You're making a false straw-man argument, you misrepresent what evolution theory actually says.
In fact, before they were birds, their ancestors were a form of reptile, and the transition to birds took many millions of years -- that's what the fossil record confirms.
Bottom line: there's no such thing as adding or subtracting genes, that's just nonsense.
What happens are modifications to existing genes, mostly negative but occasionally helpful in survival, and so naturally selected.
Over very long times these modifications accumulate to the point where interbreeding between separated populations is no longer possible, and so we classify them as separate species.
That's it, that's evolution, simplified.
I don't mean this as an insult, but our interpretation of the facts are vastly different.
You wrote... "You're making a false straw-man argument, you misrepresent what evolution theory actually says."
I didn't say a word about what "evolution theory says". I shared my opinion about what I believe happened. I don't think genes were ever modified to lead one species into being a separate species. That's all I said. So no straw man at all.
You went on to write... "In fact, before they were birds, their ancestors were a form of reptile, and the transition to birds took many millions of years -- that's what the fossil record confirms."
I look at the fossil record and without your pre-belief in the TOE, I see a very different meaning.
In short, as I said when you first posted to me, I have a vastly different view of the meaning and interpretation of facts than you accept. Best.