SGU Episode 355
Introduction
You're listening to the Skeptics' Guide to the Universe, your escape to reality.
This Day in Skepticism ( )
May 5, 1961 Alan Shepard becomes the first American in space. SGU 7 Year Anniversary
News Items
Capturing Rogue Planets ()
http://phys.org/news/2012-04-stars-capture-rogue-planets.html
Machine Monkey Interface ()
http://www.sciencedaily.com/releases/2012/04/120419104629.htm
Finding ET with Robots ()
http://www.sciencedaily.com/releases/2012/04/120418162300.htm
God Spot in the Brain ()
http://www.huffingtonpost.com/2012/04/20/god-spot-in-brain-is-not-_n_1440518.html
Special Report
SETI Update
with SETI senior astronomer Seth Shostak
Who's That Noisy? ( )
Audience Q&A ( )
The Coming Singularity
Question #1 - Singularity Should we, and how can we, hasten the coming the singularity?
Interview with ... ( )
Science or Fiction (58:16)
S: All right then, well let's move on to Science or Fiction.
Iszi Lawrence: It's time for Science or Fiction.
S: Each week, I come up with three science news items or facts
R: But not this week!
S: But not this week because Rebecca, you're going to take over.
R: That's right.
B: Is this your first one?
R: No I've done it before.
E: She's done it before.
S: No, she's done a couple. She's done a couple before.
E: We've each done it before.
R: Yeah, this was a terrible decision on my part.
B: Wasn't it? It's harder than it looks, isn't it?
E: A lot of work.
R: Especially when you're prepping for a live show and a trip.
S: You saying I make it look easy?
B: Er, no.
R: No the reason why I was really inspired to take this on though is because two weeks ago in podcasting time, Steve did a Science or Fiction that, he likes to do themes, and usually when he does a theme, he specifically picks a theme that I hate and know nothing about. So, that one was I believe carbon nanotubes.
B: Nanotubes.
S: Carbon nanotubes.
R: I could not care less about it. I care, no I care, I care. I just don't... they do everything OK I get it, they're magic.
B: You're disinterested in nanotubes?
R: Right, yes I'm completely disin... no.
E: Disinterested.
R: So I wanted to get back at Steve, basically.
S: Right.
R: So today's science or fiction, there is a theme. And the theme...
B: Is unicorns!
R: Close.
E: Rainbows.
R: Close. Sloths.
B: Ooh, I like sloths.
R: The humble sloth. OK so I, normally when we do this on line, we have the ability to send each other the items so we can read them. So in this case, so we can't do that, I'm going to read them and then I'm going to pass around my iPad so you guys can take a look at them.
J: OK.
E: Or other things on there, yeah.
R: Don't look through my porn please. My iPad porn.
E: iPorn.
R: Has that happened, has anybody? No. Maybe.
J: Somehow I think it's all unicorn stuff, isn't it?
(laughter)
R: It's mostly uniporn.
J: (laughs) Uniporn.
B: Unicorn porn.
S: Redundant, but yeah.
R: OK, and also because Steve did it, there are four items this week.
E: Awww.
J: Oh gosh.
B: I'm surprised you didn't go to five.
R: There are twelve items! No, if I had more time, totally. If the internet hadn't been so spotty. So here they are, again one of these is the fiction. Number one. Recent phylogenetic analyses suggest an extremely recent common ancestor between two-toed sloths and three-toed sloths, which occupy the same territory, subsist on the same diet, and even have the same number of toes despite the name difference. Number two. Sloths move so slowly that a blue-green algae grows on them, living symbiotically within its hollow hairs and providing sustenance for dozens of varieties of arthropods. Number three. Despite the fact that they are incapable of walking, sloths climb down from the trees, poop in a small hole at the foot of the tree, and then climb back up. And number four. Sloths are graceful swimmers who can perform a breast stroke and are descended from an aquatic sloth ancestor. Those are your items. Uuhhh, Bob.
B: Thank you.
(laughter)
E: We love Bob.
R: You just look so pleased right now, you just can't believe your luck.
B: I knew I should have sat over there.
J: Poll the audience, Bob.
S: Are we going to poll the audience?
R: Oh, yeah yeah yeah, OK.
S: All right, let's do it.
B: Good.
R: Let me see them again so I remember which one's which.
E: Give them a quick shot, yeah.
R: OK, who thinks the first item is fictional, about two-toed slots and three-toed sloths having a recent common ancestor?
(silence)
R: All right.
E: Whoa, that's a first.
J: Whoa, that is stone cold.
R: Yeah. Number two, the blue green algae, growing on sloths. Who thinks that's fiction?
(silence)
R: I think they're just scared. OK, number three. That sloths are incapable of walking but still climb down the tree to poop in a hole.
(clapping)
J: That was the only one I thought was...
(laughter)
R: OK. And number four, that sloths are forceful swimmers.
(clapping)
R: OK, so it sounds like number three and then number four are the audience favourites.
J: For fiction.
R: For fiction.
B: Uh, the first one, the phylogenetic analyses. Yeah, I can kind of see that, I don't have a problem with that one. The blue green algae for number two. Yeah, I mean how slow do you have to move for the algae to grow on you? I mean I think I've got some over... no. But uh, yeah I don't have a problem with that. They move slowly, but that wasn't bothering me either. The third one. Their hands are kind of freaky, they're really curved. I could really see them having trouble walking.
JR: Like Silvia Brown.
(laughter)
B: That boy's dead.
R: Please do not besmirch the good name of sloths by comparing them to Silvia Brown.
(laughter)
B: I've never seen them actually walking. Hmmm... how could I not know that? The swimmer one though, is just kind of freaking me out. How could sloths and graceful swimming, just don't go together for me, so I'm just going to, what the hell, I'll pick that one. Who's next?
R: All right, let's just head over to Steve.
S: Yeah I had the same reaction as Bob when I heard the swimming one, I'm like wow that sounds so crazy fiction.
B: That would be too obvious, right?
S: That would be incredible, yeah it's almost too obvious, like was that the one that inspired the whole theme?
B: Maybe that's what she wants you to believe.
R: Excuse me, my great love of sloths inspired the theme.
S: An aquatic sloth ancestor. The whole thing just sounds so crazy. The other ones all sound fine. I was trying to remember, yeah there's something about the phylogenetic relationship between two-toed and three-toed sloths that's counter-intuitive. I can't remember what it is.
B: (inaudible)
S: So that might be... no there is, there is something I can't remember, it's one of those things, there's something about that that is not what you would think it is, like they're not quite as closely related as the names might imply, both being sloths. But I don't know, I don't remember. The blue-green algae, fine, sure. The walking yeah, I mean you know sloths climb along trees in the branches I don't know if they go down to poop but they could certainly do that. I think I have to go with the swimming one too. If that's true that's amazing but that one just struck me as so obvious that I'm just going to go with that because that was my first reaction.
B: GWB.
R: All right, GWB. Evan.
S: Incidentally.
E: Yeah I'll just get right to it. I was thinking the swimming one first, the poop one second. But the audience thinks the poop one is f... a few more people were thinking that one was fiction.
JR: We've been doing a lot of poop this evening.
E: It's been a very earthy podcast.
R: Is that a new medicine you're on?
(laughter)
E: They're incapable of walking, also graceful swimmers. Swimmers. I'll go with gang, what the heck. Swimmers. Fiction!
R: All right, Jay.
J: Yeah I mean I, the think I thought of about the swimming is like if you have hooks for hands, like how the hell can you swim? Like their hands are just like Bob was saying.
E: Catch a lot of fish on the way.
J: They're like remember those monkey toys we had when we were kids?
B: Yes.
E: Yes, you hang them all together.
J: The hooked hands, you could slide them down something.
S: They didn't swim very well.
J: No, but I can't imagine sloths... it's like they can't move but they get in the water and they're like doing Olympic swimming. Like they can barely move. I saw a sloth crawl across the street. It took him like 15 minutes to crawl and there's people like blocking. And then you get them in the pool and they take off like rockets?
E: He was thinking if only I was swimming.
J: I can't imagine that being true, and this is going to be like such an amazing win for you Rebecca, because I have to say the swimming thing.
R: All right, what do you say Seth?
SS: I have to say I don't know anything about sloths except for the guys who are supposedly responsible for maintenance in our hight school so I'm not sure. The only one that I can, I mean to say and are descended from an aquatic sloth ancestor. Aren't we all descended from aquatic sloth ancestors? I found it a little bit bizarre that they would climb down from the trees and poop into a hole because I can't think of any evolutionary benefit for them doing that. And it sounds like an awful lot of work. So I'd say that's the one.
R: So you're going with...
B: If you're in a tree, why not just crap from the branch right, and just let it drop?
JR: Well, I'm going to poop on the poop one. Yeah, I can't see them climbing out of trees and digging holes, that's a little too civilised for me so I'm going to turn that one down, I think that's a loser.
R: You're going with the poop.
J: OK, there we go.
R: All right, shall we poll the audience?
J: Yes, let's poll the audience again.
R: All right, let's see if they swayed you guys at all. Who thinks that the fiction is the two-toed sloths and the three-toed sloths having an extremely recent common ancestor?
(silence)
R: Still no one, OK. Who thinks that the fiction is the sloths getting a blue-green algae?
(silence)
R: All right. Uh, poop!
(clapping)
J: Wait, we just said, people clap for poop! That was the whole point for the past two hours.
R: The only reason I (inaudible). And sloths as graceful swimmers.
(clapping)
R: It's still pretty even between the two. All right, I'm going to take them in seeming random order. Let's start with the algae, everybody seemed to buy into that pretty quickly. Sloths move so slowly that a blue-green algae grows on them, living symbiotically within its hollow hairs and providing sustenance for dozens of varieties of arthropods. That is in fact... science, so well done. Yeah, it's kind of cool, they do in fact move that slowly and the algae helps protect them because one of sloths biggest predators are raptors, not veloci- but you know, flying.
S: Birds with talons.
R: Yeah, and when the sloth is covered in the algae...
B: Camouflaged?
R: ...and just hanging there they look exactly like a big clump of leaves.
B: Cool, symbiotic relationship.
R: And yeah they have this incredible almost ecosystem of bugs all over them, it's really pretty.
S: That's what happens when you don't move.
JR: Sounds yummy.
B: Which is another good reason why they wouldn't swim. All right. I'm just throwing that out there.
J: Oh, sh...
E: Oh wow.
R: All right, let's go to the other one that everybody thought was science, which is recent phylogenetic analyses suggest an extremely recent common ancestor between two-toed sloths and three-toed sloths which occupy the same territory, subsist on the same diet and even have the same number of toes despite the name distance. That one is in fact... fiction! You all lose!
B: Oh, no way!
R: You all lose! Yeah, I thought Steve was going to get it.
S: Yeah, I was, I argh.
R: I really thought you were going to do it.
S: I knew if I remembered what I was supposed to remember about that I probably would have gotten that one.
R: The science part of that is that two- and three-toed sloths do in fact share the same territory that they have the same diet, the only real difference between them is size difference, but that's the really fascinating thing about them. They're so similar but their common ancestor is incredibly distant, incredibly distant. They've just...
B: Convergent evolution.
R: Yeah, it's a beautiful example of convergent evolution.
B: I hate convergent evolution.
(laughter)
R: Damn you convergent evolution!
E: Damn you, god!
R: Yeah, because they occupied that same area, they were under the same pressures and they evolved in pretty much exactly the same way, and actually, let me pull this note up.
J: You're really passionate about these guys.
R: I love sloths!
B: How could you not know that?
J: So do they have hooks for hands?
R: Like Captain Hook, that's what you're picturing?
E: Arrr.
J: I mean, I can't...
S: They have curved claws, yeah.
R: They have claws.
B: You see them on branches, they just kind of hang upside down.
R: Oh yeah and that's the other thing. Despite the name, all sloths have three toes, but their claws, which are technically on their sloth-hands, two-toed have two claws, and three-toed have three claws.
S: Have you ever held one?
R: No, I would die, I would melt.
B: Yeah, from all that algae and stuff.
E: Yeah, and the bugs and whatever else.
R: Uh, here's a cool thing about sloth evolution I found this quote from a researcher. Even the animals they are most closely related to, ant eaters and armadillos, are as different from sloths as whales are from bats.
J: Wow.
E: Sweet.
JR: That's a big difference.
R: Yeah, I thought that was really cool.
B: Different genetically?
R: So let's go and do the other two, even though you all lost and it's pretty much, you know. It's done now. The poop thing, so despite the fact that they are incapable of walking, sloths climb down from the trees, poop in a small hole at the foot of the tree, and then they climb back up. That's science.
J: But they are so slow, they have to actually think, I'm going to need to poop in about four hours.
(laughter)
R: Here's what that... I almost put this as the item which is, sloths, this is true, sloths poop once a week.
J: Wow.
B: That's awesome.
R: Sloths have such incredibly slow metabolisms.
E: Incredibly constipated.
JR: That's one hell of a poop!
(laughter)
R: Actually, you are absolutely correct, I read a paper that said that 30% of their body weight in one evacuation was not unheard of.
B: Wow, Jay you've done that, you've done that.
R: Again, why do you know so much about Jay and his poop?
B: He posts it on Facebook.
R: So yeah sloths do not poop in the trees and there are a number of guesses for why they do this, there's no solid evidence but some of the...
E: Ew.
JR: I got it, I got it.
R: Thank you.
S: You don't crap where you eat.
B: But they're in a tree, just let it drop.
S: But they're upside down.
B: Yeah, OK.
R: Faeces dropping from the tree are a signal to predators, like the birds that are hunting them...
J: Oh, right.
JR: They get out of the way.
B: Yeah, right but they've got the algae to protect them, they're cool.
R: Exactly though, the algae does until the sound happens and then the birds are very good at swooping, and there's video if you can stomach it, there's actually video of a bird swooping in and flipping upside down and grabbing a sloth right off of a tree branch and carrying it away.
B: Aren't they big though? I mean aren't...
R: You know, they can be like, they're I figure like a cat size, large cat sometimes.
B: Really? I thought they were a little bigger.
R: Well, two-toed are small, three-toed are a little bigger but there are some large birds that can easily snatch them.
JR: You're really fascinated with these, aren't you Rebecca.
R: (laughs) A little bit, a little bit.
B: Tell me, no.
R: There's another possible reason for not pooping from the tree and actually going down and burying it, and this is a bit more difficult to believe, but it is interesting. The poop fertilises the tree, burying it right under the tree fertilises it and produces better food for the sloth to go eat.
E: Ooh, nice.
JR: So they're farmers.
R: Yeah, they're basically farmers.
B: Hey, tell me about extinct giant slots. Weren't they like huge at one point, like bears?
R: We talked about it.
E: Mammoth.
R: I did a this day in history a few weeks ago about Jefferson discovering what he thought was a lion. Or he didn't discover it, but he delivered a paper on it.
B: Oh yeah.
R: He thought it was a lion and asked Lewis and Clark to find it on their expedition.
S: Yeah, it was a giant sloth.
R: They didn't because it was an extinct giant sloth.
B: Cool.
R: And that was another potential item, was that like bigfoot in the US in South America there's a common myth of a giant, a living giant sloth, only it's not just a giant sloth, it's terrifying. It's still very slow.
B: If you stand still for 8 hours you're in deep shit.
(laughter)
R: But like, you know zombies, very slow, very scary. It can happen.
J: What movie was that from? There's a steam roller coming at a guy and it's moving like a half a mile and he's like aaaaargh!
S: A Fish Called Wanda.
(general agreement)
S: He was cemented in, that's why he couldn't move.
J: Holy shit, I just realised something, they can swim like crazy.
R: They can swim, they can swim.
B: Oh come on I want to see a youtube video.
R: There are tons of youtube videos on it and they are amazing.
E: There is a sloth channel on youtube.
R: So they do have an ancestor that was probably a mostly aquatic sloth. There's really good evidence to suggest. They found these fossils and they looked particularly at the teeth and they found that older versions of the sloth, this is technical language, it's very late. Aquatic sloth 1.0 had teeth that were really nicked up and what they figure happened was that it lived in a desert area that ran into some water and the only plants around were by the water so the wear on the teeth they think came from sand that they scooped up as they were grabbing plants on the edge of the water but later versions of the sloth, they found that the sand was beginning to disappear and the only explanation they can come up with is that the sloth was moving further and further and further into the water until it was completely in the water and just foraging on aquatic plant life. So they do have that ancestor and right now there are sloths that live in areas that can be flooded and when that happens they literally can just drop out of the tree and immediately start swimming and they do this breast stroke. I found one thing that I could not verify was that depending on which way they land they will do either a breast stroke or a back stroke.
B: Or a back stroke, awesome.
(laughter)
R: Because the internet connection was so low I couldn't find a video of the backstroke so I didn't include that. But I thought that that was pretty cool. They are very good swimmers and you can find it on youtube.
J: Good job Rebecca, that was good.
B: Good job, nice.
(applause)
J: And Rebecca, you've stumped more people at one time than anybody else ever.
R: Awesome, I'll take it.
J: That's pretty cool.
R: This has been sloth facts with Rebecca. There was actually one other thing that I wanted to mention that I thought was really interesting but I tried, I could not verify this. But in Salmon of Doubt, Douglas Adams' book, Douglas Adams says that his favourite fact is that young sloths are so inept at climbing that they often mistake their own arms and legs for tree limbs and they fall.
(laughter)
B: Oh my god, I don't remember that part.
R: The best I could confirm was that there is evidence to suggest that climbing amongst sloths is a learned behaviour and so that could suggest that yeah, maybe baby sloths are morons at climbing.
(laughter)
R: But yeah, I couldn't find any, no video evidence of baby sloth like rrrrr, falling down. So yeah.
S: OK, good job Rebecca.
R: Thank you.
Skeptical Quote of the Week (77:46)
S: Um, Jay do you have a quote to end our live show with?
J: I have a quote from the incredible Carl Sagan. This was actually from his Cosmos TV show. And the quote is: "The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge, and there's no place for it in the endeavor of science. We do not know beforehand where fundamental insights will arise from about our mysterious and lovely solar system. The history of our study of our solar system shows us clearly that accepted and conventional ideas are often wrong, and that fundamental insights can arise from the most unexpected sources." Carl Sagan!
(laughter)
R: Thank you.
(applause)
S: Thank you for joining us everyone, Randi thanks again for joining us, Seth it was a pleasure to have you on the show.
J: Thanks guys.
S: Thank you guys for joining me this week, and thanks to our live audience.
E: Great week, great week guys.
R: Thank you. Good night!
S: And until next week, this is your Skeptics' Guide to the Universe.