You cannot go back in history and recreate the original conditions - and no one has been able to do so. Evolution has NEVER been reproduced, and it is not subject to the Scientific Method. It is impossible.
Logic wenables people to infer things they cannot personally observe from other things. Scientists use it. I'd guess you do too.
And those things infer other things and so on. When many of the things inferred are found to be true, it supports the validity of the original inference.
Also, you need to read up on the Scientific Method. Your understanding of it must be in error.
In the first place, God made idiots. That was for practice. Then he made school boards. -- Mark Twain