Genetics determine the variety of stripes in zebras. While the specific processing of determining this striping pattern isn’t known, it has something to do with selective pigmentation. Melanocyte skin cells produce the pigments that color the fur. Certain chemical messengers regulate which melanocytes deliver their pigment to the zebra [source: Camazine]. Mathematical models haven’t been able to accurately simulate the development of the pattern, but we do know that it takes place during the embryonic phase