Over at the National Science Foundation, where your tax dollars go to promoting Darwin's religious theory, evolutionist Jim Secord asks the question "Where did Charles Darwin become convinced of the truth of evolution?" That's a good way of putting it because Darwin and evolutionists ever since have indeed been convinced that evolution is true. It is, as they like to say, a fact every bit as much as gravity is a fact. That's quite a claim. You would think they might say it is a fact as much as are Alexander the Great's conquests or some other historical record. That would still be a misrepresentation of the scientific evidence, but it would not be as blatant. The comparison with gravity is downright ludicrous, and precisely for this reason it is a tipoff that evolution is not the product of empirical science. Experimental measurements and hypothesis testing do not produce metaphysical certainty.
As Secord explains, Darwin's observations led not to scientific conclusions but religious concerns:
The different varieties of tortoises and mockingbirds provided powerful evidence of the relations between the Galapagos fauna and that of nearby South America. In geographical space, as in geologic time, closely allied species emerged successively and in order, just as they did in the fossil record. These relations, which impressed Darwin throughout the voyage, suggested that species were not specially created.
Let's see now, where's that verse in Genesis about birds on islands being completely different than those on the nearest mainland? Oh well, in any case Darwin argued powerfully that special creation must be false. The evidence for evolution was weak at best, but it had to be true. Religion drives science and it matters.