The observation that DNA can be re-coded via natural processes to do the things required by evolution (one-celled to multi-celled etc.)
The discovery of an animal (A) that can fertilize the seed of animals (B) and (C) while animal B cannot fertilize the seed of C.
In other words, you want evidence that you can't have - "observing" such a thing in nature would take millions of years of watching, and neither of us is going to be around that long. And if I sling together enough mutations to do the same thing in a timely fashion in the lab, you'll simply say that this is no evidence of "natural processes" when a person does it, right?
The discovery of an animal (A) that can fertilize the seed of animals (B) and (C) while animal B cannot fertilize the seed of C.
Pick any three animals of the same species you like, and that condition is satisfied. I'll let you think about that one for a moment, and if you still don't understand, I'll explain why that condition is almost always true ;)
That would be called a ring species.
The business of "can't fertilize" is somewhat bogus. There are all kinds of gray areas here. There are humans with anomolous chromosome counts who can have children, some of whom may be fertile. There are varieties that never interbreed, even though they can be mated by artificial insemination. Then there are mules.
The notion that fertility is all or nothing doesn't match reality.
Then, maybe somebody can explain how DNA "evolved" into existence when DNA is necessary for evolution to work in the first place. Before the first mutation could be genetically passed on, DNA had to evolve into existence without the help of genetic mutation.