The concept of natural selection was the basis of Darwinism. This assertion is stressed even in the title of the book in which Darwin proposed his theory: The Origin of Species, by means of Natural Selection…

Natural selection is based on the assumption that in nature there is a constant struggle for survival. It favors organisms with traits that best enable them to cope with pressures exerted by the environment. At the end of this struggle, the strongest ones, the ones most suited to natural conditions, survive. For example, in a herd of deer under threat from predators, those individuals that can run fastest will naturally survive. As a consequence, the herd of deer will eventually consist of only fast-running individuals.

However, no matter how long this process goes on, it will not transform those deer into another species. The weak deer are eliminated, the strong survive, but, since no alteration in their genetic data takes place, no transformation of a species occurs. Despite the continuous processes of selection, deer continue to exist as deer.

The deer example is true for all species. In any population, natural selection only eliminates those weak, or unsuited individuals who are unable to adapt to the natural conditions in their habitat. It does not produce new species, new genetic information, or new organs. That is, it cannot cause anything to evolve. Darwin, too, accepted this fact, stating that "Natural selection can do nothing until favourable individual differences or variations occur."7 That is why neo-Darwinism had to add the mutation mechanism as a factor altering genetic information to the concept of natural selection.

We will deal with mutations next. But before proceeding, we need to further examine the concept of natural selection in order to see the contradictions inherent in it.

7 Charles Darwin, The Origin of Species by Means of Natural Selection, The Modern Library, New York, p. 127. (emphasis added)