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Speaker 1: Welcome to brain stuff from how stuff works, Hey, brain Stuff,

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Speaker 1: Lauren vocal bomb here. Unlike most newborn creatures, elephants look

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Speaker 1: geriatric right out of the womb, thanks in large part

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Speaker 1: to their loose fitting, wrinkly skin. But elephants aren't manipulating

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Speaker 1: the system to collect social security early. Their cracked skin

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Speaker 1: is a clever evolutionary adaptation that protects these animals from

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Speaker 1: the sun's intense rays. African bush elephants are pacaderms, a

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Speaker 1: group of large animals like hippos and rhinoceroses. The name

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Speaker 1: pacaderms is based on a Greek word that means having

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Speaker 1: thick skin. These enormous, warm blooded animals can weigh around

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Speaker 1: eleven tons that's about ten metric tons and measure up

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Speaker 1: to about thirteen feet tall at the shoulder that's about

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Speaker 1: four meters In short, it's a lot of flesh and bone,

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Speaker 1: all baking in the often brutal African heat, and as

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Speaker 1: it turns out, elephants can't sweat. Is it possible to

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Speaker 1: perspire with sympathy? Recently, a team of researchers out of

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Speaker 1: Sweden went more than skin deep in their studies of

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Speaker 1: the pacader epidermis. Using both light and electron microscopes, along

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Speaker 1: with intricately detailed computer modeling, the researchers were able to

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Speaker 1: determine the cause of elephants scaly skin. For starters, the

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Speaker 1: scientists found that the crackled appearance of elephant skin is

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Speaker 1: not a sign of aging or skin shrinkage, as is

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Speaker 1: often the case with other species. Rather, it is a

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Speaker 1: purposeful design resulting from the stress of the skin bending.

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Speaker 1: These cracks allow the skin to retain moisture and dirt,

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Speaker 1: which reduces the harmful effects of the sun and prevents

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Speaker 1: harmful swings in body temperature. The barrier also wards off

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Speaker 1: some types of pests and parasites. Elephant skin, unlike human skin,

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Speaker 1: is resistant to shedding, so the layers, particularly the super

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Speaker 1: tough top layer, the stratum corneum, stick around longer before

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Speaker 1: sloughing off. It also has a lot more keratin than

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Speaker 1: human skin, so it's more durable, keratin being the stuff

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Speaker 1: that makes up fingernails and is a small presence in

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Speaker 1: our own skin. As this thick hide is subject to

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Speaker 1: everyday movement like bending and twisting, it quickly wrinkles with

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Speaker 1: layer upon layer of wrinkly skin serving as a complex

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Speaker 1: system of channels the capture and hold moisture and dirt,

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Speaker 1: so when you see elephants basking in sloppy pools spraying

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Speaker 1: water in mud to and fro, they aren't just doing

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Speaker 1: it for fun. The mud settles into the tense cracks

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Speaker 1: in their skin, some of which are just a micrometer

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Speaker 1: across about fifty times smaller than the naked human eye

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Speaker 1: can detect. Continually wetted, the skin remains permeable, helping the

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Speaker 1: animals stay cooler. And interestingly, elephant skin doesn't just randomly wrinkle.

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Speaker 1: It cracks in geometric shapes that approximate other common sights

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Speaker 1: in our world, from drying mud to heat shattered asphalt,

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Speaker 1: or even geometrically precise rock breakage like the giants causeway

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Speaker 1: in Ireland. The result is a durable cooling system that

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Speaker 1: keeps these gigantic mammals from cooking in their own thick

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Speaker 1: skin on steamy summer days. With their huge bodies and

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Speaker 1: constant sun exposure, it would be easy to assume that

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Speaker 1: elephants often fall victim to skin cancer and its side effects,

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Speaker 1: but as it turns out, cancer is relatively rare in

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Speaker 1: these animals, thanks in part to a gene called P

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Speaker 1: fifty three, Elephant body chemistry identifies DNA abnormalities, and then

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Speaker 1: Nix's cells that seem doomed to tumors. Scientists starts studying

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Speaker 1: these so called zombie jeans to see how they might

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Speaker 1: affect human biology too. Today's episode was written by Nathan

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Speaker 1: Chandler and produced by Tyler Clang. For more on this

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Speaker 1: and lots of other wrinkly topics, visit our home planet,

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Speaker 1: how Stuff Works dot com