Darwin obviously lacked much information that is currently available
Biochemistry is an invention of the last fifty years.
It has been discovered; not invested. it's been there all along until the means to discover it were created/invented by man.
This article is discussing details of the process, not whether evolution proceeds along Darwinian lines.
If Darwin did not know what we know now; and that information contradicts his guesses, it most certainly does question his thoughts about evolution. In fact, it totally refutes them.
It doesn't even touch the history of natural selection. If you think it does, pleas be specific.