After finding the infrared photographs last week of a cat with hot feet, I started thinking about the temperature of body extremities in cats. You see, there is a “cool” example of how the environment can change what an animal looks like and it involves cats (although the same phenomena is also found in rabbits and mice.)
Ever seen a Siamese cat? These cats are light colored with darker feet, ears and noses. It turns out their color is due to a mutation in the gene that produces brown color (the protein melanin), called the Tyrosinase gene. At normal body temperatures the coat color of an animal with the Siamese variation is light. At slightly lower temperatures, such as occur on the animal’s extremities, the normal dark brown pigments are produced. Conventional wisdom says when a Siamese cat is raised in a cold climate, such as Northern Canada, it will have more extensive brown on its legs, tail, nose and ears than a Siamese raised at the equator.
Now go back and look at the infrared photograph of the cat at the infrared zoo. Are the extremities cooler? Seems to be a contradiction here. Any ideas why? Where do you think this Siamese cat in this picture from Wikimedia Commons was raised?