The Theory of Evolution we have now bears only a passing resemblance to the theory first postulated by Darwin a century and a half ago. Darwin thought protozoa was living jelly. He thought had no idea of the complexity of the structure in a protozoa. I'm sure that observation would never have shown him that it was too complex to exist by chance.
Read the links I posted in #332. Irreducible complexity may not be so irreducible.