But again, here I simply dispute the classification of species in terms of inability to breed. I think that's artificial. Inability to crossbreed is the natural result of enough reduction in genetic potential from a lot of selection pressure or population splits to make for genetic mismatches that prevent successful interbreeding. The result is an overall loss of genetic diversity rather than anything that looks like it could lead to further speciation.
Faith, you continue to reinforce the notion that you have no idea what in the world you are takling about. You're saying that we had so much genetic potential 'before the fall(tm)' that everything could breed with anything. Not only that, but now that the fall has gone on for a while, that those pour souless creatures that fail to interbreed because of loss of genetic potential also can not breed with themselves.
What an interesting notion...