Do Eyes Carry 'Scars of Evolution'? | The Institute for Creation Research
Do Eyes Carry 'Scars of Evolution'?

In a recent piece in Scientific American, neuroscientist Trevor Lamb wrote that vertebrate eyes contain numerous defects that he called "the scars of evolution." He cited these "flaws" as powerful evidence that blind evolutionary forces are responsible for the "invention" of eyes.1 But research has proven that these supposed defects are entirely fictional.

Lamb described the first "flaw" in vertebrate eyes:

The retina is inside out, so light has to pass through the whole thickness of the retina—through the intervening nerve fibers and cell bodies that scatter the light and degrade image quality—before reaching the light-sensitive photoreceptors.1

Light does indeed pass through the whole thickness of the retina, but it does not intersect the intervening nerve cell bodies. This is because special funnel-shaped Müller cells channel light through the retina directly to the photoreceptors at the back of the eye, so that the image quality is excellent.2 Far from being flawed, this arrangement serves to protect the photoreceptors from damaging UV light and allows them access to nutritive fluid.3

And not only is the light not scattered before it reaches the photoreceptors, but the Müller cells actually refine incoming light, reducing scatter. Why did Lamb fail to mention this, or the fact that retinal neurons are organized to maximize reception of incoming light?

In a report published in the journal PLoS Biology in 2009, researchers from California wrote, "The observed RFs [receptive fields] approached an optimal arrangement."4 It is not possible for a system that is "inside out," which implies a need for improvement, to also be "optimal," meaning that it cannot be improved.

The second "flaw" Lamb offers is equally fallacious. He wrote, "Blood vessels also line the inner surface of the retina, casting unwanted shadows onto the photoreceptor layer."1 The blood vessels are certainly there, but where is there any evidence of shadows? The Müller cells in vertebrate eyes act as optic fibers, literally bending light around blood vessels. Plus, without those blood vessels, there would be insufficient nutrient exchange. Inner-surface retinal blood vessels are only "unwanted" by those who don't want to see their ideal fit in the eye's internal structures.

The last supposed defect Lamb noted was that "the retina has a blind spot where the nerve fibers that run across its surface congregate before tunneling out through the retina to emerge behind it as the optic nerve."1 The retina does provide a tunnel for nerves to access the brain, but this is a necessary byproduct of having the optimal setup for the photoreceptors. And nobody with normal vision experiences a blind spot because it is fully compensated for by ingenious design features.

For example, the entry point for the retinal nerve bundle has been purposefully offset. This way, the area of highest-intensity visual detection at the center of the retina, called the fovea, is undisturbed. Also, the optical processing software in the brain constantly generates a flawless "fill-in" image to mask the blind spot.5

Not only do healthy eyes have no deficiencies, but even evolutionary researchers have recently admitted that they cannot be improved upon.6 This means that the supposed flaws listed by Lamb only apply to an imaginary, straw-man version of the vertebrate eye.

Those who insist that eyes have flawed construction should try making better eyes themselves. At the very least, they should get an updated education on the exquisite anatomy that they too easily criticize.

References

  1. Lamb, T. D. 2011. Evolution of the Eye. Scientific American. 305 (1): 64-69.
  2. Franze, K. et al. 2007. Müller cells are living optical fibers in the vertebrate retina. Proceedings of the National Academy of Sciences. 104 (20): 8287-8292.
  3. Thomas, B. Retinal Coordination: Picture Perfect Presentation of Design. ICR News. Posted on icr.org April 15, 2009, accessed August 19, 2011.
  4. Gauthier, J. L. et al. 2009. Receptive Fields in Primate Retina Are Coordinated to Sample Visual Space More Uniformly. PLoS Biology. 7 (4): e1000063.
  5. Bergman, J. and J. Calkins. 2005. Is the Backwards Human Retina Evidence of Poor Design? Acts & Facts. 34 (10).
  6. For example, a 2010 article appearing in The New York Times reported, "Photoreceptors exemplify the principle of optimization." Angier, N. Seeing the Natural World With a Physicist's Lens. The New York Times. Posted on nytimes.com November 1, 2010, accessed August 18, 2011.

* Mr. Thomas is Science Writer at the Institute for Creation Research.

Article posted on August 24, 2011.

The Latest
CREATION PODCAST
Volcanoes on Mars??? | The Creation Podcast: Episode 58
Geologic activity shows signs of youth not just on our planet, but all throughout the universe. As we discover more about our solar system and the...

NEWS
The Brain’s Amazing Ability of Visual Perception
Scientists will never fully understand the brain’s operation.1,2,3 As neurological research continues, it will only reveal more...

ACTS & FACTS
Continuous Environmental Tracking : An Engineering-Based Model...
Purpose The Institute for Creation Research is engaged in our biggest science initiative in the last two decades, and it could be our most important...

ACTS & FACTS
CET: Testing the Cavefish Model
Staff Writer Purpose The Institute for Creation Research (ICR) is testing an engineering- based model of rapid biological adaptation called...

ACTS & FACTS
Original Biochemistry in Fossils
Purpose In 1997, paleontologist Dr. Mary Schweitzer accidentally stumbled upon what appeared to be blood vessels and blood cells from a T. rex...

ACTS & FACTS
Debunking an Iconic Uniformitarian Ice Age Theory
Purpose The Milankovitch, or astronomical, theory holds that the timing of Ice Ages is controlled by slow changes in Earth’s orbital and...

ACTS & FACTS
ICR and Explaining the Ice Age
by Larry Vardiman, Ph.D., and Michael J. Oard, M.S.* Purpose There is strong geological evidence for an Ice Age, so the Institute for Creation...

ACTS & FACTS
Planetary Magnetism
Purpose In 1971, Dr. Thomas Barnes publicized a then “trade secret” of scientists studying the earth’s magnetic field, which...

ACTS & FACTS
Cosmology Research
Purpose Taking the Hebrew text of Scripture at face value without inserting gaps or revising the meanings, the universe is only about 6,000 years...

ACTS & FACTS
The Coconino Sandstone: Water, not Wind
Purpose The Coconino Sandstone is one of the most well-known formations in Grand Canyon. The blond-colored sandstone, just three layers down from...