(Intro)

Michael: Hello and welcome to SciShow Quiz Show, SciShow's best Quiz Show...and its worst Quiz Show.  It's our only Quiz Show.

Trace: Oh, I was gonna ask.

M: I'm your host, Michael Aranda.  Today on the program, our two contestants will go head-to-head in a battle of brains.  On my left side, we have Hank Green, who we managed to pry away from working on his second New York Times Bestseller.  Thanks for joining us, Hank.  

Hank: Oh, I see.  Thanks for the pressure.  

M: Here hoping to hand Hank another stunning defeat is Trace Dominguez, award-winning videomaker and creator and host of Uno Dos of Trace.  Welcome, Trace.

T: Thank you.  Thanks.  Thanks.

H: I was stunningly defeated last time.  

T: Were you?

H: Yeah.  It was a come-from-behind.  

T: You might not be this time.  

H: So the show, there's not actually any questions.  We just hit our heads together.

T: Oh.  'Cause it's a battle of literally our brains?

H: Yeah.  

T: Or skulls.  

H: 'Til one of us falls over.

T: Okay, well, why do we need the table?

H: It's just to keep us apart a little bit, 'cause otherwise, it gets the whole body involved.

T: Sure.

H: And it's really just about the heads.

T: I thought it might be for the shots.  You know, you get the like, gore on the table.  

M: As a thank you to our supporters on Patreon, we've selected two of you at random to win some prizes.  Hank, you're playing for Sean Katz.

H: Hi, Sean.

M: Trace, you're playing for Akash.

T: Akash, I'm gonna do as good as I'm gonna do.  

H: He didn't even promise to try very hard.

T: I'm doing!  

M: Stefan, show our players what they could go home with today.

Stefan: Well, hello there.  Sean and Akash, are you ready to find out about the prizes today?  Well, ready or not, here they come.  Our two colorful contestants today will be competing to acquire you both some lovely prizes.  The winner of the show will receive an 'I Won SciShow Quiz Show' pin.  This fetching piece will have you feeling your best and will definitely start a lot of conversations, but the loser of the show won't have to lament.  They'll be receiving the 'I Lost SciShow Quiz Show' pin.  

This baby's in near-mint condition and was hand-pressed with love.  Now, luckily, both of you will get autographed final answer cards from the final round of today's show, and your packages will be filled to the brim with magical fairy dust that's invisible and immaterial, which really cuts down on the shipping costs, but that's enough gum-flapping from me.  Let's get on with the show!

M: Thanks, Stefan.  I'll start both of you off with 1,000 points.  Each time you choose a correct answer, you'll win some.  If you get it wrong, you'll lose some.  Since both of you have been making science videos for years, you have a lot of random science knowledge to draw upon.

T: That's true.

M: But who can put that knowledge to best use?  

T: Neither of us, that's my guess.  Do I get points?

M: Let's find out.  Today's competition might get heated, but it will always be pleasant compared to the natural world.  So the questions in this first round are all about how nature can be, as Tennyson put it, red in tooth and claw, even when you might think it wouldn't be.

T: Yikes.

H: Every death is painful.

H: Here's the first question.  Lots of species look for safety in numbers, but the more of your comrades there are around, the more you have to compete with, and scientists have found that it's actually quite easy to get some fish to go from friendly to ruthless.  By doing one simple thing, they can get most of a seemingly cooperative school of fish to single out an individual and chase them away.  What do they do to get these fish to turn on one another: pretend to be a predator searching for food, offer an especially tasy treat, take away most of the fish's food, or separate a large school into several smaller ones?  

H: I'll go first.  I'm gonna say that you have to just take away their food and they'll turn on each other.  I was wrong.

M: That's incorrect.

T: I'm gonna go, offer an especially tasty treat.

M: That is also incorrect.  

H: Yay, we're tied!

Olivia: The answer is A, pretend to be a predator searching for food.  Lonely fish are more likely to end up as meals.  That's kind of the entire point behind schooling.  

But it turns out that schooling fish aren't as "all for one and one for all" as you might think.  Schools are an example of what researchers call selfish herds, basically, everyone is part of the school because they want to maximize their own survival, not because they're altruistic and want to protect their fellow fish.  Scientists have found that it's not all that hard to push that selfishness from a passive behavior like schooling into an active behavior.  In this case, that active behavior is dooming one of their fellows by chasing them out of the school.  This is true for all kinds of fish, but in one species called two-spot astyanax, there's an added wrinkle.  The fish have an alarm pheremone in their skin that leaks out when they get injured.  This warns other fish that there's a potential danger nearby, but it also tells predators that there's an easy meal around, and amazingly, the fish seem to take advantage of this.  When scientists pretend to be a predator searching for food, the fish will intentionally injure one of their schoolmates, basically sacrificing it so that everybody else can escape.  Talk about brutal.  What's especially interesting is that the fish don't do this when scientists mimic an ambush predator or a bird pecking from above because in those cases, the alarm smell doesn't help the predator pick up their meal, so they only sacrifice their friends some of the time, which is nicer, I guess?

T: Oh, they're like, he's the weakest link.  Or she.  

H: Yes.  Get Brad!

T: Yeah.

H: Go eat Bradley!

T: Brad, noooo!   Or Bradley.

H: He's my Brad.

M: It says here in the script, "I guess that's why they say fish are cold-blooded" bah-dum-ching.  

H: Yeah.  Well, you said it.  

M: I did what the thing said.  Anyway, the next species we're gonna talk about definitely isn't cold-blooded, unless you're talking about its killing style.

H: Humans?  

M: Many mammal species that live in groups set up territories where they can raise their young and forage in peace.  Well, peace with one another, anyway. 

In one six-year study, 47 females of this species were seen killing ground squirrels in their area, but none of these animals were killed for food.  They were simply murdered, presumably so there would be less competition for resources.  Question is, to which usually harmless species do these femme fatales belong to: meerkats--?

T: Oh, sorry, I forgot it was multiple choice.  Squirrels.  I don't know.  

M: Meerkats, lemmings, prairie dogs, or naked mole rats?

T: Meerkats.  

M: That's incorrect.

H: I don't think they overlap range with ground squirrels.  

T: I have no idea.

H: I mean, it would be best if it was naked mole rats, but it can't be, right?  A female naked mole rat can't kill a ground squirrel, but neither could a lemming.  

M: Don't underestimate a naked thing.

H: Ground squirrels are big!  

T: Yes, it's got no armor on.  Maybe it's just out there.

H: Or it's eating the babies.  Were they counting babies?  I'm gonna say prairie dogs, 'cause that's the only one that could actually kill that thing.  Yeah!  

M: That's correct.

T: Oh, green!  

H: It does happen.

T: That's the first time I saw that.  That's great.

O: The answer is C, prairie dogs.  Prairie dogs might look cute and cuddly, but scientists have discovered that they're actually little murder machines, and just like animals that kill for food or to claim territory, the animals benefit from being serial killers.  This discovery was made when scientists were studying white tailed prairie dogs in Western Colorado.  A researcher happened to spot a female prairie dog tossing around the dead body of a smaller animal and was shocked to find out that it was a ground squirrel.  The more the researchers looked, the more murders they spotted.  Nearly 1/3 of all females turned out to be ground squirrel killers, but they never ate their kill.  They just left the bodies behind, so it wasn't clear why they were doing this until the researchers looked at the overall fitness of the killers and their offspring.

Turned out, being a killer paid off, as both the individual and their offspring fared about three times better over time.  In fact, the number of ground squirrels a female killed was the only variable that predicted her lifetime success.  Things like her body size or aggressiveness towards other prairie dogs didn't seem to make a difference.  The researchers think the ground squirrels compete with the prairie dogs for food, so killing the squirrels results in more resources for the mama dogs to use raising their young.

M: Okay, that's the end of round one.  Let's see how our contestants are doing.  Looks like Hank's in the lead.

H: Yeah.

T: I'm not doing great.

M: Yellow can be mellow, but the questions in this next round are about yellow things that give species a survival boost.

H: Okay.

M: Take the yellow patches on oriental hornets, for example.  These predatory insects live in colonies much like the bees they often hunt.  They don't always eat other insects, mind you.  They sometimes scavenge, and they'll even drink nectar, but what's special about oriental hornets is that they have these giant yellow patches on their abdomens which scientists think do something really important.  

H: Okay.

M: What do they do?  Store pollen, capture solar energy, camouflage them, or store honey?

H: Oh, okay, Trace is brave.

T: Camouflage.  

H: Camouflage.

M: Incorrect.  

H: That's what I would have gone with.

T: Dang it.  

H: You should have let me go first.

T: Well.  I'm sorry.  I wanted some points.  

H: I--it's gotta be store pollen.  None of the other things make sense.

M: That is also incorrect.

H: It's wrong.  It's not solar...

O: The answer is B, capture solar energy.  Like other ground-dwelling social wasps, oriental hornets dig their burrows during the day, but while other wasps do their manual labor in the cool, morning hours, these insects work during the hottest hours.  That perplexed scientists for a long time, especially because part of the digging process involves grabbing the dirt and flying it away from their nests for disposal, and that would expose the animal to the full heat of the bright, noon-day sun.  That heat could dry them out or essentially give them a fever.

After all, there has to be a reason the other wasps seem to avoid it.  But slowly, scientists realized that the wasps seemed to be getting an energy burst from the Sun.  All the clues came together when researchers took a close look at the hornet's outer covering or cuticle.  They found that the proteins in the cuticle were structured to trap light and to get as much of it into the yellow pigment of the wasp's bright butts as possible.  That suggests this could be a mechanism for solar power, but there's more research needed because scientists haven't yet connected exactly how their solar panels translate light energy into an energetic boost.  They don't seem to have the machinery for photosynthesis like plants, so exactly how or if they really translate light into fuel remains a mystery.

M: You might be familiar with mites as animal pests, but plants have their own mites to deal with it.  Spider mites, for example, can be obnoxious garden pests.  Thankfully, (?~10:56) mites also exist.  They're hunters that dine on things like spider mites, except sometimes they eat pollen instead and research from September 2018 may have explained why.  What benefit do these predatory mites get from snacking on this yellow plant material?

H: Well, it's tasty.

M: Pollen odors which act as olfactory camouflage, yellow pigmentation which help the mites blend in visually--

T: Nice.

M: Antifungal compounds to fight against insect killing fungi--

H: I don't see why not.

M: Or protection from UV rays so they can hunt better in bright light?

T: Mite SPF.

H: So they can go to the beach.

T: Yeah.

H: I'm gonna go first and I'm gonna say it's that first  one.  I don't remember what it was, but it seemed the most--it was wrong.  What was it?  

M: Pollen odors which act as olfactory camouflage.

H: Yeah, that seemed right to me!

T: That did seem nice.  I liked that one.  I'm gonna go camouflage again.  It worked so well last time.

M: That's also incorrect.

T: Dang it.  

(?~11:58) Hank is having a good time over there.

O: The answer is D, protection from UV rays.

We're not the only species that can overdose on UV.  Phytoseiid mites also feel the mutagenic effects of solar radiation, so they have to be careful about their sun exposure.  That's why the tops of leaves tend to have fewer of these critters.  The problem is, their prey, spider mites, are less vulnerable to UV damage.  They produce some antioxidants on their own and tend to get them from their plant-based diet.  So they usually get to hang out on the exposed leaf surface without worrying about these predatory mites.  That is, unless the phytoseiid mites have been snacking on pollen.  A 2018 study found that predatory mites that were fed pollen were able to hold on to some the pollen's UVB foiling antioxidants.  They were able to survive longer in bright UV light conditions and even had more UV resilient eggs, which would suggest they could pass their hardiness onto their offspring.  That was especially interesting to the researchers, as it suggests a way to boost the overall health of mites reared in captivity.  Some scientists even think we could use these predatory mites to control other mite species, which can be agricultural pests.

H: It's very important.  You've--the sun is a deadly laser.  

T: There is only one true carcinogen.  The sun.  

H: Also being alive.

T: Yeah, true, yeah.  Just over time.  

M: While seven spot ladybirds or ladybugs, to Americans, are red and black as adults.  Their eggs are vibrant shades of yellow to orange.  They stick out like a sore thumb pretty much anywhere the beetles lay them, but that's not the only reason they're neat.  These are the only insect eggs scientists have seen that demonstrate this well-known coloration phenomenon.  Crypsis, because it helps them stay hidden from predators, disruptive camouflage, because it breaks up the egg-shape visually, aposematic coloration, because it signals toxicity, or batesian mimicry, because it looks like something more dangerous?

H: Okay, I'm going to go with aposematic--

T: That's what I was gonna--

H: Thingy.  Heeey!  

M: That's correct.

T: I guess.  High five.  Good job.  One of us got something right.

H: Yeah, yeah, yeah.

O: The answer is C, aposematic coloration.  Lots of brightly colored things are presumed to be toxic and it's just generally assumed they use these colors to warn those that might think they're edible, but these assumptions aren't often tested to see if they're true.  The brightly colored eggs of seven spot ladybird beetles are an exception.  Their bright yellow to orange colors make them stand out against the leaves and bark that they're laid on, but that's not a problem, because like the adult beetles that lay them, these eggs are packed with toxic alkaloids.  The toxins aren't responsible for the yellow hue of the eggs, though.  That comes from carotenoids, yellowy and reddish pigments, and not every egg is the same hue either.  They can range in color from sort of a pale yellow to a bright orange, and scientists have shown that color indicates just how toxic they are.  The more well-fed the adult beetles are, the more toxins and colors they can equip their offspring with, so the bright color serves as an honest signal telling potential predators to find another snack.

M: Okay, that's the end of round two, which means it's now time to place your best on your answer to the final question.  

H: What's the category?

M: You can bet any or all of your points.  

H: Can't bet more than you.

M: But not more.

H: Which I also found out.  

T: Aw man.  I can't go negative?  Okay.  

H: Yeah.

T: One billion points.

M: This next question is on the subject of going green.  In the meantime, all of you at home can enjoy this ad from our sponsor.  Welcome back.  It all comes down to this, the final question.  The color green is practically synonymous with living things, but it turns out that it isn't easy to be green unless you're a plant.  You see, chlorophylls are the main biological green pigments in the world, but most animals can't produce them.  Still, you see green in all sorts of creatures, from lizards to birds to beetles.  Some insect species like hawk moths and their relatives in the family (?~16:01) have several green stages in life, including green eggs and green caterpillars, but--

H: No green ham.

T: I was gonna say, where's the ham in this meal?

M: But how do these bugs go green?  They use structural color, they mix yellow and blue pigments, they steal chlorophylls from plants, they actually make a green pigment?  

H: Oh, you just write it down on your card.  You don't need to do that for this.

T: Sorry.

H: (?~16:33)

M: (?~16:35)

H: I'm gonna say it right now.  I don't know the answer to this question.

T: I'm gonna guess.

H: But I feel like I have a 50/50 chance.  

T: I'm guessing what I think it is, but I don't have a chance on any of them.

M: Alright, you guys ready?  

H: You've got a one in four chance at least.

T: Well, that's true.

M: Reveal your answers.  You're both incorrect.

H: Ohh, we both put the same thing, though.

T: Yeah, we did.

H: I still win.

T: You still do win.  

O: The answer is B, they mix yellow and blue pigments.  You may have heard that blue pigments are rare in animals, but they're actually used all the time by green insects.  Insecticyanins are a class of blue pigment proteins that, as the name implies, are made by insects, and they're what helps turn things like moth eggs and caterpillars green.  The eggs get their insecticyanins from their parent, but hawk moth and horn worm caterpillars synthesize the stuff in their epidermis.  Then, they either store it in special compartments or secrete it into their hemolymph, basically their version of blood.  Ultimately, that blue pigment combines with yellow carotinoids from the insects' diet or their parents to make them green, just like a first grader in art class.  Those carotenoids are especially important, too.  If you raise these moth larvae in laboratory conditions with carotenoid-free food, they never turn green.  They'll remain a vibrant blue until they become usually blander colored adults, and intriguingly, those adults don't actually produce the stuff they pass on to their young.  All the insectocyanin in their hemolymph was made when they were caterpillars.

H: Oh, that's seemed so boring!

T: Oh, come on.  

H: That was definitely not on my list of things it might be.

T: I protest.  That was not in mine either.  I'm like, they're not fingerpainting out there, come on.

M: Your protest has been logged.

T: Thank you.

H: Good job.  

T: I have zero points.

M: Hank won.  Okay, that's--I can math.  800 points.

H: I can still win!  It's possible.  

T: I got zero though, which is a nice round number.

H: Yeah, yeah.  

T: Or oval shaped, depending.

H: It's kind of a number.  It's kind of not a number.  

T: True.

H: Sean.  I'm glad that I could support you in your winning endeavors.  

T: Akash, I am sorry.  I did.  

M: You--you did.  

T: I did.

H: You did.

T: That is the best I could have--that is what I promised, so I hope that you're doing well.

M: I hope you're having a real nice day.  That's the end of our show!  If you want to see more of Trace, be sure to check out Uno Dose of Trace, which you can find over at youtube.com/tracedominguez.  And if you want to see more of Hank, well, he's here on SciShow all the time, so be sure to click that subscribe button.

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