There is a large discussion to be had and I do believe that I have some novel points to make on the subject, but what I would like to do at this point is note that just because you can't imagine another way that this could be done, it doesn't mean that it can't be done another way. You called this a fact, and that's a strong claim that I urge you to retract.

http://en.wikipedia.org/wiki/Argument_from_ignorance

To approach this from a different perspective, imagine somebody saying the following at about 1890:

"This ignores the fact that if we ever do make a heavier-than-air flying machine it will either be via (a) reverse-engineering of birds or (b) some kind of evolutionary algorithm."

That would have turned out to be false.