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Darwinists Seek to Explain the Eye’s Engineering Perfection

David Coppedge
Photo credit: v2osk via Unsplash.

Yesterday we looked at a paper by Tom Baden and Dan-Eric Nilsson in Current Biology debunking the old canard that the human eye is a bad design because it is wired backwards. We saw them turn the tables and show that, in terms of performance, the inverted retina is actually as good or better than the everted retina. Vertebrate eyes “come close to perfect,” they said. Ask the eagles with “the most acute vision of any animal,” which would include cephalopods with their allegedly more logical arrangement. Eagles win! Squids lose! Baden and Nilsson looked at eyes from an “engineer’s perspective” and shared good reasons for the inverted arrangement. They even spoke of design seven times; “the inverted retinal design is a blessing,” they argued.

And yet they maintain that eyes evolved by blind, unguided natural processes. How can they believe that? In this follow-up, we look at the strategies they use to maintain the Darwinian narrative despite the evidence.

Personification

First, they turn evolution into an engineer. Personification is a common ploy by Darwinists. Richard Dawkins envisioned a “blind watchmaker” replacing Paley’s artificer. Darwin even gave natural selection a gender:

Natural selection acts only by taking advantage of slight, successive variations. She can never take a great and sudden leap, but must advance by short and sure, though slow steps.

Evolutionists speak freely of natural selection as a “tinkerer” cobbling together whatever odd parts are handy so that a solution, however, awkward, comes to satisfy a need brought on by “selection pressure.” The resulting structures give the illusion of design but are not the work of a rational agent. Neil Thomas calls such stories “agentless acts” by which engineered structures arise by “pure automatism or magical instrumentality quite outside common experience or observability.” Evolutionists need no magician; the rabbit emerges out of the hat spontaneously, as if an invisible hand pulled on its ears. Watch how Baden and Nilsson personify evolution and turn it into a Blind Tweaker and Opportunist:

So, in general, the apparent challenges with an inverted retina seem to have been practically abolished by persistent evolutionary tweaking. In addition, opportunities that come with the inverted retina have been efficiently seized. In terms of performance, vertebrate eyes come close to perfect. [Emphasis added.]

Visualization

A second tactic Baden and Nilsson use is visualization. Figure 3 in their article shows three stages of a possible evolutionary path from a primitive photoreceptor to a “high quality spatial vision” with “usable space” between the lens and retina. “This space could be usefully filled by the addition of neurons that locally pre-process the image picked up by the photoreceptors,” the caption reads. Well, then, what personified tinkerer would not take advantage of such prime real estate? Give the Blind Tweaker room to homestead and you will shortly find him (or her) setting up shop. What’s missing in the visuals are giant leaps over engineered systems in the gaps, and an account of how they all become coordinated to make vision work.

Inevitability

Another tactic used by Baden and Nilsson is the notion of inevitability. Evolution was forced to take the path it did. Evolution had no choice, they imply, because the first time a layer of light-sensitive cells began to invaginate into a cup shape, the path forward was set in concrete.

The specific reason for our own retinal orientation is the way the nervous system was internalised by invagination of the dorsal epidermis into a neural tube in our pre-chordate ancestors. The epithelial orientation in the neural tube is truly inside out. The vertebrate eye cup develops from a frontal (brain) part of the neural tube, where the receptive parts of any sensory cells naturally project inwards into the lumen of the neural tube (the original outside). In contrast, the eyes of octopus and other cephalopods develop from cups formed in the skin, and the original epithelial outside keeps its orientation.

This tactic gives a Darwinist the flexibility to use the same theory to explain opposite things. Evolution is so rigid it must follow the path the ancestor took, but so malleable that all subsequent engineering can be optimized to perfection. Surely, though, if natural selection has the magical powers the Darwinists ascribe to it, it could have ditched ancestral traditions and remodeled the eye cup. Isn’t that how all innovations begin in the theory? 

Airy Nothings

The sneakiest tactic used by the authors is what Neil Thomas described as “notional terms.” These are “airy nothings” and “empty signifiers” that gloss over difficulties by replacing evidence with factoids. A factoid, Thomas says, is “a contention without empirical foundation or any locatable referent in the tangible world but one nevertheless held to be true by the person who proposes it” (italics in original). To use this tactic, just assume that your notion is true. Complex things evolved. They originated. They emerged. They arose. They started. They came. They developed. They improved.

Bipolar cells emerged, slotting in between the cones and the ganglion cells to provide a second synaptic layer right in the sensory periphery. Further finesse came through the addition of horizontal and amacrine cells. The result is a structurally highly stereotyped sheet of neuronal tissue present in all extant vertebrates….

Notional terms like this, that assume what need to be proved, can slip through unnoticed unless one is on guard for them. The following contains two of them, while distracting readers with the ID-friendly argument that the eye is not flawed.

Arguments for a basically flawed orientation of the vertebrate retina are built around an eye that we encounter in a grossly enlarged state compared to its humbler origins. We are now more than 500 million years down the road from where vertebrate vision started in the early Cambrian.

When the readers weren’t paying attention, they were being told that the eye had humble origins in the early Cambrian. A truer statement would have read, “Arguments for a basically flawed orientation of the vertebrate retina are built around the assumption of Darwinian evolution.”

Consensus

Baden and Nilsson might counter that they don’t need to give any details about how evolution achieved engineering perfection, because the scientific community has already reached a consensus that Darwinian evolution explains everything in biology, so they can just take it for granted. This is a form of argument from authority, but worse in this instance. As shown in the previous post, the strongest case for eye evolution — so strong that Richard Dawkins celebrated it publicly — was the 1994 graphic that Jonathan Wells and David Berlinski exposed, and Nilsson was one of the perpetrators! To take that for granted would be like drawing a picture of a unicorn in 1994 and then using that drawing as evidence for unicorns in 2022. Evolutionists leaped onto that 1994 article because nothing better had shown up since Darwin got cold shudders considering this “organ of extreme perfection,” the eye.

The Power of Master Narratives

A doctorate in a relatively rare field of expertise called the Rhetoric of Science is held by Thomas Woodward, author of Doubts About Darwin (2003). In that book he examines the role of “fantasy themes” (which he prefers to call “projection themes”) in the history of the Darwin versus Design debate. One of these is the “progress narrative” that the universe is on a continuous path toward higher complexity (p. 52). These projection themes — not empirical data — were of paramount importance in the wide acceptance of evolution when the Victorian atmosphere was fragrant with feelings of progress. Darwin and his successors had a simple, compelling story that was part “factual-empirical narrative” and part “semi-imaginative narrative” (p. 22). 

To understand how Darwinians continue to maintain what appears to ID advocates as cognitive dissonance, i.e., that nature is exquisitely engineered but emerged by blind processes, observers need to be cognizant of the projection themes and rhetorical tactics Darwinians use to forestall a Design Revolution. The ones used by Baden and Nilsson cannot be conquered merely by appeals to empirical facts. They need to be exposed as the ploys they are and supplanted by better narratives founded on stronger evidence and logic.