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Hi everybody. I am a comparative anatomist,
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and a comparative anatomist is someone who studies
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the structure of the body of lots of different animals.
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And my favorite animals are whales,
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and I like to study whales because they are so interesting.
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They've adapted to a unique environment
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of living in the water.
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And what I'm going to tell you about is
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how whales make sounds by
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basically farting with their face.
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Now, you know that they do this farting thing
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with their blowhole; they blow out air like that,
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but they also use air in lots of other ways.
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They use it for sound production,
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which is what I'm going to focus on,
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but I also study other things they do with air,
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like how they keep it out of their blood streams
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so that they don't get bubbles,
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which is what happens to human scuba divers
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when they dive and they get decompression sickness.
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But what I'd like to do is start with the story
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of how these animals make these farting noises,
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and that story begins with understanding
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how hard it is to look at whales
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because they live underwater and they're really big,
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so they're hard animals to study.
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And just in this picture, you see that animal in the middle?
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That's a baby whale and it's already the size of a bus.
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When you look at whales, you have to start
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with the top of their head, because their nose
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is on the top of their head.
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It's kind of like a built-in snorkel.
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And they breathe through that because they're mammals
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and mammals breathe air.
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And their nose can actually be opened and closed,
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kind of as if you were to pinch it like this,
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so you can see, it's open in the bottom frame there
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where the red arrows are.
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But not all whales have two nostrils.
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Whales includes the groups of dolphins and porpoises,
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and the dolphins and porpoises, the small whales,
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have only one nostril on the top of their head,
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and they open and close that nostril
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by taking what is essentially an upper lip, like this,
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and turning it back over their nose, like this.
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That's how they open and close their nose.
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So when they make sounds,
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what they're basically doing is a raspberry,
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like [mouth noises], which is kind of like a fart, right?
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Or up in New York we call it a Bronx cheer.
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And the way they do that is by taking
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that big fatty structure of a big fat lip,
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which is, as you can see here in this picture,
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which is a cut through the middle of a dolphins head,
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that big fat lip is that big yellow portion there,
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and they roll it back and forth over the top of their nose
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so that they vibrate it,
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kind of like when you let the air out of a balloon
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and it makes that weird vibration sound.
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So this is what it sounds like when they make their noise:
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[dolphin noise]
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You hear that? It's going to do it again
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when he faces the camera.
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[dolphin noise]
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Sounds like its farting underwater.
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What that dolphin is actually doing though
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is echolocation, which is making these series of pulses,
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and it uses it like a bat uses sonar.
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Well a bat uses radar, but when it's underwater
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it's sonar, so this animal is using sonar
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to see its world in sound.
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Trying to understand how this works,
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you have to look at it as if you were looking
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at the amplifier speakers of a sound system.
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The small toothed whales are basically the "tweeters,"
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and the sound is coming from that little
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nose that's moving back and forth
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and coming out of their forehead.
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But when you look at the big whales,
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they're kind of link the "woofer,"
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the big speakers that you have in an amplifier system.
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And what's happening is their sound's coming out of the throat.
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So if you tried to make sound like a whale,
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you just make a sound right now,
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like go "ah."
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Okay, now put your hand on your throat,
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on your Adam's apple, you feel that vibration right there?
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That is lost energy for you
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because that's not how you're communicating to everybody.
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You're doing it out of the mouth.
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But if you open your mouth underwater,
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no one is going to hear you.
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You have to be able to take this energy and amplify it through the water,
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and that's what whales do.
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And when you hear their sound,
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[whale sounds]
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Hear that? It's kind of like when you squeak the air out of a balloon.
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So they get a lot of squeaky noises,
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but they also have this sound:
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[whale noises]
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It sounds like it's farting, doesn't it?
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It's like it's got this giant whoopie cushion in its throat.
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So, how do you know that's what a whale's doing?
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Well, we study whales that come to us from strandings.
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These are animals that die on the beach.
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Now the small whales, like dolphins and porpoises are easy,
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we can take them back to the lab.
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But the big whales, we've got to bring the lab to the whale.
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And this is what that would look like.
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So I'm the one in the middle with the red hat.
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I'm not a very tall person,
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so you can see how big this whale is compared to me.
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The whale is 65 feet long, and my scalpel
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is this little tool on the side here.
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It basically looks like a hockey stick
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with a blade on the end of it.
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And doing a dissection of a whale is a very difficult process.
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You literally have to get into your work.
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It's kind of like a giant bloody construction zone.
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You're wearing a hard hat,
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you're working with heavy machinery.
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In this case, by the way,
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that's just the voice box of a blue whale; just the voice box.
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And I'm only five feet tall, so you can see,
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it's already like twelve feet long there.
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How do we know what's going on?
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Well, we look at the voice box, or larynx,
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and we see inside.
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This is from a baby whale so it's much smaller.
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You see this little "u" shaped thing
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that I've outlined in blue;
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that's the part that's vibrating.
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That's kind of like our vocal folds.
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And when I put my hand in there,
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that's where that blue sleeve is,
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you can see there's a sack underneath it.
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That's the whoopie cushion.
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That's the air bubble or the balloon.
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So what these animals are doing,
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and you can see in this picture,
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there's this big black balloon in the throat,
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where the digestive track, which is in blue,
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meets the breathing track, which is in light blue,
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so you have light blue and dark blue,
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and right in the middle is that black sack.
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These animals are using that sack to make these sounds.
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And so they vibrate that and send it out.
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Small toothed whales also have air sacks,
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and they're all over their heads,
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so it's kind of like they're airheads.
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And they use this to capture as much air as they can,
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to take it down with them when they're diving,
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because when you dive, pressures increase,
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and that decreases the volume of air you have available.
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But more importantly, having that sack allows them to
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recycle the air that they're using
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because air is a precious commodity.
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You don't want to have to go back up to the surface
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to get more air.
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So when you make a sound underwater,
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if you're a whale,
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let's here you start making a sound.
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Go "ah."
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But whales keep their mouths closed, so go
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[mouth noises]
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You're all humming, right?
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But whales keep their nose closed, so go
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[mouth noises]
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What happened? You can't make the sound anymore
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once you close your nose because you've pressurized the system.
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So whales by having air sacks
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keep themselves from pressurizing the system
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which means the air continues to flow,
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and so if you had a bag on the end of your nose,
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you'd be able to make air continue to flow.
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So I hope you've enjoyed that.
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That's what a comparative anatomist does for their living.
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We study the structure of these animals.
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We try to mimic it.
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We apply it back to the human situation,
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maybe making new technologies for protective devices,
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or maybe even making new treatments for medicines
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for peoples' diseases who mimic these weird environments.
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So I hope you enjoyed that. Thank you.
Krystian Aparta
The English transcript was updated on 3/3/2016.