Here is a really interesting open-access article in the journal Accounts of Chemical Research. As an exercise, try changing one word (which occurs twice) in the statement below, and eliminate the contradiction. From, “Biological Polymers: Evolution, Function, and Significance”:
Biopolymers are emergent; the properties of biological building blocks change significantly upon polymerization. In cells, biopolymers compose mutualistic networks; a cell is an Amazon Jungle of molecules. We conclude that biopolymer backbones exhibit hallmarks of evolution. Neither chemical, physical, nor geological processes can produce molecules consistent with observations. We are faced with the paradox that Darwinian evolution relies on evolved backbones but cannot alter biopolymer backbones.
And that word is…
Evolution.
Evolution — actually, the living state itself — depends on the prior existence of biopolymers (such as RNA and DNA) which were themselves not produced by abiotic processes. If X is a causal precondition of Y, then Y cannot produce X.
So you could change this sentence as follows, and eliminate the contradiction; the correct word is in bold:
We conclude that biopolymer backbones exhibit hallmarks of design.
And then, having articulated an argument for intelligent design, the paper would never have been published. In the culture of science as it’s most commonly practiced today, you see how these things work.