1 00:00:03,040 --> 00:00:06,119 Speaker 1: Welcome to Stuff to Blow your Mind from how Stuffworks 2 00:00:06,120 --> 00:00:14,800 Speaker 1: dot com. Hey, welcome to Stuff to Blow your Mind. 3 00:00:14,840 --> 00:00:17,239 Speaker 1: My name is Robert Lamb and I'm Joe McCormick and 4 00:00:17,320 --> 00:00:19,279 Speaker 1: Robert I got a question for you. What do you 5 00:00:19,280 --> 00:00:23,040 Speaker 1: think is the most underrated body part on the human 6 00:00:24,480 --> 00:00:26,079 Speaker 1: You could go in a lot of ways, right, you 7 00:00:26,160 --> 00:00:30,840 Speaker 1: really can. I mean, certainly, we we tend to put 8 00:00:30,840 --> 00:00:34,159 Speaker 1: more emphasis on the brain and the heart, and then 9 00:00:34,159 --> 00:00:37,239 Speaker 1: of course throughout human history confused the two and the 10 00:00:37,320 --> 00:00:39,720 Speaker 1: role they might play. Uh, you know, I think back 11 00:00:39,760 --> 00:00:43,080 Speaker 1: to the the the ancient Egyptians and their idea that 12 00:00:43,560 --> 00:00:45,680 Speaker 1: the heart was far more important than the brain, and 13 00:00:45,720 --> 00:00:48,839 Speaker 1: the brain was just to be removed and discarded, whereas 14 00:00:48,920 --> 00:00:53,920 Speaker 1: the heart had a privileged place in the funeral preparations 15 00:00:54,000 --> 00:00:56,880 Speaker 1: of dead pharaohs. But of course it's impossible for us 16 00:00:56,880 --> 00:00:59,480 Speaker 1: to underestimate the value of the heart and the brain 17 00:00:59,560 --> 00:01:01,840 Speaker 1: now since we know them to be so important. But 18 00:01:01,880 --> 00:01:03,920 Speaker 1: there are all kinds of body parts you have that 19 00:01:03,960 --> 00:01:06,680 Speaker 1: you probably just don't stop to be very thankful for 20 00:01:06,959 --> 00:01:09,240 Speaker 1: or think about very much, but they do you a 21 00:01:09,240 --> 00:01:12,520 Speaker 1: lot of good. I think about the underrated facility of 22 00:01:12,560 --> 00:01:17,959 Speaker 1: the toes. Yeah, yeah, to toes are granted toes maybe fetishized, 23 00:01:18,000 --> 00:01:20,520 Speaker 1: as as can any part of the human anatomy. Oh no, 24 00:01:20,600 --> 00:01:22,240 Speaker 1: I didn't mean that way. No, I mean they're like 25 00:01:22,400 --> 00:01:26,240 Speaker 1: usefulness and balance and movement. Oh yeah, yeah, certainly, but 26 00:01:26,240 --> 00:01:28,000 Speaker 1: but it's not something that we tend to attach our 27 00:01:28,040 --> 00:01:31,480 Speaker 1: identity to. Whereas the brain. Yeah, I mean our podcast 28 00:01:31,560 --> 00:01:33,800 Speaker 1: has had a brain on its logo in the past. 29 00:01:34,160 --> 00:01:37,160 Speaker 1: You know, the heart has all these symbolic meanings where 30 00:01:37,240 --> 00:01:40,120 Speaker 1: we want to attach our identity to them in addition 31 00:01:40,160 --> 00:01:43,520 Speaker 1: to the functions that they play. But then there are 32 00:01:43,520 --> 00:01:46,120 Speaker 1: parts of the body that we generally don't want to 33 00:01:46,160 --> 00:01:50,000 Speaker 1: think about, and we don't think about unless they are 34 00:01:50,040 --> 00:01:52,920 Speaker 1: giving us grief, unless there's something wrong with them, and 35 00:01:52,960 --> 00:01:55,840 Speaker 1: then they become the center of our existence. Right. It's 36 00:01:55,880 --> 00:01:58,040 Speaker 1: the same way that you never think about your internet 37 00:01:58,080 --> 00:02:01,120 Speaker 1: connection unless it's not working. Right. There are parts of 38 00:02:01,160 --> 00:02:03,440 Speaker 1: the body that you probably just never think about unless 39 00:02:03,480 --> 00:02:05,760 Speaker 1: something's going wrong, right, or we go to great pains 40 00:02:05,800 --> 00:02:07,520 Speaker 1: not to think about them. You know, we kind of 41 00:02:07,560 --> 00:02:09,880 Speaker 1: have all these blinders up. Really, the part of many 42 00:02:09,880 --> 00:02:12,520 Speaker 1: and animals anatomy that we're going to discuss here today 43 00:02:12,720 --> 00:02:16,480 Speaker 1: the anus. The anus today it's anus science on stuff 44 00:02:16,520 --> 00:02:18,640 Speaker 1: to blow your mind, right, and I I wanted to 45 00:02:18,680 --> 00:02:22,280 Speaker 1: do this episode really since I guess that's when I 46 00:02:22,320 --> 00:02:25,320 Speaker 1: really first found out about anus. Is. Yeah, I had 47 00:02:25,320 --> 00:02:27,280 Speaker 1: no idea. I had no idea what it would happened. 48 00:02:27,320 --> 00:02:30,040 Speaker 1: And then I read this, uh, this cool science paper 49 00:02:30,160 --> 00:02:32,280 Speaker 1: and I was like, whoa, this is this is this 50 00:02:32,320 --> 00:02:33,840 Speaker 1: is where it all comes from. This is this is 51 00:02:33,880 --> 00:02:36,240 Speaker 1: the center of all the activity. I really appreciate you 52 00:02:36,280 --> 00:02:38,840 Speaker 1: suggesting this topic because the anus turned out to be 53 00:02:38,919 --> 00:02:42,000 Speaker 1: far more interesting than I had ever imagined it is. 54 00:02:42,160 --> 00:02:44,160 Speaker 1: And that's what we're going to try and outline in 55 00:02:44,200 --> 00:02:46,440 Speaker 1: this this episode. Now, we we do have to drive 56 00:02:46,520 --> 00:02:48,959 Speaker 1: home since we are talking about the anus and there 57 00:02:49,040 --> 00:02:52,280 Speaker 1: is there's just so much not not really. I don't 58 00:02:52,280 --> 00:02:55,160 Speaker 1: think taboo is going to be a stumbling block for 59 00:02:55,240 --> 00:02:59,040 Speaker 1: us here, but the anus is so tied into our 60 00:02:58,840 --> 00:03:02,600 Speaker 1: our systems of humor, Like it is so giggle inducing. 61 00:03:02,600 --> 00:03:05,200 Speaker 1: When you when you saw this title pop up on 62 00:03:05,280 --> 00:03:09,200 Speaker 1: your your your your device or whatever program you used 63 00:03:09,240 --> 00:03:11,440 Speaker 1: to listen to your podcast, you may have giggled at 64 00:03:11,480 --> 00:03:14,919 Speaker 1: the prospect of listening to say in an hour's podcast 65 00:03:15,240 --> 00:03:18,240 Speaker 1: about the anus. Yeah, you'll probably notice that we talk 66 00:03:18,320 --> 00:03:20,519 Speaker 1: about biology a lot on the podcast. I've gotten to 67 00:03:20,520 --> 00:03:23,480 Speaker 1: where it's extremely easy to talk about, say, the biology 68 00:03:23,480 --> 00:03:26,119 Speaker 1: of sex, without making any jokes. That's something a high 69 00:03:26,120 --> 00:03:28,040 Speaker 1: school or might not be able to do. But you know, 70 00:03:28,080 --> 00:03:30,360 Speaker 1: when you talk about it enough, it's just an interesting 71 00:03:30,400 --> 00:03:33,639 Speaker 1: subject on its own. Well, sexist is its humor appeal? Well, 72 00:03:33,639 --> 00:03:36,400 Speaker 1: sex is one of these things. Sexual reproduction is a 73 00:03:36,440 --> 00:03:39,600 Speaker 1: case where I feel like most people, at least, you know, 74 00:03:39,680 --> 00:03:44,080 Speaker 1: most adults are capable of having both a humorous conversation 75 00:03:44,120 --> 00:03:48,000 Speaker 1: about and a serious conversation about. You reach that point 76 00:03:48,000 --> 00:03:52,120 Speaker 1: where you realize there is this entirely serious side to 77 00:03:52,240 --> 00:03:55,040 Speaker 1: the discussion, and you can switch back from one and 78 00:03:55,120 --> 00:04:00,000 Speaker 1: the other. But with the anus, there's it's almost gotten there. Yeah, 79 00:04:00,000 --> 00:04:04,400 Speaker 1: it's almost all humorous, unless you yourself are are a 80 00:04:04,800 --> 00:04:09,480 Speaker 1: proctologist or or or just a medical professional, or you 81 00:04:09,560 --> 00:04:13,080 Speaker 1: have had to deal with health issues related to the anus. 82 00:04:13,080 --> 00:04:17,240 Speaker 1: Otherwise it's just all the realm of body humor. Or 83 00:04:17,279 --> 00:04:20,080 Speaker 1: maybe you're somebody who studies the evolution of the anus, 84 00:04:20,120 --> 00:04:22,679 Speaker 1: which is something that we will definitely be touching on today. 85 00:04:23,040 --> 00:04:26,359 Speaker 1: These questions about whence this hole in the backs of 86 00:04:26,360 --> 00:04:29,080 Speaker 1: our bodies? Where does it come from? And what is 87 00:04:29,120 --> 00:04:31,320 Speaker 1: it doing. That's not so much what is it doing 88 00:04:31,360 --> 00:04:34,039 Speaker 1: that's pretty obvious, yes, but but the way that it 89 00:04:34,120 --> 00:04:36,160 Speaker 1: does it, the way that it's come to do it, 90 00:04:36,560 --> 00:04:40,080 Speaker 1: and just how how it functions. Uh, hopefully you will 91 00:04:40,160 --> 00:04:44,400 Speaker 1: leave this this episode with a whole new respect for 92 00:04:45,080 --> 00:04:47,839 Speaker 1: the anus of any animal. Okay, Now we wanted to 93 00:04:47,880 --> 00:04:50,680 Speaker 1: start with an interesting fact, Robert, that you came across, 94 00:04:50,720 --> 00:04:54,800 Speaker 1: actually a curious little book that you found on the internet, right, 95 00:04:54,920 --> 00:04:58,200 Speaker 1: that's right. So I was casting about for some mythology 96 00:04:58,240 --> 00:05:00,080 Speaker 1: related to the anus and we'll we'll get to some 97 00:05:00,120 --> 00:05:03,120 Speaker 1: of that later on gods and so forth. Yeah, yeah, 98 00:05:03,520 --> 00:05:05,400 Speaker 1: I figured, you know, it's always good to throw in 99 00:05:05,440 --> 00:05:09,080 Speaker 1: a little mythology a few monsters when we can. And 100 00:05:09,120 --> 00:05:12,000 Speaker 1: I was just plugging in different ancient cultures. I plugged 101 00:05:12,040 --> 00:05:14,600 Speaker 1: in the ancient Egyptians to see what what was up, 102 00:05:14,600 --> 00:05:17,080 Speaker 1: and I ran across this book, The herbal Lore of 103 00:05:17,160 --> 00:05:20,480 Speaker 1: Wise Women and Warp Cunners The Healing Power of Medicinal 104 00:05:20,520 --> 00:05:24,359 Speaker 1: Plants by wolf D. Storrel, and he points out that 105 00:05:24,360 --> 00:05:27,440 Speaker 1: the doctors of ancient cultures were part of the priesthood, 106 00:05:27,480 --> 00:05:31,320 Speaker 1: and for the ancient Egyptians, each physician was responsible for 107 00:05:31,400 --> 00:05:35,760 Speaker 1: curing only one illness. So the pharaoh was attended by 108 00:05:35,800 --> 00:05:39,920 Speaker 1: such specialist as the Royal Keeper of Pharaoh's left eye, 109 00:05:40,040 --> 00:05:42,960 Speaker 1: the Royal Keeper of the Pharaoh's right eye, and then 110 00:05:43,120 --> 00:05:46,880 Speaker 1: most importantly of all, perhaps the shepherd of the royal 111 00:05:46,920 --> 00:05:51,880 Speaker 1: anus or the nerofoot. If I am reading that correctly, 112 00:05:52,240 --> 00:05:55,200 Speaker 1: the Shepherd of the Royal anus. Now laugh, you may laugh, 113 00:05:55,279 --> 00:05:57,799 Speaker 1: you may, but this is actually a kind of interesting 114 00:05:57,800 --> 00:06:01,280 Speaker 1: because it's an early example of medical special realizations, something 115 00:06:01,320 --> 00:06:04,120 Speaker 1: that we've seen again in the modern world. There are 116 00:06:04,120 --> 00:06:07,839 Speaker 1: a lot of reasons that a pharaoh might have need 117 00:06:07,960 --> 00:06:11,839 Speaker 1: needed to have a special attendant to problems dealing with 118 00:06:11,880 --> 00:06:15,000 Speaker 1: their anus, because a lot of the problems you can 119 00:06:15,120 --> 00:06:17,840 Speaker 1: have with your ans can be related to, say, certain 120 00:06:17,880 --> 00:06:21,200 Speaker 1: types of over indulgent diet. Yeah, I mean just in general, 121 00:06:21,279 --> 00:06:24,560 Speaker 1: there's just so many digestive ailments they can occur in 122 00:06:24,640 --> 00:06:26,760 Speaker 1: one's life. You see this pop up in a number 123 00:06:26,800 --> 00:06:30,560 Speaker 1: of different traditional practices, for instance, moodras. Are you're familiar 124 00:06:30,600 --> 00:06:34,000 Speaker 1: with moodra's, I'm not sure. So this is a whenever 125 00:06:34,040 --> 00:06:36,200 Speaker 1: you see someone in a yoga pose and they're making 126 00:06:36,279 --> 00:06:38,560 Speaker 1: or they're a meditative state and they're making a particular 127 00:06:38,720 --> 00:06:41,640 Speaker 1: little hand uh motions. They're holding their fingers together in 128 00:06:41,640 --> 00:06:45,440 Speaker 1: a particular pattern. That is a moodra And I've read 129 00:06:45,520 --> 00:06:47,080 Speaker 1: up on them in the past, and when you start 130 00:06:47,120 --> 00:06:49,240 Speaker 1: looking at the different moods that they have them for 131 00:06:49,320 --> 00:06:53,440 Speaker 1: different things, it's you know, it's about channeling energy and whatnot. Uh. 132 00:06:53,520 --> 00:06:56,320 Speaker 1: But it seems like most of them are related to digestion, 133 00:06:56,920 --> 00:07:00,120 Speaker 1: which which makes sense when you when you think about 134 00:07:00,160 --> 00:07:03,680 Speaker 1: all the digestive ailments that can afflict an individual over 135 00:07:03,720 --> 00:07:06,360 Speaker 1: the course of their lifetime. Totally, now the sky's storial 136 00:07:06,480 --> 00:07:09,120 Speaker 1: that I want to say, this book does appear to 137 00:07:09,200 --> 00:07:12,160 Speaker 1: be kind of in a liminal or less than totally 138 00:07:12,200 --> 00:07:15,240 Speaker 1: authoritative space. I think this guy deals in some some 139 00:07:15,440 --> 00:07:18,880 Speaker 1: kind of natural apathy areas and stuff. But it was 140 00:07:19,040 --> 00:07:21,800 Speaker 1: curious and had some fun ideas in it. Yeah, he's 141 00:07:21,840 --> 00:07:24,720 Speaker 1: he's not an Egyptologist or anything. But but I I 142 00:07:24,840 --> 00:07:26,600 Speaker 1: have to point out that I did find this bit 143 00:07:26,600 --> 00:07:28,880 Speaker 1: about the Shepherd of the Royal Anist backed up in 144 00:07:28,960 --> 00:07:31,120 Speaker 1: some other works, including Medicine in the Days of the 145 00:07:31,200 --> 00:07:37,880 Speaker 1: Pharaohs by dermatologist Bruno Hella and cardiologist Bernard Ziskins from 146 00:07:37,960 --> 00:07:41,360 Speaker 1: two thousand five. Yes, I think that fact is well attested, 147 00:07:41,520 --> 00:07:43,880 Speaker 1: but also I just wanted to follow up on this 148 00:07:44,000 --> 00:07:48,200 Speaker 1: other idea. In his book, Storial argues that every culture 149 00:07:48,360 --> 00:07:52,320 Speaker 1: has a primary external metaphor that it uses to understand 150 00:07:52,400 --> 00:07:55,560 Speaker 1: medical insights, which is like a model through which to 151 00:07:55,680 --> 00:07:59,280 Speaker 1: visualize health and human function. So for the ancient Mesopotamians, 152 00:07:59,320 --> 00:08:01,840 Speaker 1: he says, this moll was the movements of the planets 153 00:08:01,880 --> 00:08:05,080 Speaker 1: through the zodiac. For the ancient Indians, he says one 154 00:08:05,120 --> 00:08:07,440 Speaker 1: of the models they used most often was the cycle 155 00:08:07,560 --> 00:08:10,800 Speaker 1: of the seasons from spring to pre monsoon to monsoon. 156 00:08:11,720 --> 00:08:14,600 Speaker 1: And for the ancient Egyptians, this model, he says, was 157 00:08:14,760 --> 00:08:19,120 Speaker 1: the Nile River quote regularly cleansing and fertilizing the thousand 158 00:08:19,200 --> 00:08:23,120 Speaker 1: mile long oasis. Just as the Nile flows from Nubia 159 00:08:23,160 --> 00:08:26,920 Speaker 1: to the Mediterranean, so the elementary tract, also known as 160 00:08:26,960 --> 00:08:30,240 Speaker 1: the digestive tract, flows from the mouth to the organs 161 00:08:30,280 --> 00:08:33,960 Speaker 1: of elimination in the human body, bringing health and cleaning 162 00:08:34,000 --> 00:08:37,719 Speaker 1: out impurities. Now, upon reading this, I couldn't help but 163 00:08:37,840 --> 00:08:40,520 Speaker 1: notice that if this is true, what what he says 164 00:08:40,559 --> 00:08:44,960 Speaker 1: about the you know, this metaphor of human health being 165 00:08:45,040 --> 00:08:49,480 Speaker 1: the Nile River, the Nile River delta, which is this lush, fertile, 166 00:08:49,640 --> 00:08:54,640 Speaker 1: agriculturally productive region that sustains the civilization around it. In 167 00:08:54,760 --> 00:08:59,040 Speaker 1: the metaphor, the delta would be the rectum in the anus. Yeah, 168 00:08:59,080 --> 00:09:01,160 Speaker 1: this reminds me of something that that I was thinking 169 00:09:01,160 --> 00:09:03,920 Speaker 1: about researching this topic as well. Like we think about 170 00:09:04,040 --> 00:09:07,959 Speaker 1: the the the track of digestion in the human experience, 171 00:09:08,080 --> 00:09:12,160 Speaker 1: the linear experience of digestion, uh, And I wondered what 172 00:09:12,320 --> 00:09:15,520 Speaker 1: extent uh that plays a role and just our understanding 173 00:09:15,559 --> 00:09:18,440 Speaker 1: of time. When we were talking about time in our 174 00:09:18,480 --> 00:09:22,560 Speaker 1: episode that this present moment we talked about comparing time 175 00:09:22,720 --> 00:09:26,000 Speaker 1: to the river we see flowing past us and so forth. 176 00:09:26,800 --> 00:09:29,160 Speaker 1: But here we have this river flowing inside us that 177 00:09:29,320 --> 00:09:33,000 Speaker 1: is an even closer uh metaphor, that's that makes itself 178 00:09:33,040 --> 00:09:36,200 Speaker 1: readily available. So you're thinking, maybe if we had evolved 179 00:09:36,440 --> 00:09:39,240 Speaker 1: to have large brains, but to not have a one 180 00:09:39,280 --> 00:09:41,880 Speaker 1: way digestive tract instead to have I don't know, one 181 00:09:41,920 --> 00:09:44,280 Speaker 1: of these open sack mouths We're going to talk about 182 00:09:44,320 --> 00:09:46,960 Speaker 1: more as the episode goes on, where you just sort 183 00:09:47,000 --> 00:09:50,240 Speaker 1: of like eat and digest and poop all through the 184 00:09:50,320 --> 00:09:53,160 Speaker 1: same one orifice and sack. Would that lead us to 185 00:09:53,200 --> 00:09:55,840 Speaker 1: have a different conception of sort of the the order 186 00:09:55,960 --> 00:09:59,760 Speaker 1: of things in history, and the meaning of structure and 187 00:09:59,800 --> 00:10:02,760 Speaker 1: our lives. Yes, I, as we proceed here, I challenge 188 00:10:02,800 --> 00:10:07,600 Speaker 1: anyone out there too imagine an alien life woman, intelligent 189 00:10:07,640 --> 00:10:10,959 Speaker 1: alien life form with one of these sort of rival 190 00:10:11,080 --> 00:10:15,280 Speaker 1: digestive systems, and imagine how that rival digestive system might 191 00:10:15,600 --> 00:10:20,040 Speaker 1: impact their perception of time or the universe. Take up 192 00:10:20,080 --> 00:10:24,920 Speaker 1: the challenge. Alright, Well, on that note, we should probably begin, uh, 193 00:10:25,280 --> 00:10:27,839 Speaker 1: well at the beginning or at the end if you'd rather, 194 00:10:28,320 --> 00:10:32,680 Speaker 1: by discussing just what the anus is and what it does? Yeah, 195 00:10:32,760 --> 00:10:35,880 Speaker 1: what is your anus and what does it do? Uh? 196 00:10:35,960 --> 00:10:38,679 Speaker 1: The anus? Of course I shouldn't giggle, should I know? 197 00:10:38,880 --> 00:10:41,400 Speaker 1: I think a little a little giggling is uh just 198 00:10:41,480 --> 00:10:45,080 Speaker 1: cannot be avoided thanks human culture. The anus, of course, 199 00:10:45,400 --> 00:10:47,559 Speaker 1: as we all know, is the point of termination for 200 00:10:47,640 --> 00:10:51,880 Speaker 1: the digestive system. It's the exit point for solid waste 201 00:10:51,960 --> 00:10:53,840 Speaker 1: in the body. And I think one of the things 202 00:10:53,920 --> 00:10:57,439 Speaker 1: we should regularly stop and be thankful for is the 203 00:10:57,520 --> 00:11:00,640 Speaker 1: fact that we have an anus. It does one job. 204 00:11:01,360 --> 00:11:04,400 Speaker 1: It is dedicated to the elimination of solid waste. There 205 00:11:04,440 --> 00:11:08,520 Speaker 1: are lots of complex animals that are not like this. Um. 206 00:11:09,000 --> 00:11:11,600 Speaker 1: We are going to talk more about some simpler animals 207 00:11:11,679 --> 00:11:14,720 Speaker 1: that have like a single opening through which everything takes place, 208 00:11:15,040 --> 00:11:19,360 Speaker 1: but even complex animals like birds, reptiles, amphibians, monitory ms 209 00:11:19,840 --> 00:11:23,080 Speaker 1: do not have an anus, but a cloaca, which serves 210 00:11:23,160 --> 00:11:27,200 Speaker 1: as a general purpose opening for solid waste, liquid waste, 211 00:11:27,400 --> 00:11:31,240 Speaker 1: and reproduction, kind of a fusing of the different categories 212 00:11:31,280 --> 00:11:34,520 Speaker 1: together exactly. So, if you imagine we had evolved from 213 00:11:34,720 --> 00:11:39,200 Speaker 1: birds instead of mammals, we would probably still defecate, urinate, 214 00:11:39,360 --> 00:11:42,360 Speaker 1: and give birth all through the same hole. Now, maybe 215 00:11:42,400 --> 00:11:44,439 Speaker 1: if that was how we were, we wouldn't mind, But 216 00:11:44,800 --> 00:11:47,680 Speaker 1: I don't know. I think most humans are probably glad 217 00:11:47,760 --> 00:11:49,640 Speaker 1: that things don't have to be that way. Well, I 218 00:11:49,920 --> 00:11:52,200 Speaker 1: think we should also be thankful that humans don't yet 219 00:11:52,320 --> 00:11:56,199 Speaker 1: have the power to decide like where their waste elimination 220 00:11:57,400 --> 00:11:59,800 Speaker 1: or if this will be and how it functions, because 221 00:11:59,840 --> 00:12:01,880 Speaker 1: we would we put it down there. We'd probably put 222 00:12:01,920 --> 00:12:04,319 Speaker 1: it down there on our heel, so we could discreetly 223 00:12:04,400 --> 00:12:06,880 Speaker 1: defecate as far from the rest of our our body 224 00:12:06,960 --> 00:12:10,760 Speaker 1: as possible. I have often wondered that same exact thing. 225 00:12:10,880 --> 00:12:14,000 Speaker 1: Why doesn't defecation happen at like the end of a 226 00:12:14,160 --> 00:12:17,960 Speaker 1: tale or something? Something farther away from you. But then again, 227 00:12:18,000 --> 00:12:20,079 Speaker 1: why would it need to And once you've got a 228 00:12:20,160 --> 00:12:22,400 Speaker 1: tale that you need to defecate through, what happens if 229 00:12:22,400 --> 00:12:24,720 Speaker 1: it gets chopped off something? And that will come up 230 00:12:24,760 --> 00:12:26,360 Speaker 1: in this episode. Hey, it has come up in the 231 00:12:26,440 --> 00:12:30,360 Speaker 1: previous episode. Uh, there's it's the anus is important and 232 00:12:30,440 --> 00:12:33,800 Speaker 1: therefore it really needs to be core and center to 233 00:12:34,040 --> 00:12:36,720 Speaker 1: the the primary trunk of the body. Now, if you're thinking, 234 00:12:36,840 --> 00:12:39,760 Speaker 1: come on, guys, or if you're not on board yet, right, 235 00:12:39,840 --> 00:12:41,800 Speaker 1: you know you're thinking, like, how can we really do 236 00:12:41,880 --> 00:12:44,120 Speaker 1: an episode on the anus? It's just a hole that 237 00:12:44,200 --> 00:12:46,679 Speaker 1: stuff comes out of. What could there be to say 238 00:12:46,720 --> 00:12:48,839 Speaker 1: about it? I would say that the anus is a 239 00:12:48,960 --> 00:12:53,079 Speaker 1: surprisingly complex organ, uh, and so I think maybe we 240 00:12:53,120 --> 00:12:57,000 Speaker 1: should look at its complexity and what it has to do. Indeed, 241 00:12:57,120 --> 00:12:59,120 Speaker 1: so as we dive in here, I want to turn 242 00:12:59,160 --> 00:13:01,800 Speaker 1: to the words of Mary Roach, who wrote a wonderful 243 00:13:01,840 --> 00:13:05,400 Speaker 1: book several years back, Gulp Adventures on the Alimentary Canal. 244 00:13:06,520 --> 00:13:09,319 Speaker 1: I've referenced this in other episodes. It's just a wonderful 245 00:13:09,520 --> 00:13:14,760 Speaker 1: exploration of human digestion and some additional topics. For instance, 246 00:13:14,760 --> 00:13:16,600 Speaker 1: there's a whole section in the book where she talks 247 00:13:16,600 --> 00:13:20,480 Speaker 1: about the practice of smuggling things in one's rectum and 248 00:13:20,679 --> 00:13:24,480 Speaker 1: sort of the science of that practice. But here's a 249 00:13:24,520 --> 00:13:28,040 Speaker 1: here's a wonderful quote where she talks about the anus quote. 250 00:13:28,080 --> 00:13:31,599 Speaker 1: Anal tissue is among the most densely innervated on the 251 00:13:31,720 --> 00:13:34,640 Speaker 1: human body. It has to be. It requires a lot 252 00:13:34,760 --> 00:13:37,800 Speaker 1: of information to do its job. The anus has to 253 00:13:37,880 --> 00:13:40,439 Speaker 1: be able to tell what's knocking at its door, is 254 00:13:40,520 --> 00:13:45,360 Speaker 1: it solid, liquid, or gas, and then selectively release either 255 00:13:45,520 --> 00:13:48,400 Speaker 1: all of it or one part of it. The consequences 256 00:13:48,480 --> 00:13:52,800 Speaker 1: of a misread are dire. They certainly are. Now. Yeah, 257 00:13:53,360 --> 00:13:56,079 Speaker 1: though I wonder I've had this thought before. Okay, So, 258 00:13:56,480 --> 00:14:01,520 Speaker 1: in modern polite society, you don't want to just whoop anytime, right, 259 00:14:01,679 --> 00:14:03,480 Speaker 1: you know, you want to be able to control that 260 00:14:03,640 --> 00:14:07,199 Speaker 1: for like cultural and privacy reasons, and maybe for some 261 00:14:07,360 --> 00:14:11,600 Speaker 1: hygiene reasons. But if you imagine us living in the wild, 262 00:14:12,559 --> 00:14:15,960 Speaker 1: what's the reason that you would need to be able 263 00:14:16,040 --> 00:14:19,720 Speaker 1: to control when you poop? Why does that matter? Well, 264 00:14:20,120 --> 00:14:23,120 Speaker 1: I mean, controlling when you defecate is really important because 265 00:14:23,160 --> 00:14:26,000 Speaker 1: outside of the particular human concerns, this is an issue 266 00:14:26,040 --> 00:14:29,720 Speaker 1: of hygiene but also survival. Being able to choose where 267 00:14:29,800 --> 00:14:33,120 Speaker 1: and how you defecate. It's tremendously important and it entails 268 00:14:33,200 --> 00:14:37,120 Speaker 1: everything from not pooping where you eat, to say, pooping 269 00:14:37,160 --> 00:14:39,440 Speaker 1: in a place where you can easily hide the stuff. 270 00:14:39,600 --> 00:14:42,400 Speaker 1: That we see this every day, or at least cat 271 00:14:42,480 --> 00:14:45,600 Speaker 1: owners do with a litter box, that the cat wants 272 00:14:45,680 --> 00:14:48,200 Speaker 1: to poop where it can hide its poop because it 273 00:14:48,320 --> 00:14:53,920 Speaker 1: has this uh evolved necessity to disguise the scent of 274 00:14:54,040 --> 00:14:57,360 Speaker 1: its of its activity. And then also sometimes you want 275 00:14:57,400 --> 00:15:00,320 Speaker 1: to produce the right sort of round poop that will 276 00:15:00,440 --> 00:15:03,160 Speaker 1: roll away from your body. This is apparently the case 277 00:15:03,200 --> 00:15:05,600 Speaker 1: with with goats. If you've ever been to a petting 278 00:15:05,680 --> 00:15:09,200 Speaker 1: zoo with a child, for instance, you probably noticed that 279 00:15:09,360 --> 00:15:12,000 Speaker 1: the round poop is basically falling out of the goats 280 00:15:12,040 --> 00:15:15,000 Speaker 1: at all times. And uh and and that he's round 281 00:15:15,200 --> 00:15:17,000 Speaker 1: so that it can roll away. Is this kind of 282 00:15:17,080 --> 00:15:19,040 Speaker 1: like when it comes out sort of like a spray 283 00:15:19,120 --> 00:15:22,840 Speaker 1: of coffee beans. Yeah, just kind of like tumbling coffee 284 00:15:22,880 --> 00:15:25,720 Speaker 1: beans and the pebbles. Yeah. And apparently the purpose is 285 00:15:25,960 --> 00:15:28,320 Speaker 1: these things would roll away. It's self hiding poop. They 286 00:15:28,360 --> 00:15:30,520 Speaker 1: don't have to bury anything at all. Now I'm curious 287 00:15:30,520 --> 00:15:33,800 Speaker 1: about what you said about the idea that controlling when 288 00:15:33,840 --> 00:15:37,200 Speaker 1: you defecate plays a role in survival? What what would 289 00:15:37,280 --> 00:15:40,120 Speaker 1: the role in survival be? Well, I ran across a 290 00:15:40,240 --> 00:15:42,480 Speaker 1: paper a few years back because from two thousand thirteen, 291 00:15:42,600 --> 00:15:47,320 Speaker 1: The Control of Defecation in Humans and Evolutionary Advantage by 292 00:15:47,480 --> 00:15:52,560 Speaker 1: Italian bowl experts UH G. Besati and V. Villainacci, And 293 00:15:52,680 --> 00:15:55,880 Speaker 1: it breaks down the particular human side of this. Uh 294 00:15:55,960 --> 00:15:58,360 Speaker 1: and this is something I've explored before when I was 295 00:15:58,400 --> 00:16:01,240 Speaker 1: looking at the Monster or Science of the Googlies. You 296 00:16:01,280 --> 00:16:05,360 Speaker 1: remember Googlies right before film. The cover was a little 297 00:16:05,440 --> 00:16:09,000 Speaker 1: monster popping out of the toilet. Yeah, tagline taste, They'll 298 00:16:09,000 --> 00:16:11,920 Speaker 1: get you in the end. But it made me think 299 00:16:11,960 --> 00:16:15,040 Speaker 1: it's like, all right, well, humans are are vulnerable when 300 00:16:15,040 --> 00:16:18,400 Speaker 1: they're on the toilet. All animals are vulnerable to some 301 00:16:18,520 --> 00:16:23,800 Speaker 1: extent when they are defecating. So how does evolution plan 302 00:16:23,880 --> 00:16:25,960 Speaker 1: to all of this? Well, in this case, the authors 303 00:16:26,040 --> 00:16:28,920 Speaker 1: point out that human fecal matter would have certainly put 304 00:16:29,000 --> 00:16:32,440 Speaker 1: early humans at risk from the apex predators of your 305 00:16:33,200 --> 00:16:36,320 Speaker 1: So if you run a human fecal sample, modern or ancient, 306 00:16:36,440 --> 00:16:42,440 Speaker 1: through complex gas uh chromatographic or mass us spectrometric analysis, 307 00:16:42,720 --> 00:16:46,240 Speaker 1: you'll discover that quote, human feces are rich in volatile 308 00:16:46,320 --> 00:16:50,560 Speaker 1: compounds likely to be identified by potential predators. So volatile compounds, 309 00:16:50,600 --> 00:16:55,280 Speaker 1: what does that mean? Smell? Yeah, And as we've driven 310 00:16:55,320 --> 00:16:57,960 Speaker 1: home before on the podcast, I think our human sense 311 00:16:58,000 --> 00:17:01,360 Speaker 1: of smell is rather limited, like we're seeing in grungy 312 00:17:01,440 --> 00:17:04,520 Speaker 1: black and white, whereas something like an apex predator or 313 00:17:04,560 --> 00:17:07,159 Speaker 1: something like even our our pet dogs and cats, especially 314 00:17:07,240 --> 00:17:11,160 Speaker 1: the dogs, they have an entirely different, like full color 315 00:17:11,359 --> 00:17:14,200 Speaker 1: HD experience of things. Well, Robert, have you ever owned 316 00:17:14,240 --> 00:17:16,240 Speaker 1: a dog. It's been a very long time. I've mostly 317 00:17:16,280 --> 00:17:18,520 Speaker 1: been a cat owner my entire adult life. I think 318 00:17:18,680 --> 00:17:21,080 Speaker 1: most people who have dogs will know what I'm talking about. 319 00:17:21,280 --> 00:17:23,840 Speaker 1: Dogs love poop. They want to smell all of the poop. 320 00:17:24,080 --> 00:17:26,560 Speaker 1: When I take my dog out on a walk, it's disgusting. 321 00:17:26,640 --> 00:17:29,560 Speaker 1: Other people's dogs leave their poop on the sidewalk wherever, 322 00:17:29,640 --> 00:17:31,320 Speaker 1: and he wants to go to all of it. And 323 00:17:31,440 --> 00:17:33,600 Speaker 1: if you try to pull him away, like no, Charlie, 324 00:17:33,680 --> 00:17:35,720 Speaker 1: you don't want to get into that, He's like no, no, 325 00:17:35,880 --> 00:17:39,800 Speaker 1: I need to. Well, there's information there. There's there's information 326 00:17:39,880 --> 00:17:42,520 Speaker 1: on a level that that that humans can barely grass. 327 00:17:42,560 --> 00:17:44,440 Speaker 1: We just know it doesn't smell pleasant, or it certainly 328 00:17:44,520 --> 00:17:48,680 Speaker 1: Lena doesn't look pleasant, but this is important environmental information 329 00:17:48,840 --> 00:17:51,280 Speaker 1: to the dog, right right. So to take us back 330 00:17:51,320 --> 00:17:53,920 Speaker 1: to the paper, then the idea is that while we 331 00:17:54,080 --> 00:17:58,119 Speaker 1: are pooping, we're producing smells that advertise our vulnerability to 332 00:17:58,200 --> 00:18:01,959 Speaker 1: potential predators exactly. And the full conclusion from the from 333 00:18:02,000 --> 00:18:04,399 Speaker 1: the paper I think is rather great. They say, quote, 334 00:18:04,440 --> 00:18:08,720 Speaker 1: we hypothesize that the voluntary control of defecation by our ancestors, 335 00:18:09,200 --> 00:18:12,680 Speaker 1: together with greater brain volume, erect stature, opposable thumbs, and 336 00:18:12,800 --> 00:18:16,000 Speaker 1: other changes, may have contributed to the successful march of 337 00:18:16,080 --> 00:18:19,840 Speaker 1: hominids along the road of evolution. In fact, by deciding when, 338 00:18:20,160 --> 00:18:23,359 Speaker 1: how and where to defecate may have several advantages in 339 00:18:23,400 --> 00:18:27,280 Speaker 1: the complex prey predator relationship because spores are left in 340 00:18:27,359 --> 00:18:30,480 Speaker 1: places undetectable by predators, or there are no fecal tracks 341 00:18:30,720 --> 00:18:36,840 Speaker 1: who sent maybe easily individualated by prey genius. So we've 342 00:18:37,080 --> 00:18:40,440 Speaker 1: we figured out evolutionarily speaking, that you need to know 343 00:18:40,800 --> 00:18:43,920 Speaker 1: when to poop, because if you just poop anytime, you 344 00:18:44,000 --> 00:18:47,800 Speaker 1: may be squandering opportunities or putting yourself in danger exactly. 345 00:18:48,320 --> 00:18:53,359 Speaker 1: So let's break down how that actually functions biologically, though, Like, 346 00:18:53,480 --> 00:18:57,560 Speaker 1: what is the actual biology of pooping. Okay, So the 347 00:18:57,600 --> 00:19:00,560 Speaker 1: first step is six to eight times a day a 348 00:19:00,680 --> 00:19:05,720 Speaker 1: peristaltic muscle contraction, called a mass movement, squeezes the contents 349 00:19:05,800 --> 00:19:09,359 Speaker 1: of the colon along the path. Yeah, and peristalsis is 350 00:19:09,480 --> 00:19:13,440 Speaker 1: the word for a wave of muscle contraction and relaxation 351 00:19:13,560 --> 00:19:17,240 Speaker 1: that travels down the length of a tube inside the body. So, 352 00:19:17,400 --> 00:19:19,680 Speaker 1: if you've ever run your fingers down the length of 353 00:19:19,720 --> 00:19:23,000 Speaker 1: a sausage casing to squeeze the sausage out, or if 354 00:19:23,040 --> 00:19:25,520 Speaker 1: you've ever tried to push the last bits of icing 355 00:19:25,600 --> 00:19:29,320 Speaker 1: out of a piping bag, you have roughly simulated peristalsis 356 00:19:29,440 --> 00:19:31,320 Speaker 1: on that on that tube. I want to say, this 357 00:19:31,440 --> 00:19:34,679 Speaker 1: is also akin to how an earthworm moves, right, It's 358 00:19:34,720 --> 00:19:38,760 Speaker 1: kind of this. Uh. This wave a wave of muscle 359 00:19:38,840 --> 00:19:42,240 Speaker 1: contraction running down the length of of a cylindrical object, 360 00:19:42,320 --> 00:19:44,679 Speaker 1: And in the sense of a hollow tube, that cylindrical 361 00:19:44,800 --> 00:19:49,119 Speaker 1: object has its contents continually pushed down the length of it. 362 00:19:50,320 --> 00:19:53,399 Speaker 1: So what happens next. The material pushes against the rectum 363 00:19:53,440 --> 00:19:57,560 Speaker 1: wall with enough pressure to trigger the stretch receptors, and 364 00:19:57,640 --> 00:20:01,720 Speaker 1: this triggers the defication reflects now. This entails a simultaneous 365 00:20:01,760 --> 00:20:05,480 Speaker 1: contraction of the rectal wall muscles and a relaxation of 366 00:20:05,560 --> 00:20:09,440 Speaker 1: the anal sphincter. Little known fact people actually have. I 367 00:20:09,520 --> 00:20:13,040 Speaker 1: had no idea until last night. Two anal sphincters. Did 368 00:20:13,080 --> 00:20:15,000 Speaker 1: you know you have to? No? No, I just thought 369 00:20:15,040 --> 00:20:17,480 Speaker 1: there was the one. No, You've got to The internal 370 00:20:17,600 --> 00:20:21,879 Speaker 1: anal sphincter is involuntary, so it holds up everything until 371 00:20:21,960 --> 00:20:25,280 Speaker 1: a certain threshold of rectal wall stretching is reached, at 372 00:20:25,320 --> 00:20:28,440 Speaker 1: which point it automatically says, okay, time to open the gate. 373 00:20:28,960 --> 00:20:31,639 Speaker 1: But then you've still got the external anal sphincter. And 374 00:20:31,760 --> 00:20:35,720 Speaker 1: this is what's under conscious executive control, perhaps for the 375 00:20:36,160 --> 00:20:39,040 Speaker 1: reasons hypothesized by the researchers we were just talking about. 376 00:20:39,160 --> 00:20:41,639 Speaker 1: It's like in a submarine movie when they're gonna launch 377 00:20:41,720 --> 00:20:44,520 Speaker 1: a nuclear missile. Yeah, you have to have like both 378 00:20:44,680 --> 00:20:47,240 Speaker 1: the key individuals push the button at the same time 379 00:20:47,920 --> 00:20:51,239 Speaker 1: because otherwise there will be disastrous consequence. Right, I've got 380 00:20:51,320 --> 00:20:54,640 Speaker 1: the missile key. Al right. So yeah, this is where 381 00:20:54,720 --> 00:20:57,560 Speaker 1: human choice enters the picture. Uh A, poop your own 382 00:20:57,560 --> 00:21:01,040 Speaker 1: adventure book, if you will, So you might choose to 383 00:21:01,200 --> 00:21:04,520 Speaker 1: bear down, and this will raise the pressure on the 384 00:21:04,560 --> 00:21:09,359 Speaker 1: rectum walls to prematurely trigger deification. So this is again 385 00:21:09,440 --> 00:21:11,440 Speaker 1: part of the choice. It's not only the idea of 386 00:21:11,520 --> 00:21:14,399 Speaker 1: the well I'm not getting ready to go yet inner sphincter. 387 00:21:14,720 --> 00:21:17,600 Speaker 1: I'm going to go seek a spot behind a bush. 388 00:21:17,880 --> 00:21:20,720 Speaker 1: You can also say, actually, I'm ready now, let's go 389 00:21:20,800 --> 00:21:25,440 Speaker 1: ahead and expedite this process. But again, likewise you can 390 00:21:25,560 --> 00:21:28,639 Speaker 1: hold it back. But the larger and more liquid the load, 391 00:21:28,920 --> 00:21:33,240 Speaker 1: the harder this is. Roacha quotes so one gut expert 392 00:21:33,320 --> 00:21:36,760 Speaker 1: in gulp as saying, quote, not even the sphincter of 393 00:21:36,880 --> 00:21:41,399 Speaker 1: Hercules can hold back water. I just I like that 394 00:21:41,640 --> 00:21:46,000 Speaker 1: by the sphincter of Hercules. I like the idea that 395 00:21:46,320 --> 00:21:49,520 Speaker 1: since Hercules is very strong, like he's got big muscles 396 00:21:49,600 --> 00:21:51,920 Speaker 1: on his arms and legs and back, he must also 397 00:21:52,040 --> 00:21:55,120 Speaker 1: have an especially strong sphincter muscle. Of course he would. 398 00:21:55,119 --> 00:21:57,360 Speaker 1: I mean, just if you have the blood of God's 399 00:21:57,760 --> 00:22:00,920 Speaker 1: running through your body, if you're a hybrid of of 400 00:22:01,119 --> 00:22:04,560 Speaker 1: humanity and deity, like, why would the why would the 401 00:22:04,560 --> 00:22:07,840 Speaker 1: anus be off limits? Why would that be untouched by 402 00:22:08,480 --> 00:22:10,560 Speaker 1: by the I corps. I want to hear from the 403 00:22:10,880 --> 00:22:13,879 Speaker 1: health and wellness experts out there in the audience, if 404 00:22:13,920 --> 00:22:16,800 Speaker 1: you know this fact does muscle training actually make your 405 00:22:16,840 --> 00:22:21,200 Speaker 1: sphincter stronger? I want to know. Uh. Interbook Roach also 406 00:22:21,320 --> 00:22:25,520 Speaker 1: quotes physician Robert Rosenbluth who says, think of it, no 407 00:22:25,840 --> 00:22:29,800 Speaker 1: engineer could design something as multi functional and fine tuned 408 00:22:29,960 --> 00:22:32,399 Speaker 1: as an anus. And then he points out that to 409 00:22:32,680 --> 00:22:36,040 Speaker 1: to call someone an anus or another crude word for anus, 410 00:22:36,359 --> 00:22:39,960 Speaker 1: that you're ultimately quote really bragging them up. Yeah, it's 411 00:22:40,000 --> 00:22:43,200 Speaker 1: saying like you are a fine tuned specimen. Nature made 412 00:22:43,240 --> 00:22:45,840 Speaker 1: you perfect. Yeah. And this comes back to the idea 413 00:22:45,880 --> 00:22:48,679 Speaker 1: of the shepherd of the anus. I think because when 414 00:22:48,760 --> 00:22:51,240 Speaker 1: we were talking about this in an email chain yesterday 415 00:22:51,640 --> 00:22:54,080 Speaker 1: before we recorded the episode, it was brought up, well, 416 00:22:54,440 --> 00:22:56,800 Speaker 1: there's only one anus, why would you need a shepherd. 417 00:22:56,880 --> 00:22:59,680 Speaker 1: A shepherd tends to a flock of sheep, and I 418 00:22:59,720 --> 00:23:02,159 Speaker 1: would wondering, Well, maybe the scenario here is more than 419 00:23:02,240 --> 00:23:06,520 Speaker 1: the anus is the shepherd, because the anus controls what 420 00:23:06,760 --> 00:23:09,040 Speaker 1: comes in and out. It has such a vital role. 421 00:23:09,080 --> 00:23:11,000 Speaker 1: It's kind of like the shepherd. It's the well, the 422 00:23:11,040 --> 00:23:14,240 Speaker 1: shepherd is the gatekeeper. Yeah, it is the shepherd of poops, 423 00:23:14,280 --> 00:23:18,160 Speaker 1: the gatekeeper of fecal matter. Yeah. Alright, Well, on that note, 424 00:23:18,400 --> 00:23:20,680 Speaker 1: we should probably take our first break, and when we 425 00:23:20,800 --> 00:23:23,760 Speaker 1: come back, we're gonna talk a little bit about mythology 426 00:23:23,840 --> 00:23:29,040 Speaker 1: and monsters before we descend into the world of anal evolution. 427 00:23:30,040 --> 00:23:34,439 Speaker 1: Than all right, we're back now. If you have been 428 00:23:34,520 --> 00:23:36,919 Speaker 1: listening to the show for a while, you've probably listened 429 00:23:36,960 --> 00:23:41,400 Speaker 1: to our episode on the Cuteness Monster Spectrum we discussed 430 00:23:41,720 --> 00:23:46,360 Speaker 1: back in October, where we talked about monsters, especially monsters 431 00:23:46,400 --> 00:23:51,400 Speaker 1: from Japanese folklore that combine elements of cuteness and horror 432 00:23:51,480 --> 00:23:54,960 Speaker 1: and monstrosity. And one of those monsters we talked about 433 00:23:55,119 --> 00:23:59,439 Speaker 1: was a little water dwelling demon called the Kappa. Oh yes, Now, 434 00:23:59,560 --> 00:24:02,359 Speaker 1: the cap will hang out in the river and if 435 00:24:02,359 --> 00:24:04,240 Speaker 1: you get too close, so pull you in and drown you. 436 00:24:04,680 --> 00:24:07,639 Speaker 1: But it gets more interesting than that, Michael Dillon Foster 437 00:24:07,800 --> 00:24:10,800 Speaker 1: writes in a paper called the Metamorphosis of the Kappa 438 00:24:10,920 --> 00:24:16,000 Speaker 1: from Asian Folklore Studies in uh he writes the following quote. 439 00:24:16,400 --> 00:24:18,879 Speaker 1: Not only does the Kappa have a penchant for pulling 440 00:24:18,960 --> 00:24:22,040 Speaker 1: both children and adults into the water, but it often 441 00:24:22,119 --> 00:24:25,359 Speaker 1: does this in order to steal the liver, a feet 442 00:24:25,440 --> 00:24:28,600 Speaker 1: it achieves by reaching its arm up through the victims 443 00:24:28,760 --> 00:24:32,800 Speaker 1: anus to snatch the desired organ. So in order to 444 00:24:32,880 --> 00:24:36,680 Speaker 1: steal the liver, uh, they believed that the kappa had 445 00:24:36,720 --> 00:24:40,679 Speaker 1: to uncork the butt, had to uncork the human anus, 446 00:24:41,119 --> 00:24:44,960 Speaker 1: removing this organ known as the shii kodama, which is 447 00:24:45,040 --> 00:24:47,560 Speaker 1: quote a ball once thought to be at the mouth 448 00:24:47,640 --> 00:24:50,440 Speaker 1: of the anus. This is this is fascinating because you 449 00:24:50,520 --> 00:24:53,440 Speaker 1: have not only you have an imaginary creature here in 450 00:24:53,520 --> 00:24:57,760 Speaker 1: the Kappa, but it is interacting with imaginary parts of 451 00:24:58,119 --> 00:25:01,600 Speaker 1: the human body. Yeah, imagine ary organs. Now, of course, 452 00:25:01,680 --> 00:25:04,639 Speaker 1: one read on this myth is that is that this 453 00:25:04,760 --> 00:25:07,560 Speaker 1: all has to do with the observation of the corpses 454 00:25:07,600 --> 00:25:10,359 Speaker 1: of drowning victims, right, that when people were pulled from 455 00:25:10,440 --> 00:25:12,919 Speaker 1: the water, they would be found to have a gaping anus, 456 00:25:13,400 --> 00:25:16,040 Speaker 1: and so it looked like something had been removed that 457 00:25:16,119 --> 00:25:18,600 Speaker 1: had been corking it up before. But in fact this 458 00:25:18,760 --> 00:25:21,480 Speaker 1: is just caused by you know, relaxation of the muscles 459 00:25:21,600 --> 00:25:24,280 Speaker 1: upon death. Right. But it also I think comes back 460 00:25:24,280 --> 00:25:27,200 Speaker 1: to this idea that maybe we don't really we don't 461 00:25:27,200 --> 00:25:29,800 Speaker 1: really think about the anus much, so you could smuggle 462 00:25:29,880 --> 00:25:34,320 Speaker 1: in an imaginary body part and maybe people would be 463 00:25:34,400 --> 00:25:36,600 Speaker 1: sort of a blind to it, are okay with They're like, okay, yeah, 464 00:25:36,600 --> 00:25:38,400 Speaker 1: I guess there's a cork down there. Yeah, I guess 465 00:25:38,480 --> 00:25:41,480 Speaker 1: if you were going to invent an imaginary organ for 466 00:25:41,640 --> 00:25:44,440 Speaker 1: any you know, semi external part of the body, that'd 467 00:25:44,480 --> 00:25:46,000 Speaker 1: be the place to do it, right, But that would 468 00:25:46,000 --> 00:25:48,480 Speaker 1: be the place where people might buy it. Now, there's 469 00:25:48,480 --> 00:25:53,960 Speaker 1: another Japanese of folkloreic creature. This is a a member 470 00:25:54,000 --> 00:25:58,880 Speaker 1: of the Okai, you know, the sort of fabulous pantheon 471 00:25:59,040 --> 00:26:02,080 Speaker 1: of spirits that encounter in Japanese folklore, and it's known 472 00:26:02,119 --> 00:26:04,520 Speaker 1: as the shira May. Now. I can't find a lot 473 00:26:04,600 --> 00:26:08,800 Speaker 1: about the chira May from academic writings, but it's at 474 00:26:08,880 --> 00:26:10,480 Speaker 1: least enough of a thing that it pops up a 475 00:26:10,560 --> 00:26:14,320 Speaker 1: lot in Japanese art and in Japanese pop culture. In fact, 476 00:26:15,119 --> 00:26:18,399 Speaker 1: it apparently even shows up in the studio ghibli film 477 00:26:18,640 --> 00:26:22,000 Speaker 1: pom Poco, which is a wonderful film. It's a it's 478 00:26:22,040 --> 00:26:25,639 Speaker 1: an animated adventure that involves these shape shifting tonukis with 479 00:26:25,800 --> 00:26:30,760 Speaker 1: magical testicles, which is a whole subject unto itself. But uh, 480 00:26:30,960 --> 00:26:33,760 Speaker 1: this this Japanese your CoA shows up. It is a 481 00:26:34,000 --> 00:26:38,000 Speaker 1: humanoid creature with an eyeball in its anus, and that's 482 00:26:38,000 --> 00:26:40,760 Speaker 1: how it kind of looks around at the world. You'd think, 483 00:26:40,800 --> 00:26:45,200 Speaker 1: given the nature of the human posterior and glutes and 484 00:26:45,280 --> 00:26:47,880 Speaker 1: all that, that that might not be a great place 485 00:26:47,960 --> 00:26:49,680 Speaker 1: to put an eyeball, because it would be kind of 486 00:26:49,720 --> 00:26:51,880 Speaker 1: hard to see out of a lot of the time. Well, 487 00:26:52,040 --> 00:26:54,440 Speaker 1: but you have the fantastic body of a of a 488 00:26:54,560 --> 00:26:59,160 Speaker 1: spirit creature. I guess if everything is possible. Now. I've 489 00:26:59,200 --> 00:27:02,800 Speaker 1: looked around for some their myths related to the anus, 490 00:27:02,960 --> 00:27:06,479 Speaker 1: and I couldn't find a lot. So certainly, listeners out there, 491 00:27:06,520 --> 00:27:09,840 Speaker 1: if you have run across some wonderful folk tales or 492 00:27:10,080 --> 00:27:14,639 Speaker 1: myths are certainly mythological or folkloric monsters, uh with some 493 00:27:14,720 --> 00:27:18,600 Speaker 1: sort of cool anal curio about them, be sure to 494 00:27:18,680 --> 00:27:21,080 Speaker 1: let us know. But I did find one cool example 495 00:27:21,240 --> 00:27:24,600 Speaker 1: in a text by John beer Horse titled Mythology of 496 00:27:24,680 --> 00:27:28,400 Speaker 1: the Lenape Guide and Texts. He points out that there's 497 00:27:28,400 --> 00:27:32,200 Speaker 1: an ice giant cannibal in the traditions of the Lenape 498 00:27:32,359 --> 00:27:36,120 Speaker 1: people known as the Mooe, and it's similar to other 499 00:27:36,280 --> 00:27:40,360 Speaker 1: cannibal ogre traditions that you encounter in Native North American 500 00:27:40,440 --> 00:27:44,560 Speaker 1: people's such as most famously the Windigo. But the movie 501 00:27:45,000 --> 00:27:49,440 Speaker 1: is this this cannibalistic monster. It's basically impervious to harm, 502 00:27:49,840 --> 00:27:52,560 Speaker 1: but it's also rather stupid, and you can kill it 503 00:27:52,800 --> 00:27:56,720 Speaker 1: by driving a steak into its anus. Wow, that that 504 00:27:56,920 --> 00:28:01,120 Speaker 1: is a great variation on vampire lore, because the vampire 505 00:28:01,200 --> 00:28:04,040 Speaker 1: doesn't really need a heart, does it? I mean, come on, 506 00:28:04,240 --> 00:28:06,679 Speaker 1: it's dead. Why does it really does it really need 507 00:28:06,720 --> 00:28:10,240 Speaker 1: to oxygenate all its tissues? But then again, it's we 508 00:28:10,359 --> 00:28:13,840 Speaker 1: know it's drinking blood. So if it's drinking blood, it's 509 00:28:13,880 --> 00:28:16,119 Speaker 1: got to be pooping, right. It's a creature defined by 510 00:28:16,160 --> 00:28:18,959 Speaker 1: its hunger, so why is it not equally defined by 511 00:28:19,000 --> 00:28:22,199 Speaker 1: its defecation? At least we see that with this creature. 512 00:28:22,280 --> 00:28:25,199 Speaker 1: This creature is defined by its ravenous hunger. And then 513 00:28:25,400 --> 00:28:28,480 Speaker 1: it's it's a Kelly's heel is essentially it's a Kelly's anus. 514 00:28:29,080 --> 00:28:31,600 Speaker 1: I have an interesting question, or you can judge whether 515 00:28:31,640 --> 00:28:36,200 Speaker 1: it's interesting. Why are giants in so many folklore traditions 516 00:28:36,359 --> 00:28:40,520 Speaker 1: believed to be dim witted? M hmm, well, you know, 517 00:28:40,720 --> 00:28:44,040 Speaker 1: giant monsters, they're usually not the smartest. I don't know, 518 00:28:44,160 --> 00:28:45,920 Speaker 1: but you don't you see that a lot? I guess 519 00:28:46,000 --> 00:28:48,920 Speaker 1: maybe part of it has to do with with something 520 00:28:48,960 --> 00:28:52,960 Speaker 1: we've touched on already, ancient humans having to compete with 521 00:28:53,080 --> 00:28:58,880 Speaker 1: apex predators creatures that are that have far superior physical strengths. 522 00:28:59,440 --> 00:29:01,560 Speaker 1: But then how are humans able to overcome them and 523 00:29:01,640 --> 00:29:04,800 Speaker 1: even eradicate them? In many cases they use their intellect, 524 00:29:04,920 --> 00:29:07,840 Speaker 1: they use their cunning, and so so many of these 525 00:29:07,920 --> 00:29:11,600 Speaker 1: cases are a giant monster is threatening the smaller human 526 00:29:11,960 --> 00:29:14,560 Speaker 1: and how do they defeat them? They outsmart them. So 527 00:29:14,720 --> 00:29:18,680 Speaker 1: maybe the giants are modeled on sabretooth cats and bears 528 00:29:18,840 --> 00:29:21,960 Speaker 1: and stuff. Maybe. So that's just my you know, off 529 00:29:22,000 --> 00:29:25,000 Speaker 1: the hip. Read on that. I'm sure there are papers 530 00:29:25,040 --> 00:29:27,080 Speaker 1: out there to dive a lot deeper into it. We'll 531 00:29:27,080 --> 00:29:29,440 Speaker 1: have to look into it. The stupidity of giants coming 532 00:29:29,520 --> 00:29:31,440 Speaker 1: soon to stuff to plow your mind. Well, now that 533 00:29:31,560 --> 00:29:34,120 Speaker 1: also makes me wonder if anybody ever hunted bear or 534 00:29:34,200 --> 00:29:38,800 Speaker 1: sabretooth tigers by attacking the anus? Mm hmmm, we we 535 00:29:38,880 --> 00:29:42,320 Speaker 1: can we can move on, Okay, so we should talk 536 00:29:42,360 --> 00:29:46,160 Speaker 1: about the evolution of the anus. Where does this organ 537 00:29:46,280 --> 00:29:48,280 Speaker 1: come from? So for this portion the podcast, we turned 538 00:29:48,280 --> 00:29:50,600 Speaker 1: to a couple of key sources, including Getting to the 539 00:29:50,680 --> 00:29:56,680 Speaker 1: Bottom of Anal Evolution by Andreas Heynal and jose M 540 00:29:57,000 --> 00:30:00,400 Speaker 1: Martin Duran, both from the University of Burke and Our Way, 541 00:30:00,840 --> 00:30:04,520 Speaker 1: and Hey, nol seems to be the key figure in 542 00:30:04,640 --> 00:30:07,800 Speaker 1: some of these studies because he's also the primary author 543 00:30:07,920 --> 00:30:10,240 Speaker 1: on another piece, The Mouth The Anus in the Blast, 544 00:30:10,280 --> 00:30:15,600 Speaker 1: a poor colon open questions about questionable openings. And that's 545 00:30:15,640 --> 00:30:18,440 Speaker 1: when he wrote with Mark Q. Martindale, I love how 546 00:30:18,760 --> 00:30:21,120 Speaker 1: both titles here remind us that you probably have to 547 00:30:21,200 --> 00:30:23,720 Speaker 1: have a sense of humor if you're an anus researcher. 548 00:30:24,080 --> 00:30:26,960 Speaker 1: I wonder if anus puns in in the titles makes 549 00:30:27,040 --> 00:30:31,040 Speaker 1: it harder or easier to get published in serious academic journals. 550 00:30:31,520 --> 00:30:33,240 Speaker 1: I don't know. I feel like that the anus is 551 00:30:33,280 --> 00:30:34,800 Speaker 1: a special case. It kind of comes back to the 552 00:30:35,160 --> 00:30:39,120 Speaker 1: sexual reproduction thing was mentioning earlier, Like we most most 553 00:30:39,160 --> 00:30:40,880 Speaker 1: of us have an ability to switch back and forth 554 00:30:40,960 --> 00:30:43,440 Speaker 1: between the serious and the comedic, but not so with 555 00:30:43,520 --> 00:30:45,920 Speaker 1: the anus. And it seems to even spill over into 556 00:30:46,440 --> 00:30:49,600 Speaker 1: into the academic world. Yeah, okay, Well, these start with 557 00:30:49,680 --> 00:30:52,600 Speaker 1: an observation, which is a pretty simple one, right, the 558 00:30:52,800 --> 00:30:57,720 Speaker 1: anus is not actually universal in animals. Obviously, lots of 559 00:30:57,840 --> 00:31:01,000 Speaker 1: organisms don't have an anus. A plant doesn't need an anus, 560 00:31:01,120 --> 00:31:04,880 Speaker 1: it doesn't eat mushrooms don't need anuses. But even not 561 00:31:05,160 --> 00:31:09,280 Speaker 1: all animals have anus, is right, That's right. Some lineages 562 00:31:09,320 --> 00:31:15,440 Speaker 1: of animals such as uh Poropera, the sponges, Placazoa, the 563 00:31:16,160 --> 00:31:21,000 Speaker 1: which are simple multicellular animals, UM Cestoda. Those are flat worms, 564 00:31:21,040 --> 00:31:24,800 Speaker 1: including the tape worm and a can'to Cephala. This is 565 00:31:24,840 --> 00:31:27,600 Speaker 1: another group of parasitic worms. They don't have a digestive 566 00:31:27,640 --> 00:31:31,760 Speaker 1: track seas no digestive track, no, no digestive track. Now 567 00:31:32,360 --> 00:31:35,960 Speaker 1: UH sea sponges and tape worms are good examples specifically 568 00:31:36,320 --> 00:31:40,200 Speaker 1: for these. Others have a gut with a single opening 569 00:31:40,600 --> 00:31:44,520 Speaker 1: that both the takes in food and excretes waste, such 570 00:31:44,560 --> 00:31:49,160 Speaker 1: as UH the to no offera, comb jellies, UH the Nigeria, 571 00:31:49,760 --> 00:31:54,520 Speaker 1: which is a large invertebrate phylum that includes the hydra, jellyfish, 572 00:31:54,640 --> 00:31:57,360 Speaker 1: sea an enemy, and coral. And then you also have 573 00:31:58,640 --> 00:32:01,880 Speaker 1: acyl A morpha and these simple soft bodied plankton animals 574 00:32:01,920 --> 00:32:03,960 Speaker 1: that live in the water uh. And then you also 575 00:32:04,040 --> 00:32:07,240 Speaker 1: have various flatworms and jaw worms as well. And the 576 00:32:07,640 --> 00:32:10,560 Speaker 1: the Acyla morpha are going to come up several times 577 00:32:10,720 --> 00:32:14,520 Speaker 1: because they are a really interesting reference organism when we're 578 00:32:14,520 --> 00:32:17,200 Speaker 1: trying to understand our evolutionary history and go back to 579 00:32:17,280 --> 00:32:21,320 Speaker 1: the beginning of what it was like when bilateral animals 580 00:32:21,400 --> 00:32:25,680 Speaker 1: first appeared. But a great many animals do have what 581 00:32:25,920 --> 00:32:29,200 Speaker 1: is called a through gut, a linear track. Food goes 582 00:32:29,240 --> 00:32:31,920 Speaker 1: in one specialized in for food uptake, and travels through 583 00:32:32,040 --> 00:32:35,800 Speaker 1: specialized regions for nutrient absorption, and then it all leaves 584 00:32:35,880 --> 00:32:39,480 Speaker 1: through a specialized excretion valve. And this of course is 585 00:32:39,520 --> 00:32:43,960 Speaker 1: the anus. Now, the anus actually becomes very evolutionarily relevant 586 00:32:44,040 --> 00:32:47,520 Speaker 1: here because you can't have a one way digestive tract 587 00:32:47,920 --> 00:32:50,560 Speaker 1: without an anus. Right has to go some Well, we 588 00:32:50,680 --> 00:32:53,480 Speaker 1: have some special cases lat on, but for the most part, 589 00:32:53,600 --> 00:32:55,400 Speaker 1: what goes in has to come out. That's right. I 590 00:32:55,440 --> 00:32:57,880 Speaker 1: guess there are a few exceptions, but generally, yeah, this 591 00:32:58,040 --> 00:33:00,680 Speaker 1: is how it works. If you don't have anus, then 592 00:33:00,720 --> 00:33:05,400 Speaker 1: you've just got another one of these digestion buckets. Basically, 593 00:33:05,480 --> 00:33:08,000 Speaker 1: you have a bucket in your body where food comes 594 00:33:08,080 --> 00:33:11,720 Speaker 1: in and digestion happens and waste comes out. Yet again, 595 00:33:11,800 --> 00:33:13,960 Speaker 1: this is one of those things that I maybe you 596 00:33:14,000 --> 00:33:16,600 Speaker 1: would like it if you were like that, but given 597 00:33:16,680 --> 00:33:18,480 Speaker 1: that you're not like that, you're probably glad you're not 598 00:33:18,640 --> 00:33:21,640 Speaker 1: like that. Well, hey, no has brought this up, he says, 599 00:33:21,880 --> 00:33:24,480 Speaker 1: Can you imagine if we had a digestive system like this, 600 00:33:24,600 --> 00:33:26,800 Speaker 1: what do you eat? And then you have to wait 601 00:33:26,960 --> 00:33:30,280 Speaker 1: eight hours or more until you can eat again, Like 602 00:33:30,360 --> 00:33:32,800 Speaker 1: there's no snacking. If you're hungry, it doesn't matter. Maybe 603 00:33:32,840 --> 00:33:34,800 Speaker 1: you wouldn't be hungry in this case, but you have 604 00:33:34,920 --> 00:33:38,400 Speaker 1: to wait until you can defecate out your mouth and 605 00:33:38,520 --> 00:33:41,520 Speaker 1: then eat again. How would that change your perception of 606 00:33:41,960 --> 00:33:44,760 Speaker 1: of everything in life? Yeah, and it's not just what's 607 00:33:44,800 --> 00:33:47,800 Speaker 1: appealing to you. I mean, Heynal points out in multiple 608 00:33:48,120 --> 00:33:53,120 Speaker 1: places that there are several reasons that having a through gut, 609 00:33:53,200 --> 00:33:56,760 Speaker 1: a one way digestive tract with an anus, is very 610 00:33:57,320 --> 00:34:00,800 Speaker 1: evolutionarily appealing. There's a lot of advantage to it. So 611 00:34:00,960 --> 00:34:02,880 Speaker 1: one of the things that's a real advantage here is 612 00:34:02,920 --> 00:34:06,120 Speaker 1: what you just mentioned, the simultaneity of digestive stages. Yeah, 613 00:34:06,200 --> 00:34:08,600 Speaker 1: you can eat more food while you're while you're you're 614 00:34:08,640 --> 00:34:11,680 Speaker 1: still digesting your last meal. Yeah, you can eat one 615 00:34:11,800 --> 00:34:14,919 Speaker 1: big mac and while it's digesting, you can eat another 616 00:34:14,960 --> 00:34:17,279 Speaker 1: big mac. Maybe in bed it doesn't matter. You can 617 00:34:17,360 --> 00:34:20,680 Speaker 1: do whatever you want instead of just sitting around waiting 618 00:34:20,719 --> 00:34:22,640 Speaker 1: to poop, So you can eat the second one. It's 619 00:34:22,680 --> 00:34:25,560 Speaker 1: getting cold, but the second one, the second one is 620 00:34:25,600 --> 00:34:30,080 Speaker 1: really interesting. I think a one way through gut allows 621 00:34:30,280 --> 00:34:34,360 Speaker 1: more efficient metabolism of food because different parts of the 622 00:34:34,480 --> 00:34:39,120 Speaker 1: digestive system can specialize in different things, and you can 623 00:34:39,200 --> 00:34:43,040 Speaker 1: perform those special functions in the best possible order so 624 00:34:43,200 --> 00:34:46,040 Speaker 1: that one gets done definitely before the other one. If 625 00:34:46,120 --> 00:34:49,400 Speaker 1: you're doing all of your gut stuff in just one bucket, 626 00:34:49,560 --> 00:34:52,719 Speaker 1: it's going to be pretty much impossible to sequence these 627 00:34:52,800 --> 00:34:56,719 Speaker 1: specializations like this. But what would these specializations be. How 628 00:34:56,760 --> 00:34:59,719 Speaker 1: about you've got a tongue and a sensitive mouth and 629 00:34:59,800 --> 00:35:02,720 Speaker 1: that it's useful because it can detect the nutritional value 630 00:35:02,760 --> 00:35:06,600 Speaker 1: of foods or reject potentially dangerous substances. Then you've got 631 00:35:06,719 --> 00:35:08,920 Speaker 1: teeth at the top of the track to begin the 632 00:35:09,040 --> 00:35:12,239 Speaker 1: processing chop stuff up. You've got a stomach full of 633 00:35:12,320 --> 00:35:15,320 Speaker 1: hydrochloric acid and other chemicals to break down foods and 634 00:35:15,360 --> 00:35:19,280 Speaker 1: trigger digestive enzymes. Uh, You've got a liver to secrete 635 00:35:19,360 --> 00:35:21,480 Speaker 1: bile and help with fatty foods. And then you've got 636 00:35:21,560 --> 00:35:24,520 Speaker 1: a long curled up in testine to absorb nutrients, and 637 00:35:24,600 --> 00:35:26,960 Speaker 1: then a colon to shuffle waist out the door. And 638 00:35:27,040 --> 00:35:29,560 Speaker 1: it's important that all this stuff happens in the order 639 00:35:29,760 --> 00:35:32,400 Speaker 1: that it happens. Yeah, I can't help but think of 640 00:35:32,480 --> 00:35:35,320 Speaker 1: an assembly line. You know. It's the difference between a 641 00:35:35,719 --> 00:35:39,239 Speaker 1: clockmaker's shop where material raw materials go in and a 642 00:35:39,320 --> 00:35:43,040 Speaker 1: single shop maker goes through every stage of production, testing 643 00:35:43,520 --> 00:35:45,879 Speaker 1: and then the clock comes right back out the front 644 00:35:45,920 --> 00:35:48,800 Speaker 1: door when it's ready. And if you compare like the 645 00:35:48,920 --> 00:35:53,080 Speaker 1: time involved there with a an assembly line where you 646 00:35:53,160 --> 00:35:56,719 Speaker 1: have multiple individuals, specialized individuals working on different parts of 647 00:35:56,760 --> 00:36:00,239 Speaker 1: the clock's production and testing and and raw materials coming 648 00:36:00,280 --> 00:36:02,040 Speaker 1: in one section, and at the end of the line 649 00:36:02,080 --> 00:36:06,000 Speaker 1: you have finished clocks just rolling off the conveyor belt. Yeah. 650 00:36:06,000 --> 00:36:09,200 Speaker 1: I think that's a great analogy, or one analogy to 651 00:36:09,280 --> 00:36:11,640 Speaker 1: the sack like gut might be that maybe you've got 652 00:36:11,719 --> 00:36:14,360 Speaker 1: all these maybe you've even got all these specialized workers, 653 00:36:14,640 --> 00:36:16,840 Speaker 1: but they're not in a line. They're just all standing 654 00:36:16,880 --> 00:36:19,800 Speaker 1: in a huge room and waiting for their turn or 655 00:36:20,200 --> 00:36:23,320 Speaker 1: kind of you know, reaching over each other's shoulders to 656 00:36:23,440 --> 00:36:26,040 Speaker 1: work on the clock. Yeah. Um. Yeah. And you can 657 00:36:26,080 --> 00:36:28,719 Speaker 1: imagine if you try to imagine your body working this way, 658 00:36:28,800 --> 00:36:31,800 Speaker 1: where you don't have well ordered organs to specialize in 659 00:36:32,000 --> 00:36:35,440 Speaker 1: all of the stages of your metabolism as it goes on. Uh, 660 00:36:35,600 --> 00:36:38,400 Speaker 1: not too good, is it? Chief right? Yeah. One more 661 00:36:38,440 --> 00:36:40,080 Speaker 1: thing I'd say is that you can also have different 662 00:36:40,120 --> 00:36:44,680 Speaker 1: species within the through gut organisms which specialize their body 663 00:36:44,760 --> 00:36:47,600 Speaker 1: parts to adapt to their diet. So, for example, once 664 00:36:47,640 --> 00:36:50,880 Speaker 1: you've got a one way digestive tract, you can say, well, 665 00:36:50,960 --> 00:36:53,160 Speaker 1: I want to have this certain type of teeth to 666 00:36:53,320 --> 00:36:56,560 Speaker 1: take advantage of this hard, chewy stuff that most people 667 00:36:56,640 --> 00:36:59,680 Speaker 1: around me can't eat, and that will be my biological niche. 668 00:37:00,000 --> 00:37:03,280 Speaker 1: So it gives you more ways to evolve. It also 669 00:37:03,520 --> 00:37:06,240 Speaker 1: means that you can grow to greater size because ultimately 670 00:37:06,320 --> 00:37:09,680 Speaker 1: you have improved digestion. You can you can you can 671 00:37:09,800 --> 00:37:16,120 Speaker 1: harvest more nutrients, and you're also not limited by I believe. Hey. No, 672 00:37:16,400 --> 00:37:18,080 Speaker 1: it makes this point as well. If you have a 673 00:37:18,120 --> 00:37:21,720 Speaker 1: particularly long organism, if it had to swallow its food 674 00:37:22,080 --> 00:37:24,239 Speaker 1: and then digest it and then send it right back 675 00:37:24,360 --> 00:37:27,440 Speaker 1: up to the head, that would be ridiculous. Imagine a 676 00:37:27,480 --> 00:37:30,239 Speaker 1: giraffe having to do that. A giraffe does not have 677 00:37:30,360 --> 00:37:32,880 Speaker 1: to do that because everything can come right out the giraffe. 678 00:37:32,920 --> 00:37:36,000 Speaker 1: As He also points out that there are two sets 679 00:37:36,040 --> 00:37:39,000 Speaker 1: of genes in particular that are tied up here, known 680 00:37:39,120 --> 00:37:43,120 Speaker 1: as the barrack. Your a gene and the para hawks 681 00:37:43,239 --> 00:37:47,120 Speaker 1: gene UH, which is also referred to as just c 682 00:37:47,280 --> 00:37:50,839 Speaker 1: d X for caudal c d x UH. And these 683 00:37:50,880 --> 00:37:53,040 Speaker 1: are present and nearly all animals, and they play a 684 00:37:53,120 --> 00:37:55,680 Speaker 1: key role in the formation of the anal orifice. Yes, 685 00:37:55,800 --> 00:37:58,719 Speaker 1: so he's saying that if you see these genes being 686 00:37:58,800 --> 00:38:01,320 Speaker 1: expressed and tissue is the brachi re gene or the 687 00:38:01,400 --> 00:38:04,440 Speaker 1: Caudal c d x often just c d X, you 688 00:38:04,600 --> 00:38:08,320 Speaker 1: know that that tissue is forming an anal orifice almost 689 00:38:08,400 --> 00:38:11,560 Speaker 1: every time. And if the animal loses its anus, and yes, 690 00:38:11,680 --> 00:38:13,920 Speaker 1: we will mention to some animals that have lost their 691 00:38:13,920 --> 00:38:17,480 Speaker 1: anus entirely, it often loses these genes as well. It 692 00:38:17,600 --> 00:38:20,040 Speaker 1: can't be true. How could you lose an anus? Well, 693 00:38:20,160 --> 00:38:22,120 Speaker 1: you know it's it's not just a matter of misplacing it. 694 00:38:22,239 --> 00:38:25,960 Speaker 1: It's just uh, it no longer becomes necessary to the 695 00:38:26,920 --> 00:38:30,520 Speaker 1: functions of the organism. Alright, So hen Al and his 696 00:38:30,640 --> 00:38:33,320 Speaker 1: colleagues they they set out to explore the evolution of 697 00:38:33,360 --> 00:38:35,480 Speaker 1: the anus, right because they said it while it had 698 00:38:35,560 --> 00:38:39,440 Speaker 1: been studied some, it hadn't gotten as much attention, especially 699 00:38:39,520 --> 00:38:45,080 Speaker 1: through genetic research, as some other types of evolutionary innovations had. 700 00:38:45,600 --> 00:38:47,640 Speaker 1: That's right, we see that's the same for the same 701 00:38:47,719 --> 00:38:51,200 Speaker 1: reasons that various ancient cultures have have either focused more 702 00:38:51,239 --> 00:38:53,320 Speaker 1: on the heart or more Today we just focus on 703 00:38:53,360 --> 00:38:55,640 Speaker 1: the brain. It seems like the anus has just received 704 00:38:55,719 --> 00:38:58,799 Speaker 1: less attention. No fewer people have asked the question, where 705 00:38:58,840 --> 00:39:02,480 Speaker 1: did the anus come from? What is the evolutionary heritage 706 00:39:02,680 --> 00:39:05,560 Speaker 1: of the anus? But studying the anus is actually pretty 707 00:39:05,600 --> 00:39:10,240 Speaker 1: interesting for learning about where at what points in evolutionary 708 00:39:10,360 --> 00:39:14,759 Speaker 1: history organisms divided off from one another. Yeah. They point 709 00:39:14,760 --> 00:39:17,000 Speaker 1: out that studying the anus and animals is difficult in 710 00:39:17,120 --> 00:39:20,280 Speaker 1: part because it appears and disappears again within many animal 711 00:39:20,360 --> 00:39:24,080 Speaker 1: groups convergent evolution. Yeah. For instance, that most flat worms 712 00:39:24,200 --> 00:39:28,160 Speaker 1: are anus lists, but others have independently independently evolved one. 713 00:39:28,760 --> 00:39:33,480 Speaker 1: And then there's the polyclad flatworm actually has multiple anuses 714 00:39:33,680 --> 00:39:38,680 Speaker 1: all over their backs. How many anuses multiple? It's like, 715 00:39:39,440 --> 00:39:43,000 Speaker 1: I think it's less than fifty. I'd say it's more 716 00:39:43,200 --> 00:39:46,120 Speaker 1: like six to a dozen. Based on the image that 717 00:39:46,360 --> 00:39:48,640 Speaker 1: I saw in the paper. What if you had fifty 718 00:39:48,680 --> 00:39:51,160 Speaker 1: anuses on your back and they all just pooped a little? 719 00:39:53,239 --> 00:39:55,600 Speaker 1: I don't know if that would be helpful. I mean, 720 00:39:56,840 --> 00:40:00,120 Speaker 1: it does not seem adaptive for our ecological niche up. 721 00:40:00,160 --> 00:40:02,839 Speaker 1: Thankfully that is not a design that really was picked 722 00:40:02,920 --> 00:40:05,800 Speaker 1: up by natural selection. But most of this is interesting. 723 00:40:05,880 --> 00:40:09,480 Speaker 1: Most members of the super phylum due to Rostomes, which 724 00:40:09,520 --> 00:40:13,640 Speaker 1: includes everything from c cucumbers to all vertebrates, they have anuses. 725 00:40:14,160 --> 00:40:17,279 Speaker 1: But see stars have dropped the anus from its anatomical 726 00:40:17,360 --> 00:40:19,840 Speaker 1: lineup completely. Okay, so they were in this group, but 727 00:40:19,960 --> 00:40:23,200 Speaker 1: then they lost the anus, right, These are the losers 728 00:40:23,239 --> 00:40:26,839 Speaker 1: of the anus. And then some animals develop anuses as 729 00:40:26,880 --> 00:40:29,200 Speaker 1: they grow. This is I feel like I've touched on 730 00:40:29,280 --> 00:40:32,800 Speaker 1: this in the past, but lacewings, you know, a small insect, 731 00:40:33,160 --> 00:40:36,239 Speaker 1: they don't poop during their larval stages. They have what's 732 00:40:36,239 --> 00:40:40,040 Speaker 1: called a blind gut, in which everything just pushes to 733 00:40:40,120 --> 00:40:42,319 Speaker 1: the back of the gut as they eat. And then 734 00:40:42,360 --> 00:40:45,719 Speaker 1: after they go through metamorphosis they gain an anus, and 735 00:40:45,800 --> 00:40:49,640 Speaker 1: then immediately upon emerging they poop out everything they ever 736 00:40:49,880 --> 00:40:53,440 Speaker 1: ate prior to their metamorphosis. That's beautiful. And then the 737 00:40:53,480 --> 00:40:56,319 Speaker 1: adults probably say, oh to be young and anus list again. 738 00:40:58,840 --> 00:41:01,000 Speaker 1: And then there of course animals that lose their anus 739 00:41:01,120 --> 00:41:03,560 Speaker 1: during the course of their lifetime. A big example here, 740 00:41:03,600 --> 00:41:05,160 Speaker 1: and this is one we've touched on before in our 741 00:41:05,480 --> 00:41:08,520 Speaker 1: our our two part are on tails, is that of 742 00:41:08,600 --> 00:41:11,719 Speaker 1: a certain scorpions that shed their tails an act of autotommy. 743 00:41:12,000 --> 00:41:14,279 Speaker 1: This is like when lizards are attacked and they drop 744 00:41:14,360 --> 00:41:17,920 Speaker 1: a tail, that sort of thing. Well take that, I'll 745 00:41:18,000 --> 00:41:20,239 Speaker 1: run away. Yeah, I'd rather you just eat my tail 746 00:41:20,280 --> 00:41:23,320 Speaker 1: than eat my entire body. But the thing is with 747 00:41:23,400 --> 00:41:26,400 Speaker 1: the scorpions, they have their anus on one of their 748 00:41:26,480 --> 00:41:29,879 Speaker 1: tail segments, and if they lose it, uh, they lose 749 00:41:29,920 --> 00:41:32,600 Speaker 1: their anus and then they simply never poop again. They 750 00:41:32,640 --> 00:41:36,600 Speaker 1: simply fill up with poop for the rest of their lives, 751 00:41:37,040 --> 00:41:39,960 Speaker 1: swelling with their their own excrement, unable to release it. 752 00:41:40,200 --> 00:41:43,440 Speaker 1: That's no good. And this is a super fun too. 753 00:41:44,040 --> 00:41:47,600 Speaker 1: Anuses can be multi purpose. Oh yeah, so this is 754 00:41:47,640 --> 00:41:50,520 Speaker 1: where we're going to talk about c cucumbers right. Oh yes, 755 00:41:50,960 --> 00:41:53,960 Speaker 1: So the c cucumber does have an anus that it 756 00:41:54,080 --> 00:41:58,839 Speaker 1: defecates through it's anial opening, but it also breathes through 757 00:41:58,880 --> 00:42:01,759 Speaker 1: its anus. That is an interesting trick. Yeah. I have 758 00:42:01,920 --> 00:42:04,040 Speaker 1: not figured out how to do that yet, I would say, 759 00:42:04,200 --> 00:42:06,279 Speaker 1: I dare say most of you out there haven't either, 760 00:42:07,239 --> 00:42:10,279 Speaker 1: but yeah, amazing. So the c cucumber lives under the 761 00:42:10,320 --> 00:42:15,240 Speaker 1: water and it can contract and expand its anal cavity 762 00:42:15,360 --> 00:42:18,839 Speaker 1: to draw in breaths of water in much the same 763 00:42:18,880 --> 00:42:21,640 Speaker 1: way that we expand and contract our lungs to draw 764 00:42:21,760 --> 00:42:23,759 Speaker 1: in air. Right, So we've got like a diaphragm. We 765 00:42:23,840 --> 00:42:26,000 Speaker 1: can open up the lungs, suck in the air, and 766 00:42:26,120 --> 00:42:29,440 Speaker 1: get the oxygen we need out of it. They expand 767 00:42:29,560 --> 00:42:32,279 Speaker 1: the anal cavity, suck in the water, and then they 768 00:42:32,400 --> 00:42:36,359 Speaker 1: extract dissolved oxygen from the water where the water it's 769 00:42:36,400 --> 00:42:39,160 Speaker 1: fed into this large branching set of tissues known as 770 00:42:39,200 --> 00:42:41,800 Speaker 1: a respiratory tree, kind of like the you know the 771 00:42:42,400 --> 00:42:45,320 Speaker 1: pathways you see in the lungs when they expand, and 772 00:42:45,440 --> 00:42:48,000 Speaker 1: then when you've extracted the oxygen, the water is pushed 773 00:42:48,080 --> 00:42:51,080 Speaker 1: back out of the anus. Another fact about the c 774 00:42:51,280 --> 00:42:55,279 Speaker 1: cucumber's anus that I found interesting it is often inhabited 775 00:42:55,360 --> 00:42:59,120 Speaker 1: by a crafty little stowaway. One of the best parasite 776 00:42:59,200 --> 00:43:01,640 Speaker 1: riders out there, Ed Young has a great blog post 777 00:43:01,680 --> 00:43:04,120 Speaker 1: from sixteen where he tells a story about this, and 778 00:43:04,200 --> 00:43:06,600 Speaker 1: I have to relate it. So in this story he 779 00:43:06,680 --> 00:43:11,600 Speaker 1: tells in ninety a biologist named Victor ben o'myer Rachao 780 00:43:12,360 --> 00:43:15,279 Speaker 1: was diving in the water off an island in Indonesia 781 00:43:15,440 --> 00:43:18,680 Speaker 1: when he collected a leopard sea cucumber. So it was 782 00:43:18,719 --> 00:43:22,480 Speaker 1: about forty centimeters long and fourteen centimeters wide. And he 783 00:43:22,560 --> 00:43:24,800 Speaker 1: gets the sea cucumber home and he stores it in 784 00:43:24,840 --> 00:43:29,400 Speaker 1: a bucket of water under refrigeration. Quote. Sometime later, a 785 00:43:29,560 --> 00:43:33,440 Speaker 1: slender eel like fish swam out of the sea cucumber's anus. 786 00:43:34,280 --> 00:43:37,360 Speaker 1: It was a star pearl fish, and it wasn't alone. 787 00:43:37,920 --> 00:43:43,280 Speaker 1: Another wriggled out, and another. After ten hours, fourteen pearl 788 00:43:43,360 --> 00:43:47,520 Speaker 1: fish had evacuated from the animal's bomb, each between eight 789 00:43:47,600 --> 00:43:52,680 Speaker 1: and sixteen centimeters long. Another one stayed inside, so fifteen 790 00:43:52,719 --> 00:43:55,879 Speaker 1: pearl fish in its anus. Now there is more than 791 00:43:55,960 --> 00:43:58,680 Speaker 1: one species of pearl fish, and they occupied the bodies 792 00:43:58,719 --> 00:44:01,959 Speaker 1: of lots of different marine animals, even oysters. It writes 793 00:44:02,040 --> 00:44:04,560 Speaker 1: that the pearl fish get their name from a case 794 00:44:04,600 --> 00:44:07,520 Speaker 1: when a dead specimen was found not only inside an oyster, 795 00:44:07,680 --> 00:44:11,920 Speaker 1: but buried inside a pearl uh and some species of 796 00:44:11,960 --> 00:44:14,880 Speaker 1: pearl fish merely hide inside the sea cucumber, leaving the 797 00:44:14,960 --> 00:44:17,880 Speaker 1: anus to forage for prey and then returning, but others 798 00:44:17,960 --> 00:44:21,319 Speaker 1: have been thought to parasitize the host, like eating its 799 00:44:21,400 --> 00:44:24,960 Speaker 1: gonads in the walls of the respiratory tree. So does 800 00:44:25,040 --> 00:44:27,600 Speaker 1: the does the cea cucumber get anything out of this 801 00:44:27,800 --> 00:44:31,960 Speaker 1: or is it not that I found Uh, if they 802 00:44:32,040 --> 00:44:34,520 Speaker 1: do get anything back, I've not discovered it yet. So 803 00:44:34,640 --> 00:44:36,880 Speaker 1: that is a good question. If the sea cucumber doesn't 804 00:44:36,960 --> 00:44:39,160 Speaker 1: get anything out of it, why doesn't it just close 805 00:44:39,200 --> 00:44:42,319 Speaker 1: off its anus and restrict access to the pearl fish. Well, 806 00:44:42,520 --> 00:44:45,120 Speaker 1: wait a minute, it has to breathe, remember, breathes through 807 00:44:45,160 --> 00:44:48,600 Speaker 1: its anus. So for the full body horror equivalent, try 808 00:44:48,640 --> 00:44:51,359 Speaker 1: to imagine a parasite that wanted to get in your 809 00:44:51,560 --> 00:44:54,480 Speaker 1: lungs and you could try to plug up your nose 810 00:44:54,520 --> 00:44:56,840 Speaker 1: in your mouth to deny it access, but you'd have 811 00:44:56,920 --> 00:45:00,480 Speaker 1: to breathe sometime. Interesting, so we we we've probably are 812 00:45:00,520 --> 00:45:04,120 Speaker 1: seeing the trade off to an adaptation here. Like it's 813 00:45:04,200 --> 00:45:06,120 Speaker 1: on one level, yes, you can breathe through your anus, 814 00:45:06,280 --> 00:45:09,400 Speaker 1: but then the tradeoff is this opens your anus to 815 00:45:09,960 --> 00:45:13,719 Speaker 1: even more parasitic activity. Yes, exactly. Now, to go back 816 00:45:13,760 --> 00:45:16,520 Speaker 1: to autotomy. When we talked about the scorpion that drops 817 00:45:16,600 --> 00:45:19,960 Speaker 1: its own tail as a defense mechanism, see, cucumbers have 818 00:45:20,040 --> 00:45:24,839 Speaker 1: an even more amazing version of anal defensive autotomy. It's 819 00:45:24,920 --> 00:45:29,719 Speaker 1: known as quote evisceration. This is a defensive ejection of 820 00:45:29,880 --> 00:45:35,440 Speaker 1: one's own internal organs, Like, is it nearly turning itself 821 00:45:35,520 --> 00:45:39,640 Speaker 1: inside out? Is it uh an inversion of its body cavity, 822 00:45:39,719 --> 00:45:43,360 Speaker 1: or is it just straight spraying sprays its own guts 823 00:45:43,440 --> 00:45:46,400 Speaker 1: out and lets them go. So if you go handle 824 00:45:46,480 --> 00:45:49,640 Speaker 1: a c cucumber, which we are not recommending, do not 825 00:45:49,800 --> 00:45:52,120 Speaker 1: be surprised if it poops all of its guts out 826 00:45:52,200 --> 00:45:55,719 Speaker 1: at you. When the c cucumber opts for defensive advisceration, 827 00:45:55,840 --> 00:45:59,520 Speaker 1: it contracts its muscles to push much of its respiratory 828 00:45:59,680 --> 00:46:03,840 Speaker 1: tree out through its anus at the perceived attacker, and 829 00:46:04,000 --> 00:46:06,759 Speaker 1: once ejected, the respiratory tree kind of turns into this 830 00:46:07,000 --> 00:46:11,279 Speaker 1: sticky net which can confuse and entrap a predator. And 831 00:46:11,400 --> 00:46:15,520 Speaker 1: it also contains toxins called saponins. So after doing this, 832 00:46:15,800 --> 00:46:19,640 Speaker 1: the sea cucumber can regenerate it's lost tissues. Not sure 833 00:46:19,680 --> 00:46:22,240 Speaker 1: why it doesn't do this to protect to protect against 834 00:46:22,280 --> 00:46:24,480 Speaker 1: the pearl fish. I think we don't know the answer 835 00:46:24,520 --> 00:46:26,880 Speaker 1: there yet. I wonder it just basically breaks down to 836 00:46:27,480 --> 00:46:30,880 Speaker 1: like the cost of spraying out its gusts and then 837 00:46:30,960 --> 00:46:34,319 Speaker 1: regenerating them versus the cost of having the parasites there, 838 00:46:34,440 --> 00:46:37,080 Speaker 1: and maybe it's just not quite worth the effort, Like 839 00:46:37,160 --> 00:46:40,759 Speaker 1: it's it's ultimately cheaper to allow the parasites to do 840 00:46:40,880 --> 00:46:43,839 Speaker 1: their thing. It could be the case. But one more thing. 841 00:46:43,920 --> 00:46:47,040 Speaker 1: When it comes to anal breathing, it is not just 842 00:46:47,280 --> 00:46:50,560 Speaker 1: the sea cucumber. I don't know if you've read about this, Robert, 843 00:46:50,600 --> 00:46:53,239 Speaker 1: but some turtles breathe through their butts. Oh no, this 844 00:46:53,400 --> 00:46:56,360 Speaker 1: is all new to me. Yeah. So some water dwelling turtles, 845 00:46:56,440 --> 00:46:59,880 Speaker 1: such as, for example, the Fitzroy River turtle, use a 846 00:47:00,000 --> 00:47:02,120 Speaker 1: anal respiration or I guess I should be saying more 847 00:47:02,160 --> 00:47:09,040 Speaker 1: accurately cloacal respiration. Yeah, honoring the distinction there, but uh, 848 00:47:09,239 --> 00:47:11,799 Speaker 1: anal chloacle, whichever way you call it. They breathe out 849 00:47:11,880 --> 00:47:15,480 Speaker 1: of the backside opening of their their digestive tract. Uh. 850 00:47:15,560 --> 00:47:18,440 Speaker 1: It's sort of like having gills in your rectum. They 851 00:47:18,560 --> 00:47:22,760 Speaker 1: suck water into the cloaca, absorb oxygen, and then expel 852 00:47:22,880 --> 00:47:25,759 Speaker 1: the water that they've taken the oxygen out of. Huh. 853 00:47:26,280 --> 00:47:29,040 Speaker 1: I wonder if the if the kappa would be capable 854 00:47:29,080 --> 00:47:32,440 Speaker 1: of a similar feat. I don't know, I'm not considered it. 855 00:47:33,000 --> 00:47:34,719 Speaker 1: All right, we're gonna take one more break and when 856 00:47:34,760 --> 00:47:37,080 Speaker 1: we come back, we will touch on the topic of 857 00:47:37,440 --> 00:47:43,560 Speaker 1: transient anuses. All right, we're back, Okay, Roberts. So we've 858 00:47:43,600 --> 00:47:47,800 Speaker 1: discussed the evolutionary benefits of anuses, what creatures can do 859 00:47:47,920 --> 00:47:50,680 Speaker 1: with their multi purpose annuses. But what's this idea that 860 00:47:51,040 --> 00:47:55,439 Speaker 1: transient anuses some organisms can gain and lose their anus. Yeah. 861 00:47:55,600 --> 00:47:58,080 Speaker 1: According to hay Now quote, there are several cases in 862 00:47:58,160 --> 00:48:02,040 Speaker 1: which additional openings, connections between openings of different organ systems, 863 00:48:02,360 --> 00:48:05,160 Speaker 1: and reductions of a through gut to a sack like 864 00:48:05,360 --> 00:48:09,480 Speaker 1: gut can be identified. So there's a jaw worm called 865 00:48:10,000 --> 00:48:14,080 Speaker 1: Haplognatia and it has an anal poor. And then there's 866 00:48:14,320 --> 00:48:19,800 Speaker 1: a microscopic uh platozoan animal known as Limnognathia, And this 867 00:48:20,000 --> 00:48:23,120 Speaker 1: is actually a fairly recently discovered organism, and it has 868 00:48:23,200 --> 00:48:26,520 Speaker 1: a temporary opening that likely serves as an anus. But 869 00:48:26,600 --> 00:48:29,000 Speaker 1: it's never been caught or at least as a as 870 00:48:29,040 --> 00:48:31,000 Speaker 1: of the publication of this paper, it has never been 871 00:48:31,080 --> 00:48:34,160 Speaker 1: caught in the act of defecating. Wow, So it can 872 00:48:34,640 --> 00:48:38,440 Speaker 1: get an opening that appears and people suspect it's ananus, 873 00:48:39,040 --> 00:48:41,400 Speaker 1: but they've never seen it poop. Right, And in both cases, 874 00:48:41,480 --> 00:48:45,680 Speaker 1: these are on the creature's dorsal side, and H. Haynal. 875 00:48:45,760 --> 00:48:47,960 Speaker 1: Points out that the secondary evolution of the anal openings 876 00:48:47,960 --> 00:48:49,640 Speaker 1: this seems to be connected with the evolution of the 877 00:48:50,280 --> 00:48:53,960 Speaker 1: of the extension of body length or overall size of 878 00:48:54,040 --> 00:48:56,240 Speaker 1: the body. Okay, Well, this would go with the general 879 00:48:56,360 --> 00:49:00,279 Speaker 1: idea that as organisms become larger and longer, they have 880 00:49:00,400 --> 00:49:03,280 Speaker 1: more of an incentive to develop a through gut instead 881 00:49:03,320 --> 00:49:06,640 Speaker 1: of just a sack gut. Yes, and thus the invention 882 00:49:06,719 --> 00:49:09,480 Speaker 1: of the anus or the evolution of the anus. Okay, 883 00:49:09,520 --> 00:49:11,400 Speaker 1: But I want to ask a kind of different question. Now, 884 00:49:12,080 --> 00:49:15,400 Speaker 1: how did the anus come to be? We've established that 885 00:49:15,440 --> 00:49:18,800 Speaker 1: the anus has evolved multiple times in different animal lineages, 886 00:49:18,840 --> 00:49:22,240 Speaker 1: so it's sort of a convergent evolution. Different clades figured 887 00:49:22,280 --> 00:49:25,440 Speaker 1: out over time that they want to that they want 888 00:49:25,480 --> 00:49:28,520 Speaker 1: to have a back opening of the digestive system. And 889 00:49:28,880 --> 00:49:32,320 Speaker 1: also that the anus evolved in animals as they grew larger. 890 00:49:32,440 --> 00:49:34,520 Speaker 1: As your body grows larger, it makes less and less 891 00:49:34,520 --> 00:49:39,200 Speaker 1: sense to have a sack shaped or bucket shaped digestive system. Um. So, 892 00:49:39,719 --> 00:49:42,640 Speaker 1: so you've got all these advantages. That's how evolution pays 893 00:49:42,800 --> 00:49:45,359 Speaker 1: for the through gut and the anus. But how did 894 00:49:45,440 --> 00:49:48,600 Speaker 1: it happen? How did animals go from one gut opening 895 00:49:48,719 --> 00:49:51,200 Speaker 1: to two? Well? To answer that question, I think we 896 00:49:51,320 --> 00:49:53,520 Speaker 1: first want to go back to a paper that Hainal 897 00:49:53,719 --> 00:49:55,719 Speaker 1: was one of the authors of in two thousand eight. 898 00:49:55,880 --> 00:49:59,360 Speaker 1: So this was by Hanal and another researcher named Mark Q. 899 00:49:59,560 --> 00:50:02,960 Speaker 1: Martin Day. I think we already mentioned him also, But yeah, 900 00:50:03,719 --> 00:50:06,160 Speaker 1: the two of these published paper in Nature in two 901 00:50:06,520 --> 00:50:11,640 Speaker 1: eight called a seal development indicates the independent evolution of 902 00:50:11,719 --> 00:50:15,200 Speaker 1: the Bilaterian mouth and anus. All right, now that that 903 00:50:15,320 --> 00:50:18,480 Speaker 1: paper title is lacking in a humor department, I would admit, yeah, 904 00:50:18,560 --> 00:50:20,680 Speaker 1: they didn't. They had didn't have their pun game going yet. 905 00:50:21,320 --> 00:50:22,960 Speaker 1: So what did they find? How do you get from 906 00:50:23,120 --> 00:50:26,600 Speaker 1: one opening to two? Well, in previous thinking, and this 907 00:50:26,840 --> 00:50:29,480 Speaker 1: was expressed in a Nature News article on the paper 908 00:50:29,600 --> 00:50:32,560 Speaker 1: by a researcher named debt Leva Rent who's at the 909 00:50:32,719 --> 00:50:37,560 Speaker 1: European Molecular Biology Laboratory in Heidelberg, it doesn't make sense 910 00:50:37,680 --> 00:50:39,759 Speaker 1: for a new hole on the opposite end of the 911 00:50:39,840 --> 00:50:42,440 Speaker 1: body from the mouth to just appear, so instead a 912 00:50:42,560 --> 00:50:46,120 Speaker 1: Rent and others believed that over time what happened is 913 00:50:46,360 --> 00:50:52,279 Speaker 1: the mouth elongated and eventually separated into two mouths more 914 00:50:52,440 --> 00:50:56,239 Speaker 1: side by side connecting to the same digestive sack, So 915 00:50:56,360 --> 00:50:58,919 Speaker 1: you wouldn't have a one way through gut, yet you'd 916 00:50:58,960 --> 00:51:03,279 Speaker 1: have sort of a U shaped digestive sack with two mouths. Okay, 917 00:51:03,360 --> 00:51:07,200 Speaker 1: so the ideas imagine an alien species eats through its mouth, 918 00:51:07,360 --> 00:51:09,560 Speaker 1: digest and then poops at its mouth, and then it 919 00:51:09,640 --> 00:51:12,280 Speaker 1: evolves to where it just has two mouths, the pooping 920 00:51:12,320 --> 00:51:14,799 Speaker 1: mouth and the eating mouth. Yeah, exactly. So you've got 921 00:51:14,920 --> 00:51:17,239 Speaker 1: to all purpose mouths that go both ways, and this 922 00:51:17,400 --> 00:51:20,239 Speaker 1: evolves over time to a through gut that goes one way. 923 00:51:20,920 --> 00:51:23,240 Speaker 1: And you know, once you have these two mouth openings, 924 00:51:23,320 --> 00:51:26,320 Speaker 1: one of them could sort of migrate back over time 925 00:51:27,040 --> 00:51:30,560 Speaker 1: and go down to the bottom of the organism, developed 926 00:51:30,600 --> 00:51:34,160 Speaker 1: different specialization and eventually become an anus. Of course, we 927 00:51:34,239 --> 00:51:37,320 Speaker 1: do have some organisms where they still have that essential 928 00:51:37,520 --> 00:51:41,839 Speaker 1: you shape, uh say, say snails and slugs. Slugs even 929 00:51:41,880 --> 00:51:46,200 Speaker 1: though they have no shell, evolved from shelled snails and 930 00:51:46,280 --> 00:51:49,880 Speaker 1: therefore they still have the front loaded defecation model. Oh 931 00:51:49,960 --> 00:51:53,120 Speaker 1: but deem know if in their case, is it just 932 00:51:53,239 --> 00:51:55,360 Speaker 1: two mouths and it goes either way or is it 933 00:51:55,440 --> 00:51:57,520 Speaker 1: a one way system? I believe it is a one 934 00:51:57,560 --> 00:52:00,680 Speaker 1: way system. Yes, okay, I'm thinking back to pass slug 935 00:52:00,760 --> 00:52:04,600 Speaker 1: and snail research. All right. Uh, so here's where Hanal 936 00:52:04,680 --> 00:52:08,680 Speaker 1: and Martindale disagreed. So they so that that was the 937 00:52:08,760 --> 00:52:11,400 Speaker 1: old view, right, that you'd have two mouths and eventually 938 00:52:11,440 --> 00:52:14,879 Speaker 1: the two mouths became a mouth and an anus differently specialized, 939 00:52:15,480 --> 00:52:18,680 Speaker 1: but Hanal and Martindale disagreed. They studied an organism called 940 00:52:18,760 --> 00:52:22,400 Speaker 1: convolo taloba longefic euro, which is a flat worm with 941 00:52:22,520 --> 00:52:25,719 Speaker 1: this kind of U shaped two gut or two mouth gut, 942 00:52:26,160 --> 00:52:28,359 Speaker 1: and they compared it to worms with a one way 943 00:52:28,440 --> 00:52:31,440 Speaker 1: gut containing a mouth and an anus. Now, earlier we 944 00:52:31,560 --> 00:52:34,920 Speaker 1: mentioned that there are genes associated with the presence of 945 00:52:34,960 --> 00:52:37,759 Speaker 1: an anus, right, Uh, there were the two genes we 946 00:52:37,840 --> 00:52:40,480 Speaker 1: mentioned earlier. Now, when those get expressed, the body is 947 00:52:40,640 --> 00:52:44,160 Speaker 1: usually building anal tissue. Well, in this earlier case from 948 00:52:44,200 --> 00:52:47,680 Speaker 1: two thousand eight, Hanal and Martindale discovered that longer Ficura 949 00:52:47,840 --> 00:52:52,120 Speaker 1: expressed mouth building genes, not anal or hind gut building 950 00:52:52,239 --> 00:52:54,759 Speaker 1: genes when building its two mouths. So both of those 951 00:52:54,840 --> 00:52:59,000 Speaker 1: genes were genetically reading as mouths or both of those mouths. Sorry, 952 00:52:59,040 --> 00:53:02,680 Speaker 1: we're genetically reading his mouths. But but the longer ficure 953 00:53:02,920 --> 00:53:06,839 Speaker 1: did express hindgut or anal building genes found in other 954 00:53:06,960 --> 00:53:10,080 Speaker 1: species at the rear end of its body. And this 955 00:53:10,239 --> 00:53:12,880 Speaker 1: suggests that a mouth did not turn into an anus, 956 00:53:12,960 --> 00:53:17,320 Speaker 1: but the anus developed from some other structure being expressed 957 00:53:17,360 --> 00:53:20,120 Speaker 1: at the rear end of the animal. So if it 958 00:53:20,360 --> 00:53:23,400 Speaker 1: wasn't a mouth that turned into an anus, what is 959 00:53:23,600 --> 00:53:25,759 Speaker 1: this structure or tissue at the rear end of the 960 00:53:25,840 --> 00:53:28,960 Speaker 1: animal that could give rise to the development of an anus. 961 00:53:29,600 --> 00:53:33,320 Speaker 1: And they thought, what about sexual tissue exactly? So this 962 00:53:33,440 --> 00:53:36,480 Speaker 1: brings us back to the two fifteen paper by Hano 963 00:53:36,640 --> 00:53:39,879 Speaker 1: and Martin Duran, and all of this relates to something 964 00:53:39,960 --> 00:53:43,840 Speaker 1: known as the gonopour. This is an opening that releases sperm. 965 00:53:44,360 --> 00:53:47,960 Speaker 1: In the Aceila class of simple or at least evolutionarily 966 00:53:48,080 --> 00:53:52,480 Speaker 1: simple invertebrates, they have no through gut, no circulatory system, 967 00:53:52,600 --> 00:53:56,719 Speaker 1: no respiratory system, and no anus. And the researchers think 968 00:53:56,760 --> 00:54:00,400 Speaker 1: that the origin of the gnipur may be linked to 969 00:54:00,560 --> 00:54:03,239 Speaker 1: the origin of the anus. Yeah, going back to that 970 00:54:03,320 --> 00:54:06,040 Speaker 1: point about the genes, they say the gene expression of 971 00:54:06,120 --> 00:54:09,960 Speaker 1: the seal orthologues of Brachii and the caudal c d 972 00:54:10,200 --> 00:54:13,920 Speaker 1: X gene c d X in the posterior male gonopore, 973 00:54:14,080 --> 00:54:17,120 Speaker 1: meaning the male sex organ at the back of these 974 00:54:17,239 --> 00:54:21,400 Speaker 1: little organisms. It suggests that instead there is quote an 975 00:54:21,440 --> 00:54:26,839 Speaker 1: evolutionary relationship between the bilaterryan hindgut and the acal gonopre. 976 00:54:27,000 --> 00:54:29,880 Speaker 1: So they're looking at the way genes are expressed and 977 00:54:30,000 --> 00:54:32,320 Speaker 1: saying like, there there appears to be a genetic to 978 00:54:32,520 --> 00:54:36,280 Speaker 1: tissue link between this sex organ in this very simple 979 00:54:36,520 --> 00:54:42,080 Speaker 1: multicellular organism and what eventually turns into the anus in 980 00:54:42,280 --> 00:54:46,120 Speaker 1: more complex creatures that have an anus. But they admit 981 00:54:46,239 --> 00:54:49,160 Speaker 1: in their paper that this is not a lock. It's 982 00:54:49,239 --> 00:54:52,600 Speaker 1: not like we know exactly where the anus came from 983 00:54:52,880 --> 00:54:55,919 Speaker 1: or that it's linked to the secial gonopre. They say 984 00:54:56,120 --> 00:54:59,400 Speaker 1: it's still vague, quote how the acal gonop or should 985 00:54:59,440 --> 00:55:03,879 Speaker 1: be related to the bilaterryan hindgut. A possible scenario, they write, 986 00:55:04,280 --> 00:55:07,680 Speaker 1: could be the connection of the male reproductive organ system 987 00:55:07,760 --> 00:55:12,320 Speaker 1: to the bilatery in digestive tract forming back to the cloaca. 988 00:55:12,960 --> 00:55:15,840 Speaker 1: So so you'd get a cloaca because remember, as we 989 00:55:15,880 --> 00:55:21,440 Speaker 1: said earlier, the cloaca combines a hole that deals with reproduction, 990 00:55:21,600 --> 00:55:24,640 Speaker 1: It deals with excretion of liquid waste, and excretion of 991 00:55:24,719 --> 00:55:27,320 Speaker 1: solid waste. It puts it all in one hole. So 992 00:55:27,480 --> 00:55:30,000 Speaker 1: they're saying, what if what happened is you got this, uh, 993 00:55:30,480 --> 00:55:34,120 Speaker 1: you know, this ancient double duty hole that became a cloaca, 994 00:55:34,840 --> 00:55:37,960 Speaker 1: And then they say, quote, this would thus provide an 995 00:55:37,960 --> 00:55:41,840 Speaker 1: alternative hypothesis which would connect first the male reproductive system 996 00:55:42,160 --> 00:55:47,560 Speaker 1: with the gut and later with the female reproductive system. Alright, 997 00:55:47,600 --> 00:55:51,040 Speaker 1: So if I'm understanding this argument correctly, something like the 998 00:55:51,120 --> 00:55:54,520 Speaker 1: ganabar is an arcade serves as an archaic body opening. Yes, 999 00:55:54,640 --> 00:55:57,480 Speaker 1: this primitive sex organ that we think something like it 1000 00:55:57,600 --> 00:56:00,680 Speaker 1: was present in our way way distant, and sters with 1001 00:56:00,840 --> 00:56:03,759 Speaker 1: that had bilateral symmetry, and as such it's something of 1002 00:56:03,920 --> 00:56:07,719 Speaker 1: not only a primitive sex organ, it's sort of a protoanus. Yes, 1003 00:56:07,800 --> 00:56:11,840 Speaker 1: it becomes the proto anus, which eventually joins together the 1004 00:56:11,960 --> 00:56:16,160 Speaker 1: reproductive and the digestive tract, and then over time, in 1005 00:56:16,320 --> 00:56:19,560 Speaker 1: much later organisms, those things can separate again. In two 1006 00:56:19,560 --> 00:56:22,040 Speaker 1: thousand fifteen, when this paper came out of the BBC 1007 00:56:22,239 --> 00:56:25,719 Speaker 1: talked to Hainal and he had this wonderful quote that 1008 00:56:25,800 --> 00:56:28,880 Speaker 1: he shared. Our own hypothesis is that the anal opening 1009 00:56:29,000 --> 00:56:32,320 Speaker 1: has some evolutionary connection to the male ghanipour. This of 1010 00:56:32,400 --> 00:56:35,080 Speaker 1: course makes the whole subject even more delicate, But this 1011 00:56:35,200 --> 00:56:38,360 Speaker 1: is how nature is. Nature does not care about taboos 1012 00:56:38,400 --> 00:56:43,080 Speaker 1: in human society. Look at him flout in those taboos. Yeah. Yeah, 1013 00:56:43,160 --> 00:56:45,040 Speaker 1: and it's you know, it's just another example of how 1014 00:56:45,160 --> 00:56:48,320 Speaker 1: if we ignore the anus, we do ourselves a disservice, 1015 00:56:48,400 --> 00:56:51,839 Speaker 1: in this case, in the realm of evolutionary biology. Yeah, 1016 00:56:52,600 --> 00:56:55,960 Speaker 1: don't don't let social morays keep you from studying ancient anus. 1017 00:56:56,120 --> 00:56:58,360 Speaker 1: Is exactly so. I I hope at the end of 1018 00:56:58,400 --> 00:57:02,640 Speaker 1: this episode everyone does have a new respect for the anus, 1019 00:57:02,760 --> 00:57:04,960 Speaker 1: and new respect for the development of the anus and 1020 00:57:05,040 --> 00:57:07,319 Speaker 1: how we we got to the point that we have them. 1021 00:57:07,440 --> 00:57:10,120 Speaker 1: Because unless you had some sort of magical idea in 1022 00:57:10,200 --> 00:57:13,759 Speaker 1: your head that you know, a fallen Titan brought the 1023 00:57:13,840 --> 00:57:16,720 Speaker 1: Promethean anus to the people of Earth and and and 1024 00:57:16,880 --> 00:57:20,480 Speaker 1: thus relieve them of their uh, their dire constipation, you 1025 00:57:20,520 --> 00:57:22,480 Speaker 1: know it had to come from somewhere. And I think 1026 00:57:22,680 --> 00:57:24,960 Speaker 1: part of that whole like taboo aspect of the anis 1027 00:57:25,000 --> 00:57:27,360 Speaker 1: don't think about the anus. It makes us often not 1028 00:57:27,640 --> 00:57:31,040 Speaker 1: question where it came from and how it developed over time. Well. Also, 1029 00:57:31,160 --> 00:57:34,360 Speaker 1: one thing you will hear from doctors and proctologists is uh, 1030 00:57:34,600 --> 00:57:36,440 Speaker 1: you know, you you might want to pay attention to 1031 00:57:36,480 --> 00:57:38,160 Speaker 1: your anus. You might want to think about it. Like 1032 00:57:38,440 --> 00:57:41,480 Speaker 1: some anal cancers can be caught early if you pay 1033 00:57:41,520 --> 00:57:44,920 Speaker 1: attention to it. Also, one thing I randomly came across 1034 00:57:44,960 --> 00:57:47,720 Speaker 1: while we were preparing for this episode. Apparently you shouldn't 1035 00:57:47,720 --> 00:57:51,560 Speaker 1: sit on the toilet for a really long time. Doctors said, don't. 1036 00:57:51,640 --> 00:57:53,720 Speaker 1: Don't just sit there on your phone for an hour. 1037 00:57:54,000 --> 00:57:56,720 Speaker 1: I know people do that now sometimes phone the sun 1038 00:57:56,800 --> 00:58:00,240 Speaker 1: games are better than ever before, so it's understand bole. 1039 00:58:00,440 --> 00:58:02,840 Speaker 1: But apparently that's not good for your anus. Okay, So 1040 00:58:03,000 --> 00:58:06,320 Speaker 1: if you are listening to this podcast right now on 1041 00:58:06,440 --> 00:58:09,040 Speaker 1: the toilet, and you have listened to the entire episode 1042 00:58:09,080 --> 00:58:11,320 Speaker 1: on the toilet, it's probably time to move. Can I 1043 00:58:11,360 --> 00:58:14,440 Speaker 1: add one more thing about the research process here? While 1044 00:58:14,480 --> 00:58:16,600 Speaker 1: we were reading, uh, you know, I was looking for 1045 00:58:16,720 --> 00:58:20,400 Speaker 1: good scientific articles about the anus, uh, And one thing 1046 00:58:20,480 --> 00:58:23,480 Speaker 1: I came across was this article full of obvious lies 1047 00:58:23,560 --> 00:58:27,040 Speaker 1: about how brown recluse spiders make nests in the human anus. 1048 00:58:27,600 --> 00:58:29,960 Speaker 1: It's not true, but I laughed a very hard. I'm 1049 00:58:29,960 --> 00:58:32,000 Speaker 1: not sure what prompted the writing of such a thing. 1050 00:58:32,440 --> 00:58:35,320 Speaker 1: I ran across a few things that made me giggle. 1051 00:58:35,400 --> 00:58:39,040 Speaker 1: One in particular, though, I saw one of these questions sites. 1052 00:58:39,080 --> 00:58:40,640 Speaker 1: I forget which one it was, but it's the one 1053 00:58:40,720 --> 00:58:43,080 Speaker 1: where you click on the answer and like it slides, 1054 00:58:43,520 --> 00:58:45,440 Speaker 1: you click on the question and it slides over and 1055 00:58:45,480 --> 00:58:49,520 Speaker 1: gives you an answer. It's also users submitted. Oh boy, Yeah, 1056 00:58:50,200 --> 00:58:52,520 Speaker 1: some good answers of it. Yeah. The question was do 1057 00:58:52,680 --> 00:58:55,960 Speaker 1: butterflies have anuses? And the answer was yes, they have 1058 00:58:56,080 --> 00:59:00,200 Speaker 1: the second largest on Earth. I do not the leave 1059 00:59:00,240 --> 00:59:02,840 Speaker 1: that is is accurate, but it it made me laugh. 1060 00:59:05,240 --> 00:59:07,680 Speaker 1: Oh man, they have the second largest on Earth and 1061 00:59:07,760 --> 00:59:11,720 Speaker 1: it's often colonized by brown recluse nests, probably according to 1062 00:59:12,080 --> 00:59:16,160 Speaker 1: you know, user generated scientific knowledge. So yeah, hopefully you're 1063 00:59:16,200 --> 00:59:19,680 Speaker 1: leaving this episode more knowledgeable of the anus uh than 1064 00:59:19,720 --> 00:59:21,640 Speaker 1: you were when you came in. Yeah, the anus. It's 1065 00:59:21,640 --> 00:59:26,280 Speaker 1: scientifically interesting, it's useful. You should appreciate it. All right, 1066 00:59:26,400 --> 00:59:29,960 Speaker 1: As we uh reach the posterior end of the podcast, 1067 00:59:30,040 --> 00:59:31,680 Speaker 1: we should drive home that. Hey, if you want to 1068 00:59:31,720 --> 00:59:33,400 Speaker 1: check out more episodes of Stuff to Blow Your Mind, 1069 00:59:33,640 --> 00:59:36,200 Speaker 1: if you want to explore some blog posts and find 1070 00:59:36,280 --> 00:59:39,120 Speaker 1: links to our very social media accounts, head on over 1071 00:59:39,200 --> 00:59:41,720 Speaker 1: to stuff to Blow your Mind dot com. Big thanks 1072 00:59:41,800 --> 00:59:45,400 Speaker 1: as always to our audio producers Alex Williams and Tarry Harrison. 1073 00:59:45,560 --> 00:59:47,120 Speaker 1: And if you want to get in touch with us 1074 00:59:47,160 --> 00:59:49,720 Speaker 1: directly to let us know feedback on this episode or 1075 00:59:49,720 --> 00:59:51,880 Speaker 1: any other, or to let us know a topic you'd 1076 00:59:51,920 --> 00:59:53,480 Speaker 1: like us to do in the future, or just to 1077 00:59:53,560 --> 00:59:56,600 Speaker 1: say hi, you can email us as always at blow 1078 00:59:56,720 --> 01:00:10,160 Speaker 1: the Mind at how stuff works dot com for more 1079 01:00:10,200 --> 01:00:12,520 Speaker 1: on this and thousands of other topics. Does it how 1080 01:00:12,560 --> 01:00:25,080 Speaker 1: stuff works dot com. The Big