[xm177e2]

But, if a male randomly mutated, what would he mate with? It takes two to tango...

Take for example mules, half-horse and half-donkey.

If a man has a minor (or even major) mutation, he may still be able to mate with a "normal" woman and produce viable offspring.

[irishtenor]

How many "random mutations" would it take to change a lizzard into a bird? And what about the inbetween mutations? Where are they? There would have to be some (actually many) around. Remember, too, that the jenny (the offspring of a horse and a mule) is sterile.