Darwin showed that material causes are a sufficient explanation not only for physical phenomena, as Descartes and Newton had shown, but also for biological phenomena with all their seeming evidence of design and purpose. By coupling undirected, purposeless variation to the blind, uncaring process of natural selection, Darwin made theological or spiritual explanations of the life processes superfluous. Together with Marx's materialistic theory of history and society and Freud's attribution of human behavior to influences over which we have little control, Darwin's theory of evolution was a crucial plank in the platform of mechanism and materialism
---Douglas Futuyma's Evolutionary Biology (1998, 3rd Ed., Sinauer Associates), p. 5
But Darwin, like Newton and Descarte didn't explain everything.
So now we have amorphous/probability physics and fuzzy math.
I don't think Darwin ever envisioned the complexity of the
simple "bags of protoplasm" that we now know are highly
coordinated, organized cells.