BrainStuff Classics: Why Is Elephants' Skin So Wrinkly?

Elephants have a thick hide that's wrinkled from birth, but why? Learn about the research that's revealed the secrets to elephant skin in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/mammals/scientists-figure-out-why-elephants-skin-so-cracked.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,
Lauren Vogel bomb here with a classic from our archives.
In this one, we delve into the deep wrinkles an
elephant's skin. It turns out though it's wrinkles have a
number of really useful purposes. Hey brain Stuff, Laurin vocal

(00:24):
bomb here. Unlike most newborn creatures, elephants look geriatric right
out of the womb, thanks in large part to their
loose fitting, wrinkly skin. But elephants aren't manipulating the system
to collect social security early. Their cracked skin is a
clever evolutionary adaptation that protects these animals from the sun's
intense rays. African bush elephants are pacoderms, a group of

(00:46):
large animals like hippos and rhinoceroses. The name pacoderms is
based on a Greek word that means having thick skin.
These enormous, warm blooded animals can weigh around eleven tons
that's about ten metric tons and measure up to about
thirteen feet tall at the shoulder that's about four meters.
In short, it's a lot of flesh and bone, all
baking in the often brutal African heat, and as it

(01:09):
turns out, elephants can't sweat, is it possible to perspire
with sympathy? Recently, a team of researchers out of Sweden
went more than skin deep in their studies of the
pacoderm epidermis. Using both light and electron microscopes, along with
intricately detailed computer modeling, the researchers were able to determine
the cause of elephant's scaly skin. For starters, the scientists

(01:31):
found that the crackled appearance of elephants skin is not
a sign of aging or skin shrinkage, as is often
the case with other species. Rather, it is a purposeful
design resulting from the stress of the skin bending. These
cracks allow the skin to retain moisture and dirt, which
reduces the harmful effects of the sun and prevents harmful
swings in body temperature. The barrier also wards off some

(01:53):
types of pests and parasites. Elephant skin, unlike human skin,
is resistant to shedding, so the layers, particularly the super
tough top layer the stratum corneum, stick around longer before
sloughing off. It also has a lot more keratin than
human skin, so it's more durable keratin, being the stuff
that makes up fingernails and is a small presence in

(02:14):
our own skin. As this thick hide is subject to
everyday movement like bending and twisting, it quickly wrinkles, with
a layer upon layer of wrinkly skin, serving as a
complex system of channels the capture and hold moisture and dirt.
So when you see elephants basking in sloppy pools, spraying
water and mud to and fro, they aren't just doing

(02:34):
it for fun. The mud settles into the tense cracks
in their skin, some of which are just a micrometer across,
about fifty times smaller than the naked human eye can detect.
Continually wetted, the skin remains permeable, helping the animals stay cooler.
And interestingly, elephants skin doesn't just randomly wrinkle. It cracks
in geometric shapes that approximate other common sights in our world,

(02:57):
from drying mud to heat shattered asphalt, or even geometrically
precise rock breakage like the Giant's Causeway in Ireland. The
result is a durable cooling system that keeps these gigantic
mammals from cooking in their own thick skin on steamy
summer days. With their huge bodies and constant sun exposure,
it would be easy to assume that elephants often fall
victim to skin cancer and its side effects, but as

(03:19):
it turns out, cancer is relatively rare in these animals,
thanks in part to a gene called p fifty three.
Elephant body chemistry identifies DNA abnormalities, and then nix's cells
that seem doomed to tumors. Scientists start studying these so
called zombie genes to see how they might affect human
biology too. Today's episode is based on the article Scientists

(03:44):
figure out Why Elephant's skin is so cracked on how
stuffworks dot Com, written by Nathan Chandler. Brain Stuff is
production of iHeartRadio in partnership with how stuffworks dot Com
and is produced by Tyler Klang. For more podcasts my
Heart Radio, visit the iHeartRadio app, Apple Podcasts, or ever
you listen to your favorite shows. M