Darwin on Trail Edit
It is not difficult to understand how leading Darwinists were led to
formulate natural selection as a tautology. The contemporary
neo-Darwinian synthesis grew out of population genetics, a field
anchored in mathematics and concerned with demonstrating how rapidly
very small mutational advantages could spread in a population. The
advantages in question were assumptions in a theorem, not qualities
observed in nature, and the mathematicians naturally tended to think
of them as "whatever it was that caused the organism and its
descendants to produce more offspring than other members of the
species." This way of thinking spread to the zoologists and
paleontologists, who found it convenient to assume that their
guiding theory was simply true by definition. As long as outside
critics were not paying attention, the absurdity of the tautology
formulation was in no danger of exposure.
What happened to change this situation is that Popper's comment
received a great deal of publicity, and creationists and other
unfriendly critics began citing it to support their contention that
Darwinism is not really a scientific theory. The Darwinists themselves
became aware of a dangerous situation, and thereafter critics
raising the tautology claim were firmly told that they were simply
demonstrating their inability to understand Darwinism. As we shall see
in later chapters, however, in practice natural selection continues to
be employed in its tautological formulation.
If the concept of natural selection were really only a tautology I
could end the chapter at this point, because a piece of empty
repetition obviously does not have the power to guide an
evolutionary process in its long journey from the first replicating
macro-molecule to modern human beings. But although natural
selection can be formulated as a tautology, and often has been, it can
also be formulated in other ways that are not so easily dismissed.
We must go on to consider these other possibilities.