In the end
life is life, regardless of where we are from, what country or what planet, whether we have two arms or nine.
You cannot truly believe, as the smart person I know you to be, that self-interest or instinct grant us a
genuine right to do something. Our entire way of life as a species relies on the principle that we cannot just do something because we want to or need to.
Thus I feel the answer as to whether "humanity has the right to extinguish alien races" lies within common sense,
we cannot just give ourselves a right because we may need to.
I will admit I have no idea what gives someone a
genuine right to do something, infact one thing I have concluded in my mind from this debate is that:
I do not believe there is such thing as a true right.
We will always as a species impose on ourselves
what we concieve to be a right, simply out of neccessity to exist, but when you look deeply into what a genuine right actualy is, I think everyone will find that it is much more complicated than deciding we have one based on self imposed factors.