Cambrian Eyes Challenge Evolution
Figure 1 Compound Eyes of an Insect credit: Indiana Public Media
“And God said, ‘Let there be light,’ and there was light. And God saw that the light was good.” Of course, one of the most important aspects of light is that it makes it possible to “see”, that is, to observe and appreciate, God’s glorious creation. God also knew that to accomplish this, he would have to plan for his creatures, both on land and in the sea, to have light receptors, e.g., eyes. If Jesus demonstrated his authority to restore sight to the blind, we can be confident that it was he (the Godhead) who created sight in the first place. When did God first place complex eyes into his creatures? Turns out it was at least 550 million years ago in the Cambrian period. Let us take a closer look at some Cambrian fauna.
Ever come eyeball-to-eyeball with an insect? Does not matter if it were a housefly, honeybee, spider, or dragonfly, or even a crustacean like a shrimp, the two eyes staring back at you would look somewhat like the eyes in Figure 1 – compound eyes.
Insects and shrimp are part of a higher classification group known as invertebrates; they belong to the phyla Arthropoda and have segmented bodies, jointed legs, a tough outer exoskeleton, and compound eyes. Humans are vertebrates that belong to the phyla Chordata; we have internal skeletons, a backbone, and eyes that can change shape (accommodate) to focus on objects at varying distances; humans do not have compound eyes. Figure 2 is a fossil example of a 500-million-year-old compound eye.
Figure 2 Internal Structure of a Trilobite Eye credit: Natural history Museum
A “lagerstaette” is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation, sometimes even preserving soft tissues – a virtual fossil museum. Two of the more famous laggerstaetten containing Cambrian-age fossils are the Burgess Shale in British Columbia and Emu Bay Shale on Kangaroo Island, South Australia. These deposits reveal hundreds of species of trilobites and radiodonts in such detail that one can even observe internal components of their eyes (see Figure 2). A quick comparison of the modern insect eye in Figure 1 with the 500-million-year-old trilobite eye in Figure 2 reveals an amazing possibility – the design of compound eyes appears not to have evolved much over time!
Figure 3 Trilobite with Two Protruding Compound Eyes credit:Trilobite.info
In Figure 3 you are looking directly at the face (cephalon) of a fossil trilobite. The center portion is the cheek; to the left and to the right are the eyes. Because these eyes have relatively few receptors (hexagonal lenses), scientists speculate this creature was primarily a bottom feeder in poorly lit waters.
The most ancient fossil exhibiting compound eyesight was a Cambrian trilobite named Olenellus fowleri. In addition to trilobites, a whole different Order of Cambrian-age creatures with compound eyes has been identified, the radiodonts. Two radiodont species have recently excited the scientific community: Anomalocaris canadensis (British Columbia) and Anomalocaris briggei (Australia). So, what is the buzz? Both ‘canadensis’ and ‘briggei’ possess compound eyes, but with significant differences. ‘Canadensis’ has two stalked eyes (ommatophore) that protrude away from the body for a better field of view (see Figure 4), needed to spot swimming prey in shallow, well-lighted seas. Each eye measures 40 milimeters and consists of 24,000 hexagonal lenses. ‘Briggei’ eyes are not on stalks but are sessile. Each eye measures 7-9 milimeters across and consists of 13,000 hexagonal lenses, perfectly designed to detect plankton in dimly lit waters. The buzz – how could two completely different types of compound eye morphologies, each suited for its own unique environment, emerge simultaneously in geologic history? Before the Cambrian there were no known creatures with eyes; with the advent of the Cambrian there were multiple creatures with diverse highly developed sight. This begs the question: “does evolution or creation better explain the rapid emergence of complex animals?”
Figure 4 Anomalocaris credit: Fossils Facts Finds
Compound eyes that distinguish trilobites and radiodonts are visual organs characteristic of all arthropods, including modern insects and crustaceans. They may contain thousands of hexagonal-shaped ommatidia which are independent photoreception units consisting of a cornea, lens, and photoreception cells with axon terminals to set up a visual map to the brain. Compound eyes are fixed; they cannot move like human eyes. They can distinguish brightness and color, can see in all directions at once with a 360-degree view angle, can detect fast movement, but generally have rather poor image resolution. The ability to “see” is a characteristic of success in the animal kingdom. Of the 36 new animal phyla that emerged in the Cambrian, only 7 phyla have eyes. Of those, 4 phyla have image-forming eyes; 3 of the 4 are mollusks, arthropods, and chordates (humans), which account for 96 percent of all modern-day species.
Figure 5 Radiodonts credit Wikipedia
Figure 5 depicts some of the variety found in Cambrian radiodonts. The upper right radiodont is Anomalocaris canadensis. Just like modern insects and crustaceans, these radiodonts have a head (cephalon), a body (thorax) and a tail (pygidium). Each variety has two protruding compound eyes, breathing gills, swimming fins, and large pincers to grasp prey.
Many different types of compound eyes suddenly appeared in the Cambrian fossils. Amazingly, these exact same designs have a counterpart in modern insects and crustaceans, 500 million years later. Here are six of the compound eye categories:
Apposition: bees
Afocal apposition: butterflies
Neural superposition: flies
Refracting superposition: beetles
Parabolic superposition: mayflies
Reflecting superposition: shrimp
FYI, the common house fly is endowed with compound eyes of neural superposition. This type of eye is super-sensitive to any motion. Combine this with the ability to see in all directions at once, and is it any wonder you cannot seem to sneak up on a fly?
When comparing ancient trilobites with present insects, it appears our Creator ‘got it right the first time’ when he designed compound eyes. There is very little evidence that today’s arthropods benefited from evolution regarding their eyesight. This same phenomenon is observed with certain bacteria, whereby modern species are identical to their fossil-equivalent three-billion-year-old ancestors. I am not suggesting evolution has no value to the scientific process, but there appear to be enough “exceptions” to allow room for the “mystery” of our Creator.
