So this thread is interesting. Lets just go the route and say you can't prove/disprove anything like evolution or how the earth was formed because we weren't there.
Anyway I'll give you some
evidence (yes, evidence) I remember from biology class.
Our DNA is all made up of the same things DNA->nucleotides->nucleic acids, the evidence factor is low, but it can imply that life was started and changed and built of the bases of how it started, or evolution. (dont bitch about grammar)
Bio genesis, I think this can be considered evidence, living things come from living things. So if we have all these different species and such we can assume evolution.
Personal thought: If evolution doesn't exists, and god doesn't exist, how do you explain it? I'm not sure if silent (or whoever disagrees with evolution) what you believe in, but If its god I have to say that Noahs Arc story is bullshit. All the sudden peoples boats didn't work?
Fossil records, this is good evidence. We can see by rock layer that we have fish and some sea weed, next layer land shrubs and crabs, then flowering plants and lizards, etc... like i said none of this
proves anything it just provides reason to believe in evolution.
analogous and homologous structures, animals of different family trees or just species with similar structures. Kind of like a wood pecker and a chicken have wings but a chicken cant fly for shit. Implying evolution like the you have a common bird that evolves one way to a wood pecker another way to a chicken. Similar structures different use.
Vestigial structures, whales have some kind of pelvic bones that they dont use at all, i know pelvic sounds like its for swimming but they don't use it. Its pretty much extra organs or stuff on an animal that it doesn't need or use. Kind of like the human appendix.
The symbiosis theory and how life started theory. How life started, certain gases and chemicals were in a puddle by chance and lightning hit it changing the chemicals and creating a simple organelle for a micro organisms. The symbiosis part, the organelles came together to form a functioning organism. That explains how life started, and if you introduce evolution into that you can explain roughly how we got here today. (thats a really rough explanation you'd have to look up exactly how it goes)
Micro organisms today, i already said this but yea. MO's have short life spans and multiply rapidly which mean they would mutate or evolve faster than multi-cellular organisms would. Example: We first found penicillin and it was the "wonder drug" because it killed the shit out of bacteria and stuff. We killed all the vulnerable MO's leaving only mutant MO's resistant to penicillin so only they multiplied and the others just died. Now penicillin is way less effective because by mutation, luck, whatever. Same idea goes for bugs and pesticides.
So there you go. Here is the belief system. God, evidence - slim to none, enough beyond a reasonable doubt - no. Evolution, evidence - lots, enough beyond a reasonable doubt - yes.
None.