A gap is fatal to it.

If a family dies out, that is the end of it.

You can not resuscitate it after a few centuries, and go on with that breed; much less can you pick up a breed quite different, and attach it to your old genealogy.

But in the line of evolution we meet these fatal gaps; and no evolutionist has bridged them, because they can not possibly be bridged.
The first great gap is the abyss between death and life.

No human power can cross it.