Thus it is the total body of evidence that is foundational to the ongoing study of the process of evolution. But then, that is how science works.
Creationists often ask for the single best piece of evidence supporting the theory of evolution. They are disappointed when one is not forthcoming.
The evidence is housed in thousands of libraries and in tens of thousands of journals, in tens of thousands of books, and in many hundred museums.
Distilling all of this down into one bit of evidence is a fool's errand. In reality there is no "best" evidence, if you are looking for a single fact, such as a date or a fossil.
The "best" evidence we have is that the theory of evolution works, and it is internally consistent; it accounts for all of the known facts, it is not contradicted by any significant facts, and it makes predictions leading to the discovery of previously unknown facts.
Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.