cofty, I don't think I was not equivocating about 'proof'. Instead I was thinking about it in the strict way you mentioned regarding proof, such as in the realm of mathematics and in formal deductive logic, but even those involve starting with premises/assumptions/axioms (even if such are well supported). For all we known, that which we perceive as reality could merely be simulation on some powerful computer. A number of atheistic scientists who fully accept evolution say that is a very real possibility. I consider such ideas, and the similar idea in the science fiction movie called the Matrix, as well as the idea everything I perceive and experience might be dream I am having. There have many times in my life when I though I had woke from a horrible dream only to find I was in another dream (or perhaps a different phase of the same dream), and even to find myself later in a third dream, before I actually became awake.
Though I am highly convinced that all of the current species on Earth have descended from a common ancestral species, it has technically not been proven (in the strict sense of proof in mathematics). For example, perhaps some of the species on Earth descended from an ancestor which never existed on Earth (such as by panspermia from another world, perhaps even by a life designed and created by an unknown extraterrestrial intelligence). The idea is very well illustrated in the science fiction movie called "MIssion to Mars" (and I own a DVD of the movie). It is a very good movie.
Furthermore, as many evolutionist scientists have admitted, there is no way to prove that a god didn't create all of the types of life on Earth by a nonevolutionary process (with them being given the appearance of having descended from the same ancestor). Those scientists have said creationism (depending on how it is worded) is unfalsifiable, since the creationist can say God did it by some mysterious supernatural means.
The perspectives contribute that what I said in the earlier post about "proof'. I am philosophical. I own books specifically about philosophy.