The Evidential Support for Darwin’s Theory

Abstract

The last remarks on Popper permit us to return to our discussion of Darwin’s arguments. For Darwin clearly assumes that natural selection is not only sufficient but also necessary for the origin of the species, or, at least, that it is for the most part necessary. (“I am convinced that Natural Selection has been the most important, but not the exclusive, means of modification.”²) This appeal to natural selection to explain the origin of the species is developed in Darwin’s original paper on the subject. In our discussion thus far we arrived at the point³ where Darwin (in effect) defined fitness in terms of chance and argued that the forces of natural selection cause the fittest to survive and reproduce in greater numbers than the non-fit, in the long run eliminating the latter. Directly after this passage he shows how one might appeal to those mechanisms to explain the origin of the species.