Atlantic titi barrier such as a river and are thus completely genetically isolated from one another). Distinctions between each of the "Callicebus" subspecies are based on coat color. The evolution of these coat colors is termed metachromism. The pigments are produced by melanocytes which deposit the pigments into the medulla of growing hair so that the hair grows with the color of that distinct pigment. The characteristic pigment of the "Callicebus" is eumelanin (dark brown or black) found in the iris, skin, and hair (usually on the forehead, crown and tail). Atlantic titis are opportunistic feeders. In other words, they eat based
Chameleon heat more efficiently, then a lighter grey colour to reflect light during the heat of the day. It may show both colors at the same time, neatly separated left from right by the spine. For a long time it was thought that chameleons change colour by dispersion of pigment-containing organelles within their skin. However, research conducted in 2014 on panther chameleons has shown that pigment movement only represents part of the story. Chameleons have two superimposed layers within their skin that control their colour and thermoregulation. The top layer contains a lattice of guanine nanocrystals, and by exciting this lattice