WEBVTT - Tail as Old as Time: Part 2 0:00:03.120 --> 0:00:06.000 Welcome to Stuff to Blow your Mind from how Stuff 0:00:06.000 --> 0:00:13.840 Works dot com. Hey, welcome to Stuff to Blow your Mind. 0:00:13.840 --> 0:00:16.079 My name is Robert Lam and I'm Joe McCormick, and 0:00:16.120 --> 0:00:18.119 this is going to be part two of our two 0:00:18.160 --> 0:00:21.919 part episode about tales Now. Last time, we talked about 0:00:21.960 --> 0:00:25.640 many of the wonderful biological mysteries of tales, about the 0:00:25.720 --> 0:00:29.680 unsettled science of courtship tales and the role they play 0:00:29.720 --> 0:00:33.600 in p foul mating. We talked about propulsion, We talked 0:00:33.640 --> 0:00:38.560 about pre intile tales, climbing, climbing and anchoring, kangaroos using 0:00:38.560 --> 0:00:42.880 their tails, as as as what to become the rockham 0:00:42.880 --> 0:00:46.840 sock'em robots that kangaroos are. They lean back on those 0:00:46.840 --> 0:00:51.240 wonderful stumpy things. Talked about energy conservation, fat storage. But 0:00:51.320 --> 0:00:54.680 today we're going to talk about biological methods of communication 0:00:54.760 --> 0:00:59.760 through tales, tales in in self mutilation for survival, and 0:00:59.800 --> 0:01:03.000 the question of human tales. Where are they are? Where 0:01:03.040 --> 0:01:05.720 they go? Are we going to get them back? Perhaps 0:01:05.720 --> 0:01:08.399 when the world is is perfect, we'll grow that that 0:01:08.720 --> 0:01:11.160 new utopian tail. We'll get to that too. So one 0:01:11.200 --> 0:01:14.000 of the first things that we should address is the 0:01:14.120 --> 0:01:18.280 role of tales in animal communication. I remember we mentioned 0:01:18.280 --> 0:01:22.640 in the echo Board podcast that much of human communication 0:01:22.760 --> 0:01:25.759 is nonverbal. It's one of the reasons it's so easy 0:01:25.800 --> 0:01:29.080 to be misinterpreted over email or in a text message. 0:01:29.280 --> 0:01:32.600 Your tone, your facial expressions, and your body language supplies 0:01:32.640 --> 0:01:35.920 sort of the shadow grammar of what you're saying. And 0:01:36.000 --> 0:01:39.080 for dogs, the tail can do a lot of this work. 0:01:39.120 --> 0:01:41.919 In fact, it might be especially important for dogs because 0:01:42.319 --> 0:01:44.960 dogs don't have language. They can't speak. They might be 0:01:45.040 --> 0:01:50.559 able to communicate something roughly through barks and other vocalizations. 0:01:50.560 --> 0:01:53.240 But but the tail is where it's at. And you 0:01:53.320 --> 0:01:55.560 know this, like some of these things you already know 0:01:55.680 --> 0:01:58.240 by heart, dogs tuck their tails between their legs to 0:01:58.280 --> 0:02:02.680 show submissiveness. That's pretty obvious and widely accepted. You could 0:02:02.680 --> 0:02:07.360 even compare this tail tucking to closed body language and humans. 0:02:07.400 --> 0:02:10.600 We you ever thought about that? Yeah, yeah, so sort 0:02:10.600 --> 0:02:13.160 of even without the tail, we kind of assume that posture, 0:02:13.280 --> 0:02:18.359 this sort of you know, passive, helpful pronosaurus uh kind 0:02:18.400 --> 0:02:21.200 of positioning you can take. Yeah, or if we're if 0:02:21.240 --> 0:02:24.519 we're feeling apprehensive, we can fold our arms and kind 0:02:24.520 --> 0:02:27.320 of shrink the way you you would when a dog 0:02:27.360 --> 0:02:30.400 tucks its tail and gets low. Uh. And we we 0:02:30.440 --> 0:02:33.040 think that dogs wag their tails to show they're happy. 0:02:33.280 --> 0:02:35.720 This is sometimes the case, but not always. I read 0:02:35.760 --> 0:02:39.400 an interesting National Geographic article that talked to an Oregon 0:02:39.480 --> 0:02:43.760 State University animal sciences professor named Monique ou Dell. And 0:02:43.800 --> 0:02:47.760 according to this article, dog's signal playfulness with a circular 0:02:47.880 --> 0:02:51.000 kind of wild, circling wag. But they can also signal 0:02:51.040 --> 0:02:55.000 apprehensiveness too by a showing a slower, more controlled wag. 0:02:55.080 --> 0:02:57.919 That might be the case in general, but some research 0:02:57.960 --> 0:03:01.519 shows it gets even more specific with what dogs communicate 0:03:02.240 --> 0:03:04.040 by their wags. And I want to talk about a 0:03:04.080 --> 0:03:08.360 couple of interesting papers in current biology on dogtail wagging. 0:03:08.440 --> 0:03:11.120 So if you have a dog at home, next time 0:03:11.120 --> 0:03:15.440 it starts to wag its tail, look at the directional 0:03:15.560 --> 0:03:18.480 amplitude of tail wagging. And I do want to throw 0:03:18.520 --> 0:03:21.080 in you yourself or a dog owner? Oh yeah, yeah, 0:03:21.120 --> 0:03:24.640 Are you no a dog? No? I'm I just have 0:03:24.800 --> 0:03:28.240 one horrible cat right now. Um, and they've never really 0:03:28.280 --> 0:03:30.120 been a dog person. But I know that some people 0:03:30.200 --> 0:03:33.520 new to the either new to the show or who 0:03:33.560 --> 0:03:36.880 are used to you know, previous host arrangements. Um, you 0:03:36.880 --> 0:03:38.560 know it may not be familiar that we now have 0:03:39.080 --> 0:03:43.040 dog owners dog people on the podcast right. Well, I 0:03:43.080 --> 0:03:45.520 have one dog. My wife Rachel and I have a 0:03:45.560 --> 0:03:48.960 dog named Charles Darwin. Charlie and I have not yet 0:03:49.160 --> 0:03:53.280 tried to track Charlie's asymmetric tail wagging, which I'm about 0:03:53.280 --> 0:03:55.280 to get into, but I plan on doing that for 0:03:55.280 --> 0:03:57.480 the rest of the week. Anyway, there was a paper 0:03:57.560 --> 0:04:02.400 in March two thousand seven called asymmetric tail wagging responses 0:04:02.440 --> 0:04:06.200 by Dogs two different emotive stimuli. And this, like I said, 0:04:06.240 --> 0:04:09.240 was in Current Biology, and here a group of researchers 0:04:09.320 --> 0:04:13.840 discovered what they called quote differential amplitudes of tail wagging 0:04:14.120 --> 0:04:17.400 to the left or the right side associated with the 0:04:17.440 --> 0:04:21.360 type of visual stimulus the animals were looking at. So 0:04:21.400 --> 0:04:24.680 what this means is, depending on how you visually stimulated 0:04:24.720 --> 0:04:27.240 the dog, what you show a dog, it would tend 0:04:27.320 --> 0:04:30.200 to wag to the right or to the left. Now, 0:04:30.440 --> 0:04:33.200 the tail. If you're picturing how a dog's tail wags, 0:04:33.240 --> 0:04:35.800 it goes both ways. It wags back and forth, but 0:04:35.920 --> 0:04:38.719 the amplitude varies, so as it goes back and forth, 0:04:38.760 --> 0:04:42.200 it might trend more to the left or trend more 0:04:42.279 --> 0:04:45.159 to the right. I've never noticed that before. Yeah, And 0:04:45.240 --> 0:04:48.400 so the experimenters put each dog in a special no 0:04:48.560 --> 0:04:52.240 distractions box that didn't allow it to look at anything 0:04:52.279 --> 0:04:55.320 else interesting, and it had one opening that the dogs 0:04:55.880 --> 0:04:57.960 could see through, and it would allow them to see 0:04:57.960 --> 0:05:01.400 things in one direction. And the shoal stimuli they tested 0:05:01.400 --> 0:05:05.799 were the dog's owner, and then an unknown person stranger danger, 0:05:06.360 --> 0:05:10.039 and then a dominant unfamiliar dog, so this is a 0:05:10.080 --> 0:05:13.040 dog that has been trained to be the boss and 0:05:13.160 --> 0:05:16.159 kind of scary, and then a cat, and then of 0:05:16.160 --> 0:05:18.960 course a control of a blank panel. And they were 0:05:19.040 --> 0:05:22.960 very interesting results when they observed the dogs in these conditions. 0:05:22.960 --> 0:05:24.919 They found that when the dogs looked at their owners, 0:05:24.960 --> 0:05:28.680 they showed a strong right side wag bias uh, and 0:05:28.760 --> 0:05:32.440 the unfamiliar human got less wagging and a weaker right 0:05:32.480 --> 0:05:35.640 side bias. The cat got much less wagging and a 0:05:35.800 --> 0:05:40.119 very very slight right side bias, the unfamiliar dominant dog 0:05:40.200 --> 0:05:43.760 got a left side bias, and then the blank control 0:05:43.839 --> 0:05:47.440 also got a slight left side wag bias. And the 0:05:47.480 --> 0:05:51.599 interpretation of these results actually had to do with brain lateralization, 0:05:52.240 --> 0:05:56.200 possibly in anticipation of motor control. They said, quote in 0:05:56.240 --> 0:06:00.839 our experiment stimuli that could be expected to elicit approach tendencies, 0:06:00.880 --> 0:06:03.760 So the dog wanting to approach, such as seeing the 0:06:03.800 --> 0:06:07.440 dog's owner, were associated with higher amplitude of tail wagging 0:06:07.520 --> 0:06:11.640 movements to the right side left brain activation, and stimuli 0:06:11.720 --> 0:06:15.599 that could be expected to elicit withdrawal tendencies such as 0:06:15.640 --> 0:06:20.320 seeing a dominant unfamiliar dog were associated with higher amplitude 0:06:20.360 --> 0:06:22.840 of tail wagging movements to the left side, and they 0:06:22.839 --> 0:06:26.240 thought this meant right brain activation. So in the study 0:06:26.360 --> 0:06:29.560 we learned something about how the lateral bias of a 0:06:29.600 --> 0:06:33.920 tailwag indicates the mindset of a dog. But the big 0:06:34.000 --> 0:06:38.400 question is do other dogs notice this? Yeah? Like it? 0:06:38.960 --> 0:06:40.880 I mean it would seem like they would. I mean, 0:06:40.880 --> 0:06:43.719 just based on what we've studied about, you know, human 0:06:43.760 --> 0:06:46.440 micro expressions and whatnot, so many things that are that 0:06:46.520 --> 0:06:49.880 we end up picking up either consciously or subconsciously as 0:06:49.920 --> 0:06:53.039 we're observing another person's body language. And we found out 0:06:53.120 --> 0:06:57.240 the dogs totally do notice this. So the same authors 0:06:57.320 --> 0:07:00.160 of the two thousand seven study, three of them, were 0:07:00.000 --> 0:07:05.400 also authors on a November studying Current biology called seeing 0:07:05.560 --> 0:07:10.320 left or right Asymmetric tail wagging produces different emotional responses 0:07:10.360 --> 0:07:13.120 and dogs. So this is dogs looking at video of 0:07:13.160 --> 0:07:16.480 another dog wagging its tail to the left or right, 0:07:16.960 --> 0:07:20.520 or also a frozen no wag posture, And then I 0:07:20.520 --> 0:07:22.480 thought this was really clever. They tried this both with 0:07:22.640 --> 0:07:25.400 normal video of a dog wagging its tail and then 0:07:25.480 --> 0:07:29.120 also just with a black silhahwett of the wagging dog 0:07:29.160 --> 0:07:32.360 on a white background to eliminate other possible cues from 0:07:32.360 --> 0:07:35.520 the dog, like eyes or facial expressions, and they discovered 0:07:35.520 --> 0:07:38.400 this didn't really make a difference. The silhouette wasn't It 0:07:38.520 --> 0:07:40.680 wasn't a big difference from looking at regular video of 0:07:40.680 --> 0:07:44.600 the dog, And so the researchers measured the dog's heart 0:07:44.720 --> 0:07:48.040 rate and then just observe their behavior as they watched 0:07:48.080 --> 0:07:51.120 the different wags, and the results were that there wasn't 0:07:51.160 --> 0:07:54.640 really a difference between how dogs reacted to the right 0:07:54.720 --> 0:07:58.440 wagon static control, but when they saw a left wag, 0:07:58.600 --> 0:08:01.840 the dog started showing elevated heart rates as if they're 0:08:01.880 --> 0:08:06.720 now experiencing stress or anxiety, and the behavioral observation also 0:08:06.720 --> 0:08:10.160 showed that the dogs exhibited more behaviors associated with stress 0:08:10.200 --> 0:08:14.800 when they saw the left wag. Curiously, both the left 0:08:14.840 --> 0:08:17.800 wag and the static control were more stressful than the 0:08:17.880 --> 0:08:21.400 right wag according to this observation metric. So a dog 0:08:21.440 --> 0:08:24.600 sees another dog with the right wag, that's cool. Dog 0:08:24.680 --> 0:08:27.960 sees a dog that isn't wagging at all, It seems 0:08:28.000 --> 0:08:30.720 like the dog might be getting some stress reaction there, 0:08:30.760 --> 0:08:33.040 maybe because it can't figure out what to make of 0:08:33.120 --> 0:08:35.720 this dog if it's not wagging at all. Dog sees 0:08:35.720 --> 0:08:39.200 a dog with a left wag. That's definitely a stress reaction. 0:08:39.320 --> 0:08:42.439 Something's going on here, okay, And this is definitely the 0:08:42.520 --> 0:08:43.840 kind of thing that a human could pick up on 0:08:43.920 --> 0:08:47.760 two right, Like that that it's not so uh slide 0:08:47.760 --> 0:08:50.160 a movement that we wouldn't be able to see it. No, no, no, 0:08:50.200 --> 0:08:53.080 I mean they were able to measure it with video. Yeah, 0:08:53.120 --> 0:08:54.679 but I wouldn't sure that meant that you had to, like, 0:08:54.760 --> 0:08:56.600 you know, slow it down and all right, let's zoom 0:08:56.640 --> 0:08:59.000 in on the tail and see to what degree it's 0:08:59.040 --> 0:09:01.360 actually moving. You know, this is something we would be 0:09:01.400 --> 0:09:03.640 able to observe. Say that your local dog park. Yeah, 0:09:03.679 --> 0:09:05.800 from everything I could tell, I think, I mean you'd 0:09:05.840 --> 0:09:08.880 have to pay close attention. Okay, So maybe the dog 0:09:08.920 --> 0:09:11.160 park might be too distracting a location to try to 0:09:11.200 --> 0:09:13.480 stop yeah, And so they didn't want to draw too 0:09:13.520 --> 0:09:17.480 many conclusions about exactly what this means about the dog's emotions. 0:09:17.600 --> 0:09:19.560 I I might have gone a little too far if 0:09:19.559 --> 0:09:22.720 I said it was definitely stress a minute ago, because 0:09:22.720 --> 0:09:25.760 what they could look at was these these external behaviors 0:09:25.800 --> 0:09:29.400 and then elevated heart rate. So that could mean any 0:09:29.480 --> 0:09:31.520 number of things. But at least when a dog sees 0:09:31.559 --> 0:09:34.920 another dog wagging left it, it's having some kind of 0:09:34.960 --> 0:09:40.000 elevated response. So in this way, dogs do communicate something 0:09:40.160 --> 0:09:44.720 very relevant about their state of mind with a wag, 0:09:44.880 --> 0:09:48.679 and they can see it in other dogs. And that 0:09:49.000 --> 0:09:52.840 makes me think some interesting questions about the nature of communication. Like, 0:09:52.880 --> 0:09:56.080 in a very different way, the idea of communication by 0:09:56.080 --> 0:10:00.200 tail could also apply to something like a rattlesnake. Mean, 0:10:00.200 --> 0:10:03.520 the rattlesnake is definitely communicating with its tail. It is 0:10:03.520 --> 0:10:07.520 saying don't get near me. Yeah, And so what did 0:10:07.520 --> 0:10:11.040 the dog and the rattlesnake have in common if we 0:10:11.080 --> 0:10:15.720 assume dogs inadvertently communicating information with tail wags, and I 0:10:15.760 --> 0:10:18.400 mean inadvertently here, I'm talking about the fact that the 0:10:18.440 --> 0:10:23.320 evolutionary purpose of the right or left side bias isn't 0:10:23.360 --> 0:10:26.680 necessarily to share information with others. It might simply be 0:10:26.720 --> 0:10:31.200 a totally accidental byproduct of this brain lateralization they're talking about, 0:10:31.440 --> 0:10:33.040 you know what I mean, Like the wag might not 0:10:33.280 --> 0:10:37.959 be an adaptation that was selected for because it shared information. 0:10:38.040 --> 0:10:41.440 It might be an accident, but it's an accident that 0:10:41.640 --> 0:10:44.520 does share information, and now they've learned how to make 0:10:44.600 --> 0:10:48.600 something of that. So in what sense could we say 0:10:48.640 --> 0:10:52.800 that this is communication if it's just an accidental byproduct 0:10:53.080 --> 0:10:57.160 that we've learned how to draw information from. And to 0:10:57.240 --> 0:11:01.040 what extent does communication have to be deliberate? Yeah? I 0:11:01.080 --> 0:11:04.840 mean that kind of underlies the complexity of communication in general, 0:11:04.960 --> 0:11:09.160 you know, this mix of deliberate and accidental cues and 0:11:09.200 --> 0:11:12.680 then and mis cues that we have to make sense off. Yeah, 0:11:12.720 --> 0:11:15.400 it makes me wonder about the origins of human language. 0:11:15.400 --> 0:11:17.720 I know that's not exactly the subject today, but just 0:11:17.800 --> 0:11:21.360 like could human could something like human language have come 0:11:21.520 --> 0:11:27.199 from originally I don't know, incidental vocalizations that were not 0:11:27.640 --> 0:11:32.440 intended to communicate information, but they did, And then that 0:11:32.520 --> 0:11:37.120 could develop into something where we harness that for deliberate use. Yeah, 0:11:37.120 --> 0:11:38.920 it could all begin with just a simple you know, 0:11:39.200 --> 0:11:42.320 scream when you're scared, you know, and then that the 0:11:42.360 --> 0:11:46.240 various nuances involved in in in how we interpret that screen. 0:11:46.559 --> 0:11:50.080 Now here's another topic related to tails that I think 0:11:50.120 --> 0:11:53.320 you've done a whole episode on before, which is when 0:11:53.360 --> 0:11:58.520 you pick up a bluetail lizard, you catch it, say, 0:11:58.600 --> 0:12:01.559 in a shoe box, and then its tail comes off 0:12:01.679 --> 0:12:05.840 and the children start screaming, Yes, what's going on there? Well, 0:12:05.920 --> 0:12:09.040 this brings us into the area of autotomy. Uh, as 0:12:09.040 --> 0:12:12.600 it's referred this is the shedding of a tail. Nada. 0:12:12.960 --> 0:12:15.200 You know that the animals not chewing the tail off, 0:12:15.280 --> 0:12:18.199 it's not pulling the tail off. It's just simply and 0:12:18.280 --> 0:12:20.559 not a mouse in a glue trap situation here, just 0:12:20.559 --> 0:12:24.760 a straight up shedding of the tail. And indeed lizards 0:12:25.400 --> 0:12:28.080 get go skinks. H. This is where you you see 0:12:28.160 --> 0:12:32.200 most of the examples of Caudle autonomy caudles and related 0:12:32.240 --> 0:12:34.559 to the tail. And certainly there is a there's a 0:12:34.559 --> 0:12:36.320 whole episode of stuff to blow your mind that goes 0:12:36.360 --> 0:12:39.719 into this in a lot more detail and draws from 0:12:39.800 --> 0:12:43.240 specific studies. Uh, But for our purposes here, I just 0:12:43.280 --> 0:12:48.480 wanted to go over in brief what's occurring. Yeah, and uh, 0:12:48.600 --> 0:12:51.240 you mentioned blue tailed skinks. Skilton skink, which is a 0:12:51.240 --> 0:12:53.440 blue tailed skink, is a is a perfect example of 0:12:53.440 --> 0:12:56.080 autotomy because the tail is bright blue, so it just 0:12:56.160 --> 0:12:59.880 adds to the attractiveness of this what is essentially thought 0:12:59.920 --> 0:13:03.000 of as a predator bribe. So like a cat sees 0:13:03.000 --> 0:13:05.120 a lizard and says, I'm gonna eat that lizard, and 0:13:05.160 --> 0:13:08.880 the lizards might not eat it yet. Yeah, yeah, certainly 0:13:08.880 --> 0:13:12.120 there's a whole the I'm going to torture. Yeah, the 0:13:12.160 --> 0:13:16.319 game of cat perdition is is rather complicated and cruel, 0:13:16.559 --> 0:13:19.960 but essentially the lizard reaction is, look, I'm gonna leave, 0:13:20.400 --> 0:13:24.480 but I'm going to leave a little of me behind. Uh. 0:13:24.520 --> 0:13:26.760 First of all, it has fat in it, it's part 0:13:26.760 --> 0:13:28.800 of me. You can eat it and you will get 0:13:28.800 --> 0:13:31.520 a meal out of it. I'm gonna leave you a meal. Uh, 0:13:31.559 --> 0:13:33.600 that's gonna be easier to catch and put up less 0:13:33.600 --> 0:13:36.240 of a fight. But it's also thrashing around as if 0:13:36.240 --> 0:13:38.920 it's alive. It's also bright blue, so it's easier to see. 0:13:39.000 --> 0:13:41.040 So it really is in a sense of bribe. It's 0:13:41.080 --> 0:13:43.880 not just a decoy. It's not just something that the 0:13:43.920 --> 0:13:46.160 cat gets nothing out of. You could eat the tail 0:13:46.160 --> 0:13:49.120 and get some nutrition. Yeah, it's like the you know, 0:13:49.160 --> 0:13:50.640 if you have some sort of like a bank heist 0:13:50.679 --> 0:13:55.400 movie where I've seen this pop up in various stories before, 0:13:55.480 --> 0:13:58.679 where the antiheroes are the heroes have made off with 0:13:58.720 --> 0:14:01.760 the loot that somebody the law enforcement is chasing them. 0:14:01.800 --> 0:14:04.040 Then you have to say, how much money would I 0:14:04.040 --> 0:14:06.199 have to drop out of the back of this truck 0:14:07.040 --> 0:14:09.840 where they would stop, like they would actually pick up 0:14:10.480 --> 0:14:12.240 some of the loot and make off on their own, 0:14:12.400 --> 0:14:14.920 or you know, be satisfied with it. So it's it's 0:14:14.960 --> 0:14:17.520 kind of a gamble that the lizard is making. Another 0:14:17.600 --> 0:14:21.600 example of this kind of behavior. And this isn't certain, 0:14:21.680 --> 0:14:25.520 but there are arguments that a vulture vomits when threatened 0:14:25.840 --> 0:14:28.160 as as a as a form of bribery as well 0:14:28.400 --> 0:14:30.400 just saying you can eat me, I'm going to put 0:14:30.480 --> 0:14:33.240 up a fight, or I could just barf up some 0:14:33.360 --> 0:14:36.040 food here and you can eat that because delicious as 0:14:36.120 --> 0:14:39.800 we all know, I mean, particularly dogs of many animals, 0:14:40.160 --> 0:14:42.440 they're they're not gonna be too picky about their food. 0:14:42.600 --> 0:14:44.280 If it's just because it's been in the belly of 0:14:44.320 --> 0:14:47.920 a vulture, it doesn't mean it can't be eaten. Fascinating. 0:14:48.280 --> 0:14:54.440 Now there's a there's another theory about lizard autotomy, and 0:14:54.520 --> 0:14:56.280 this one comes to us from a two thousand nine 0:14:56.400 --> 0:14:59.600 University of Michigan study of lizards in Greece that concluded 0:14:59.600 --> 0:15:03.080 that the are there drop their tails when bitten on 0:15:03.200 --> 0:15:07.320 the tail by venomous snakes. Wow. Yeah, so it's the same. 0:15:09.280 --> 0:15:11.360 It's they or maybe they don't know. I mean, maybe 0:15:11.400 --> 0:15:13.600 it's not a brain response, but there's some kind of 0:15:13.640 --> 0:15:16.600 automated response. That's that's amazing. Yeah, I mean it's it 0:15:16.840 --> 0:15:19.480 matches up rather nicely with our you know, our zombie 0:15:20.040 --> 0:15:22.200 fiction where someone's bit by a zombie, you know, on 0:15:22.240 --> 0:15:23.800 the Walking Dead, and then you have to solve that 0:15:23.960 --> 0:15:26.880 limb off so that the so that that the zombie 0:15:26.960 --> 0:15:29.520 juice won't seep in and affect the whole organism. But 0:15:29.600 --> 0:15:31.760 the great thing about that, in the zombie stories, you 0:15:31.880 --> 0:15:34.800 never really know if it's gonna work. Yeah, it's true. Well, 0:15:35.080 --> 0:15:37.600 you don't have settled zombie science, do you. It seems 0:15:37.600 --> 0:15:40.200 like it always does. Like there seems to be a 0:15:40.280 --> 0:15:43.440 silent rule of zombie fiction that if you go and 0:15:43.640 --> 0:15:49.400 actually do the grueling hard to watch the limb amputation scene, 0:15:49.800 --> 0:15:52.920 then that character has to survive. You know, I think 0:15:52.960 --> 0:15:55.200 I've encountered it in ways that say it buys you 0:15:55.400 --> 0:15:59.360 some time, but it doesn't completely solve the problem. Maybe 0:15:59.360 --> 0:16:02.520 you've got to a smaller concentration of of zombie juice 0:16:02.560 --> 0:16:07.920 in the door. Then, um, so science scientist, you know, 0:16:08.360 --> 0:16:10.440 to to go back to the cat example, Like scientists 0:16:10.480 --> 0:16:12.320 have long thought the tail shedding is an issue of 0:16:12.440 --> 0:16:15.760 predator pressure. But and so this would mean that the 0:16:15.840 --> 0:16:18.440 more predators there are for a species in a given area, 0:16:18.560 --> 0:16:21.040 the greater the need for an effective defense mechanism. So 0:16:21.120 --> 0:16:25.760 tail dropping explodes in in any area of high lizard 0:16:26.160 --> 0:16:30.760 predator pressure. But this two thousand nine study, um, you know, 0:16:30.960 --> 0:16:33.680 argues that the lizards of the offshore A, G, and 0:16:33.760 --> 0:16:37.080 C Islands examined in the study, Um, in these cases 0:16:37.120 --> 0:16:39.920 it all comes down to an evolutionary reaction to their 0:16:40.040 --> 0:16:43.360 single most pressing predator, in this case the vipers. So 0:16:43.720 --> 0:16:46.920 these are specialized lizard predators, and so you see an 0:16:46.920 --> 0:16:53.080 emergence of a of a specialized uh anti predator defense. Now, 0:16:53.160 --> 0:16:58.520 I wonder how this adaptation affects the viper hunting strategy. Indeed, Yeah, 0:16:58.520 --> 0:17:01.240 because any of these these areas, it's Uh, you know, 0:17:01.280 --> 0:17:03.960 it's an arms race with one side trying to keep 0:17:04.040 --> 0:17:09.080 up with the other. Certainly, So here's a question I've 0:17:09.160 --> 0:17:12.360 never found out. Can they grow it back? They can 0:17:12.720 --> 0:17:15.000 grow it back, but it's not the best way to 0:17:15.040 --> 0:17:17.320 think of it is it's not a full size spare. 0:17:17.840 --> 0:17:22.280 You'll grow back a tail that is uh less functional, 0:17:22.680 --> 0:17:25.200 you know, but but also a tail that can be 0:17:25.920 --> 0:17:28.879 can also be dropped again. So when they dropped the tail, 0:17:29.440 --> 0:17:33.440 the muscles that encircle uh this particular plane of the 0:17:33.920 --> 0:17:38.399 creatures of body, they constrict kind of natural tourniquet to 0:17:38.840 --> 0:17:41.160 to keep the you know, blood from from bleeding out. 0:17:41.760 --> 0:17:45.280 And then immediately after this, the skin also contracts around 0:17:45.280 --> 0:17:47.560 the end of the of the tail, forming a stub, 0:17:47.680 --> 0:17:50.000 and then it goes out from there. In these little 0:17:50.040 --> 0:17:53.359 lizards that are everywhere, that's that's science fiction. It's got 0:17:53.440 --> 0:17:56.600 a natural tourniquet. Yeah. And if you're wondering how it 0:17:56.680 --> 0:17:59.240 even uh severs it to begin with, there's been some 0:17:59.320 --> 0:18:01.639 cool studies and of this they point out that the 0:18:02.560 --> 0:18:09.320 tail autonomy occurs at preformed horizontal fracture points. So essentially, um, 0:18:10.040 --> 0:18:13.600 it's a fracture plane across the vertebra. Um or the 0:18:14.040 --> 0:18:18.520 the the intervertebral and the lizard assists the the autatonomy 0:18:18.600 --> 0:18:22.320 by by contracting the muscles around that fracture plane. And 0:18:22.480 --> 0:18:25.679 here the structural integrity of the tail in its connection 0:18:25.720 --> 0:18:27.399 to the rest of the body is maintained by the 0:18:27.640 --> 0:18:32.320 adhesion force of integrated muscles, complete with micro structures that 0:18:32.760 --> 0:18:36.840 mushroom out when it's time to release the tail man. Now, 0:18:36.920 --> 0:18:38.840 it's of course, it's it's interesting when you start thinking 0:18:38.840 --> 0:18:41.119 about the costs here. You know, the cost of that 0:18:41.280 --> 0:18:43.879 bribe if you're making, or the cost of losing that 0:18:44.000 --> 0:18:46.800 limb to the zombie or the or the viper. Well, 0:18:46.960 --> 0:18:49.720 it's a it's a calculated risk because it sounds like 0:18:49.880 --> 0:18:53.399 losing the tail isn't going to hurt the lizard, except 0:18:53.480 --> 0:18:57.480 that it's just admitting defeat on a certain front. It's saying, Okay, 0:18:57.880 --> 0:19:00.440 I've put a certain number of resources into the tail. 0:19:01.080 --> 0:19:03.560 I'm gonna have to give it up. Yeah, it's letting. 0:19:03.680 --> 0:19:06.120 It's letting the bad money go down the drain. Yeah, 0:19:06.200 --> 0:19:08.359 the bad money's gone down the drain. And then what 0:19:08.480 --> 0:19:10.520 do you do when another cat shows up. That's it's 0:19:10.520 --> 0:19:14.040 a wonderful trick. But once you've you've used it. You've 0:19:14.080 --> 0:19:16.000 got to regrow that tail to get to the point 0:19:16.040 --> 0:19:20.600 where you can drop it again. Um. So it's a 0:19:20.640 --> 0:19:23.359 it's an interesting strategy and and indeed a gamble, but 0:19:23.560 --> 0:19:25.680 one that's been paying off for him because it's it 0:19:25.800 --> 0:19:29.040 remains a staple of of a number of different reptiles. 0:19:29.200 --> 0:19:32.880 Does anything other than a lizard drop its tail, Yes, 0:19:32.960 --> 0:19:37.040 And that brings us back to the scorpion um. There 0:19:37.960 --> 0:19:40.560 there are rare there are a few rare South American 0:19:40.600 --> 0:19:47.679 scorpions of the Anatrists genus who also practice coddle autotomy. 0:19:48.560 --> 0:19:51.439 And when they lose their tails, First of all, they 0:19:51.480 --> 0:19:53.480 lose it for good. There's no growing the tail back 0:19:53.520 --> 0:19:56.639 in this case. Uh they have. They just drop it 0:19:56.720 --> 0:19:59.920 and it's gone. But also if they lose their tail, 0:20:00.440 --> 0:20:04.720 they lose their anus, and that's because the scorpions anus 0:20:04.880 --> 0:20:07.280 is located at the end of the tail the gut. 0:20:08.680 --> 0:20:12.520 The gut extends through the tail and opens up at 0:20:12.560 --> 0:20:14.760 the back of the fifth segment, just ahead of the 0:20:14.800 --> 0:20:18.600 stinger segment um initially draws. You know, we're talking about 0:20:18.600 --> 0:20:21.200 what's the difference between tails? What are tails like? This 0:20:21.359 --> 0:20:25.480 is a drastically different tail structure than you find in 0:20:25.640 --> 0:20:29.719 other creatures because the gut extends back there. I mean, 0:20:29.760 --> 0:20:32.040 the the anus is at the almost the end of 0:20:32.119 --> 0:20:35.560 the tail. That's crazy. Can you imagine if you had 0:20:35.680 --> 0:20:39.200 an appendage that you pooped out of, like if you 0:20:39.240 --> 0:20:42.280 could if you could reach into a hole and then 0:20:42.359 --> 0:20:45.720 poop in the hole, it would it would totally change 0:20:45.760 --> 0:20:49.240 our bathroom behavior, that's for sure. Now you probably wonder 0:20:49.320 --> 0:20:51.720 what happens to the scorpion when it's lost its tail 0:20:51.760 --> 0:20:56.720 and it's lost its anus, uh fleeing from a predator. Well, 0:20:57.320 --> 0:20:59.960 it essentially cannot poop again for the rest of its lie. 0:21:00.160 --> 0:21:02.959 So it ends up just inflating like a fecal balloon 0:21:03.440 --> 0:21:07.680 until it dies. That's a nightmare. Yeah, but hey, it's 0:21:07.680 --> 0:21:10.399 a living nightmare as opposed to just dying. So, I mean, 0:21:10.440 --> 0:21:14.000 that's the hard truth of survival right there. And when 0:21:14.040 --> 0:21:16.480 you've got when you've got pinching claws like a scorpion, 0:21:16.880 --> 0:21:18.840 what else really matters? Yeah, you still have your claws 0:21:18.960 --> 0:21:21.000 like the pinch the world. The creature is still functional. 0:21:21.080 --> 0:21:23.600 As we pointed out in the last episode, um, a 0:21:23.680 --> 0:21:27.600 scorpion doesn't even use its tail when it's dealing with 0:21:27.840 --> 0:21:31.040 a smaller or easier to handle prey, so so you 0:21:31.200 --> 0:21:34.880 can keep stuffing yourself with things that you cannot poop. Ever, right, 0:21:34.960 --> 0:21:36.720 it's it's not game over. It just means you can't 0:21:36.760 --> 0:21:41.200 staying and you can't poop. But life goes on, Life 0:21:42.119 --> 0:21:45.280 finds a way, you know. One of the one more 0:21:45.359 --> 0:21:48.080 thing about autotomy that I thought was interesting is that 0:21:48.200 --> 0:21:52.920 it reminds me of certain mythological tales in these mythical creatures. 0:21:53.160 --> 0:21:55.080 You know, there are tons of mythical creatures that are 0:21:55.080 --> 0:21:58.240 amalgamations of different kinds of animals. So they've got the 0:21:58.320 --> 0:22:00.960 head of a lion and the ways of an eagle 0:22:01.119 --> 0:22:06.159 and the beak of squid or something. But there are 0:22:06.240 --> 0:22:09.080 some animals that have tails that are snake tails, but 0:22:09.160 --> 0:22:11.920 they're not just snake tails as in the tail of 0:22:12.000 --> 0:22:14.960 a snake like a snake's tail, but they have a 0:22:15.040 --> 0:22:18.040 tail that is a snake, as in the front half 0:22:18.119 --> 0:22:20.440 of a snake, a snake with a head. I know, 0:22:20.560 --> 0:22:23.240 I've seen this mentioned, and at least some versions of 0:22:23.359 --> 0:22:28.280 the cerberus or caraboss, smith, the chimera, and I think 0:22:28.359 --> 0:22:32.600 the new a creature all seem to have at least 0:22:32.640 --> 0:22:35.240 in some versions that I've seen mentioned the tales that 0:22:35.560 --> 0:22:39.040