I`m no biologist, AF, but the fact that bacteria have intruded into other species to a limited (but life-necessary) extent, seems to point to multiple lines of abiogenesis. I imagine in a time of non-bacterial dependence, other species may have managed on their own, but I can`t conceive how they coped.
Morphology seems to point to different origins, too, with a large number of species having mouth, eyes and other sense organs in close proximity and excretory organs at a distance. Versus others that have evolved along different lines.