True colours: Scientists unlock the secret to chameleon morphing

The secret to Chameleon skin change is out, according to a new study from the journal Nature Communication. Researchers used spectroscopy to examine in detail how light and matter interact within the chameleons’ skin and found the colour-changing takes place via crystals – iridophores – arranged under the chameleons’ skin. The iridophores are formed from guanine, one of the building blocks of DNA, and they’re “efficiently organised” across the chameleons’ skin in a triangular lattice design.

When the skin is in the relaxed state, the nanocrystals in the iridophore cells are very close to each other – hence, the cells specifically reflect short wavelengths, such as blue.

Senior study author Michel Milinkovitch, a professor of genetics and evolution at the University of Geneva in Switzerland

When the chameleon becomes agitated – by fear, dominance or a willingness to mate, for example – the latticework stretches. That changes the wavelengths of light the crystals reflect. In other words: According to the research, it’s not pigments that change the chameleons’ color; it’s the creatures’ sparkling skin.

Science