1 00:00:01,560 --> 00:00:04,760 Speaker 1: Welcome to Stuff from the Science Lab from how stuff 2 00:00:04,760 --> 00:00:16,280 Speaker 1: works dot com. Hey guys, and welcome to the podcast. 3 00:00:16,320 --> 00:00:18,360 Speaker 1: This is Alison madam Ilk the science that are how 4 00:00:18,440 --> 00:00:20,640 Speaker 1: stuff works dot com. And this is Robert Lamb, science 5 00:00:20,640 --> 00:00:23,239 Speaker 1: writer at how stuff works dot com. Today we're talking 6 00:00:23,239 --> 00:00:27,440 Speaker 1: about the process of regeneration. And this topic comes to 7 00:00:27,480 --> 00:00:30,400 Speaker 1: you compliments of one Rob Chef, my colleague of ours 8 00:00:30,400 --> 00:00:33,400 Speaker 1: at how stuff works, and Rob send us a story 9 00:00:33,440 --> 00:00:37,600 Speaker 1: about a jellyfish, particular kind of jellyfish that can be 10 00:00:37,640 --> 00:00:40,839 Speaker 1: immortal essentially. Yeah, it's like that old saying immortality was 11 00:00:40,840 --> 00:00:45,199 Speaker 1: wasted on the jellyfish. Yeah, yeah, that old saying. Yeah. So, 12 00:00:45,440 --> 00:00:48,960 Speaker 1: the definition of regeneration is um the ability to regrow 13 00:00:48,960 --> 00:00:51,879 Speaker 1: lost tissue or destroyed organs or parts, and can be 14 00:00:51,960 --> 00:00:55,440 Speaker 1: routine or it can be sustained after injury. And the 15 00:00:55,440 --> 00:00:58,640 Speaker 1: regeneration is truly an amazing process. I mean, lest you 16 00:00:59,240 --> 00:01:02,200 Speaker 1: not regarded such, let me just regalue with a quote. 17 00:01:03,040 --> 00:01:05,440 Speaker 1: If there were no regeneration, there could be no life. 18 00:01:05,920 --> 00:01:09,040 Speaker 1: If everything regenerated, then there could be no death. And 19 00:01:09,120 --> 00:01:14,440 Speaker 1: that's the quote from the developmental biologist Richard Jay goss Um. 20 00:01:14,440 --> 00:01:17,040 Speaker 1: And goss was a pioneer in the field of developmental 21 00:01:17,040 --> 00:01:21,680 Speaker 1: biology and regeneration. Gossa taught up Brown for decades until 22 00:01:21,680 --> 00:01:25,280 Speaker 1: his death ironically from cancer actually, and a lot of 23 00:01:25,319 --> 00:01:29,000 Speaker 1: cellular and tissue growth. So that's pretty interesting. And Goss 24 00:01:29,080 --> 00:01:32,160 Speaker 1: was actually interested in antler regeneration and he published a 25 00:01:32,160 --> 00:01:36,160 Speaker 1: book called Deer Antlers in I was harping on this earlier, 26 00:01:36,160 --> 00:01:38,360 Speaker 1: but it's like, this is the guy, this guy's life work, 27 00:01:38,400 --> 00:01:39,880 Speaker 1: and he's just so passionate about and he just calls 28 00:01:39,880 --> 00:01:43,600 Speaker 1: the book dear Antlers just dear Antlers. Just sometimes the 29 00:01:43,640 --> 00:01:46,840 Speaker 1: topic speaks for itself, Robert, but not the complete Dear 30 00:01:46,880 --> 00:01:51,440 Speaker 1: Antlers or amazing or my life with Dear Antlers something. 31 00:01:51,520 --> 00:01:53,560 Speaker 1: I don't know. It just seems like a very gland title. Well, 32 00:01:53,640 --> 00:01:56,360 Speaker 1: Gas was a scientist, perhaps he felt no need for embellishment. 33 00:01:57,720 --> 00:02:00,960 Speaker 1: Unless the cover was a picture of himself with deer antlers, 34 00:02:01,440 --> 00:02:04,560 Speaker 1: then I would forgive the title. So anyway, Goss was 35 00:02:04,600 --> 00:02:07,600 Speaker 1: one of the main men in a pioneering regeneration um. 36 00:02:07,640 --> 00:02:11,839 Speaker 1: But there are some other pioneers in the field as well. Yeah, 37 00:02:11,840 --> 00:02:14,679 Speaker 1: I mean this is uh, the idea of regeneration is 38 00:02:14,840 --> 00:02:16,440 Speaker 1: is not know people have been noticing this for a 39 00:02:16,440 --> 00:02:19,040 Speaker 1: while Aristotle was writing about it, and if you go 40 00:02:19,120 --> 00:02:21,680 Speaker 1: back to the Greek myths, you might remember a certain 41 00:02:21,720 --> 00:02:26,560 Speaker 1: titan by the name of Prometheus, the firebringer um. And 42 00:02:27,320 --> 00:02:29,840 Speaker 1: his punishment UM was that he was chained to a 43 00:02:29,880 --> 00:02:33,120 Speaker 1: big rock and eagle would swoop down, eat his liver, 44 00:02:33,639 --> 00:02:36,359 Speaker 1: fly off, and then what happens, liver grows right back. 45 00:02:36,360 --> 00:02:39,520 Speaker 1: It's one of those eternal punishment type deals, but with 46 00:02:39,560 --> 00:02:43,120 Speaker 1: the bonus of livery generation um. And then also in greeknests, 47 00:02:43,160 --> 00:02:45,480 Speaker 1: you have the hydra, which is the multi headed serpent, 48 00:02:45,760 --> 00:02:47,880 Speaker 1: and every time you cut off one of its heads, 49 00:02:47,919 --> 00:02:50,640 Speaker 1: what happens, two of them grow back. That's correct, to 50 00:02:50,720 --> 00:02:53,239 Speaker 1: grow back in its place, um. And Hercules killed the 51 00:02:53,320 --> 00:02:56,640 Speaker 1: hydra correct, yeah, because he would, if I remember it correctly, 52 00:02:56,680 --> 00:02:59,160 Speaker 1: he had he realized, Hey, I just need to bring 53 00:02:59,160 --> 00:03:01,120 Speaker 1: a sword and a worch, and so every time he 54 00:03:01,200 --> 00:03:04,560 Speaker 1: cut off a head, he'd he'd cauterized the wound, burn it, 55 00:03:04,800 --> 00:03:06,600 Speaker 1: you know, shut. And so after a while you just 56 00:03:06,639 --> 00:03:09,920 Speaker 1: had this monster that was nothing but stumps, and I 57 00:03:09,919 --> 00:03:11,840 Speaker 1: guess it was dead. But it's a mythological creature, so 58 00:03:11,840 --> 00:03:14,400 Speaker 1: who knows. Who knows how these things work? As it 59 00:03:14,440 --> 00:03:17,880 Speaker 1: turns out, though, hydra eventually became a real thing, or 60 00:03:18,000 --> 00:03:21,560 Speaker 1: rather we applied that name to a living creature. Yeah, 61 00:03:21,600 --> 00:03:24,839 Speaker 1: it's a little tensicle microscopic animal. Yeah, I remember looking 62 00:03:24,880 --> 00:03:28,079 Speaker 1: at him in science class. This was discovered by Abraham 63 00:03:28,120 --> 00:03:32,639 Speaker 1: trimbley Um in seventeen forty and he picked the name 64 00:03:32,680 --> 00:03:35,160 Speaker 1: for it because every time one of the heads is 65 00:03:35,160 --> 00:03:36,920 Speaker 1: cut off, you can grow a new one, and as 66 00:03:36,960 --> 00:03:39,560 Speaker 1: it turns out, the human liver can also regenerate itself. 67 00:03:40,200 --> 00:03:44,000 Speaker 1: But that was an old Abraham different Abraham was main 68 00:03:44,000 --> 00:03:48,040 Speaker 1: really interested in the hydas. Then seventeen twelve you had 69 00:03:48,040 --> 00:03:50,160 Speaker 1: another guy that was really interested in this. So with 70 00:03:50,240 --> 00:03:52,880 Speaker 1: the last name renew and I can't say the rest 71 00:03:52,880 --> 00:03:55,040 Speaker 1: of it. You're gonna have to jump in with your French. Yeah, 72 00:03:55,080 --> 00:03:59,040 Speaker 1: I believe his name is a renee Antoine Fair. So 73 00:03:59,120 --> 00:04:03,720 Speaker 1: he made the first scientific observations of regeneration in crayfish, 74 00:04:03,880 --> 00:04:06,720 Speaker 1: which I was kind of surprised to hear that they 75 00:04:06,760 --> 00:04:10,960 Speaker 1: could regenerate because my wife's um of Cajun descent, so 76 00:04:11,240 --> 00:04:13,720 Speaker 1: I've never seen a crayfish have really a good chance 77 00:04:13,760 --> 00:04:17,360 Speaker 1: at surviving anything, just right in the pot. Yeah, So 78 00:04:17,560 --> 00:04:20,080 Speaker 1: back then a regeneration actually caught on with the public, 79 00:04:20,160 --> 00:04:23,479 Speaker 1: and according to Bruce Carlson, who published a textbook on 80 00:04:23,560 --> 00:04:27,760 Speaker 1: regenerative biology, the public just you know, went wild for 81 00:04:27,800 --> 00:04:29,680 Speaker 1: this concept. And so all of a sudden you have 82 00:04:29,760 --> 00:04:32,760 Speaker 1: members of the French nobility wandering out into their gardens 83 00:04:32,800 --> 00:04:34,800 Speaker 1: and chopping the heads off snails just to see the 84 00:04:34,800 --> 00:04:37,400 Speaker 1: poor snails grow new one. And I'm glad that's where 85 00:04:37,400 --> 00:04:39,680 Speaker 1: that story went, because when you first told me about it, 86 00:04:39,720 --> 00:04:42,119 Speaker 1: I had this vision of, um, you know, a French 87 00:04:42,160 --> 00:04:44,440 Speaker 1: noble has been getting all excited about regeneration, just hacking 88 00:04:44,440 --> 00:04:48,520 Speaker 1: off loombs, willy nilly, you know. Yeah, the French evidently 89 00:04:48,520 --> 00:04:51,400 Speaker 1: have a propensity for hacking off stuff, the poor snails. 90 00:04:52,440 --> 00:04:55,880 Speaker 1: So there are other examples of limb regeneration among animals. There's, 91 00:04:55,920 --> 00:04:59,400 Speaker 1: of course, the aforementioned hydra, which is that you know, 92 00:04:59,520 --> 00:05:02,479 Speaker 1: small to of their freshwater polyp, and the crayfish, which 93 00:05:02,480 --> 00:05:05,000 Speaker 1: we just talked about. There's the starfish. Do you remember 94 00:05:05,040 --> 00:05:07,200 Speaker 1: that scene in life that we just read about, Yeah, 95 00:05:07,200 --> 00:05:10,040 Speaker 1: where the crab snatches one of the limbs away. Yeah, 96 00:05:10,040 --> 00:05:11,760 Speaker 1: the starfish is just sitting there and minding its own 97 00:05:11,800 --> 00:05:15,400 Speaker 1: business and along comes this kid king crab. Don't don't, 98 00:05:15,400 --> 00:05:18,760 Speaker 1: don't do, and he just wrenches off the appendage. Well 99 00:05:18,800 --> 00:05:21,040 Speaker 1: you should. I mean, he's got he's got plenty to spare, 100 00:05:21,080 --> 00:05:23,560 Speaker 1: so I might as well grab one. Yeah, especially since 101 00:05:23,600 --> 00:05:26,719 Speaker 1: the starfish can can regrow them. Yeah, and this is um, 102 00:05:26,920 --> 00:05:28,880 Speaker 1: you can. You can kind of hack a starfish to 103 00:05:28,880 --> 00:05:30,919 Speaker 1: pieces as I recall, and each one will become a 104 00:05:30,920 --> 00:05:33,760 Speaker 1: new starfish pretty much. Did you do this in science class? Um? No, 105 00:05:33,960 --> 00:05:35,800 Speaker 1: but I remember hearing about it. We didn't have access 106 00:05:35,839 --> 00:05:38,680 Speaker 1: to starfish. But it's just like the SORCER's a press, 107 00:05:38,720 --> 00:05:44,599 Speaker 1: you know, SORCER's apprentice. Tell me Walt Disney Fantasia, Mickey 108 00:05:44,600 --> 00:05:47,880 Speaker 1: Mouse in a wizard costume. Mickey Mouse is practicing your generation. No, 109 00:05:47,960 --> 00:05:52,240 Speaker 1: he's practicing sorcery. But he has a there's like a 110 00:05:52,240 --> 00:05:55,359 Speaker 1: broom that gets chopped to pieces. Then all the little 111 00:05:55,400 --> 00:06:01,000 Speaker 1: they've turned all these little brooms and start marching everywhere. Yeah, yeah, yeah, 112 00:06:01,000 --> 00:06:03,080 Speaker 1: I do you remember that? Now? That's magical regeneration. That's 113 00:06:03,080 --> 00:06:06,640 Speaker 1: a whole different can of worms. Speaking of worms, yeah, 114 00:06:06,760 --> 00:06:09,520 Speaker 1: the ability to regenerate, that's a that's a good example. 115 00:06:09,960 --> 00:06:13,120 Speaker 1: And so regeneration is common among invertebrates, or at least 116 00:06:13,120 --> 00:06:16,000 Speaker 1: more common than it is among vertebrates like us, like 117 00:06:16,080 --> 00:06:19,760 Speaker 1: as humans, but a mind. Vertebrates. Salamanders are the kings 118 00:06:19,800 --> 00:06:23,279 Speaker 1: of regeneration. Yeah, they can like regenerate things like their 119 00:06:23,279 --> 00:06:25,880 Speaker 1: retina's right, I mean, it's just yeah, they can regenerate 120 00:06:25,920 --> 00:06:27,760 Speaker 1: a ton of stuff like their limbs and their tail, 121 00:06:28,279 --> 00:06:32,080 Speaker 1: their jaws there, and then yeah, eye tissues that you're saying, 122 00:06:32,600 --> 00:06:35,040 Speaker 1: that's one they had to move underground because the French 123 00:06:35,240 --> 00:06:38,200 Speaker 1: people were just trying to chop them up like crazy. Yeah, 124 00:06:38,200 --> 00:06:40,920 Speaker 1: they can even regenerate parts of the heart. And then 125 00:06:40,960 --> 00:06:44,640 Speaker 1: frogs they can they can survive from a broken heart then, right, 126 00:06:45,120 --> 00:06:48,160 Speaker 1: I guess I guess right, Yeah, his heart and he's 127 00:06:48,160 --> 00:06:51,160 Speaker 1: back out on the scene the next night. I'm sorry, 128 00:06:51,160 --> 00:06:54,440 Speaker 1: I'm getting a stuft topic, but anyway, you're to other animals, um. 129 00:06:54,520 --> 00:06:58,719 Speaker 1: And then, according to Scientific American, the embryos of some 130 00:06:58,800 --> 00:07:02,479 Speaker 1: mammals may be able to replace developing limb buds. But 131 00:07:02,680 --> 00:07:06,320 Speaker 1: this happens way, way, way way before the mammals are born, 132 00:07:06,480 --> 00:07:09,400 Speaker 1: right and then after they're born. That's so we humans 133 00:07:09,400 --> 00:07:12,600 Speaker 1: are capable of regeneration to just not necessarily limb regeneration. 134 00:07:13,400 --> 00:07:15,080 Speaker 1: But if you think about it, we're i mean human 135 00:07:15,120 --> 00:07:18,280 Speaker 1: limbs aren't really all that different from a salamanders, according 136 00:07:18,360 --> 00:07:20,680 Speaker 1: to the Scientific American story that I read. I mean, 137 00:07:20,720 --> 00:07:23,520 Speaker 1: they both have bones and muscles and tendons and nerves 138 00:07:23,560 --> 00:07:25,800 Speaker 1: and blood vessels and all this kind of things that 139 00:07:26,000 --> 00:07:30,920 Speaker 1: make a limb necessary. Um, mine are pretty pasty and 140 00:07:31,000 --> 00:07:34,520 Speaker 1: are a little freckled. Yeah, but if a salamander were 141 00:07:34,560 --> 00:07:36,880 Speaker 1: to lose a limb, it can regrow over and over 142 00:07:36,920 --> 00:07:39,120 Speaker 1: and over again. In fact, they think that this process 143 00:07:39,200 --> 00:07:42,400 Speaker 1: of regrowth can happen indefinitely, which is kind of crazy. 144 00:07:42,400 --> 00:07:45,400 Speaker 1: Whereas we just form a scar and that's the end 145 00:07:45,440 --> 00:07:48,080 Speaker 1: of the process by a peg lag and we're good 146 00:07:48,080 --> 00:07:51,200 Speaker 1: to go. So, yeah, what are the types of regeneration? Yeah, 147 00:07:51,200 --> 00:07:53,640 Speaker 1: as exciting as getting a whole new limb is as 148 00:07:53,640 --> 00:07:56,640 Speaker 1: exciting as getting a whole new limb, Maybe regeneration and 149 00:07:56,680 --> 00:07:59,480 Speaker 1: compasses is a lot more. In fact, you're probably doing 150 00:07:59,680 --> 00:08:03,320 Speaker 1: um little or a lot of regeneration right now while 151 00:08:03,320 --> 00:08:04,680 Speaker 1: you're listening to this. And I don't just mean the 152 00:08:05,080 --> 00:08:08,160 Speaker 1: salamanders out there. Um. So, here are a few different 153 00:08:08,200 --> 00:08:12,560 Speaker 1: ways that regeneration occurs in animals. Um, do you want 154 00:08:12,560 --> 00:08:16,320 Speaker 1: to take the first time? Yeah? Okay, So, according to Carlson. Um, 155 00:08:16,360 --> 00:08:19,520 Speaker 1: there's physiological regeneration, and that's just you know, think of 156 00:08:19,560 --> 00:08:23,400 Speaker 1: it as your body replacing worn out body parts. Yeah, 157 00:08:23,520 --> 00:08:26,160 Speaker 1: wearing out and building itself back up again. Yeah. It 158 00:08:26,160 --> 00:08:28,520 Speaker 1: can be as simple as replacing blood. You know, so 159 00:08:28,600 --> 00:08:30,840 Speaker 1: you just give blood, you know, you have to replace 160 00:08:30,840 --> 00:08:33,360 Speaker 1: the blood, right. Yeah. It's like they're you know, people 161 00:08:33,360 --> 00:08:35,240 Speaker 1: often you know, point that it's like you're not even 162 00:08:35,280 --> 00:08:37,840 Speaker 1: like the same person after a certain amount of time, 163 00:08:37,880 --> 00:08:40,840 Speaker 1: you know, because you've replaced so many different cells. Al Right, 164 00:08:40,880 --> 00:08:44,200 Speaker 1: I remember you talking about this. This is fascinating and uh, 165 00:08:44,280 --> 00:08:46,640 Speaker 1: and some people even take the extra mile and like 166 00:08:46,840 --> 00:08:49,200 Speaker 1: sort of talk about the how the mind changes and 167 00:08:49,200 --> 00:08:50,720 Speaker 1: about how you're not even the same you're not the 168 00:08:50,720 --> 00:08:54,120 Speaker 1: same person physically anymore after a certain amount of time, 169 00:08:54,120 --> 00:08:58,079 Speaker 1: and you're not the same person, uh you know mentally, uh, 170 00:08:58,760 --> 00:09:03,000 Speaker 1: constantly changing, constantly regenerating. Right, So the regeneration kind of 171 00:09:03,240 --> 00:09:05,360 Speaker 1: leading to this whole new composition of the body, and 172 00:09:05,400 --> 00:09:08,280 Speaker 1: that's the whole new person. Yeah. Yeah, that's really interesting. 173 00:09:08,679 --> 00:09:10,439 Speaker 1: Like I like to point out to you sort of 174 00:09:10,440 --> 00:09:12,199 Speaker 1: in a way, you're sort of building that new body 175 00:09:12,240 --> 00:09:14,679 Speaker 1: out of the things you buy the grocery store. So 176 00:09:15,000 --> 00:09:16,800 Speaker 1: which is my whole argument for why would you buy 177 00:09:16,800 --> 00:09:19,240 Speaker 1: a whole bunch of crappy food? You know, why don't 178 00:09:19,240 --> 00:09:21,560 Speaker 1: you buy a whole bunch of you know whatever kind 179 00:09:21,600 --> 00:09:24,360 Speaker 1: of crappy food is not in some way you know, 180 00:09:25,679 --> 00:09:30,400 Speaker 1: right right right? Well food food arguments aside. Um regeneration 181 00:09:30,440 --> 00:09:32,679 Speaker 1: also happens, you know, just on a very basic level 182 00:09:32,720 --> 00:09:34,720 Speaker 1: with your skin cells. You know, think about it. You're 183 00:09:34,760 --> 00:09:37,439 Speaker 1: constantly shedding skin cells. Did you forgear that fact about? 184 00:09:37,800 --> 00:09:39,760 Speaker 1: You know, if you have a mattress for a couple 185 00:09:39,800 --> 00:09:42,679 Speaker 1: of years, what percentage of that mattress is basically just 186 00:09:42,720 --> 00:09:46,000 Speaker 1: your dead skin cells filling it up? Yeah, well there's 187 00:09:46,040 --> 00:09:47,960 Speaker 1: a crazy fact out there, but I can't remember exactly 188 00:09:48,000 --> 00:09:51,640 Speaker 1: what percentages, Like your mattress just becomes your skin cells 189 00:09:52,559 --> 00:09:54,280 Speaker 1: or you might you need to check when you buy 190 00:09:54,280 --> 00:09:57,720 Speaker 1: a mattress because it's not composed only of skin cells. 191 00:09:57,720 --> 00:10:01,000 Speaker 1: Before we're not the ladder um. There's another form of 192 00:10:01,000 --> 00:10:05,840 Speaker 1: regeneration called hypertrophy, and this one is when an oregan 193 00:10:05,920 --> 00:10:09,280 Speaker 1: gets bigger to compensate for um. So you lost a 194 00:10:09,320 --> 00:10:12,200 Speaker 1: kidney or donated to kidney, so then you just have 195 00:10:12,320 --> 00:10:14,040 Speaker 1: one and it's got a whole lot more work to 196 00:10:14,080 --> 00:10:17,240 Speaker 1: do so it gets bigger. UM. They've also documented this 197 00:10:17,360 --> 00:10:22,360 Speaker 1: taking place with the lungs. UM livers. Pancreas can also 198 00:10:22,400 --> 00:10:25,000 Speaker 1: experience some regeneration if they're damaged. This reminds me a 199 00:10:25,040 --> 00:10:28,000 Speaker 1: little bit of that phenomena they've talked about in UM. 200 00:10:28,160 --> 00:10:30,559 Speaker 1: People who lose the sense, you know, visually impaired people, 201 00:10:31,360 --> 00:10:33,720 Speaker 1: and you know the other senses compensating for that. I 202 00:10:33,720 --> 00:10:37,800 Speaker 1: wonder like you you go blind, you're hearing gets better. UM, 203 00:10:37,880 --> 00:10:42,000 Speaker 1: you go deaf, you're smelling gets better. So the final 204 00:10:42,040 --> 00:10:44,839 Speaker 1: kind of regeneration is called reparative regeneration. And you might 205 00:10:44,840 --> 00:10:47,000 Speaker 1: find this happening and your muscle, bone, and your skin, 206 00:10:47,080 --> 00:10:51,120 Speaker 1: your heart, tissues, anything along those lines. And this is 207 00:10:51,120 --> 00:10:53,720 Speaker 1: also where that handy ability to form new limbs would fall. 208 00:10:54,800 --> 00:10:58,400 Speaker 1: And Um, this happens with courtesy of a blastema. And 209 00:10:58,480 --> 00:11:01,400 Speaker 1: the blastema is just a grouping of undifferentiated cells that 210 00:11:01,440 --> 00:11:04,880 Speaker 1: are capable of growth and later differentiation. And so by 211 00:11:04,920 --> 00:11:07,240 Speaker 1: differentiation we just mean you know it's going to go on. 212 00:11:07,640 --> 00:11:10,040 Speaker 1: It starts off life, maybe without a purpose, it's a 213 00:11:10,040 --> 00:11:11,840 Speaker 1: blank slate, and then it goes on to become a 214 00:11:11,840 --> 00:11:15,600 Speaker 1: heart cell. Say that's all we mean by differentiation. Well, 215 00:11:15,679 --> 00:11:19,720 Speaker 1: let's bring it all back to jellyfish. What about Tatopsis ah. 216 00:11:19,760 --> 00:11:23,520 Speaker 1: Tatopsis s. Neutricula is a particular species of jellyfish that 217 00:11:23,600 --> 00:11:26,480 Speaker 1: maybe the only animal in the world that's a maybe 218 00:11:26,520 --> 00:11:28,760 Speaker 1: has something in common with vampires, and that is it's 219 00:11:28,800 --> 00:11:32,360 Speaker 1: a it may live forever and how many do that? Well, 220 00:11:32,440 --> 00:11:35,640 Speaker 1: it's capable of cycling, uh, from an adult to to 221 00:11:35,760 --> 00:11:40,719 Speaker 1: an immature stage, the polyp stage, like a frog being 222 00:11:40,720 --> 00:11:43,880 Speaker 1: able to rewind to tadpole form and then advance into 223 00:11:43,920 --> 00:11:47,080 Speaker 1: frog again then rewinded the tadpole form, that kind of thing. Yeah, 224 00:11:47,120 --> 00:11:49,079 Speaker 1: So as you can imagine, if you have this kind 225 00:11:49,080 --> 00:11:51,800 Speaker 1: of ability, your numbers, your population numbers of this particular 226 00:11:51,840 --> 00:11:54,480 Speaker 1: species would probably spike, as they are. In fact with 227 00:11:54,720 --> 00:11:59,000 Speaker 1: Totopsis neutricula they were found originally in the Caribbean, I believe, 228 00:11:59,040 --> 00:12:01,160 Speaker 1: but now they've spread to waters all over the world. 229 00:12:01,920 --> 00:12:05,040 Speaker 1: And so the key in this process that allows um 230 00:12:05,080 --> 00:12:07,520 Speaker 1: a mature adult to cycle back into this immature poly 231 00:12:07,600 --> 00:12:11,439 Speaker 1: up stage lies in a cellular process called trends differentiation, 232 00:12:11,640 --> 00:12:14,640 Speaker 1: which we've just kind of touched on a little bit. So, yeah, 233 00:12:14,640 --> 00:12:19,280 Speaker 1: differentiation is the process by which an unspecified imbryonic cell 234 00:12:19,360 --> 00:12:22,680 Speaker 1: acquires the features of a specialized cell, such as a 235 00:12:22,720 --> 00:12:25,400 Speaker 1: hard liver or muscle cell, all right, and it's controlled 236 00:12:25,400 --> 00:12:28,480 Speaker 1: by an interaction of the cells genes with physical or 237 00:12:28,520 --> 00:12:35,960 Speaker 1: chemical properties. Trans Differentiation is a little different in this 238 00:12:36,080 --> 00:12:40,400 Speaker 1: adult stem cells can differentiate into cell types of scene 239 00:12:40,400 --> 00:12:42,720 Speaker 1: and organs or tissues other than those expected from the 240 00:12:42,760 --> 00:12:48,480 Speaker 1: cells predicted lineage. So like brains, like brain stem cells 241 00:12:48,880 --> 00:12:54,280 Speaker 1: might differentiate into blood cells or blood forming cells, um 242 00:12:54,679 --> 00:12:57,080 Speaker 1: into brain cells, et cetera. Yeah, I mean it's kind 243 00:12:57,120 --> 00:12:59,839 Speaker 1: of amazing. Jellyfish typically die after the propagate, but this 244 00:13:00,000 --> 00:13:03,040 Speaker 1: particular jellyfish can just i mean, keep on reproducing and 245 00:13:03,080 --> 00:13:05,679 Speaker 1: you know, carrying on its life forever. I mean, as 246 00:13:05,679 --> 00:13:09,679 Speaker 1: a mom, I find that prospect a little horrifying, the 247 00:13:09,720 --> 00:13:11,920 Speaker 1: fact that, you know, perhaps you might have to go 248 00:13:12,000 --> 00:13:15,240 Speaker 1: through childbirth numerous times. Not the jellyfish in fact go 249 00:13:15,280 --> 00:13:18,280 Speaker 1: through childbirth, but just comparing it to my own human 250 00:13:18,320 --> 00:13:22,040 Speaker 1: perspective on the reproduction cycle, Yeah, it's kind of like 251 00:13:23,080 --> 00:13:26,959 Speaker 1: it's almost like they're going through just repetitive midlife crisis. 252 00:13:27,240 --> 00:13:29,200 Speaker 1: You know. It's like, oh, I'm getting old, I'm gonna 253 00:13:29,520 --> 00:13:31,960 Speaker 1: act like a young jellyfish again. But they actually become 254 00:13:31,960 --> 00:13:34,480 Speaker 1: a young jellyfish. But the interesting thing is they have 255 00:13:34,480 --> 00:13:36,320 Speaker 1: no idea what how this happens. They don't know the 256 00:13:36,320 --> 00:13:39,040 Speaker 1: mechanism behind the life cycle. They know that cells are 257 00:13:39,360 --> 00:13:41,760 Speaker 1: able to turn from one type into another, from general 258 00:13:41,760 --> 00:13:44,439 Speaker 1: to specific, from specific to general, and keep going back 259 00:13:44,440 --> 00:13:46,600 Speaker 1: and forth, but if they don't know why, and it's 260 00:13:46,640 --> 00:13:49,360 Speaker 1: not very I mean, ultimately, it's not like a sustainable thing. 261 00:13:49,720 --> 00:13:52,720 Speaker 1: Like you mentioned the vampires um our own. Josh Clark 262 00:13:52,920 --> 00:13:55,800 Speaker 1: did a blog post a while back where some scientists 263 00:13:55,840 --> 00:13:57,560 Speaker 1: like sit down and look at the whole vampire thing, 264 00:13:57,559 --> 00:14:00,480 Speaker 1: and they're like, look, it could never happen because obviously 265 00:14:00,520 --> 00:14:03,040 Speaker 1: you'd end up with more vamps, so many more vampires 266 00:14:03,040 --> 00:14:05,360 Speaker 1: than humans. It wouldn't be any humans to feed on, 267 00:14:05,440 --> 00:14:08,959 Speaker 1: and you just have vampires and they'd starve or whatever. Right, 268 00:14:08,960 --> 00:14:13,480 Speaker 1: It's not so immortality is just not sustainable. Sustainable. Yeah, So, I, 269 00:14:13,600 --> 00:14:16,479 Speaker 1: for one, I'm very interested in regeneration and its prospects 270 00:14:16,480 --> 00:14:18,800 Speaker 1: for medicine and stem cells in the lake in the future. 271 00:14:18,840 --> 00:14:20,480 Speaker 1: So I would love to do a follow up podcast 272 00:14:20,480 --> 00:14:22,200 Speaker 1: on this. Let us know if you guys are interested 273 00:14:22,520 --> 00:14:25,840 Speaker 1: um in a in a podcast also on regeneration in 274 00:14:25,880 --> 00:14:28,240 Speaker 1: the meantime, come check out our blogs, where we'll keep 275 00:14:28,280 --> 00:14:31,320 Speaker 1: you up to date on whatever we're podcasting about for 276 00:14:31,320 --> 00:14:34,520 Speaker 1: the week and uh any other interesting scientific tidbits that 277 00:14:34,600 --> 00:14:37,760 Speaker 1: cross our desk. And if you guys have a question 278 00:14:37,840 --> 00:14:42,440 Speaker 1: about immortality, vampires, jellyfish, or regeneration in fact, send us 279 00:14:42,440 --> 00:14:44,440 Speaker 1: an email at science stuff at how stuff works dot 280 00:14:44,520 --> 00:14:54,400 Speaker 1: com for more on this and thousands of other topics 281 00:14:54,440 --> 00:14:57,480 Speaker 1: because at how stuff works dot com. Want more how 282 00:14:57,560 --> 00:15:00,400 Speaker 1: stuff works, check out our blogs on the how soworth 283 00:15:00,480 --> 00:15:01,440 Speaker 1: dot com home page.