A Study Tells You How Chameleon Changes Colors
The magical ability to change colors owned by chameleon has been puzzling, but a recent study published on Nature Communications unveiled the secrets.
Scientists have discovered chameleon can adjust a layer of special cells under the skin to quickly change color. Compared to the squid and octopus discoloration, chameleon didn’t use the accumulation or dispersion of pigment cells in the skin to change color. It is interesting that this lizard applied the light reflection on the skin by changing skin structure.
To investigate this color changing capability of reptile, the researchers studied five adult males, four females and four young Madagascar leopard chameleons. The researchers found that the chameleon has two overlapping rainbow thick cells (iridescent cells): Iridescent cells have pigments and are capable of reflecting light. More importantly, iridescent cells have different shapes and different sizes arranged nanocrystals, which is the key of color changing. By “tensing” or “relaxing” the skin cells, chameleon reorganizes the structure of the upper arrangement of iridescent cells. For example, a male chameleon is clutching a sprig leisurely watching, this time he is likely in a “relaxed” state; when he encounters another male competitors, he will become “nervous”.
The professor at the University of Geneva said, “When the chameleon’s skin is in a” relaxed “state, the photonic crystal in iridescent cells will arrange together closely and specifically reflect short wavelengths of light, such as blue, when blue light goes into our eyes, we see blue. However, when the skin is in “tension” state, the interval of nanocrystals increase and the skin is capable of selectively reflecting long-wavelength light, such as yellow and red. Chameleon is not always blue, there is a yellow pigment, yellow and blue will generate green. It is a way to help them hidden in the green color of the trees and find a perfect cover. ”
The researchers also wrote in the paper. “When stimulated, the skin of red color tends not to experience drastic changes, but the brightness will increase. In addition, the researchers also found a buried deeper and thicker layer of cells in chameleon that is capable of reflecting a large amount of near-infrared light. Although these cells do not seem to change the color, it may help chameleon reflect heat, to avoid overheating of the body.
To study the iridescent cells, researchers used a range of methods. They shot the color changing process with high-resolution video technology and mathematically modeled to predict how nanocrystals are reflecting light. Exciting is that the experimental observations and the results of the simulation are the same.
This work can inspire engineers and scientists to learn chameleon’s ability!