Against the theory of creationism, the theory of evolution may provide some overwhelming evidence, but that does not mean that neither is flawed or questionable.
Darwin's theory has two aspects: the "historical phenomenon" that all species of living things are descended from common ancestors, and "the main mechanism causing that phenomenon," which is natural selection, all falling into biogeography, paleontology, embryology, and morphology.
What Darwin failed to recognise was the ability of species to interbreed (the Galapogos finches etc) and create separate species. Also, the Cambrian explosion, in which many of the major groups ("phyla") of animals appeared in a geologically short time with no fossil evidence of common ancestry - which Darwin himself considered a "serious" problem that "may be truly urged as a valid argument against" his theory. (not e he used the word theory)
It is actually morphology which Darwin himself called the 'very soul' of natural history, that provides the basis for the other three. In each category, similarity in morphology ("homology") is interpreted as evidence for evolutionary relatedness. According to Darwin, features in different organisms are homologous because they were inherited from a common ancestor through a process he called "descent with modification." But determining whether homology in living things comes from common ancestry or common design by simply pointing to the similarities themselves is relatively insufficient. Since whilst we can see the possibility that humans came from apes, what did the apes come from? Scientists are still looking for the �missing link�. He never really could explain the �Origin� of species. Some scientific conjecture is that the �origins� arrived from natural resources contained within comets from the Oort cloud that crashed into the earth many years ago. Another theory, but another one with claims/denials in the scientific world that we