Apart from the theoretical weaknesses mentioned above, the theory of evolution by natural selection comes up against a fundamental impasse when faced with concrete scientific findings. The scientific value of a theory must be assessed according to its success or failure in experiment and observation. Evolution by natural selection fails on both counts.

Since Darwin's time, there has not been a single shred of evidence put forward to show that natural selection causes living things to evolve. Colin Patterson, the senior paleontologist at the British Museum of Natural History in London and a prominent evolutionist, stresses that natural selection has never been observed to have the ability to cause things to evolve:

No one has ever produced a species by the mechanisms of natural selection. No one has ever got near it, and most of the current argument in neo-Darwinism is about this question.11

Pierre-Paul Grassé, a well-known French zoologist and critic of Darwinism, has these words to say in "Evolution and Natural Selection," a chapter of his book The Evolution of Living Organisms.

The "evolution in action" of J. Huxley and other biologists is simply the observation of demographic facts, local fluctuations of genotypes, geographical distributions. Often the species concerned have remained practically unchanged for hundreds of centuries! Fluctuation as a result of circumstances, with prior modification of the genome, does not imply evolution, and we have tangible proof of this in many panchronic species [i.e. living fossils that remain unchanged for millions of years].12

A close look at a few "observed examples of natural selection" presented by biologists who advocate the theory of evolution, would reveal that, in reality, they do not provide any evidence for evolution.

11 Colin Patterson, "Cladistics", Interview by Brian Leek, interviewer Peter Franz, March 4, 1982, BBC (emphasis added)
12 Phillip E. Johnson, Darwin On Trial, Intervarsity Press, Illinois, 1993, p. 27.