OK. I'll start with this one. The postulate that natural selection operating on random genetic fluctuations produced all the organisms in the fossil record can never be tested rigorously, because most of the organisms are extinct, and there was no intelligent life to describe and analyze the process in (say) the Paleozoic. This means that Darwinian macroevolution (speciation) will forever remain unprovable by the standards normally used in most of physical science: experiments which can be replicated. Macroevolution is plausible, but not testable the way gravity, magnetism, quantum theory, etc. are. It's really incorrect to say that macroevolution is a fundamental piece of science, as are those theories, which must be learned by every little public school captive.
We now know much that Darwin didn't, including that many of the changes seen in the fossil record were probably driven by catastrophic extinction events, not by gradual change.
Now...how long till the flames and insults start?
I think the insults started somewhere in the first 3-6% of this thread.