(Intro plays)

Emily Graslie: Hey everybody! Let's welcome Destin from Smarter Every Day! We have a new, uh, game show that we're doing here on The Brain Scoop called What The Function.

Destin Sandlin: Okay.

EG: There's surprises, Vanna White comes out...

DS: Really?

EG: No, not at all. You don't want...You don't win anything.

DS: Okay. Just a bunch of dead stuff.

EG: Just dead stuff. I picked these things, keeping your background as an engineer in mind...

DS: Okay.

EG: ...because I figured you could use your prior knowledge to help puzzle out what these things are.

DS: But I'm going to look really dumb, aren't I?

EG: Probably.

DS: (Laugh) Let's do it!

EG: Yeah!

DS: Why are they rounded?

EG: That's part of the What the Function question.

DS: What the function is this?

EG: Don't touch the, uh, frilly bits.

DS: The whiskery frilly bits. These are obviously gills.

EG: Okay.

DS: Okay...this is a fish.

EG: Yes.

DS: Because all freaky things that I've learned are parts of fishes.

EG: Yup.

DS: Are these teeth?

EG: Yes!

DS: Okay, these are teeth. So gills, teeth. So...no! This is...the mouth is up here... 

EG: Hmm!

DS: ...the mouth is up here and this is behind the mouth.

EG: Exactly.

DS: Got it, and so...

EG: Which would put the teeth..?

DS: Back in the esophagus...?

EG: Yeah!

DS: That's right?

ES: In the throat!

DS: It's made to grind up hard things.

EG: (Claps) Ding ding ding ding ding!

DS: You're welcome.

EG: You got it!

DS: Okay, what is the animal and what does it grind up?

EG: This is from a black drum fish. A saltwater drum fish. And this is called a pharyngeal palate. So these are teeth and I'll...

DS: Do all fish have these?

EG: No! Not all fish. Some higher order fish do, which means like...more...uh, more evolved fishes have them. That's the bottom part, and this is the top part. Why they have a palate that's this big and this dense with this many teeth is that these fish eat really densely shelled crustaceans. And they have to have some way to chew those up.

DS: Crush 'em.

EG: To crush 'em. So they have this part of the palate, which is a little more flexible. So this goes on top. It'll create that negative pressure...that vaccuum to suck up the mollusk, and then crush it in its throat, (sound effects) expell all of the shelled bits out the side, and then continue consuming the animal.

We're with Anna Goldman, assistant collections manager of mammals here at the Field Museum, and she brought us some stuff to challenge Destin and see if he can figure out what it is.

DS: Bring it, Anna.

EG: Yeah.

Anna Goldman: I got it.

DS: Let's see some mammals.

EG: Yeah.

DS: Can I touch it?

AG: Yeah. But you've gotta be careful. Very careful. There we go.

EG: Yeah, there we go.

DS: That's amazing.

AG: What is it? And then what are these things right under here?

DS: Okay. So this is what's confusing me. So you've got the feet up front, and then you've got this long thumb, but it's where your pinky would be.

AG: Mhm.

DS: And then you've got the skin attached to it...

Ag: Mhm

DS: ...so I'm going to say that this thing has the word gliding in its name.

EG: Yeah.

DS: And...uhm...

EG: Bingo.

DS: Gliding gopher. That's what it is.

EG: No. It's a type of flying squirrel.

DS: Well yeah, okay.

AG: Squirrel.

DS: Flying...gliding squirrel.

AG: Mhm.

DS: Okay.

AG: So what are these? And so, like, you can brush your fingers down that way and then try and go back up.

DS: Right.

EG: It's got these little barbs on the underside of its tail, kind of near its anus.

DS: Wait, wait, wait, time out!

AG: Okay, go.

DS: I got it. It's like... it's like what a, uh, a... lineman uses when he's climbing a telephone pole. So he goes up, or like hunters with deer stands, they have these check valves, like a mechanical check valve that can go up the tree, and then, when they press down, it engages into the tree and keeps them in position. So if this guy has to...if he glides, he has to climb, so as he's climbing he can glide and then he can like stick his tail into it, and then he can push off with his tail as he's climbing up. It's a mechanical check valve...uh, thing.

AG: Does that count?

EG: Well...

DS: It's right. I mean, if you guys...

EG: That's an interesting assessment.

AG: Oh that's right?

DS: That's the correct answer.

EG: Zoologist Destin over here.

AG: Yeah, hello.

DS: What is it called?

AG: These are scutes. And they say that it can help them climb trees, so yeah...

DS: Yeah? Yeah.

AG: But it also helps them stop when they're gliding, and to land on a tree. It goes (screeching tire noise) like your little brakes.

EG: It's a brake.

AG: On a...on your...

DS: How does it help it...

AG: On your roller blades.

DS: How does it help it stop when it's gliding?

EG: Well, not when it's gliding but when it...

AG: Lands.

EG: When it lands. 

DS: Oh!

EG: So when it's coming at a tree, it's coming down and then it's gotta loop its legs under...

DS: It's like the hook under a fighter jet for an aircraft carrier.

EG: Mhm, and then it goes (swooping noise)

DS: All I know are springs and hydraulics.

EG: Yeah!

DS: Got it.

AG: Most flying squirrels have this piece of cartiledge coming out from their wrist, and those are true flying squirrels, but these guys have it coming out of their elbow. So, they actually have free hands and mostly when you see the the flying squirrels, they kind of look like they're all just like a, uh, complete half circle...

EG: Yeah.

AG: ...from their foot. And so this actually look like they're superheroes. They're just...they're like...the greatest.

DS: They have a cape. I actually did a study on bats one time, and this piece of skin right here...

AG: Mhm.

DS: ...some bats have it, some bats don't.

EG: Yeah.

DG: Right. And that's for like...

AG: Yeah.

DG: ...when you're gliding in, you can make...you make adjustments.

EG: Yeah.

AG: They also...their tails can act like rudders as well.

DS: Right.

EG: They can flatten them out sometimes.

AG: Yeah.

EG: Some gliding squirrels have more fur at the bottom to kind of act like a little rudder... steerring rudder.

AG: Yeah.

DS: And where do these things live? 

AG: Central Africa, Angola, Tanzania, Kenya.

DS: Nice.

AG: Derbianus. That's my guy! 

(All laugh)

EG: I love this little white top on his head. 

AG: I know! He's so cute! There's so much color in here.

EG: Yeah.

AG: And they look like feathers. 

EG: Yeah.

AG: It's really spectacular.

EG: It's beautiful.

(AG kisses squirrel, all laugh)

EG: Awww!

DS: Boop! 

(All laugh)

(Music plays)

EG: And don't read the label, cause that will give it away.

Offset: Don't read the label. 

DS: It appears to be a plant - 

EG: Yes!  

DS: These appear to be...needles with holes in them which leads me to believe that there's liquid in here that gets injected into animals. Maybe seeds?

EG: Nope. Nope, not really. 

DS: Is this a carniverous plant?

EG: No, it's not.

DS: Oh! When animals eat the... the tree like leaves, then they get stuck with that?

EG: You're getting a little bit closer.

DS: It's a giraffe...

EG: It is a giraffe-proof tree.

DS: Yes.

EG: I'll give that to you.

DS: Yes. Uhm.

EG: Which means that you find these in..?

DS: Africa?

EG: Good.

DS: Okay... and... I have no idea, Emily, I really don't.

EG: Really?

DS: I want to know if there's poison that comes out of these things. Bacteria?

EG: No. Getting closer.

DS: Is it a symbiotic relationship with something else?

EG: Yeah it does!

DS: Okay! So parasites live in there. When animals bite these leaves, the parasites go onto a new host. I don't know.

EG: Yeah, that's pretty close.

DS: I have no idea what I'm talking about.

EG: This is from an acacia tree, and all acacias...

DS: I've seen the wood.

EG: Yeah!

DS: Okay!

EG: Yup! All acacias have these big thorns, but the thorns actually are homes for stinging ants.

DS: Shut up.

EG: Yeah! So whenever a giraffe or another animal comes by and starts eating the leaves of the acacia, ants come streaming out of these holes, and they sting the crap out of whatever's trying to eat the acacia.

DS: That's just mean.

EG: Yeah! But in turn...

DS: But cool.

EG: Yeah! It's really cool! The symbiotic relationship means that for the stinging ants helping to protect the acacia tree, these thorns help... they, uh, secrete a, like... nutrients through nectars so the ants can live off of what's growing inside of the thorns and then... they'll protect the tree.

DS: That is cool!

EG: It's a win-win for both.

DS: Thank you for teaching me that.

EG: Yeah...

DS: I feel smarter today.

EG: Good! We get smarter every day.

DS: Every single day.

EG: Every day.

(Outro Plays)