Please define your terms more carefully.
By "all of recorded history" do you mean "during the time of written records"?
By"not one example" do you mean directly observed 'as it was happening' as opposed to "inferred from indirect evidence"?
What do you mean by "specie" ...?
As far as beneficial, have you considered The Nylon Bug?
Cheers! Cheers!
Sure.
By "all of recorded history" do you mean "during the time of written records"?
What else would it mean? It's a common phrase.
By "not one example" do you mean directly observed 'as it was happening' as opposed to "inferred from indirect evidence"?
I mean either observed and recorded as it happened or inferred from direct evidence. Taking two similar fossils and "inferring" one is a mutation from the other is simply a wild guess, not inference from evidence.
What do you mean by "specie" ...?
You really needed to ask that? I mean what species always means, a taxonomic group whose members can interbreed.
As far as beneficial, have you considered The Nylon Bug?
Yes, but it's been awhile. There's a bit of a fudge here, but I cannot remember what it is. At least, it's not a beneficial mutation of a species, since bacteria do not breed. I have to consult someone and I'll get back to you, probably.
Thanks for the questions.
Hank