One of the Most Important Questions in Evolutionary Biologyexplains:
Lyell, however, deeply influenced Darwin, and just as Lyell invoked uniformitarianism as part of his efforts to make geology a science, I believe Darwin followed suit in his development of evolutionary thought. Huxley famously wrote to Darwin immediately before publication of The Origin, suggesting that Darwin had adopted a gradual view of evolution too unreservedly.
But what if Darwin had not cast his evolution as a gradual, law-like process? If he had allowed for saltations to explain the discontinuities, rather than gaps left by an imperfect fossil record, then his theory would have been less compelling. Now, 150 years later, we have yet another false prediction and evolutionists struggling to patch the theory. And if something as fundamental as this remains in question, then certainly evolution is not a scientific fact.