WEBVTT - BrainStuff Classics: Why Is Elephants' Skin So Wrinkly?

0:00:01.840 --> 0:00:07.520
<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,

0:00:07.600 --> 0:00:10.600
<v Speaker 1>Lauren Vogel bomb here with a classic from our archives.

0:00:11.280 --> 0:00:14.640
<v Speaker 1>In this one, we delve into the deep wrinkles an

0:00:14.640 --> 0:00:18.319
<v Speaker 1>elephant's skin. It turns out though it's wrinkles have a

0:00:18.440 --> 0:00:24.160
<v Speaker 1>number of really useful purposes. Hey brain Stuff, Laurin vocal

0:00:24.200 --> 0:00:28.280
<v Speaker 1>bomb here. Unlike most newborn creatures, elephants look geriatric right

0:00:28.280 --> 0:00:30.600
<v Speaker 1>out of the womb, thanks in large part to their

0:00:30.640 --> 0:00:34.960
<v Speaker 1>loose fitting, wrinkly skin. But elephants aren't manipulating the system

0:00:34.960 --> 0:00:37.960
<v Speaker 1>to collect social security early. Their cracked skin is a

0:00:37.960 --> 0:00:41.720
<v Speaker 1>clever evolutionary adaptation that protects these animals from the sun's

0:00:41.760 --> 0:00:46.479
<v Speaker 1>intense rays. African bush elephants are pacoderms, a group of

0:00:46.560 --> 0:00:50.159
<v Speaker 1>large animals like hippos and rhinoceroses. The name pacoderms is

0:00:50.200 --> 0:00:52.800
<v Speaker 1>based on a Greek word that means having thick skin.

0:00:53.680 --> 0:00:56.800
<v Speaker 1>These enormous, warm blooded animals can weigh around eleven tons

0:00:56.840 --> 0:00:59.520
<v Speaker 1>that's about ten metric tons and measure up to about

0:00:59.520 --> 0:01:02.360
<v Speaker 1>thirteen feet tall at the shoulder that's about four meters.

0:01:03.080 --> 0:01:05.800
<v Speaker 1>In short, it's a lot of flesh and bone, all

0:01:05.840 --> 0:01:09.080
<v Speaker 1>baking in the often brutal African heat, and as it

0:01:09.120 --> 0:01:13.039
<v Speaker 1>turns out, elephants can't sweat, is it possible to perspire

0:01:13.080 --> 0:01:17.400
<v Speaker 1>with sympathy? Recently, a team of researchers out of Sweden

0:01:17.600 --> 0:01:19.560
<v Speaker 1>went more than skin deep in their studies of the

0:01:19.600 --> 0:01:23.840
<v Speaker 1>pacoderm epidermis. Using both light and electron microscopes, along with

0:01:23.880 --> 0:01:27.520
<v Speaker 1>intricately detailed computer modeling, the researchers were able to determine

0:01:27.520 --> 0:01:31.520
<v Speaker 1>the cause of elephant's scaly skin. For starters, the scientists

0:01:31.560 --> 0:01:34.000
<v Speaker 1>found that the crackled appearance of elephants skin is not

0:01:34.120 --> 0:01:36.840
<v Speaker 1>a sign of aging or skin shrinkage, as is often

0:01:36.840 --> 0:01:40.200
<v Speaker 1>the case with other species. Rather, it is a purposeful

0:01:40.280 --> 0:01:44.000
<v Speaker 1>design resulting from the stress of the skin bending. These

0:01:44.160 --> 0:01:47.360
<v Speaker 1>cracks allow the skin to retain moisture and dirt, which

0:01:47.400 --> 0:01:50.280
<v Speaker 1>reduces the harmful effects of the sun and prevents harmful

0:01:50.280 --> 0:01:53.760
<v Speaker 1>swings in body temperature. The barrier also wards off some

0:01:53.840 --> 0:01:58.520
<v Speaker 1>types of pests and parasites. Elephant skin, unlike human skin,

0:01:58.680 --> 0:02:01.960
<v Speaker 1>is resistant to shedding, so the layers, particularly the super

0:02:02.000 --> 0:02:05.720
<v Speaker 1>tough top layer the stratum corneum, stick around longer before

0:02:05.760 --> 0:02:09.000
<v Speaker 1>sloughing off. It also has a lot more keratin than

0:02:09.080 --> 0:02:11.960
<v Speaker 1>human skin, so it's more durable keratin, being the stuff

0:02:11.960 --> 0:02:14.440
<v Speaker 1>that makes up fingernails and is a small presence in

0:02:14.480 --> 0:02:17.760
<v Speaker 1>our own skin. As this thick hide is subject to

0:02:17.800 --> 0:02:21.280
<v Speaker 1>everyday movement like bending and twisting, it quickly wrinkles, with

0:02:21.320 --> 0:02:24.000
<v Speaker 1>a layer upon layer of wrinkly skin, serving as a

0:02:24.000 --> 0:02:28.360
<v Speaker 1>complex system of channels the capture and hold moisture and dirt.

0:02:29.080 --> 0:02:32.520
<v Speaker 1>So when you see elephants basking in sloppy pools, spraying

0:02:32.560 --> 0:02:34.919
<v Speaker 1>water and mud to and fro, they aren't just doing

0:02:34.960 --> 0:02:38.079
<v Speaker 1>it for fun. The mud settles into the tense cracks

0:02:38.120 --> 0:02:40.640
<v Speaker 1>in their skin, some of which are just a micrometer across,

0:02:40.680 --> 0:02:43.480
<v Speaker 1>about fifty times smaller than the naked human eye can detect.

0:02:44.080 --> 0:02:48.440
<v Speaker 1>Continually wetted, the skin remains permeable, helping the animals stay cooler.

0:02:50.080 --> 0:02:53.880
<v Speaker 1>And interestingly, elephants skin doesn't just randomly wrinkle. It cracks

0:02:53.880 --> 0:02:57.079
<v Speaker 1>in geometric shapes that approximate other common sights in our world,

0:02:57.280 --> 0:03:00.600
<v Speaker 1>from drying mud to heat shattered asphalt, or even geometrically

0:03:00.639 --> 0:03:04.240
<v Speaker 1>precise rock breakage like the Giant's Causeway in Ireland. The

0:03:04.280 --> 0:03:07.680
<v Speaker 1>result is a durable cooling system that keeps these gigantic

0:03:07.720 --> 0:03:10.480
<v Speaker 1>mammals from cooking in their own thick skin on steamy

0:03:10.480 --> 0:03:14.399
<v Speaker 1>summer days. With their huge bodies and constant sun exposure,

0:03:14.560 --> 0:03:16.760
<v Speaker 1>it would be easy to assume that elephants often fall

0:03:16.840 --> 0:03:19.720
<v Speaker 1>victim to skin cancer and its side effects, but as

0:03:19.760 --> 0:03:22.680
<v Speaker 1>it turns out, cancer is relatively rare in these animals,

0:03:23.080 --> 0:03:25.519
<v Speaker 1>thanks in part to a gene called p fifty three.

0:03:25.840 --> 0:03:30.440
<v Speaker 1>Elephant body chemistry identifies DNA abnormalities, and then nix's cells

0:03:30.440 --> 0:03:33.920
<v Speaker 1>that seem doomed to tumors. Scientists start studying these so

0:03:34.080 --> 0:03:36.640
<v Speaker 1>called zombie genes to see how they might affect human

0:03:36.640 --> 0:03:44.520
<v Speaker 1>biology too. Today's episode is based on the article Scientists

0:03:44.520 --> 0:03:47.480
<v Speaker 1>figure out Why Elephant's skin is so cracked on how

0:03:47.520 --> 0:03:50.920
<v Speaker 1>stuffworks dot Com, written by Nathan Chandler. Brain Stuff is

0:03:50.960 --> 0:03:53.760
<v Speaker 1>production of iHeartRadio in partnership with how stuffworks dot Com

0:03:53.760 --> 0:03:56.680
<v Speaker 1>and is produced by Tyler Klang. For more podcasts my

0:03:56.720 --> 0:04:00.160
<v Speaker 1>Heart Radio, visit the iHeartRadio app, Apple Podcasts, or ever

0:04:00.200 --> 0:04:12.600
<v Speaker 1>you listen to your favorite shows. M