It is amazing what evolutionists say when confronted with their own words. Perhaps the most consistent claim of evolutionists is that evolution is a fact. For centuries evolutionary thinkers have been making high truth claims, and the evolution-is-fact claim is now standard in the literature. But when confronted with this claim in light of the facts of biology which contradict their idea, evolutionists retort that you don't understand the concept of a "fact." But what is there not to understand? Evolutionists say their idea is a fact as much as is gravity. It is beyond a shadow of a doubt, and it would be perverse to doubt it.
Evolutionists have made their claim of facthood quite clear. The facts of biology are also quite clear, and so there is a contradiction. The facts of biology certainly do not demonstrate evolution to be a fact. Not even close. There is biological evidence for evolution, but there is also plenty of contradictory evidence. There certainly is room for debate about how badly evolution fares in light of biology. And of course certain facets of the idea fare better than others. But a fact it is not. It may be true, but we cannot know that from the evidence at hand.
Such problems induce a curious reaction on the part of evolutionists. They say you do not understand what constitutes a fact. Just because evolution is a fact doesn't mean we understand it completely. Just as there are questions about how gravity works, so too there are questions about how evolution works. But both remain as facts. The laws of nature do not suspend themselves, as Stephen Jay Gould once explained, while scientists debate the particulars.
It is true that no one would doubt gravity just because we don't fully understand the mechanism. After all, we observe and feel gravity everyday. It is an empirical fact. But evolution is not an empirical fact. We do not observe a fish evolving into a giraffe over eons of time. It must be inferred from evidence, and this brings us back to those thorny biological facts.
But wait, evolutionists just explained that biological facts don't matter--that evolution is a fact regardless of whether we have it figured out. Their explanation is that evolution has an ontological status that transcends the scientific details. There is the fact of evolution, and then there is the theory of evolution. This fact-theory dichotomy is a key apologetic in evolutionary thought. Notice that it decouples evolution from the evidence and makes the theory immune to the facts of biology. You can point out all the evidential problems you want--they don't affect the facthood of evolution.
But if the facts of biology can't hurt evolution, then they can't help either. How then do we know evolution is a fact? If evolution is not an empirical fact, and we cannot infer it from the evidence without substantial speculation and heroics, then why are evolutionists so sure?