In other words it's one absurd assumption compounding another crazy assumption.
Those are, to be sure, other words. But it is not the same thing in other words.
Try reading it again; and bear in mind that if you don't immediately understand something, it's not always the thing that you don't understand that is stupid. Occasionally it may be you.
Even if we were to assume that the gene evolved as you indicate, this still doesn't imply two evolutionary events.
I have no idea what you're talking about.
You make the assumption I guess on the basis that you have assumed a closer relationship between humans and chimps than other primates.
No: on the basis that chimps do not lie outside a clade which includes humans and gorillas and macaques.
---
Let me try to explain the reasoning by analogy. Suppose you have seen 100 of the same make of car. 99 of them have a winged horse as a hood ornament. One of them does not. If you had to chose between the following two explanations, which would you find most likely?
(1) The hood ornament is standard, but one car has lost its hood ornament.
(2) Having no hood ornament is standard, but 99% of drivers have by complete coincidence chosen to accessorize their cars in exactly the same way.
Both accounts of the history of the cars is possible; but one of them is overwhelmingly more probable, is it not?
Edited by Dr Adequate, : No reason given.