It was a sweltering day in the Madagascan forest when a creature cautiously approached into view. Mitten-like feet daintily grasped and propelled it along a branch and his body was brilliantly hued in reds, oranges, greens, and blues. Suddenly a similarly colored competitor came into view. Their calm behavior took a turn as they realized the presence of one another. Like Las Vegas billboards in slow motion, it wasn’t long before their brilliant greens and blues changed to yellows and whites. The reds remained the same but got brighter. As minutes passed and as they went on their way, the chameleon males were back to their original colors. The amazing color-change abilities of these marvelously designed animals have caught the attention of researchers. What the scientific findings reflect is consistent with an all-wise Engineer whose intellect far surpasses human thought and whose palette of color makes any human artist jealous.
Chameleons are unique lizards of the reptile clan. The family contains 200 species and has many unique features that may qualify it as a single created kind.1 The panther chameleon (Furcifer pardalis) has been a major research subject in color technology.2 Male adults of this species have a greater range of color variation than juveniles and females. Although they can change color and be camouflaged with their environment, male color change is based mostly on their emotional state. Emotions change when they meet other competitive males, or when females capture their interest. Skin color can shift dramatically as blue patches turn yellow to white and red patches grow brighter without changing hue. In just a few minutes their colors can revert back to the original. How do they do this?
The way the light hits their skin may qualify these cells as photonic crystals. In some organisms like peacocks and various butterflies, pigments are not producing the stunning coloration, but photonic crystals are. Photonic crystals are structures that are designed in such a way that their nooks and crannies at the microscopic level bounce and absorb light to produce beautiful and vibrant hues of the color spectrum. Engineers are trying to duplicate photonic crystals and are making some progress, but human technology has a long way to go.
How light is being bounced and absorbed for color production begins with the cells that make up their skin. Under the outer layer or epidermis, panther chameleons have two other layers. The layer directly below the epidermis is made of cells (iridophores) that bounce and absorb light and are designed so that colors appear to change, depending on how the light hits them or from what angle you view them. This phenomenon is called iridescence. This layer is called the superficial layer of iridophores. It is fully developed only in adult males, and the iridophores contain closely packed crystals of guanine. Guanine is needed by living things because it is a crucial part of the DNA structure required by all life. You may also be more familiar with guanine than you know. Guanine crystals often produce the shimmering sparkle found in metallic paint, eye shadow, and nail polish!
In iridophores, guanine crystals also function in color emission. They tend to be closer together when male chameleon emotions haven’t been heightened (the resting state), which is when blues and greens are observed on the skin. When their emotions change, crystals move farther apart and the result is that the blues and greens change to whites and yellows (the excited state). It is thought that the shifting of one vibrant color to another is caused by the changing distances and spacing of the guanine crystals in the iridophores, which affects what wavelengths of color will be seen. Tests of the crystals themselves show that they can easily expand and contract depending on the chemical conditions of the cell and may explain why skin color is reversible.
The superficial layer is chemically different if the animal has red on its skin. Though there are generally large concentrations of iridophores, there are also large numbers of red-pigmented erythrophores, which is why red stays red during the excitement state but gets noticeably brighter.
Located under the superficial layer is the deep iridophore layer. This layer is not only virtually identical in all genders and ages of panther chameleons, but also in chameleons that are considered distantly related. Guanine crystals there are larger and more brick shaped. Though color change is not occurring in this layer, the function may help protect the chameleon from extreme temperatures. Studies have found that this layer reflects 45% of incoming heat (infra-red) radiation, and this heat screen may protect them from overheating. There is more research needed to confirm this.
Biomimicry is the biological discipline that studies design in nature in order to improve human technology. Engineers are looking into chameleon design for use in a number of different ways. They include the following:
Our God created light and is described as light. His light reveals evil, but illuminates the truth and the way to restore human relations with Himself, each other, and the Creation. His created light gives us color and, for those who have eyes to see, the colorful chameleon points to a wise Creator who desires to make Himself known!
Answers in Genesis is an apologetics ministry, dedicated to helping Christians defend their faith and proclaim the good news of Jesus Christ.