Casey Luskin muses on the many hand-waving accounts of how the complexity of the eye developed by accident, for example:
As a further example of these hyper-simplistic accounts of eye evolution, Francisco Ayala in his book Darwin’s Gift to Science and Religion asserts, “Further steps — the deposition of pigment around the spot, configuration of cells into a cuplike shape, thickening of the epidermis leading to the development of a lens, development of muscles to move the eyes and nerves to transmit optical signals to the brain — gradually led to the highly developed eyes of vertebrates and cephalopods (octopuses and squids) and to the compound eyes of insects.” (p. 146)
Ayala’s explanation is vague and shows no appreciation for the biochemical complexity of these visual organs. Thus, regarding the configuration of cells into a cuplike shape, biologist Michael Behe asks (in responding to Richard Dawkins on the same point):
“And where did the “little cup” come from? A ball of cells–from which the cup must be made–will tend to be rounded unless held in the correct shape by molecular supports. In fact, there are dozens of complex proteins involved in maintaining cell shape, and dozens more that control extracellular structure; in their absence, cells take on the shape of so many soap bubbles. Do these structures represent single-step mutations? Dawkins did not tell us how the apparently simple “cup” shape came to be. Michael J. Behe, Darwin’s Black Box: the Biochemical Challenge to Evolution, P. 15 (Free Press, 1996)”
An Integrated System
Likewise, mathematician and philosopher David Berlinski has assessed the alleged “intermediates” for the evolution of the eye. He observes that the transmission of data signals from the eye to a central nervous system for data processing, which can then output some behavioral response, comprises an integrated system that is not amenable to stepwise evolution…Casey Luskin, “More Implausible Stories about Eye Evolution” at Evolution News and Science Today (April 8, 2022)
Surely the best approach is to see these convenient cascades of functional machinery as the miracle stories of Darwinism. They are not subject to criticism as to their probability, which is why no Darwinian need take such criticism seriously.