[The_Victor]

Because the actual number of total genetic combinations is a finite number, any combination you create in a lab, is possible in nature. Incredibly unlikely perhaps, but none the less possible. So you can't actually say that it would never occur.

Yeah, I know, I'm quibbling over the mathematics of infinity.

[oldasrocks]

I won’t be happy till they engineer the liberal gene out of humans.

[Roos_Girl]

Well, since they are crossing pacific salmon and atlantic salmon and artic eel pout, I feel pretty confident in saying they would never naturally breed with each other, though the atlantic salmon and eel pout do have overlapping native regions.