[Junior]

There is no "proof" in science. There is a preponderance of evidence, but proof never enters into it.

[Fatalis]

Agreed, which is why arguments that start with a demand for proof are fruitless.

The timescales involved in evolution make actual observations of macroevolution unlikely. Obviously, the absence of evidence isn't evidence of absence, but it seems to me that if evolutionary discussions were predicated on concepts like "preponderance of evidence" and "reasonable doubt," it might be useful to those who are sincerely on the fence between evolution and literal creationism.