WEBVTT - Creature with the Crystal Skin 0:00:03.000 --> 0:00:05.360 Welcome to Stuff to Blow Your Mind production of My 0:00:05.480 --> 0:00:14.880 Heart Radio. Hey you welcome to Stuff to Blow your Mind. 0:00:15.080 --> 0:00:18.079 My name is Robert Lamb, and I'm Joe McCormick. And 0:00:18.160 --> 0:00:22.200 today we're gonna be talking about a biological topic which 0:00:22.480 --> 0:00:24.880 has has fascinated me for a while, ever since I 0:00:24.920 --> 0:00:27.120 was reading about a family of frogs that I'm going 0:00:27.160 --> 0:00:29.560 to come back to in a bit. And uh, and 0:00:29.880 --> 0:00:35.519 this is the idea of transparency or translucency in animals, 0:00:35.560 --> 0:00:40.040 animals that have clear or at least translucent skin or 0:00:40.120 --> 0:00:45.120 other body parts. Yeah, and just thinking about this topic 0:00:45.440 --> 0:00:47.199 brought me back made me think about some stories that 0:00:47.240 --> 0:00:50.000 I probably haven't read in about twenty years now, but 0:00:50.560 --> 0:00:55.240 the tales of Fritz Lieber genre Ryder, who lived nineteen 0:00:55.280 --> 0:00:59.240 ten through fun Note he was the son of actor 0:00:59.360 --> 0:01:02.440 Fritz Lieber, so he's technically junior to his senior. Fritz 0:01:02.560 --> 0:01:05.640 Leeber Senior was in films like nineteen threes, Phantom of 0:01:05.680 --> 0:01:09.640 the Opera starting Claude Rains, and then Fritz Lieber junr 0:01:09.800 --> 0:01:12.840 Son Justin Lieber was a philosopher and a sci fi 0:01:12.880 --> 0:01:15.000 author in his own right. I think at some point 0:01:15.080 --> 0:01:17.520 I just popped open his Wikipedia page, and I saw 0:01:17.560 --> 0:01:20.120 there was a top line reference to him also being, 0:01:20.200 --> 0:01:22.759 in addition to being like a sword and sorcery author 0:01:22.840 --> 0:01:25.920 and science fiction author, a chess expert. And that was 0:01:25.959 --> 0:01:27.440 one of those things where I was like, is that 0:01:27.560 --> 0:01:30.280 real or is that just like something that that the 0:01:30.319 --> 0:01:33.480 author themselves or someone associated with them kind of snuck 0:01:33.480 --> 0:01:36.800 in there. I don't know, I'm not I'm not ass 0:01:36.880 --> 0:01:40.840 up on the full Fritz Lieber biography there, but but 0:01:40.920 --> 0:01:43.840 he wrote a lot of stuff in various genre works. 0:01:44.280 --> 0:01:46.720 Some of his stories even were also adapted into I 0:01:46.720 --> 0:01:49.120 think like a couple of episodes of Night Gallery back 0:01:49.120 --> 0:01:52.800 in the day. But the closest, the thing that's closest 0:01:52.800 --> 0:01:55.200 to my heart, the material that I'm familiar with, are 0:01:55.240 --> 0:01:58.560 these stories he wrote about these two characters, uh Fowford 0:01:58.840 --> 0:02:01.440 and the Gray Mouser. Uh So this is your sort 0:02:01.480 --> 0:02:05.760 of iconic adventuring duo, and he's these stories helped him 0:02:05.760 --> 0:02:08.600 make it iconic. You have a pair of barbarian in 0:02:08.600 --> 0:02:11.560 a rogue and they get into all manner of adventures. 0:02:11.639 --> 0:02:13.919 These were these were very popular stories. I think they 0:02:13.919 --> 0:02:17.040 had an influence on the development of dungeons and dragons, 0:02:17.400 --> 0:02:19.440 and they hold a hold up pretty well too. Well, 0:02:19.480 --> 0:02:21.680 if it's a barbarian in a rogue that sounds like 0:02:22.040 --> 0:02:25.799 Conan and Subatie, Yeah yeah, yeah, very much of that 0:02:25.880 --> 0:02:29.840 vein um so that they're great fun. They're always encountering 0:02:29.919 --> 0:02:35.160 various enemies and magic and magical creatures. And in one 0:02:35.240 --> 0:02:38.560 work in particular, I believe this is The Swords of 0:02:38.680 --> 0:02:45.359 Lankamer from Night, they encounter ghoules. Now, I love ghoules 0:02:45.440 --> 0:02:48.040 as they appear in various other works of fiction. Uh, 0:02:48.040 --> 0:02:50.799 these goals are very or rather different, and I think 0:02:50.800 --> 0:02:54.680 when I first read Fritz Lieber's ghouls, I was a 0:02:54.720 --> 0:02:57.160 little I wasn't mad into him. I was like this, 0:02:57.320 --> 0:02:59.080 this is this is a little too different from what 0:02:59.120 --> 0:03:01.600 I'm used to. I just want, you know, bone chewing 0:03:02.120 --> 0:03:05.600 pallid humanoids, because he takes the idea in a in 0:03:05.639 --> 0:03:08.680 a rather different direction. Okay, so your standard ghoul is 0:03:08.720 --> 0:03:11.720 just a sort of deathly looking humanoid who hangs out 0:03:11.720 --> 0:03:15.760 in graveyards and eats grave flesh, right right. These ghouls 0:03:16.840 --> 0:03:21.160 have translucent anatomy. Essentially, they just look like a walking 0:03:21.240 --> 0:03:24.840 skeleton because all of the soft tissues in their bodies 0:03:25.120 --> 0:03:28.120 are transparent. So the only thing you can actually see 0:03:28.800 --> 0:03:31.960 is the skeleton unless like the light is just right, 0:03:32.000 --> 0:03:35.360 because you know, it's not true and it's not magical invisibility. 0:03:35.360 --> 0:03:39.760 It's supposed to be uh, you know, translucent tissue based invisibility, 0:03:40.000 --> 0:03:42.840 so you would only see the skeleton in most cases, 0:03:42.920 --> 0:03:45.800 though there is more than the skeleton. They've got some 0:03:45.800 --> 0:03:48.720 some fleshy, soft, squishy bits, but those those just let 0:03:48.760 --> 0:03:51.560 the light pass right through. Yeah, everything is see through 0:03:51.800 --> 0:03:54.640 except for the skeleton. So I actually just want to 0:03:54.680 --> 0:03:57.200 read a little bit from the Swords of of Lachmar 0:03:57.320 --> 0:04:02.440 from After an instant and shock, Fawford realized that these 0:04:02.520 --> 0:04:05.680 must be ghouls, whose flesh and inner organs he had 0:04:05.720 --> 0:04:09.680 heard with much skepticism, but now no longer were transparent, 0:04:09.880 --> 0:04:15.000 except when the skin became slowly or rosalie translucent on 0:04:15.080 --> 0:04:18.360 the genital organs or on the lops and small breasts 0:04:18.400 --> 0:04:21.440 of their women. It was said also that they ate 0:04:21.520 --> 0:04:25.760 only flesh human by preference, and that it was strange, indeed, 0:04:25.800 --> 0:04:28.800 to watch the raw gobbits they gulped, course down and 0:04:28.960 --> 0:04:32.280 churn within the bars of their ribs, gradually turning to 0:04:32.400 --> 0:04:36.560 mush and fading from sight as their sightless blood assimilated 0:04:36.600 --> 0:04:40.080 and transformed the food, granting that a mere normal man 0:04:40.200 --> 0:04:43.960 might ever have the opportunity to watch Ghoule's feast without 0:04:43.960 --> 0:04:49.000 becoming a supply of gobbitts himself. That is some pros. Yeah, yeah, 0:04:49.000 --> 0:04:51.320 it was a good good writer. There's there's a lot 0:04:51.360 --> 0:04:55.080 of fun and whimsy too. Um So, the ghouls in 0:04:55.080 --> 0:05:00.039 this story they described themselves as being crystal fleshed and 0:04:59.680 --> 0:05:01.400 h and that they see it as a sort of 0:05:01.400 --> 0:05:05.359 sacred responsibility to consume the flesh of say, human beings, 0:05:05.720 --> 0:05:09.080 because our flesh is um is murkier, you know, it's 0:05:09.160 --> 0:05:14.440 it's not that translucent purity. So when they eat it, uh, 0:05:14.440 --> 0:05:18.200 they eat our flesh, it eventually becomes translucent, It becomes 0:05:18.240 --> 0:05:22.320 crystal inside of them. There's a female ghoul that pops 0:05:22.360 --> 0:05:25.440 up in these stories that the believe of Fafford actually 0:05:25.520 --> 0:05:28.480 ends up falling for after a while. And she also 0:05:28.560 --> 0:05:33.440 has a great story about ghoul romance. Yeah yeah, google romance. Uh. 0:05:33.480 --> 0:05:36.760 But there's a bit where where she's talking about like 0:05:36.800 --> 0:05:40.400 the differences between um between ghouls and humans and she 0:05:40.520 --> 0:05:43.280 tells him bones are beautiful, they're made to be seen. 0:05:44.600 --> 0:05:48.679 And there's another part where Faford asked his asking questions 0:05:48.680 --> 0:05:51.040 about what's it like to be a ghoule, and he 0:05:51.080 --> 0:05:55.080 picks up on a bit of a scientific critique that 0:05:55.120 --> 0:05:58.559 often comes up when discussing things like HD Wells Invisible Man. 0:05:59.000 --> 0:06:02.120 He says, well, how can you see anything if light 0:06:02.360 --> 0:06:05.640 passes right through you? He asked her if ghoules happened 0:06:05.680 --> 0:06:07.920 to see with the inside of the back of their skulls, 0:06:08.279 --> 0:06:11.800 and she responds, quote, look closely into my eyes, No, 0:06:12.000 --> 0:06:14.840 without getting between them and the fire. Can you see 0:06:14.839 --> 0:06:18.080 a small rainbow in each That's where the light is 0:06:18.200 --> 0:06:21.080 refracted to the seeing part of my brain and a 0:06:21.200 --> 0:06:25.720 very tiny real image formed there. I love alternative visual anatomy. 0:06:25.880 --> 0:06:30.280 That's great. Yeah, I love that he made sure to 0:06:30.360 --> 0:06:33.440 actually throw that in there to address how his ghouls 0:06:33.640 --> 0:06:35.720 see anything. But anyway, like I said, when I first 0:06:35.720 --> 0:06:38.280 read of these creatures, I was I was like, oh, 0:06:38.320 --> 0:06:40.760 this is too different. I these are not googles I 0:06:40.760 --> 0:06:42.640 can really get behind. But now, as we're about to 0:06:43.080 --> 0:06:47.440 jump into the discussion of some amazing natural world organisms 0:06:47.480 --> 0:06:50.920 that have various levels of translucency to their bodies, I'm 0:06:50.960 --> 0:06:53.040 looking back on Fritz Leeber's ghouls and I'm like, these 0:06:53.040 --> 0:06:56.600 are amazing. These ideas of these uh, these translucent fleshed 0:06:57.000 --> 0:07:00.440 beings like jumping into battle with their axes and everyone 0:07:00.600 --> 0:07:03.920 on the other side they just look like skeletons because 0:07:03.920 --> 0:07:08.400 that's the only part that isn't see through. That is great. Okay, well, 0:07:08.440 --> 0:07:10.840 I guess the first example of a of a real 0:07:10.880 --> 0:07:14.000 animal I want to talk about today a group of 0:07:14.040 --> 0:07:18.320 animals actually known as the glass frogs, and a little 0:07:18.320 --> 0:07:21.560 bit of terminology distinction. I guess we've already said these words. 0:07:21.600 --> 0:07:26.280 But um, but transparency versus translucency if you're not familiar, 0:07:26.280 --> 0:07:29.520 Transparency you can think of as being clear like glass, 0:07:29.720 --> 0:07:33.560 pretty much allowing all light to to pass through, whereas 0:07:33.600 --> 0:07:37.400 translucency you can think of like frosted glass, is allowing 0:07:37.440 --> 0:07:39.600 a lot of light to pass through, but not as 0:07:39.680 --> 0:07:42.400 much as as a total clarity. You'll find that these 0:07:42.400 --> 0:07:47.880 are though sometimes used interchangeably, even sometimes in scientific papers though. Yeah. So, 0:07:48.200 --> 0:07:52.280 the so called glass frogs comprise many different species, but 0:07:52.280 --> 0:07:55.520 they all belong to the family central in a day, 0:07:55.560 --> 0:07:58.320 which is found in regions throughout Central and South America. 0:07:58.840 --> 0:08:02.840 These are mostly arboreal creatures, meaning they live in trees, 0:08:02.960 --> 0:08:07.400 often in rainforests and especially near sources of fresh water. 0:08:07.640 --> 0:08:11.200 So if you want to find a glass frog, most 0:08:11.240 --> 0:08:13.360 of the time a good place to look it's like 0:08:13.440 --> 0:08:18.000 on leaves overhanging the bank of a jungle stream. But 0:08:18.400 --> 0:08:20.080 if you were to go out looking for one of 0:08:20.120 --> 0:08:23.360 these creatures, you might have a bit of difficulty. The 0:08:23.480 --> 0:08:26.840 difficulty finding the frog even if you're looking right at 0:08:26.840 --> 0:08:30.920 the leaf where it's perched, because glass frogs can blend 0:08:30.960 --> 0:08:34.560 in very well with foliage, and Robbi attached a couple 0:08:34.559 --> 0:08:37.280 of pictures for you to look at here of various 0:08:37.360 --> 0:08:41.680 green and yellow species of glass frogs perched on a leaf. 0:08:41.720 --> 0:08:43.719 It's especially good to look at like a leaf that's 0:08:43.720 --> 0:08:46.800 sort of lit from behind, and the frog will be 0:08:46.920 --> 0:08:50.320 right next to a collection of what looked like little 0:08:50.760 --> 0:08:55.680 semi transparent, semi opaque spherical globules, And these are actually 0:08:55.760 --> 0:08:59.400 the frog's eggs. One of the most striking things about 0:08:59.400 --> 0:09:03.600 the glass for family is their skin. Now, most species 0:09:03.600 --> 0:09:07.360 of glass frogs appear from above to have a kind 0:09:07.400 --> 0:09:13.520 of uh moderately translucent skin, especially on some parts of 0:09:13.679 --> 0:09:17.000 their their dorsal sides, such as like the toes or 0:09:17.040 --> 0:09:20.480 the legs, and so you can see the blurry specter 0:09:20.600 --> 0:09:23.760 of bones in their toes or in their legs, which 0:09:23.800 --> 0:09:26.600 is very creepy and very cool that this this would 0:09:26.600 --> 0:09:30.120 be like crystal ghoules. You can actually see the bones 0:09:30.240 --> 0:09:33.800 through the skin. Some species take this even further and 0:09:33.840 --> 0:09:38.120 have not only semi translucent legs or parts of the backs, 0:09:38.559 --> 0:09:42.600 but nearly totally transparent bellies. So this would be the 0:09:42.640 --> 0:09:46.120 belly the ventral side. Again not all species, but with 0:09:46.160 --> 0:09:48.960 some it can be almost as clear as glass, and 0:09:49.000 --> 0:09:53.040 you can look through and see their internal organs in 0:09:53.160 --> 0:09:56.720 full color, including a little tiny beating heart and a 0:09:56.800 --> 0:09:59.720 big thick red artery going down the middle of the 0:10:00.440 --> 0:10:05.000 of the inside of the stomach, big coiled white massive intestines, 0:10:05.120 --> 0:10:08.320 and so forth. I mean they remind you of the 0:10:08.760 --> 0:10:13.520 visible man and the visible woman anatomy kits. I think 0:10:13.559 --> 0:10:15.800 we we all grew up with, uh, you know where 0:10:15.800 --> 0:10:18.280 you have the plastics see through skin, and you have 0:10:18.320 --> 0:10:20.680 you you put all the little organs in there. It's 0:10:20.720 --> 0:10:23.439 it's like this frog, isn't it to be an anatomical 0:10:24.400 --> 0:10:30.280 education tool? Now? Another feature only tangentially related to their 0:10:30.320 --> 0:10:34.079 transparency or translucency. If you've ever seen the Planet Earth 0:10:34.200 --> 0:10:37.560 feature on glass frogs, it includes at least one species 0:10:37.559 --> 0:10:42.239 of glass frog that shows this amazing egg defense behavior. 0:10:42.440 --> 0:10:44.839 So with these frogs will often happen is that there 0:10:44.840 --> 0:10:49.080 will be a clutch of fertilized eggs sticking to the 0:10:49.160 --> 0:10:51.720 side of a leaf that may be hanging above the water, 0:10:52.559 --> 0:10:56.200 and there will be a father frog guarding the eggs. 0:10:56.800 --> 0:11:01.240 These eggs are apparently a favorite food of local carnivorous 0:11:01.320 --> 0:11:03.720 wasps that will kind of zoom in and try to 0:11:04.040 --> 0:11:06.439 you know, munch on them and pull the pull a 0:11:06.679 --> 0:11:09.440 partially formed tadpole out of the egg and take it 0:11:09.480 --> 0:11:14.080 away to eat it. But the frog fathers actually defend 0:11:14.200 --> 0:11:18.560 their eggs literally by kicking the wasps, which is amazing 0:11:18.600 --> 0:11:21.280 to watch. You should look up this clip. Yes, I 0:11:21.320 --> 0:11:23.800 was watching this earlier as yeahs, As is often the 0:11:23.840 --> 0:11:28.120 case with Planet Earth footage, very impressive, gorgeous to watch, 0:11:28.160 --> 0:11:32.680 but it also really drives home how much the glass 0:11:32.679 --> 0:11:35.360 frog looks like a clutch of eggs on the back 0:11:35.440 --> 0:11:38.679 of that leaf. Yes, they often have marking or coloration 0:11:38.720 --> 0:11:41.720 patterns on their backs. That makes the adult male frog 0:11:42.240 --> 0:11:44.960 look like a clutch of eggs itself, so it just 0:11:45.040 --> 0:11:48.400 kind of blends in and then when the wasp gets close, 0:11:48.720 --> 0:11:51.800 it kicks. One of the amazing things is seeing So 0:11:51.840 --> 0:11:54.120 it's this tiny little frog and a lot of these, uh, 0:11:54.200 --> 0:11:56.440 these frogs are so small. They might be just a 0:11:56.880 --> 0:11:59.480 you know, the size of the size of a finger tip, 0:11:59.600 --> 0:12:02.360 maybe a couple of cinameters. I mean, they vary in 0:12:02.400 --> 0:12:05.480 size with different species, but most of them are very small. 0:12:05.760 --> 0:12:08.800 But then when you see that leg suddenly launch out 0:12:08.920 --> 0:12:13.400 like a spring, it's like enormous that it's an incredible 0:12:13.440 --> 0:12:16.200 how far it reaches. But to come back to the 0:12:16.280 --> 0:12:20.760 glass element of the glass frog, what is this translucent 0:12:21.040 --> 0:12:25.199 or in some cases nearly transparent skin. For why would 0:12:25.200 --> 0:12:29.040 it be of evolutionary benefit to this frog to to 0:12:29.120 --> 0:12:32.640 have parts of its body being almost clear? Well, I 0:12:32.640 --> 0:12:35.640 think for a long time it was presumed to have 0:12:35.840 --> 0:12:39.680 some kind of role in camouflage, but we didn't really 0:12:39.720 --> 0:12:42.800 know for sure. But there was a paper published in 0:12:43.640 --> 0:12:46.920 by James B. Barnett at All in uh Proceedings of 0:12:46.960 --> 0:12:51.720 the National Academy of Sciences called Imperfect Transparency and Camouflage 0:12:51.760 --> 0:12:56.480 in glass Frogs, And this was really interesting. It did 0:12:56.559 --> 0:13:00.199 some experiments to try to look at the translucent inin 0:13:00.320 --> 0:13:03.160 of a glass frog and say, what does it actually 0:13:03.240 --> 0:13:07.160 do in practice, like does it work as camouflage and 0:13:07.280 --> 0:13:10.360 if so, how Now They start by giving some background 0:13:10.400 --> 0:13:15.160 on biological camouflage in general. For example, camouflage patterns on 0:13:15.240 --> 0:13:18.160 animals can can help in multiple ways. They say they 0:13:18.160 --> 0:13:21.680 can prevent both detection and recognition, so you can imagine 0:13:21.679 --> 0:13:25.320 those is two slightly different things. Preventing detection might mean 0:13:25.400 --> 0:13:28.080 that a predator doesn't notice you at all, like they 0:13:28.080 --> 0:13:32.240 don't see that you're there, whereas preventing recognition might mean 0:13:32.320 --> 0:13:35.640 that if the predator sees you, it doesn't recognizize you 0:13:35.880 --> 0:13:38.800 as what you are, maybe you look like something else. 0:13:39.320 --> 0:13:42.480 And the authors mentioned that there are multiple ways camouflage works. 0:13:42.520 --> 0:13:45.240 It can work by say, matching a background, and there 0:13:45.240 --> 0:13:47.000 are lots of examples of this. But you can think 0:13:47.040 --> 0:13:50.440 about a moth or a butterfly that has patterns and 0:13:50.480 --> 0:13:54.479 coloration on its wings that resemble the patterns and coloration 0:13:54.559 --> 0:13:56.680 of the bark of the trees. It lands on the tree, 0:13:56.679 --> 0:13:59.080 and it just kind of blends in. Another thing would 0:13:59.120 --> 0:14:04.040 be mimicking particular background features, trying to trying to recreate 0:14:04.160 --> 0:14:07.880 textures that would exist in the background. And another thing 0:14:07.880 --> 0:14:12.400 would be disrupting or breaking up edges trying to have 0:14:12.520 --> 0:14:15.599 patterns that make it harder to tell where the outline 0:14:15.640 --> 0:14:19.080 of an animal would be. But they raise an interesting question. 0:14:19.200 --> 0:14:21.240 What if you're an animal that lives in a habitat 0:14:21.240 --> 0:14:24.800 where you can't always predict an advance, what kind of 0:14:24.840 --> 0:14:28.920 background you will be the foreground of What if you're 0:14:28.920 --> 0:14:32.400 a vulnerable creature that needs camouflage but you live in 0:14:32.440 --> 0:14:37.000 a highly variable environment. Evolution has at least one solution 0:14:37.040 --> 0:14:41.400 to this, which is active color change. So, uh, we've 0:14:41.400 --> 0:14:43.160 talked about this on the show before, but think of 0:14:43.200 --> 0:14:47.360 octopuses with their chromatophore cells that allow them to shift 0:14:47.440 --> 0:14:50.480 colors and blend in with seaweed or rocks or the 0:14:50.920 --> 0:14:54.480 sandy floor of the ocean. There there are tons of 0:14:54.520 --> 0:14:57.400 amazing videos of this. You can look up where you know, 0:14:57.760 --> 0:15:00.520 you wouldn't even see it, Like an octopus just lands 0:15:00.520 --> 0:15:03.520 among some rocks or some coral or seaweed or something 0:15:03.760 --> 0:15:07.920 and it just becomes them. It's amazing. Yeah. I just, uh, 0:15:08.360 --> 0:15:11.360 almost a year ago, I got to observe an octopus 0:15:11.400 --> 0:15:14.600 in the wild and in Hawaii and uh yeah, it 0:15:14.760 --> 0:15:17.640 got to watch it do this. It was amazing. Like 0:15:17.640 --> 0:15:19.720 one of these situations where you watch it go to 0:15:20.000 --> 0:15:23.400 some rocks or a bit of coral blend in. And 0:15:23.440 --> 0:15:25.880 since you've been watching it, you can still make out 0:15:25.880 --> 0:15:28.720 where it is. But if you move your eyes away 0:15:28.760 --> 0:15:30.520 from it from just a step for just a second 0:15:30.960 --> 0:15:34.400 and then come back, uh, you can't see it anymore. 0:15:34.480 --> 0:15:36.000 It's still there right in front of you. But the 0:15:36.040 --> 0:15:39.640 camouflage is so perfect. Uh, it's just quite amazing to 0:15:39.680 --> 0:15:43.480 behold totally. And another classic example one probably everybody is 0:15:43.520 --> 0:15:47.520 familiar with chameleons. They can change colors to match background, uh, 0:15:47.720 --> 0:15:51.600 the surfaces in order to better blend in. But of 0:15:51.640 --> 0:15:55.840 course having something like chromato four cells evolving this capability 0:15:56.000 --> 0:15:59.840 is is of course a very niche evolutionary specialization, so 0:16:00.000 --> 0:16:02.400 you need that that history feeding into it is also 0:16:02.440 --> 0:16:07.040 of course biologically costly, and the authors point out that 0:16:07.120 --> 0:16:11.480 the efficacy of active color change can actually be limited 0:16:11.520 --> 0:16:16.040 by things such as the range of patterns available. So 0:16:16.080 --> 0:16:19.280 an animal that can actively change it's it's markings and 0:16:20.000 --> 0:16:24.320 color patterns can't do that to an infinite degree of flexibility. 0:16:24.360 --> 0:16:27.560 You know, it's still it's going to have surface features 0:16:27.560 --> 0:16:30.840 and colors and and like it can change somewhat, but 0:16:30.920 --> 0:16:35.440 it can't look like absolutely anything, right. And another thing 0:16:35.560 --> 0:16:38.400 is the speed of change, So it takes a minute. 0:16:38.400 --> 0:16:40.480 You know, you can see this even with octopuses that 0:16:40.520 --> 0:16:44.080 can change very fast, but it still takes a few 0:16:44.120 --> 0:16:53.760 seconds sometimes. So is there any other way to blend 0:16:53.800 --> 0:16:58.880 in with your surroundings? Well, what about transparency. Transparency, of 0:16:58.920 --> 0:17:02.920 course has the ability to create very high fidelity camouflage 0:17:03.000 --> 0:17:06.800 because you can literally see through to the background. They 0:17:06.840 --> 0:17:09.840 can match anything in the background. There's no limitation on 0:17:09.880 --> 0:17:13.439 the colors or patterns available because you're just actually seeing 0:17:13.440 --> 0:17:17.800 the background, and it works instantaneously. There's no time needed 0:17:17.840 --> 0:17:21.280 to change if you just are transparent. Of course, there 0:17:21.320 --> 0:17:24.760 are difficulties with transparency as well, but one example I 0:17:25.040 --> 0:17:27.679 might use would be um if you've ever seen pictures 0:17:27.720 --> 0:17:30.200 of this, there is a butterfly known as the glass 0:17:30.280 --> 0:17:34.639 wing butterfly that has uh, you know, like all butterflies, 0:17:34.680 --> 0:17:37.600 it has large, beautiful wings, but most of the surface 0:17:37.640 --> 0:17:40.879 of its wings is actually transparent, like a like a 0:17:40.920 --> 0:17:42.840 pane of glass. It has a sort of orange and 0:17:42.920 --> 0:17:46.119 black and white outline of the wings, but most of 0:17:46.160 --> 0:17:48.840 the wings you can just see right through them and 0:17:48.880 --> 0:17:51.320 they're not even reflective. They don't cause a glare. I 0:17:51.720 --> 0:17:54.560 was watching a video about this. Actually, in the glass 0:17:54.560 --> 0:17:58.480 wing butterflies are able to prevent their wings from being 0:17:58.560 --> 0:18:01.639 too reflective or or or shining back with a glare 0:18:02.080 --> 0:18:06.520 by having these little tiny nano pillars of wax on 0:18:06.600 --> 0:18:10.760 the surface of the transparent membranes that sort of break 0:18:10.840 --> 0:18:13.280 up light patterns. I think kind of like the way 0:18:13.320 --> 0:18:15.919 that you might have, uh, you know, cones of foam 0:18:16.000 --> 0:18:18.000 on the walls of a studio to break up the 0:18:18.000 --> 0:18:20.560 reflection of sound waves. On this they would break up 0:18:20.560 --> 0:18:23.600 the reflection of light waves with these tiny little wax 0:18:23.680 --> 0:18:25.760 spikes all over the wings. Of course you can't see 0:18:25.800 --> 0:18:28.320 them because they're too small. Instead, it just looks like 0:18:28.400 --> 0:18:32.000 clear glass. Yeah, these are weird to see in in 0:18:32.040 --> 0:18:34.160 the wild because it does look even as they're you're 0:18:34.160 --> 0:18:36.879 watching them fly around, it looks like, well, something or 0:18:36.920 --> 0:18:39.199 something has come along and just punch sections of their 0:18:39.240 --> 0:18:43.000 wing out. Uh, it's just completely translucent. But the wings 0:18:43.000 --> 0:18:45.719 wouldn't work, of course, if they just had holes in them. Instead, 0:18:45.760 --> 0:18:48.879 they actually had to evolve layers of cells in their wings, 0:18:48.920 --> 0:18:51.480 thin layers of cells that would allow light to pass 0:18:51.600 --> 0:18:55.000 right through and would prevent the surface of the wings 0:18:55.040 --> 0:18:58.200 from picking up glare from the sunlight, but also would 0:18:58.240 --> 0:19:01.680 still be solid enough to work as wings. Yeah, that 0:19:01.840 --> 0:19:05.880 they're they're sort of like Wonder Woman's invisible plane, right right, right, 0:19:06.280 --> 0:19:10.240 But I think it works for the butterfly because the 0:19:10.320 --> 0:19:14.200 material of wings can be very thin, right, it's a 0:19:14.240 --> 0:19:17.320 sort of thin. I believe it's made mostly of kitan 0:19:17.400 --> 0:19:20.280 in this case, you know, kitan and and cells that 0:19:20.320 --> 0:19:23.080 can allow that to happen. It's gonna be harder to 0:19:23.119 --> 0:19:26.560 do with, say, like the thick, fleshy body parts of 0:19:26.640 --> 0:19:30.879 something like a frog. And they're also strategic limitations to 0:19:31.480 --> 0:19:36.600 camouflage via transparency, especially on land. Some aquatic animals use 0:19:36.720 --> 0:19:39.520 transparency for camouflage, and we'll get more into that in 0:19:39.560 --> 0:19:41.680 a bit when I know there's some examples you wanted 0:19:41.720 --> 0:19:45.240 to talk about, rob but terrestrial animals run into some 0:19:45.359 --> 0:19:49.880 different problems because on land, the author's right quote, image 0:19:49.960 --> 0:19:53.600 distortion maybe more obvious than in water, and that kind 0:19:53.600 --> 0:19:55.920 of makes sense, right, It might be easier to see 0:19:56.600 --> 0:19:59.760 the weird way that even a pretty clear thing like 0:19:59.800 --> 0:20:03.360 a glass wing, butterflies wing still causes a little bit 0:20:03.400 --> 0:20:05.840 of distortion in the background. It does. It's not as 0:20:05.840 --> 0:20:09.440 if there's nothing there. It's just remarkably clear for an 0:20:09.440 --> 0:20:15.000 actual biological surface. Now, of course, glass frogs are terrestrial animals. 0:20:15.240 --> 0:20:18.919 They make use of transparency or translucency, especially pronounced in 0:20:19.000 --> 0:20:23.199 some species, and it is presumably a camouflage tactic, but 0:20:23.280 --> 0:20:25.960 as I said earlier, we don't really know for sure, 0:20:26.040 --> 0:20:28.239 or at least before this paper, it was harder to know, 0:20:28.400 --> 0:20:32.160 Like is, if it is a camouflage tactic, how exactly 0:20:32.200 --> 0:20:34.880 does it work and does it does it work at all? 0:20:34.960 --> 0:20:39.160 Could that be empirically verified? Uh, and especially given some 0:20:39.320 --> 0:20:41.919 strange features such as the fact that the that in 0:20:42.119 --> 0:20:45.520 the ones that are very clear, the really clear part 0:20:45.560 --> 0:20:48.040 of the skin is usually on the ventral side, the 0:20:48.080 --> 0:20:51.440 belly side, and that's the part that would be facing 0:20:51.640 --> 0:20:55.160 down to the surface that they're perched on. More often 0:20:55.200 --> 0:20:57.960 they tend to have some dorsal pigmentation, so on the 0:20:58.000 --> 0:21:01.000 back they might have sort of green and yellow color patterns. 0:21:01.040 --> 0:21:03.000 You can see they're not totally clear on the back. 0:21:03.520 --> 0:21:06.520 And so the authors of this paper did a number 0:21:06.520 --> 0:21:09.320 of different experiments contained within it to to try to 0:21:09.359 --> 0:21:11.520 figure out what was going on with these frogs. So 0:21:11.560 --> 0:21:16.040 they like simulated the vision of predators that prey on 0:21:16.080 --> 0:21:19.199 the frogs in the lab and looked at frogs with 0:21:19.320 --> 0:21:23.560 differing levels of translucency or opacity to see if it 0:21:23.640 --> 0:21:26.879 made a difference for those predators. They also tested it 0:21:26.960 --> 0:21:29.600 just with humans looking at them to see if there 0:21:29.600 --> 0:21:34.320 were differences in in detection or recognition times based on 0:21:34.400 --> 0:21:38.360 how translucent or opaque the frog is. And then they 0:21:38.400 --> 0:21:42.440 also performed an experiment in the wild with simulated frogs. 0:21:42.480 --> 0:21:46.639 They like made fake glass frogs out of gelatin uh 0:21:46.880 --> 0:21:51.280 with with different levels of opacity versus translucency to see 0:21:51.320 --> 0:21:55.720 if it affected predation. And what these experiments found was 0:21:55.840 --> 0:22:00.240 that the quote perceived luminants of the frogs was the 0:22:00.320 --> 0:22:04.040 big thing that really changed, and it changed depending on 0:22:04.119 --> 0:22:08.000 the background compared to opaque frogs. So I think one 0:22:08.000 --> 0:22:10.200 of the really important things to understand here is that 0:22:10.680 --> 0:22:14.560 the translucency of the glass frog doesn't actually change the 0:22:14.800 --> 0:22:17.840 color of the frog very much. I mean it's it's 0:22:17.960 --> 0:22:21.159 basically most of them have some kind of green or 0:22:21.160 --> 0:22:25.080 green yellow coloration pattern and that pretty much stays the same. 0:22:25.640 --> 0:22:29.280 What actually changes is the amount of light that is 0:22:29.320 --> 0:22:32.560 allowed to pass through the frog, and specifically parts of 0:22:32.600 --> 0:22:36.080 the frogs, such as the outlines of the toes and 0:22:36.160 --> 0:22:40.160 the legs, and the transparency of these frogs actually did 0:22:40.240 --> 0:22:42.920 help them blend in with the background, especially when they're 0:22:42.920 --> 0:22:44.960 you know, they're on something like a leaf, and it 0:22:45.000 --> 0:22:48.159 will allow light to pass through their bodies in a 0:22:48.240 --> 0:22:52.480 manner consistent with the leaf underneath, especially at the edges 0:22:52.480 --> 0:22:55.680 where their legs are meeting the surface. And they did 0:22:55.680 --> 0:22:59.720 find ecologically that this level of transparency did increase survival. 0:22:59.800 --> 0:23:03.320 So frogs that let more light through their skin got 0:23:03.320 --> 0:23:07.399 preyed on by birds less. Now coming to I mentioned 0:23:07.440 --> 0:23:11.040 the legs, they say that the legs made the biggest 0:23:11.080 --> 0:23:13.680 difference here. They said it was the legs quote which 0:23:13.720 --> 0:23:18.160 surround the body at rest and create a diffuse transition 0:23:18.320 --> 0:23:22.880 from background to frog luminants, rather than a sharp, highly 0:23:23.000 --> 0:23:25.840 salient edge. So I think that's the important way to 0:23:25.880 --> 0:23:29.679 think about this. What does the glass frogs translucent skin do. 0:23:30.359 --> 0:23:33.400