Zebra stripes are unique to each individual zebra, reports LiveScience, in an article shared by long-time Slashdot reader fahrbot-bot. And even if you look at the three different zebra species, their skin is always the same color: black (according to Tim Caro, a behavioral and evolutionary ecologist and conservation biologist at the University of California, Davis).
But this still doesn’t answer the question of whether their fur is black with white stripes or white with black stripes.
For that, we have to look to the zebra’s melanocytes, or the cells that produce pigment for their fur. Although zebras have black skin, different developmental processes determine their fur color, just like a light-skinned person can have dark hair, Caro said. In fact, zebras actually have more light-colored hair than dark — their bellies are usually light — so it may seem that zebras are white with black stripes.
But that’s not the case. Here’s why: Every piece of hair — both light and dark — grows from a follicle filled with melanocyte cells, according to a 2005 review in the Journal of Investigative Dermatology. These cells produce a pigment that determines the color of hair and skin. This pigment is known as melanin; a lot of melanin leads to darker colors, like dark brown or black, while less melanin leads to lighter colors, such as hazel or blond, Live Science previously reported. Zebras’ black fur is chock-full of melanin, but melanin is absent from white fur, in essence, because the follicles that make up the stripes of white hair have “turned off” melanocytes, meaning they don’t churn out pigment.
The production of melanin from melanocytes is “prevented during the development of a white hair, but not of a black hair,” Caro told Live Science in an email. In other words, for zebras, the animals’ default state is to produce black hair, making them black with white stripes, according to Brittanica….
This unique pattern may keep away biting flies, according to research by Caro and his colleagues. In a study published in 2020 in the journal Proceedings of the Royal Society B, they found that African horseflies landed less frequently on horses wearing striped or checked rugs than they did on horses wearing solid-colored rugs. These biting flies can carry diseases that are fatal to zebras.
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Source:: Slashdot