"Expertise on any matter does not matter unless you are able to communicate it to others."

This seems dubious to me, surely expertise by it's very nature rules out communicating it easily to most people, or you wouldn't have to be an expert to understand it in the first place. Science has the advantage that experts have to have their ideas scrutinised the same as anyone else, and falsification or even a retraction would severely harm their reputation, scientists don't indulge in hubris except when they are being misrepresented in newspaper articles and religious apologetics.

"Sheldon isn't asking for substantiation lol. He wants me to win the Nobel Prize first before he considers my argument."

That is simply a lie John, not once have I ever claimed to want any such thing. This is not a benchmark I am arbitrarily setting, it is the kind of recognition such an achievement would inevitably receive. Any claims creationists make to have valid objections to species evolution are meaningless nonsense, and to be honest I always feel a little sad for anyone so deluded, they genuinely believe they have paradigm shifting evidence that would reverse an entire field of science, and are sharing this news in an internet chatroom, I place the claims in the same category as conspiracy theorists who think we never really put men on the moon, and flat earthers. To be honest it's again a little sad you can't see how silly such claims are. Do your professors really indulge these ideas at the university you attend?

If anyone could falsify species evolution or had valid scientific objections we'd know about it, and not first hand in an internet chatroom. These crackpot claims only ever come from creationist, and the really sad thing is that even if evolution were completely reversed tomorrow, about as likely as finding out the earth is flat and the sun moves around it, creationism would still be naught but an ancient superstitious myth without a shred of evidence to support it.

I agree that if one is interested in the argument then ending it with an authority quote would be inappropriate. Thus, if two people were debating the idea of a flat earth, authority quotes would be an illegal attempt to cut the debate short.

On the other hand, if one is interested in evaluating the credibility of an idea (rather than debating it) then authority quotes are important. The overwhelming consensus of relevant scientific authority, for example, suggests that we should do something about global warming. It may reasonably be assumed that such a consensus is the result of much scrutinizing of the facts and arguments.