Researchers have unraveled the mystery behind the stripes in animals like zebra and tiger. The stripes are found to be determined by a mathematical predictability.

Harvard researchers assembled a range of mathematical models into that of a singular equation. This equation is set to determine what variables control the natural patterns of animal stripes.

"We wanted a very simple model in hopes that it would be big picture enough to include all of these different explanations," Tom Hiscock, lead author and PhD student in Sean Megason's systems biology lab at Harvard Medical School, explained.

The stripes found in animals are actually simple to model in mathematical terms. For example, tigers have parallel stripes that are evenly spaced and perpendicular to the spine. These natural patterns are essentially emerging in the interaction of substances that create waves of pigment concentrations. This does not thoroughly explain how stripes orient themselves. This particular study is to find out how the stripes "choose" to orient in a certain fashion.

"We now get to ask what is common among molecular, cellular, and mechanical hypotheses for how living things orient the directions of stripes, which can then tell you what kinds of experiments will (or won't) distinguish between them," Hiscock added. He also explained  that the stripe formation is using a very simple mathematical equation; however, the details are not exactly known yet -- even with the breakgthrough that they discovered. 

The researchers have created a master model that predicts three perturbations that can influence stripe orientation. The first is a change in "production gradient" (amplification of stripe pattern density), the second is the "parameter gradient" (involves the formation of the stripes), and the third is the physical change in the detraction of molecular, cellular or mechanical origin of the stripe.

Previous research introduced a possibility that zebra stripes are evolutionary defense against flies. However, Hiscock's study is more on the explanation of the reason of the stripes occurring in a regular manner.