SGU Episode 583

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SGU Episode 583
September 10th 2016
(brief caption for the episode icon)
SGU 582                      SGU 584
Skeptical Rogues
S: Steven Novella
B: Bob Novella
C: Cara Santa Maria
J: Jay Novella
E: Evan Bernstein
Guest
BB: Brian Brushwood
Quote of the Week
Good grief. If we can’t laugh at ourselves, and at one another, in good spirit and without malice, then what fun can there be? If we must withhold all ribbing in the name of protecting everyone’s feelings, then we truly are a toothless society.
George Takei
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Show Notes
Forum Discussion

Introduction

You're listening to the Skeptics' Guide to the Universe, your escape to reality.

News Items

Lightning Reindeer Death (7:00)

• http://news.nationalgeographic.com/2016/08/norway-reindeer-lightning-weather/

Space Train (16:16)

• http://www.sciencealert.com/meet-solar-express-the-space-train-concept-that-can-get-to-mars-in-two-days

Evolving Tasmanian Devils (25:52)

• http://phys.org/news/2016-08-tasmanian-devils-evolve-resist-deadly.html

(Commercial at 32:23)

Juno at Jupiter (36:43)

• http://www.nasa.gov/feature/jpl/jupiter-s-north-pole-unlike-anything-encountered-in-solar-system

Finding Galactic Missing Matter (38:25)

• http://news.harvard.edu/gazette/story/2016/08/milky-way-had-blowout-bash-6-million-years-ago/

What's the Word (47:01)

• Thanatosis

S: All right, Cara, I believe it's time for What's the Word.

C: All right! Well, the word this week is thanatosis. Anybody in the audience, you guys know it already? Any ecologists. (Audience member shouts) Zoologists. Yeah, we got a few there!

S: I think I saw somebody in there with a Thanatosis costume.

C: Yeah, yeah. Thanatotic ... Um, so this was sent in by a listener, Ben K, from Hyattsville, Maryland. The definition of thanatosis is, “The cessation of all voluntary activity, an assumption of a posture of apparent death.” So, you'll also hear it known as, playing dead, feigning death, apparent death, tonic immobility, or playing possum. That's where that phrase comes from.

So, thanatosis occurs in a lot of reptile and insect species, especially beetles. Beetles are apparently really epic at this. Some amphibians and even mammals, like the possum. Thanatosis is actually a Greek root meaning “death.” And some linguists argue that the more appropriate term would actually be thanatopsis, because the suffix “opsis” actually refers to sight. So, death sight, or this looking dead, seems to be a more appropriate term. But we actually do say thanatosis.

And in fact, thanatopsis is the name of a famous poem by William Colin Bryant. He wrote it in 1811. When I was digging about thanatosis, I started reading about early descriptions of it, before the term was actually used. In the 1600's, this behavior was actually described in the literature as animal hypnosis, because handlers would encounter when they would pick up an animal, or otherwise get in the animal's way, that they would feign death. And they thought that they were hypnotizing them.

So, you'll see that term used in a lot of older citations, and then thanatosis became the more scientific term for it.

S: Have you ever seen a possum playing dead?

B: No

C: I've seen a possum gape, which is what they do immediately before they play dead, and they're hideous. Possums can be so cute and so hideous.

J: That's because, see, look at the picture. This guy has a possum friend, and he's like, “So how's this?” And he plays dead. And the other guy goes, “No, no, no, no. Open your hand a little. Okay, good. No, we could do better. All right, open your mouth too. All right, you got it. Perfect.”

S: So, I've seen two possums with apparent state. The one was at my mother-in-law's house. They have dogs. I think the dogs scared them.

J: Steve, wait. Don't confuse that possum playing dead for your mother-in-law.

(Audience groans)

J: Thanks Joc. It was her mom that was talking.

C: Angry wife on hand.

S: Okay, so possum, they look freakin' dead. They're good.

C: Yeah, they are.

S: The curled lip sold it. Really, I was impressed. I was like, “Are you sure that thing's not actually dead? 'Cause I think the dog killed the thing.” So we kept an eye on it, and it got up and ran away after, whatever, an hour of being left alone. So then, couple years later, my wife again comes in. “Oh, our dog must have killed a possum. He's laying dead in the middle of the driveway. Would you get rid of it?” I'm like, “Okay, I've been there before, right?” So I go out, and there's a possum playing dead in the drive way.

J: This possum literally threw his intestines out on the driveway before Steve.

S: So, it turns out that it was actually dead.

B: How long did you wait before you conclude that?

S: So, literally, I waited a couple of hours. I went out, like, “Shit, that thing is still in the middle of the driveway. I guess it's”

E: Its eyes are starting to get out (Inaudible)

S: Right

C: But I do think that's a good course of action. You know, if there's an insect in your house, a spider, a beetle, something like that; or you are handling it, and then it fell on the floor, and it looked like you killed it. Don't flush it down the toilet. It might still be alive. Just set it outside, let nature take its course, or let it fly away.

I think it's funny, because possums are really good at playing dead, right? They look dead. You know who's kind of crap at it, are snakes. Have you ever seen a snake play dead? Aw, look at that – they don't play dead!

J: He's so fakin' it.

C: They just turn upside-down, and they're like, “I think that's enough.”

(Audience laughs)

C: That's good enough, right?

BB: So, my question is, when you encounter the possums playing dead, when do they give up the act? How much do, you're juggling them around, and finally, it's like, “All right, that's enough.”

C: No, no, no. You have to leave it alone. It's not about, the more you interrogate it, the more it will stay.

BB: So if you're holding it, he'll just keep up the act

C: Yes

BB: playing dead?

B: Yep, yep

BB: Flopping him all around? And we talk about this like it's a voluntary ... this is actually, for most animals, kind of a reaction. It's an involuntary action.

B: Does it mimic rigor after a little while?

C: They look like they're in rigor.

S: They look dead, yeah.

C: But snakes don't. Snakes just look like they're playing. (Audience laughs) He's adorable, right? Yeah. Aw.

J: Is that a frog?

S: That's a frog.

C: So, like I said, some animals are better than others. Some just kind of flop onto their backs. And there's different reasons that scientists say that thanatosis occurs. Sometimes it's, we think of it as being a defence mechanism. Like, if I play dead, the predator's not gonna want to eat me, because if I'm already dead, and they're not scavengers, it's gonna be less appealing to them.

But there are also examples of thanatosis for mating purposes, like it's a way to say (audience laughs) “It's okay.” Like, “I'm giving you permission.”

S: So, we're going to do science or fiction.

(Applause)

S: Everybody's favorite segment

(Commercial at 52:37)

Science or Fiction ()

• Item #1: Researchers find that 30% of college students flush their unused prescription medication down the drain.
• Item #2: A new study finds that simply wearing glasses reduced facial recognition by people to a statistically significant degree.
• Item #3: For the first time engineers have created carbon nanotube transistors that outperform state-of-the-art silicon transistors.

Skeptical Quote of the Week (1:01:45)

Good grief. If we can’t laugh at ourselves, and at one another, in good spirit and without malice, then what fun can there be? If we must withhold all ribbing in the name of protecting everyone’s feelings, then we truly are a toothless society.

- George Takei

S: The Skeptics' Guide to the Universe is produced by SGU Productions, dedicated to promoting science and critical thinking. For more information on this and other episodes, please visit our website at theskepticsguide.org, where you will find the show notes as well as links to our blogs, videos, online forum, and other content. You can send us feedback or questions to info@theskepticsguide.org. Also, please consider supporting the SGU by visiting the store page on our website, where you will find merchandise, premium content, and subscription information. Our listeners are what make SGU possible.

References