Never been observed

I am happy to agree that natural selection has never been observed to produce something as complex as the vertebrate eye. Intelligent agents have never been observed to bring universes into being or to create life from scratch, but Sean [Pitman] has no trouble believing that occurred. The fact remains that there is voluminous circumstantial evidence supporting the claim that natural selection can in principle and has in natural history produced complex adaptations.

via Probability and Evolution – EvolutionBlog.