knife is found.
Now there may be opposing explanations about some topics (who is the victim; who fired the gun; who stabbed; what killed the victim, the bullet or the stabbing; why was he killed; etc) but regardless of those contradicting explanations, the known facts remain solid, and we can think of only one logical explanation for these facts: this guy was (99.99% certain) killed.
And the contradicting explanations or unknowns might be resolved when more evidence is uncovered.
With evolution, it's similar: evolution is a fact. Some topics are not clearly understood (yet), but the facts remain. And the only logical explanation to all known facts found by geologists, biologists etc is evolution.
It's not that someone made up a story and now we try to find evidence for it; someone(s) tried to explain the facts we already knew. And the explanation (murder/evolution) neatly fits the known facts.
And when new facts come to light, they either confirm the current explanation, or the explanation is updated to be in line with all the facts.