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Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,

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Speaker 1: Lauren Vogel bomb here with a classic from our archives.

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Speaker 1: In this one, we delve into the deep wrinkles an

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Speaker 1: elephant's skin. It turns out though it's wrinkles have a

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Speaker 1: number of really useful purposes. Hey brain Stuff, Laurin vocal

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Speaker 1: bomb here. Unlike most newborn creatures, elephants look geriatric right

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Speaker 1: out of the womb, thanks in large part to their

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Speaker 1: loose fitting, wrinkly skin. But elephants aren't manipulating the system

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Speaker 1: to collect social security early. Their cracked skin is a

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Speaker 1: clever evolutionary adaptation that protects these animals from the sun's

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Speaker 1: intense rays. African bush elephants are pacoderms, a group of

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Speaker 1: large animals like hippos and rhinoceroses. The name pacoderms is

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Speaker 1: based on a Greek word that means having thick skin.

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Speaker 1: These enormous, warm blooded animals can weigh around eleven tons

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

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Speaker 1: thirteen feet tall at the shoulder that's about four meters.

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

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

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Speaker 1: turns out, elephants can't sweat, is it possible to perspire

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

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

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Speaker 1: pacoderm epidermis. Using both light and electron microscopes, along with

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

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Speaker 1: the cause of elephant's scaly skin. For starters, the scientists

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Speaker 1: found that the crackled appearance of elephants skin is not

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Speaker 1: a sign of aging or skin shrinkage, as is often

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

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

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

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

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

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

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Speaker 1: complex 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 and 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 across,

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Speaker 1: about fifty times smaller than the naked human eye can detect.

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Speaker 1: Continually wetted, the skin remains permeable, helping the animals stay cooler.

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Speaker 1: And interestingly, elephants skin doesn't just randomly wrinkle. It cracks

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Speaker 1: in geometric shapes that approximate other common sights in our world,

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Speaker 1: from drying mud to heat shattered asphalt, or even geometrically

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Speaker 1: precise rock breakage like the Giant's Causeway in Ireland. The

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Speaker 1: result is a durable cooling system that keeps these gigantic

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Speaker 1: mammals from cooking in their own thick skin on steamy

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Speaker 1: summer days. With their huge bodies and constant sun exposure,

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Speaker 1: it would be easy to assume that elephants often fall

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Speaker 1: victim to skin cancer and its side effects, but as

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Speaker 1: it turns out, cancer is relatively rare in these animals,

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Speaker 1: thanks in part to a gene called p fifty three.

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Speaker 1: Elephant body chemistry identifies DNA abnormalities, and then nix's cells

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Speaker 1: that seem doomed to tumors. Scientists start studying these so

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Speaker 1: called zombie genes to see how they might affect human

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Speaker 1: biology too. Today's episode is based on the article Scientists

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Speaker 1: figure out Why Elephant's skin is so cracked on how

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Speaker 1: stuffworks dot Com, written by Nathan Chandler. Brain Stuff is

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Speaker 1: production of iHeartRadio in partnership with how stuffworks dot Com

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Speaker 1: and is produced by Tyler Klang. For more podcasts my

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