Why zebras have black and white stripes is a question that has intrigued scientists and spectators for centuries. Evolutionary theories include a form of camouflage, a mechanism of heat management, and disrupting predatory attack by confusing carnivores. In order to better understand the black and white stripe evolution, a research team led by the University of California, Davis, has now examined this riddle systematically, and what they found is that biting flies, including horseflies and tsetse flies, play a major role as the evolutionary driver for zebra stripes. The team mapped the geographic distributions of the seven different species of zebras, horses and asses, and of their subspecies, noting the thickness, locations, and intensity of their stripes on several parts of their bodies. Their next step was to compare these animals' geographic ranges with different variables, including woodland areas, ranges of large predators, temperature, and the geographic distribution of glossinid (tsetse flies) and tabanid (horseflies) biting flies. They then examined where the striped animals and these variables overlapped.