Thus "survival by natural selection" or by selection of the "fittest" has no effect on the "origin" of species, and adds nothing by way of explanation to Darwin's theory.
(survival by natural selection" or by selection of the "fittest; has; no effect on the "origin" of species) (survival by natural selection" or by selection of the "fittest; adds; nothing)
survival by natural selection" or by selection of the "fittest survival by natural selection" or by selection of the "fittest
has adds
no effect on the "origin" of species
nothing