Later research by Robin McKenzie showed that the shape of the spine is a natural design for upright posture, and maintaining the lordosis curve improved the health of sufferers. Treatments have more recently been developed that support the perfectly designed lordosis curve, and recognition of perfect human design has proven medical benefits.
It is often claimed that the human retina is poorly designed because it appears to be placed in the eye backwards. Its design, therefore, requires that light travel through the nerves and blood vessels to reach the photoreceptor cells located behind the eye’s wiring. We now know that specific functional reasons exist for this so-called backward placement of the photoreceptors. A major reason for the retina reversal is that it allows the rods and cones to interact with the retinal pigment epithelial cells that provide nutrients to the retina, recycle photopigments, provide an opaque layer to absorb excessive light, and perform other functions. This design is superior to other systems, because it allows close association with the pigmented epithelium required to maintain the photoreceptors. It is also critical in both the development and normal function of the retina.
A common claim by evolutionists is that the human body is poorly designed, which to them is evidence that it was not intelligently designed, but rather cobbled together by the unintelligent process of evolution. One of the most frequent examples of poor design cited by evolutionists today is the recurrent laryngeal nerve (RLN), which controls the mammalian larynx (voice box) muscles. Paleontologist Donald Prothero wrote that examples of "poor or at least very puzzling design can be accumulated endlessly," thus proving evolution, with one of the best examples being "the recurrent laryngeal nerve, which connects the brain to the larynx and allows us to speak."
Human-designed devices, such as radios and computers, do not need to function until their assembly is complete. By contrast, living organisms must function to a high degree in order to thrive during every developmental stage from a single-cell zygote to adult. The embryo as a whole must be a fully functioning system in its specific environment during every second of its entire development. For this reason, adult anatomy can be understood only in the light of development. An analogy Blechschmidt uses to help elucidate this fact is the course of a river, which "cannot be explained on the basis of a knowledge of its sources, its tributaries, or the specific locations of the harbors at its mouth. It is only the total topographical circumstances that determine the river's course."
Arguing that the left RLN is poorly designed implies that God should have used different embryo developmental trajectories for all the structures involved to avoid looping the left RLN around the aorta. One who asserts that the RLN is a poor design assumes that a better design exists, a claim that cannot be asserted unless an alternative embryonic design from fertilized ovum to fetus--including all the incalculable molecular gradients, triggers, cascades, and anatomical twists and tucks--can be proposed that documents an improved design. Lacking this information, the "poor design" claim uses evolution to fill in gaps in our knowledge. Furthermore, any alternative embryonic design pathway would likely result in its own unique set of constraints, also giving the false impression of poor design.
The left recurrent laryngeal nerve is not poorly designed, but rather is clear evidence of intelligent design:
Much evidence exists that the present design results from developmental constraints.
There are indications that this design serves to fine-tune laryngeal functions.
The nerve serves to innervate other organs after it branches from the vagus on its way to the larynx.
The design provides backup innervation to the larynx in case another nerve is damaged.
No evidence exists that the design causes any disadvantage.
The arguments presented by evolutionists are both incorrect and have discouraged research into the specific reasons for the existing design.
Jerry Bergman, Ph.D.