WEBVTT 00:00:00.000 --> 00:00:03.279 I want you to picture a forest, let's say Northern 00:00:03.279 --> 00:00:07.919 Europe, and let's dial the clock back, oh, about 00:00:07.919 --> 00:00:10.500 2 ,000 years. Okay, I'm with you. You're sitting 00:00:10.500 --> 00:00:13.060 around a fire with your tribe. It's dark, the 00:00:13.060 --> 00:00:15.919 woods are thick, and you can hear the wind howling 00:00:15.919 --> 00:00:17.660 a little. You're talking about the hunt, maybe 00:00:17.660 --> 00:00:21.140 the weather, the spirits of the trees, but there's 00:00:21.140 --> 00:00:24.019 one thing, one specific thing that you absolutely 00:00:24.019 --> 00:00:26.949 do not talk about. You're setting a pretty spooky 00:00:26.949 --> 00:00:29.670 scene here to kick things off. I am, because 00:00:29.670 --> 00:00:32.189 I'm talking about a taboo. A taboo so strong 00:00:32.189 --> 00:00:35.090 that it actually changed the English language 00:00:35.090 --> 00:00:37.310 forever. That's a big claim. Well, think about 00:00:37.310 --> 00:00:40.810 it. We have words for wolf, fox, deer. These 00:00:40.810 --> 00:00:43.109 are ancient, original names. They go way, way 00:00:43.109 --> 00:00:44.750 back to the roots of our language. Yeah. But 00:00:44.750 --> 00:00:46.990 the word we use for the apex predator of those 00:00:46.990 --> 00:00:49.890 woods, the king of the forest. Yeah. It's a lie. 00:00:50.130 --> 00:00:52.670 It is. It's a complete fabrication. It's a placeholder. 00:00:53.250 --> 00:00:55.289 Today on the Deep Drive, we are talking about 00:00:55.289 --> 00:00:59.469 the bear. And I think the best place to start, 00:00:59.549 --> 00:01:02.049 I mean, it has to be, is with that word itself. 00:01:02.530 --> 00:01:05.150 Because bear isn't its name, is it? No, it's 00:01:05.150 --> 00:01:08.090 not. Not its true name, anyway. From a linguistic 00:01:08.090 --> 00:01:11.840 perspective, bear... is basically a nickname 00:01:11.840 --> 00:01:14.680 that got, well, completely out of hand. A nickname. 00:01:14.980 --> 00:01:17.299 Yeah. If you trace the etymology back, it comes 00:01:17.299 --> 00:01:19.980 from the Old English word bara, and that links 00:01:19.980 --> 00:01:22.480 back to these proto -Germanic roots that just 00:01:22.480 --> 00:01:25.359 mean the brown one. The brown one. That sounds 00:01:25.359 --> 00:01:26.859 like something straight out of a Tolkien novel. 00:01:27.150 --> 00:01:29.549 Like a character name. It does, but the reasoning 00:01:29.549 --> 00:01:32.730 was incredibly practical. It's a euphemism. The 00:01:32.730 --> 00:01:35.269 theory, and it's a very strong one, it's supported 00:01:35.269 --> 00:01:38.590 by a lot of historical linguistics, is that the 00:01:38.590 --> 00:01:41.069 proto -Germanic peoples were just genuinely terrified 00:01:41.069 --> 00:01:43.189 of this animal. So terrified they couldn't even 00:01:43.189 --> 00:01:45.510 say its name. They believed in a sort of magical 00:01:45.510 --> 00:01:48.469 causality. If you spoke the true name of the 00:01:48.469 --> 00:01:50.590 beast, you might summon it. Like Beetlejuice. 00:01:51.109 --> 00:01:53.709 If you say his name three times. Essentially, 00:01:53.810 --> 00:01:56.900 yes. Or, you know, Voldemort. He who must not 00:01:56.900 --> 00:01:59.340 be named. It's the same principle. Right. You 00:01:59.340 --> 00:02:01.920 have to put yourself in their shoes. For these 00:02:01.920 --> 00:02:04.560 tribes, a bear wasn't just an animal. It was. 00:02:04.700 --> 00:02:07.859 It was a monster. It could stand on two legs 00:02:07.859 --> 00:02:09.620 like a man. It could disappear into the earth 00:02:09.620 --> 00:02:11.379 for the winter and then come back to life in 00:02:11.379 --> 00:02:13.520 the spring. A symbol of resurrection. Exactly. 00:02:13.819 --> 00:02:16.219 And it could kill you with a single swipe of 00:02:16.219 --> 00:02:18.860 its paw. So out of pure fear, they just stopped 00:02:18.860 --> 00:02:20.460 saying the true name. They called it the brown 00:02:20.460 --> 00:02:22.580 one. And the crazy part, the part that really 00:02:22.580 --> 00:02:25.139 gets me, is that we did this so effectively that 00:02:25.139 --> 00:02:27.699 we actually lost the real name. We did. It was 00:02:27.699 --> 00:02:29.560 a conscious effort that became an unconscious 00:02:29.560 --> 00:02:32.780 habit. And it just, it wiped the word from the 00:02:32.780 --> 00:02:35.740 entire Germanic branch of languages. It's gone. 00:02:35.759 --> 00:02:38.439 So how do we even know it's missing? Well, we 00:02:38.439 --> 00:02:40.460 can guess at it by looking at other languages 00:02:40.460 --> 00:02:43.099 that didn't have this specific taboo. You look 00:02:43.099 --> 00:02:46.400 at the Greek Arcturus or the Latin Ursus. Ah, 00:02:46.560 --> 00:02:49.800 so Ursa Major. Precisely. The original Proto 00:02:49.800 --> 00:02:52.120 -Indo -European word was probably something like 00:02:52.120 --> 00:02:55.520 Ercto. But in English and German and Swedish, 00:02:55.819 --> 00:03:00.439 the true name is gone, extinct, wiped from the 00:03:00.439 --> 00:03:03.439 vocabulary. That is such a heavy way to start 00:03:03.439 --> 00:03:06.879 an episode. It really frames how we've always 00:03:06.879 --> 00:03:09.379 seen this animal, doesn't it? It's always been 00:03:09.379 --> 00:03:12.560 this figure of myth and deep primal fear. Absolutely. 00:03:12.939 --> 00:03:16.240 But our mission today is to strip away that Brown 00:03:16.240 --> 00:03:18.719 One label. We want to find the actual creature 00:03:18.719 --> 00:03:20.939 that's hiding underneath the euphemism. And the 00:03:20.939 --> 00:03:23.759 creature underneath... is well it's fascinating 00:03:23.759 --> 00:03:26.180 because it is a walking contradiction it really 00:03:26.180 --> 00:03:28.080 is i was looking through the source material 00:03:28.080 --> 00:03:30.979 you sent over and my biggest takeaway was that 00:03:30.979 --> 00:03:32.939 bears don't seem to know what they want to be 00:03:32.939 --> 00:03:34.900 how do you mean well they have the digestive 00:03:34.900 --> 00:03:37.699 system of a pure carnivore but most of them eat 00:03:37.699 --> 00:03:40.360 berries they look like big dogs but they move 00:03:40.360 --> 00:03:43.120 and stand up like people they're these massive 00:03:43.120 --> 00:03:45.879 high calorie burning machines yet they've completely 00:03:45.879 --> 00:03:48.300 mastered the art of doing absolutely nothing 00:03:49.050 --> 00:03:51.590 for months at a time that's the ursidian paradox 00:03:51.590 --> 00:03:54.370 as some biologists call it they are members of 00:03:54.370 --> 00:03:57.030 the order carnivora that have for the most part 00:03:57.030 --> 00:04:00.430 abandoned meat an apex predator that's mostly 00:04:00.430 --> 00:04:03.210 vegetarian exactly they're often more peaceful 00:04:03.210 --> 00:04:05.169 than we give them credit for and biologically 00:04:06.129 --> 00:04:08.969 Oh, biologically. They have solved medical problems 00:04:08.969 --> 00:04:12.069 like muscle atrophy, kidney failure, that modern 00:04:12.069 --> 00:04:14.349 science is still just scratching its head over. 00:04:14.469 --> 00:04:16.709 We are definitely going to get into the medical 00:04:16.709 --> 00:04:19.350 miracle of hibernation later on because the fact 00:04:19.350 --> 00:04:24.170 that they don't pee for 100 days is, well, it's 00:04:24.170 --> 00:04:26.930 both disturbing and incredibly impressive. Physiological 00:04:26.930 --> 00:04:29.290 masterpiece. There's no other word for it. But 00:04:29.290 --> 00:04:31.410 first, I want to figure out what a bear actually 00:04:31.410 --> 00:04:34.509 is. Because when I go to the zoo or I see a grizzly 00:04:34.509 --> 00:04:37.290 in a nature documentary, my brain automatically 00:04:37.290 --> 00:04:40.970 categorizes it as big dog. Which is fair. It's 00:04:40.970 --> 00:04:42.990 an understandable classification. Is it accurate, 00:04:43.089 --> 00:04:45.660 though? It is, to a point. Texonomically, they 00:04:45.660 --> 00:04:47.959 are caniforms. That literally means dog -like 00:04:47.959 --> 00:04:50.180 carnivorans. Okay, so there is a link. A very 00:04:50.180 --> 00:04:52.759 old one. If you go back about, say, 40 or 50 00:04:52.759 --> 00:04:55.279 million years, the ancestors of dogs and the 00:04:55.279 --> 00:04:58.060 ancestors of bears were undeniably cousins. They 00:04:58.060 --> 00:05:00.480 split from a common lineage. They share a lot 00:05:00.480 --> 00:05:02.660 of the same hardware, you know. Non -retractable 00:05:02.660 --> 00:05:05.420 claws, similar snout structures. But they aren't 00:05:05.420 --> 00:05:08.579 dogs. They're not just giant Labradors. No. They 00:05:08.579 --> 00:05:12.250 split off a long, long time ago. And this is 00:05:12.250 --> 00:05:13.949 where the family tree gets really interesting. 00:05:14.290 --> 00:05:16.509 If you want to find the bear's closest living 00:05:16.509 --> 00:05:18.670 relative. The one you could do a DNA test on 00:05:18.670 --> 00:05:20.850 today and get the closest map. Exactly. You don't 00:05:20.850 --> 00:05:22.850 look at the wolf. You don't even look on land. 00:05:23.170 --> 00:05:25.529 Wait, what? Where do you look? You look in the 00:05:25.529 --> 00:05:27.810 ocean. You're kidding me. Not at all. You look 00:05:27.810 --> 00:05:29.850 at the pinnipeds. Pinnipeds, you mean like seals. 00:05:30.129 --> 00:05:33.430 Sea lions. Seals, sea lions, walruses. Genetically, 00:05:33.550 --> 00:05:36.430 they are the bear's sister group. My mind is 00:05:36.430 --> 00:05:39.209 officially blown. A grizzly bear walking through 00:05:39.209 --> 00:05:43.170 Yellowstone is basically a... A land seal. Or 00:05:43.170 --> 00:05:46.310 a seal is a water bear. Both statements are true. 00:05:46.910 --> 00:05:48.970 Morphologically and molecularly, they are sisters. 00:05:49.069 --> 00:05:52.069 They split off from a common ancestor. What was 00:05:52.069 --> 00:05:54.470 that ancestor? Do we know? We do. We have fossils. 00:05:54.670 --> 00:05:57.310 They're a group called the Amphicenodontinae. 00:05:58.269 --> 00:06:00.009 Amphicenodontinae. Okay, try saying that three 00:06:00.009 --> 00:06:02.230 times fast. I'd rather not. But just picture 00:06:02.230 --> 00:06:04.430 a creature that looks like a mix between a small 00:06:04.430 --> 00:06:07.170 bear, an otter, and maybe a beaver. So a little 00:06:07.170 --> 00:06:09.740 water weasel thing. A semi -aquatic mammal, yeah. 00:06:10.100 --> 00:06:12.560 And at some point in their history, one group 00:06:12.560 --> 00:06:14.639 of them decided, you know what, the water is 00:06:14.639 --> 00:06:17.500 great, let's just go all in. Those became the 00:06:17.500 --> 00:06:20.180 seals and walruses. And the other group? The 00:06:20.180 --> 00:06:22.899 other group said, nah, we prefer dry land, thanks. 00:06:23.139 --> 00:06:25.800 And they evolved into the bears we know today. 00:06:26.139 --> 00:06:29.529 Is there definitive fossil proof of this? Or 00:06:29.529 --> 00:06:31.470 is this just kind of pieced together from DNA? 00:06:31.750 --> 00:06:34.689 Oh, there's proof. There's a really famous fossil 00:06:34.689 --> 00:06:37.269 called Kuihila darwini, which was found up in 00:06:37.269 --> 00:06:40.310 the Canadian Arctic. It's often nicknamed a walking 00:06:40.310 --> 00:06:42.910 seal. A walking seal. It had these big webbed 00:06:42.910 --> 00:06:45.310 feet, but it also had long legs and a long tail. 00:06:45.470 --> 00:06:47.670 It looked a lot like a modern otter, but the 00:06:47.670 --> 00:06:52.069 skull? The skull was undeniably bear -like. It's 00:06:52.069 --> 00:06:54.430 the perfect missing link that connects that grizzly 00:06:54.430 --> 00:06:56.589 in the mountains to the walrus on an ice floe. 00:06:56.750 --> 00:06:58.790 That actually explains the swimming. I mean, 00:06:58.829 --> 00:07:00.709 we've all seen polar bears swim, and that makes 00:07:00.709 --> 00:07:02.870 sense. They live on ice. But I've seen footage 00:07:02.870 --> 00:07:05.009 of black bears and brown bears just swimming 00:07:05.009 --> 00:07:07.470 across these massive lakes, and they look so 00:07:07.470 --> 00:07:09.709 incredibly comfortable in the water. It's in 00:07:09.709 --> 00:07:12.310 their blood. Or rather, it's deep in their ancient 00:07:12.310 --> 00:07:15.189 history. Even a black bear living in the middle 00:07:15.189 --> 00:07:18.310 of Tennessee has that deep ancestral memory of 00:07:18.310 --> 00:07:21.009 being semi -aquatic. It's just baked into their 00:07:21.009 --> 00:07:25.149 biology. So, okay. We have this water -loving 00:07:25.149 --> 00:07:28.569 ancestor, this walking seal. How do we get from 00:07:28.569 --> 00:07:32.389 that to the massive Kodiak bears of today? Because 00:07:32.389 --> 00:07:35.129 the sources mentioned an early ancestor called 00:07:35.129 --> 00:07:38.550 Perictus. Well, it wasn't very impressive. Perictus. 00:07:38.550 --> 00:07:41.170 No, not impressive at all. If you saw one running 00:07:41.170 --> 00:07:43.589 around in the late Eocene about 38 million years 00:07:43.589 --> 00:07:45.370 ago, you wouldn't run away screaming. You'd probably 00:07:45.370 --> 00:07:47.720 try to pet it. How small are we talking? raccoon 00:07:47.720 --> 00:07:50.459 sized maybe even smaller think of a very small 00:07:50.459 --> 00:07:53.779 slender badger a badger bear basically it was 00:07:53.779 --> 00:07:56.079 living in a world that was much warmer much more 00:07:56.079 --> 00:07:58.660 tropical than today it was a little scavenger 00:07:58.660 --> 00:08:01.040 eating insects maybe some small lizards it was 00:08:01.040 --> 00:08:03.060 an underdog really so it took a long time for 00:08:03.060 --> 00:08:05.980 the bear lineage to bulk up millions of years 00:08:06.670 --> 00:08:08.970 The real grandfather of all the modern bears 00:08:08.970 --> 00:08:11.750 is a genus called Ursavus, which showed up in 00:08:11.750 --> 00:08:13.949 the Alligocene. That's when you start to see 00:08:13.949 --> 00:08:16.889 the real size increase and, crucially, the teeth 00:08:16.889 --> 00:08:19.509 starting to change to handle more vegetation. 00:08:19.990 --> 00:08:22.730 And from Ursavus, the family tree just basically 00:08:22.730 --> 00:08:25.529 explodes. It branches out, yeah. It really diversifies. 00:08:25.810 --> 00:08:28.009 And this is where we get the cast of characters 00:08:28.009 --> 00:08:30.509 for the modern bear family. And the very first 00:08:30.509 --> 00:08:32.850 one to pack its bags and leave the family reunion 00:08:32.850 --> 00:08:36.009 was the panda. The panda is always the outlier. 00:08:35.980 --> 00:08:39.600 outlier isn't it in almost every single way Genetically, 00:08:39.799 --> 00:08:41.860 the ancestors of the giant panda, that's the 00:08:41.860 --> 00:08:45.159 subfamily Eluropodinae, diverged from the main 00:08:45.159 --> 00:08:48.700 bear line about 19 million years ago. 19 million. 00:08:48.820 --> 00:08:51.740 That is a massive separation. It's huge. To put 00:08:51.740 --> 00:08:53.940 that in perspective for you, humans and chimpanzees 00:08:53.940 --> 00:08:57.419 only split maybe 6 or 7 million years ago. Pandas 00:08:57.419 --> 00:08:59.340 have been doing their own thing, completely separate 00:08:59.340 --> 00:09:02.200 from all other bears, for nearly 20 million years. 00:09:02.340 --> 00:09:04.259 It actually explains so much why they look so 00:09:04.259 --> 00:09:06.539 different, why they act so different. Precisely. 00:09:06.600 --> 00:09:08.909 There are the weird cousins. that moved to a 00:09:08.909 --> 00:09:10.990 commune up in the mountains and just stopped 00:09:10.990 --> 00:09:14.029 answering emails. While all the other bears were 00:09:14.029 --> 00:09:16.350 evolving to hunt or scavenge across these diverse 00:09:16.350 --> 00:09:19.370 landscapes, the panda backed itself into an evolutionary 00:09:19.370 --> 00:09:22.009 corner with bamboo. We are definitely going to 00:09:22.009 --> 00:09:24.230 do a deep dive on the panda problem later on, 00:09:24.309 --> 00:09:26.750 how an animal survives on what is essentially 00:09:26.750 --> 00:09:29.529 cardboard. Yeah. But I want to stick to the timeline 00:09:29.529 --> 00:09:32.509 for now. So the panda leaves. What happens next? 00:09:32.909 --> 00:09:34.909 Then you get the invasion of the Americas. A 00:09:34.909 --> 00:09:37.409 group called the Tree Martinae, or the short 00:09:37.409 --> 00:09:39.809 -faced bears, makes its way across. The sources 00:09:39.809 --> 00:09:42.350 describe these things as the terrors of the Ice 00:09:42.350 --> 00:09:44.250 Age. And they were. They were absolute nightmares. 00:09:44.809 --> 00:09:47.450 Specifically, a species called Arctodosimus, 00:09:47.590 --> 00:09:50.509 the giant short -faced bear. How big are we talking? 00:09:50.669 --> 00:09:52.830 Standing on its hind legs, it was maybe 12 feet 00:09:52.830 --> 00:09:55.429 tall. It had these long, lanky legs, almost like 00:09:55.429 --> 00:09:58.250 a hyena. It was built for running down prey on 00:09:58.250 --> 00:10:01.799 the open plains of Ice Age America. Unlike modern 00:10:01.799 --> 00:10:04.159 bears, which are built for stability, these things 00:10:04.159 --> 00:10:06.779 were built for speed and devastating power. They 00:10:06.779 --> 00:10:08.879 were the dominant megafauna predator in North 00:10:08.879 --> 00:10:11.179 America for a very long time. And they're all 00:10:11.179 --> 00:10:14.159 gone now. Almost all of them. The Ice Age ended, 00:10:14.419 --> 00:10:16.899 the megafauna they preyed on died out, and they 00:10:16.899 --> 00:10:20.730 couldn't adapt. But there is one survivor. One 00:10:20.730 --> 00:10:23.429 lonely descendant of that terrifying lineage 00:10:23.429 --> 00:10:26.570 still alive today. The spectacled bear. The spectacled 00:10:26.570 --> 00:10:29.669 bear, yes. Down in the Andes Mountains of South 00:10:29.669 --> 00:10:32.610 America. It's much smaller, it's very shy, it 00:10:32.610 --> 00:10:35.690 mostly eats fruit and bromeliads. But if you 00:10:35.690 --> 00:10:38.710 look at its genetics, it is the last of the short 00:10:38.710 --> 00:10:41.750 -faced giants. That's kind of tragic in a way. 00:10:41.909 --> 00:10:44.870 Evolution is often tragic, but it's also incredibly 00:10:44.870 --> 00:10:47.850 prolific. Because while the short -faced bears 00:10:47.850 --> 00:10:50.809 were dying out, Another subfamily, the ursinae, 00:10:50.809 --> 00:10:53.269 the modern bears, was taking over the entire 00:10:53.269 --> 00:10:55.210 world. So this is where we get the ones we know 00:10:55.210 --> 00:10:57.509 today. This is the explosion that happened about 00:10:57.509 --> 00:10:59.950 5 million years ago. This gives us the American 00:10:59.950 --> 00:11:02.590 black bear, the brown bear, the sun bear in Asia, 00:11:02.730 --> 00:11:05.049 the sloth bear in India. And the king of the 00:11:05.049 --> 00:11:07.830 north, the polar bear, where does he fit in? 00:11:07.929 --> 00:11:10.470 The polar bear is the new kid on the block. He's 00:11:10.470 --> 00:11:13.070 the latest model off the production line. How 00:11:13.070 --> 00:11:15.740 new are we talking? Shockingly new. The genetic 00:11:15.740 --> 00:11:18.679 evidence suggests that polar bears diverged from 00:11:18.679 --> 00:11:21.759 a population of brown bears only about 400 ,000 00:11:21.759 --> 00:11:25.340 years ago. Wait, only 400 ,000? Yeah. In evolutionary 00:11:25.340 --> 00:11:27.559 time, that is. That's the blink of an eye. It's 00:11:27.559 --> 00:11:30.000 nothing. It's yesterday. So what happened? Some 00:11:30.000 --> 00:11:32.399 brown bears just wandered north, got stuck by 00:11:32.399 --> 00:11:35.080 glaciers during an ice age, and turned white. 00:11:35.279 --> 00:11:38.600 That is essentially it. A population got isolated, 00:11:38.860 --> 00:11:41.179 probably around the British Isles, and they adapted 00:11:41.179 --> 00:11:43.940 with frightening speed. What kind of adaptations? 00:11:44.360 --> 00:11:46.580 Well, they went from being omnivores eating berries 00:11:46.580 --> 00:11:49.080 and salmon to being hyper carnivores that survive 00:11:49.080 --> 00:11:52.919 almost exclusively on seal blubber. Their fur 00:11:52.919 --> 00:11:55.960 turned white. Well, technically it's transparent 00:11:55.960 --> 00:11:58.480 hollow hairs, but it looks white for camouflage. 00:11:59.120 --> 00:12:02.659 Their paws became these massive webbed paddles 00:12:02.659 --> 00:12:05.100 for swimming. Their necks got longer to keep 00:12:05.100 --> 00:12:07.299 their heads above water when they hunt. And because 00:12:07.299 --> 00:12:09.460 it was so recent, they're still genetically compatible, 00:12:09.779 --> 00:12:11.639 right? They can interbreed. Yes, absolutely. 00:12:11.840 --> 00:12:14.259 A brown bear and a polar bear can still mate 00:12:14.259 --> 00:12:16.519 and produce fertile offspring. They call them 00:12:16.519 --> 00:12:19.000 piddly bears or growler bears. A growler bear. 00:12:19.320 --> 00:12:21.360 That sounds like a creature from a Dungeons and 00:12:21.360 --> 00:12:23.240 Dragons campaign. It kind of looks like one, 00:12:23.299 --> 00:12:25.720 too. They often have the white fur but with brown 00:12:25.720 --> 00:12:28.500 patches and they have the humped back of a grizzly 00:12:28.500 --> 00:12:31.519 but the longer neck of a polar bear. It's a living 00:12:32.090 --> 00:12:35.590 walking reminder of just how closely related 00:12:35.590 --> 00:12:38.230 these two species still are. It really highlights 00:12:38.230 --> 00:12:40.549 that adaptability you mentioned earlier. The 00:12:40.549 --> 00:12:42.909 bear family seems to have a tool for every single 00:12:42.909 --> 00:12:45.750 job. You have the panda eating bamboo, the polar 00:12:45.750 --> 00:12:48.230 bear hunting seals on the ice, the sloth bear 00:12:48.230 --> 00:12:50.409 sucking termites out of mounds in India. And 00:12:50.409 --> 00:12:53.029 yet underneath all of that incredible specialization, 00:12:53.169 --> 00:12:55.730 the basic chassis is the same, the skeleton, 00:12:55.889 --> 00:12:59.409 the muscles, the brain. It's all unmistakably. 00:13:00.179 --> 00:13:02.799 bear. And that chassis is built very, very differently 00:13:02.799 --> 00:13:04.899 from the other carnivores we know. That's the 00:13:04.899 --> 00:13:06.639 perfect segue. I want to talk about that chassis 00:13:06.639 --> 00:13:09.600 because when I see a wolf run, it flows. It's 00:13:09.600 --> 00:13:12.659 graceful. When I see a bear move, well, it lumbers. 00:13:12.659 --> 00:13:14.980 It looks heavy. Why is the design so different? 00:13:15.120 --> 00:13:17.000 It all comes down to their feet and how they 00:13:17.000 --> 00:13:19.639 walk. Their feet. Yeah. If you look at a cat 00:13:19.639 --> 00:13:22.240 or a dog or even that wolf you mentioned, they 00:13:22.240 --> 00:13:25.740 are walking on their toes. It's a posture called 00:13:25.740 --> 00:13:28.259 being digitigrade. It's like they are wearing 00:13:28.259 --> 00:13:30.559 high heels all the time. And that gives them 00:13:30.559 --> 00:13:34.179 speed. Exactly. That leverage gives them that 00:13:34.179 --> 00:13:38.039 explosive springy speed. But bears aren't wearing 00:13:38.039 --> 00:13:40.899 high heels. No. Bears are wearing combat boots. 00:13:41.080 --> 00:13:43.519 They are planet grade. They walk with their entire 00:13:43.519 --> 00:13:46.480 foot from the toe all the way to the heel flat 00:13:46.480 --> 00:13:49.059 on the ground, just like you and I do. So what's 00:13:49.059 --> 00:13:51.490 the evolutionary tradeoff there? Because if I'm 00:13:51.490 --> 00:13:53.750 an apex predator, don't I want speed? You want 00:13:53.750 --> 00:13:56.210 speed if you're chasing gazelles across the savannah. 00:13:56.389 --> 00:13:59.269 But bears aren't endurance runners. Their tradeoff 00:13:59.269 --> 00:14:01.789 is for stability and power. How does walking 00:14:01.789 --> 00:14:04.350 flat -footed give them power? By having that 00:14:04.350 --> 00:14:06.809 flat foot, a bear has a much lower center of 00:14:06.809 --> 00:14:09.230 gravity and just incredible balance. This allows 00:14:09.230 --> 00:14:11.889 them to do two things that wolves can't. First, 00:14:11.970 --> 00:14:13.730 they can stand up comfortably on their hind legs 00:14:13.730 --> 00:14:16.049 for long periods of time. Which is terrifying 00:14:16.049 --> 00:14:17.690 when you see it in the wild. It makes them look 00:14:17.690 --> 00:14:20.970 uncannily human. It does, and it lets them survey 00:14:20.970 --> 00:14:23.789 the landscape, smell the wind from a higher vantage 00:14:23.789 --> 00:14:26.490 point, and intimidate rivals. But the second 00:14:26.490 --> 00:14:29.169 advantage is grappling. Grappling. A bear can 00:14:29.169 --> 00:14:31.610 fight with its front paws because its back legs 00:14:31.610 --> 00:14:34.570 are solid anchors on the ground. A wolf has to 00:14:34.570 --> 00:14:37.269 bite. A bear can literally wrestle you to the 00:14:37.269 --> 00:14:39.570 ground. It also frees up those front paws to 00:14:39.570 --> 00:14:42.330 do more than just run. Exactly. This is a huge 00:14:42.330 --> 00:14:44.409 point. Because they aren't relying on their front 00:14:44.409 --> 00:14:47.309 paws for that explosive speed, they've retained 00:14:47.309 --> 00:14:50.029 a level of dexterity that is really rare in large 00:14:50.029 --> 00:14:52.769 carnivores. They can rotate their forearms. They 00:14:52.769 --> 00:14:55.169 can grasp things. I read about them being able 00:14:55.169 --> 00:14:58.029 to peel fruit. Oh, easily. A bear can hold a 00:14:58.029 --> 00:15:00.730 fish between its paws. It can tear open a log 00:15:00.730 --> 00:15:03.570 to get at grubs. Or it can delicately pluck individual 00:15:03.570 --> 00:15:06.509 berries from a bush. In the case of the panda, 00:15:06.690 --> 00:15:09.730 they've even evolved a false thumb. It's an enlarged 00:15:09.730 --> 00:15:12.330 wrist. bone just for the purpose of holding bamboo 00:15:12.330 --> 00:15:14.669 stems. A false thumb. It's a level of object 00:15:14.669 --> 00:15:17.570 manipulation that you usually only see in primates. 00:15:17.690 --> 00:15:19.830 Now, you mentioned they stand up to smell the 00:15:19.830 --> 00:15:22.690 wind. The sources were pretty emphatic about 00:15:22.690 --> 00:15:25.149 their sense of smell. We always hear about bloodhounds, 00:15:25.210 --> 00:15:27.509 but the bear is in a totally different league. 00:15:27.750 --> 00:15:30.090 The bloodhound is the gold standard for dogs, 00:15:30.210 --> 00:15:32.450 but the bear is the gold standard for mammals, 00:15:32.590 --> 00:15:35.809 period. The olfactory bulb in a bear's brain, 00:15:35.970 --> 00:15:38.049 that's the part that processes smell, is up to 00:15:38.049 --> 00:15:40.690 five times larger than a human's, and it's significantly 00:15:40.690 --> 00:15:43.929 larger than even a dog's. Can we even quantify 00:15:43.929 --> 00:15:46.169 that? What does that mean in the real world? 00:15:46.309 --> 00:15:48.730 How much better is it? It's hard to put a number 00:15:48.730 --> 00:15:51.960 on it, but think of it this way. A human navigates 00:15:51.960 --> 00:15:54.480 the world primarily by sight. We see a mountain, 00:15:54.620 --> 00:15:57.559 we walk toward it. A bear navigates by creating 00:15:57.559 --> 00:16:00.480 a scent map of its world. A scent map. They aren't 00:16:00.480 --> 00:16:02.580 just smelling a dead deer. They are smelling 00:16:02.580 --> 00:16:05.159 the 3D geometry of the wind currents carrying 00:16:05.159 --> 00:16:08.200 that scent. They can detect a carcass from 20 00:16:08.200 --> 00:16:11.059 miles away if the wind is right. They can smell 00:16:11.059 --> 00:16:13.399 a female in estrus from miles and miles away. 00:16:13.559 --> 00:16:16.639 They can smell grubs buried inside a log. That's 00:16:16.639 --> 00:16:18.899 a superpower. And to go with that super nose, 00:16:19.100 --> 00:16:21.340 they have pretty good eyes too, right? Unlike 00:16:21.340 --> 00:16:23.799 most carnivores, they have color vision. Yes. 00:16:24.259 --> 00:16:27.759 Most keneads, like dogs, are red -green colorblind, 00:16:27.960 --> 00:16:30.679 but bears have color vision that's very similar 00:16:30.679 --> 00:16:33.179 to ours. Why? What's the advantage? Because they 00:16:33.179 --> 00:16:36.259 need to spot ripe fruit. A patch of red berries 00:16:36.259 --> 00:16:38.940 against a backdrop of green leaves is almost 00:16:38.940 --> 00:16:42.480 invisible to a dog, but for a bear, it pops like 00:16:42.480 --> 00:16:45.039 a neon sign. This brings us right back to that 00:16:45.039 --> 00:16:47.740 digestive paradox I mentioned at the start. We 00:16:47.740 --> 00:16:50.279 have this animal with the nose of a super predator, 00:16:50.519 --> 00:16:53.360 the claws of a digger, and the eyes of a fruit 00:16:53.360 --> 00:16:55.919 gatherer. But then you look at the gut. And the 00:16:55.919 --> 00:16:59.279 gut is where things get really confusing. Anatomy 00:16:59.279 --> 00:17:02.019 -wise, a bear is a carnivore. It has a single 00:17:02.019 --> 00:17:04.400 stomach, a very short, small intestine, and no 00:17:04.400 --> 00:17:06.440 cecum. Okay, remind me what a cecum is again. 00:17:06.519 --> 00:17:08.839 It's a pouch in the digestive tract. In true 00:17:08.839 --> 00:17:11.240 herbivores, like horses or rabbits, the cecum 00:17:11.240 --> 00:17:13.819 is this big fermentation tank. It's filled with 00:17:13.819 --> 00:17:16.079 specialized bacteria that break down tough plant 00:17:16.079 --> 00:17:17.980 cellulose so the animal can actually get energy 00:17:17.980 --> 00:17:20.210 from it. Bears don't have one. So if they eat 00:17:20.210 --> 00:17:23.170 a salad, it passes right through them. Largely, 00:17:23.170 --> 00:17:25.869 yes. They are incredibly inefficient at digesting 00:17:25.869 --> 00:17:28.890 plants. And yet, for most bears, brown bears, 00:17:29.190 --> 00:17:31.490 black bears' plants make up a huge percentage 00:17:31.490 --> 00:17:34.519 of their diet. Roots, grasses, berries. So they're 00:17:34.519 --> 00:17:36.119 just running a volume game. They just have to 00:17:36.119 --> 00:17:38.559 eat constantly. Exactly. They have to eat massive 00:17:38.559 --> 00:17:40.500 amounts because they aren't extracting all the 00:17:40.500 --> 00:17:42.880 nutrients from what they consume. But the most 00:17:42.880 --> 00:17:46.039 extreme, almost absurd example of this inefficiency 00:17:46.039 --> 00:17:48.880 is the giant panda. The panda problem. It really 00:17:48.880 --> 00:17:51.720 is a biological problem. Here you have an animal 00:17:51.720 --> 00:17:55.119 that eats bamboo, which is almost entirely tough 00:17:55.119 --> 00:17:58.720 cellulose for 99 % of its diet. Right. But it 00:17:58.720 --> 00:18:01.680 still has the short, carnivorous gut of a bear. 00:18:02.359 --> 00:18:05.220 It has the genes for digesting meat, not plants. 00:18:05.440 --> 00:18:08.319 It completely lacks the specialized gut microbes 00:18:08.319 --> 00:18:10.720 that other herbivores use to break down cellulose 00:18:10.720 --> 00:18:12.420 efficiently. So how is it alive? How does that 00:18:12.420 --> 00:18:15.000 even work? By doing absolutely nothing else but 00:18:15.000 --> 00:18:17.799 eating. Because they digest less than 20 % of 00:18:17.799 --> 00:18:19.619 what they eat, they have to process about 20 00:18:19.619 --> 00:18:22.140 to 40 pounds of bamboo every single day. 40 pounds? 00:18:22.259 --> 00:18:25.359 To do that, they have to eat for 12 to 15 hours 00:18:25.359 --> 00:18:28.390 a day. Their entire life is just a desperate 00:18:28.390 --> 00:18:31.049 race to consume enough calories to not starve. 00:18:31.269 --> 00:18:33.769 That sounds miserable. It's an evolutionary trap. 00:18:34.029 --> 00:18:36.289 They found a food source that no one else wanted, 00:18:36.509 --> 00:18:39.329 bamboo, so there was no competition. But the 00:18:39.329 --> 00:18:41.069 cost is that they have to spend their entire 00:18:41.069 --> 00:18:44.210 waking life just chewing. And because they get 00:18:44.210 --> 00:18:46.289 so little energy from it, they can't afford to 00:18:46.289 --> 00:18:49.190 move much. That's why pandas seem so lazy. They're 00:18:49.190 --> 00:18:51.029 not lazy. They're energy bankrupt. And then on 00:18:51.029 --> 00:18:53.130 the complete other end of the dietary spectrum, 00:18:53.289 --> 00:18:55.759 you have the sloth bear. I saw the note about 00:18:55.759 --> 00:18:57.160 its teeth and I had to double check it because 00:18:57.160 --> 00:18:59.380 I thought it was a typo. The vacuum cleaner adaptation. 00:18:59.859 --> 00:19:03.599 It's amazing. The sloth bear in India eats termites 00:19:03.599 --> 00:19:06.759 and ants. To do this, it has evolved to lose 00:19:06.759 --> 00:19:09.940 its two upper front teeth, the incisors. It just 00:19:09.940 --> 00:19:12.440 has a gap in its grill. A permanent gap. They 00:19:12.440 --> 00:19:14.839 can seal their lips around a termite hole, close 00:19:14.839 --> 00:19:16.980 their nostrils so they don't inhale bugs, and 00:19:16.980 --> 00:19:19.180 then suck air through that gap in their teeth. 00:19:19.339 --> 00:19:22.019 So it's literally a vacuum. A high -powered organic 00:19:22.019 --> 00:19:25.400 vacuum. is incredibly loud. You can apparently 00:19:25.400 --> 00:19:27.859 hear it from hundreds of yards away. It's just 00:19:27.859 --> 00:19:30.559 amazing how the face and the habits can change 00:19:30.559 --> 00:19:33.920 so drastically. But the gut remains this stubborn 00:19:33.920 --> 00:19:36.460 primitive carnivore tube. It just shows that 00:19:36.460 --> 00:19:38.480 evolution works with what it has. It doesn't 00:19:38.480 --> 00:19:41.859 design perfection from scratch. It hacks together 00:19:41.859 --> 00:19:44.890 solutions that are good enough. To survive. Speaking 00:19:44.890 --> 00:19:47.490 of good enough, let's talk about the thing that 00:19:47.490 --> 00:19:49.849 bears do better than almost any other animal 00:19:49.849 --> 00:19:53.210 on Earth. Hibernation. The metabolic miracle. 00:19:53.609 --> 00:19:55.769 Yeah. We grew up thinking, oh, the bear just 00:19:55.769 --> 00:19:57.970 sleeps. It's cartoon image. You know, the bear 00:19:57.970 --> 00:20:00.390 puts on a nightcap, gets into a cozy bed and 00:20:00.390 --> 00:20:03.150 wakes up in the spring. But the reality is so 00:20:03.150 --> 00:20:05.509 much more alien than that. It is not sleep. Let's 00:20:05.509 --> 00:20:08.029 be very, very clear about that. Sleep is a brain 00:20:08.029 --> 00:20:11.509 state. Hibernation is a total metabolic overhaul. 00:20:12.130 --> 00:20:14.809 It is a state of dormancy that pushes the very 00:20:14.809 --> 00:20:18.089 boundaries of what is biologically possible for 00:20:18.089 --> 00:20:20.109 a mammal of that size. Okay, so let's look at 00:20:20.109 --> 00:20:21.730 the stats. What happens to the engine when they 00:20:21.730 --> 00:20:23.589 park the car for the winter? First, let's talk 00:20:23.589 --> 00:20:26.009 about the heart rate. A normal resting heart 00:20:26.009 --> 00:20:28.430 rate for a bear is around 55 beats per minute. 00:20:28.589 --> 00:20:31.130 When it goes into the den, that drops. To what, 00:20:31.250 --> 00:20:35.119 30? As low as nine beats per minute. Nine. No 00:20:35.119 --> 00:20:38.039 way. The laws is to tap a slow rhythm. But beat. 00:20:38.200 --> 00:20:41.220 Long pause. Beat. That's essentially dead. It's 00:20:41.220 --> 00:20:43.259 hovering right on the edge. But here's the really 00:20:43.259 --> 00:20:46.519 weird catch. In small hibernators like ground 00:20:46.519 --> 00:20:48.700 squirrels or bats, their body temperature drops 00:20:48.700 --> 00:20:51.039 to near freezing. They basically become little 00:20:51.039 --> 00:20:54.559 ice cubes. Right. But the bear. its body temperature 00:20:54.559 --> 00:20:57.299 only drops a few degrees maybe from 37 degrees 00:20:57.299 --> 00:21:00.960 celsius down to 33 degrees or 30 degrees c why 00:21:00.960 --> 00:21:02.740 keep the heat on if the heart is barely beating 00:21:02.740 --> 00:21:04.579 that seems like a huge waste of precious energy 00:21:04.579 --> 00:21:07.380 it's very expensive energetically speaking yes 00:21:07.380 --> 00:21:11.220 but they do it for two critical reasons one Defense. 00:21:11.319 --> 00:21:14.460 Defense. If a wolf or a wolverine crawls into 00:21:14.460 --> 00:21:17.099 a ground squirrel's burrow, that squirrel is 00:21:17.099 --> 00:21:19.880 a frozen popsicle. It can't move. It takes hours 00:21:19.880 --> 00:21:22.480 for it to warm up. But if a threat enters a bear 00:21:22.480 --> 00:21:24.619 den, the bear is warm enough that it can wake 00:21:24.619 --> 00:21:27.000 up and fight almost instantly. Wow. Okay. And 00:21:27.000 --> 00:21:29.660 the second reason. The cubs. Bears give birth 00:21:29.660 --> 00:21:31.880 in the middle of winter in the den. You cannot 00:21:31.880 --> 00:21:34.980 nurse and raise tiny, hairless, helpless newborns 00:21:34.980 --> 00:21:37.400 if your body is at zero degrees Celsius. The 00:21:37.400 --> 00:21:39.539 mother has to be a radiant heater for them. We'll 00:21:39.539 --> 00:21:40.880 get to the cubs. That's a whole other story. 00:21:40.960 --> 00:21:42.960 But I want to stay on the physiology for a second. 00:21:43.660 --> 00:21:46.359 The sources mentioned a specific protein called 00:21:46.359 --> 00:21:48.960 myosin. This seemed to be the secret sauce for 00:21:48.960 --> 00:21:51.299 how the heart can do this. This is brand new 00:21:51.299 --> 00:21:54.519 science, and it's incredible. Myosin is the protein 00:21:54.519 --> 00:21:56.759 in our muscle fibers that makes them contract. 00:21:57.200 --> 00:22:00.319 In a normal state, our muscles are always burning 00:22:00.319 --> 00:22:02.279 a little bit of energy, a little bit of ATP, 00:22:02.539 --> 00:22:05.380 even when they're at rest. Just to maintain tone. 00:22:05.680 --> 00:22:08.579 Right. But in hibernating bears, their myosin 00:22:08.579 --> 00:22:11.220 shifts into what scientists are calling a super 00:22:11.220 --> 00:22:14.880 relaxed state. The molecules physically rearrange 00:22:14.880 --> 00:22:17.900 themselves to stop consuming ATP. So they just 00:22:17.900 --> 00:22:20.200 disconnect the battery from the muscle. Effectively, 00:22:20.200 --> 00:22:22.900 yes. This allows the heart to beat that slowly 00:22:22.900 --> 00:22:25.140 without the muscle tissue degrading and without 00:22:25.140 --> 00:22:27.339 burning through their precious fat stores too 00:22:27.339 --> 00:22:29.960 quickly. It's molecular efficiency at the highest 00:22:29.960 --> 00:22:32.180 possible level. But the thing that really stops 00:22:32.180 --> 00:22:35.339 me in my tracks, the thing that I think most 00:22:35.339 --> 00:22:37.859 listeners will have a hard time believing. is 00:22:37.859 --> 00:22:40.740 the bathroom situation. The no bathroom rule. 00:22:40.920 --> 00:22:42.980 Walk us through this because it sounds like science 00:22:42.980 --> 00:22:46.400 fiction. It is simple and frankly terrifying. 00:22:46.819 --> 00:22:49.660 A hibernating bear does not eat, does not drink, 00:22:49.819 --> 00:22:53.099 does not urinate, and does not defecate for up 00:22:53.099 --> 00:22:55.519 to 100 days, sometimes even longer. Okay, let's 00:22:55.519 --> 00:22:56.700 break that down. Let's start with urination. 00:22:57.079 --> 00:23:00.480 If I, a human, didn't pee for a week, I would 00:23:00.480 --> 00:23:02.859 be dead. You would die of uremic poisoning, yes. 00:23:03.339 --> 00:23:06.500 Your kidneys filter waste, specifically a compound 00:23:06.500 --> 00:23:10.519 called urea, out of your blood. Urea is the byproduct 00:23:10.519 --> 00:23:12.839 of breaking down protein. If you don't pee it 00:23:12.839 --> 00:23:15.299 out, it builds up in your blood, becomes toxic 00:23:15.299 --> 00:23:18.079 ammonia, and it kills you. So how does the bear 00:23:18.079 --> 00:23:20.740 not poison itself? This is the absolute genius 00:23:20.740 --> 00:23:22.900 part of the whole system. The bear recycles it. 00:23:22.960 --> 00:23:25.880 It recycles its pee. It recycles the urea. Instead 00:23:25.880 --> 00:23:28.180 of sending the urea -rich blood to the kidneys 00:23:28.180 --> 00:23:30.460 to be filtered out, the bear's body takes that 00:23:30.460 --> 00:23:32.839 urea and pumps it back into the blood and then 00:23:32.839 --> 00:23:35.779 into the gut. Into the gut. What for? Yes. In 00:23:35.779 --> 00:23:37.900 the gut, there are specific bacteria that break 00:23:37.900 --> 00:23:41.160 the urea down into ammonia. And then, and this 00:23:41.160 --> 00:23:43.819 is the magic trick, the bear's liver takes that 00:23:43.819 --> 00:23:46.299 ammonia and uses it to build new amino acids. 00:23:46.569 --> 00:23:48.769 specifically an amino acid called glutamine. 00:23:48.910 --> 00:23:52.450 Wait, hold on. So they're taking the toxic waste 00:23:52.450 --> 00:23:54.769 product that usually kills you and they were 00:23:54.769 --> 00:23:56.390 turning it back into the fundamental building 00:23:56.390 --> 00:23:59.029 blocks of muscle. Exactly. They are literally 00:23:59.029 --> 00:24:02.809 turning their own pee into protein. This is the 00:24:02.809 --> 00:24:05.230 secret to why bears don't lose significant muscle 00:24:05.230 --> 00:24:07.849 mass in the winter. If you laid in a hospital 00:24:07.849 --> 00:24:10.829 bed for three months, your muscles would atrophy 00:24:10.829 --> 00:24:14.059 to nothing. You'd be weak as a kitten. A bear 00:24:14.059 --> 00:24:16.279 wakes up strong because it has been synthesizing 00:24:16.279 --> 00:24:18.799 new protein from its own waste the entire time. 00:24:18.880 --> 00:24:21.759 That is a perfect closed loop system. It's like 00:24:21.759 --> 00:24:23.900 a space station. It is the ultimate biological 00:24:23.900 --> 00:24:27.119 recycling plant. It's magnificent. Yeah, the 00:24:27.119 --> 00:24:29.819 other end of the system. The solid waste. Well, 00:24:29.960 --> 00:24:31.859 since they aren't eating, there isn't much new 00:24:31.859 --> 00:24:34.460 waste being produced. But there are cells shedding 00:24:34.460 --> 00:24:36.640 from the intestinal wall, hair they swallow while 00:24:36.640 --> 00:24:39.059 grooming before they go to sleep. All this stuff 00:24:39.059 --> 00:24:41.140 forms what's called a fecal plug in the lower 00:24:41.140 --> 00:24:43.720 colon. A plug. A literal plug. It's a hard, dry 00:24:43.720 --> 00:24:46.400 mass of hair, cells, and plant material that 00:24:46.400 --> 00:24:48.920 blocks the exit. It keeps everything sealed up 00:24:48.920 --> 00:24:51.880 tight until spring. When they wake up, expelling 00:24:51.880 --> 00:24:53.819 that plug is the very first order of business. 00:24:54.480 --> 00:24:57.059 I can only imagine. It's just incredible that 00:24:57.059 --> 00:24:59.420 evolution figured this out. Don't waste the nitrogen. 00:24:59.539 --> 00:25:02.400 Let's build biceps with it instead. And interestingly, 00:25:02.660 --> 00:25:05.460 size acts as a constraint here. The system works 00:25:05.460 --> 00:25:08.240 best when you are big, but the smaller bears 00:25:08.240 --> 00:25:10.700 can actually hibernate for longer periods than 00:25:10.700 --> 00:25:13.599 the really massive males. How does that work? 00:25:13.720 --> 00:25:15.880 Because they have a better surface area to volume 00:25:15.880 --> 00:25:18.420 ratio, they can lower their metabolic rate more 00:25:18.420 --> 00:25:21.420 easily and cool down more efficiently. The massive 00:25:21.420 --> 00:25:23.900 boars have a harder time shedding heat, so they 00:25:23.900 --> 00:25:26.579 burn through their energy reserves faster. So 00:25:26.579 --> 00:25:29.039 the big dog is actually a very delicate thermal 00:25:29.039 --> 00:25:31.400 engine. Precisely. Okay, let's step out of the 00:25:31.400 --> 00:25:33.960 den now. The bear wakes up. It pulls the plug, 00:25:34.099 --> 00:25:36.720 literally. What is their life like out in the 00:25:36.720 --> 00:25:38.880 world? Yeah. Because based on all the research, 00:25:39.079 --> 00:25:41.339 they seem like the ultimate loners. They are. 00:25:41.460 --> 00:25:43.920 With the major exception of a mother and her 00:25:43.920 --> 00:25:47.059 cubs, bears are fundamentally asocial animals. 00:25:47.480 --> 00:25:49.539 They don't have packs like wolves. They don't 00:25:49.539 --> 00:25:52.220 have herds. They actively avoid each other. But 00:25:52.220 --> 00:25:54.799 wait, we've all seen the videos. The famous ones 00:25:54.799 --> 00:25:57.779 from Brooks Walls in Alaska. There are 20, 30 00:25:57.779 --> 00:26:00.319 bears all standing in the river at once during 00:26:00.319 --> 00:26:02.829 the salmon run. That is the exception that proves 00:26:02.829 --> 00:26:06.500 the rule. Bears are pragmatic. They will tolerate 00:26:06.500 --> 00:26:08.880 each other's presence only when a resource is 00:26:08.880 --> 00:26:11.839 so overwhelmingly abundant, like a massive salmon 00:26:11.839 --> 00:26:14.599 run, that fighting over it isn't worth the energy. 00:26:14.720 --> 00:26:16.599 There's enough for everyone. So they're not hanging 00:26:16.599 --> 00:26:18.960 out. They're just commuting to the same cafeteria. 00:26:19.259 --> 00:26:22.000 Exactly. And if you watch those videos closely, 00:26:22.240 --> 00:26:24.140 they aren't being social. They are maintaining 00:26:24.140 --> 00:26:28.259 a very strict personal bubble. There is a clear 00:26:28.259 --> 00:26:31.299 hierarchy in place. How is that hierarchy established? 00:26:31.680 --> 00:26:35.019 By size and aggression. brutal system the biggest 00:26:35.019 --> 00:26:37.799 most dominant males get the best fishing spots 00:26:37.799 --> 00:26:39.839 the ones at the top of the falls where the salmon 00:26:39.839 --> 00:26:42.240 literally jump right into their mouths and everyone 00:26:42.240 --> 00:26:44.799 else the females the younger sub -adults they 00:26:44.799 --> 00:26:46.839 get the perimeter they have to wait for scraps 00:26:46.839 --> 00:26:49.400 downstream and if you step out of line if a younger 00:26:49.400 --> 00:26:52.960 bear tries to take a prime spot Swift and decisive 00:26:52.960 --> 00:26:55.619 violence. If you ever see footage of those old 00:26:55.619 --> 00:26:58.000 male bears up close, you'll see their faces are 00:26:58.000 --> 00:27:01.160 just covered in scars. Their ears are torn and 00:27:01.160 --> 00:27:03.819 they have missing patches of fur. Those are the 00:27:03.819 --> 00:27:06.400 receipts of a lifetime of enforcing dominance. 00:27:06.839 --> 00:27:08.940 So if they don't like to fight unless they have 00:27:08.940 --> 00:27:11.539 to, how do they communicate? If I'm a bear and 00:27:11.539 --> 00:27:13.200 I want to tell you to back off without actually 00:27:13.200 --> 00:27:15.640 biting you, what do I do? You use a whole suite 00:27:15.640 --> 00:27:17.859 of sound and body language. We all think of the 00:27:17.859 --> 00:27:20.400 big roar. But bears are actually much more subtle 00:27:20.400 --> 00:27:22.279 than that. If a bear is stressed or annoyed, 00:27:22.480 --> 00:27:24.880 it does something called jaw popping. Jaw popping. 00:27:25.099 --> 00:27:26.980 What does that sound like? It's a loud crack. 00:27:27.220 --> 00:27:29.200 They snap their jaws together with incredible 00:27:29.200 --> 00:27:31.559 force. It sounds like a gunshot or a dry branch 00:27:31.559 --> 00:27:34.720 breaking. It's a very clear, unambiguous signal. 00:27:35.019 --> 00:27:39.200 I am anxious. I am dangerous. Go away now. Are 00:27:39.200 --> 00:27:50.059 there friendly sounds? They also leave messages 00:27:50.059 --> 00:27:52.019 for each other, right? I was reading about the 00:27:52.019 --> 00:27:54.440 scent marking. It sounded like they're treating 00:27:54.440 --> 00:27:56.859 the forest like a community bulletin board. They 00:27:56.859 --> 00:28:00.460 absolutely are. A big male bear will find a prominent 00:28:00.460 --> 00:28:03.140 tree on a trail, stand up on his hind legs to 00:28:03.140 --> 00:28:05.380 his full height, and rub his back and shoulders 00:28:05.380 --> 00:28:07.740 against it. He's grinding his personal scent 00:28:07.740 --> 00:28:09.640 deep into the bark. Then he might turn around 00:28:09.640 --> 00:28:12.779 and bite the tree, tearing out huge chunks of 00:28:12.779 --> 00:28:15.599 it. So he's leaving a message that says, I smell 00:28:15.599 --> 00:28:18.460 this strong and my mouth is this high off the 00:28:18.460 --> 00:28:21.880 ground. Exactly. It's a measurement. If another 00:28:21.880 --> 00:28:24.920 smaller bear comes along and smells that mark, 00:28:25.099 --> 00:28:27.779 but his own nose is two feet lower than the bite 00:28:27.779 --> 00:28:30.259 mark, he knows, OK, the guy who lives here is 00:28:30.259 --> 00:28:32.299 a giant. I should probably just keep moving and 00:28:32.299 --> 00:28:34.890 avoid trouble. And the panda, being the panda, 00:28:35.049 --> 00:28:36.769 has to do it differently, of course. Of course. 00:28:37.109 --> 00:28:39.529 The panda has specialized scent glands under 00:28:39.529 --> 00:28:43.529 its tail. It secretes this waxy substance. And 00:28:43.529 --> 00:28:45.829 to get it as high up on a tree as possible, a 00:28:45.829 --> 00:28:48.190 panda will essentially do a handstand. A handstand. 00:28:48.210 --> 00:28:50.250 They back up to the tree with their hind legs 00:28:50.250 --> 00:28:52.450 walking up the trunk until they're almost upside 00:28:52.450 --> 00:28:55.170 down, just to leave their mark as high as they 00:28:55.170 --> 00:28:58.710 possibly can. That is a hilarious image. An acrobatic 00:28:58.710 --> 00:29:01.269 pee contest. It works for them. And for polar 00:29:01.269 --> 00:29:03.490 bears living out on the sea ice, the problem 00:29:03.490 --> 00:29:05.509 is that there are no trees, so they leave scent 00:29:05.509 --> 00:29:08.509 in their footprints. In the snow. How does that 00:29:08.509 --> 00:29:11.849 work? They have sweat glands in their paws. As 00:29:11.849 --> 00:29:13.849 they walk across the ice, they leave a chemical 00:29:13.849 --> 00:29:16.849 trail. In the endless, featureless white void 00:29:16.849 --> 00:29:19.430 of the Arctic, those footprints are the only 00:29:19.430 --> 00:29:22.910 road signs. A male polar bear can follow a female's 00:29:22.910 --> 00:29:25.289 tracks for days just by the scent she leaves 00:29:25.289 --> 00:29:27.269 behind in the ice crystals. Let's talk about 00:29:27.269 --> 00:29:29.750 that female. Because the reproduction cycle of 00:29:29.750 --> 00:29:33.549 the bear is... Well, the word bizarre is the 00:29:33.549 --> 00:29:35.710 only one that comes to mind. It features a very 00:29:35.710 --> 00:29:39.150 clever biological trick called delayed implantation. 00:29:39.349 --> 00:29:42.130 A biological pause button. The ultimate pause 00:29:42.130 --> 00:29:44.950 button. So bears will mate in the late spring 00:29:44.950 --> 00:29:47.869 or early summer. The egg is fertilized. It divides 00:29:47.869 --> 00:29:50.250 a few times to become a blastocyst. Just a... 00:29:50.509 --> 00:29:54.130 tiny ball of cells. But then it stops. It doesn't 00:29:54.130 --> 00:29:56.049 attach to the uterine wall. It just floats there 00:29:56.049 --> 00:29:59.150 in suspended animation. For how long? For months. 00:29:59.269 --> 00:30:01.670 All through the summer and into the late autumn. 00:30:01.849 --> 00:30:04.089 What is the logic there? Why not just start growing 00:30:04.089 --> 00:30:06.230 the baby right away? Because the mother doesn't 00:30:06.230 --> 00:30:07.470 know if she's going to have a good year yet. 00:30:07.670 --> 00:30:10.450 She needs to spend the entire summer and autumn 00:30:10.450 --> 00:30:13.250 just eating. She needs to pack on hundreds of 00:30:13.250 --> 00:30:15.390 pounds of fat to survive the winter and produce 00:30:15.390 --> 00:30:17.950 milk. If she gets to November and she's skinny, 00:30:18.089 --> 00:30:20.140 her body makes a calculated decision. decision. 00:30:20.259 --> 00:30:23.819 We can't afford this. The embryo is simply reabsorbed. 00:30:23.819 --> 00:30:26.680 No pregnancy that year. That is incredibly smart. 00:30:26.839 --> 00:30:29.400 It's like a biological escrow account. It's crucial 00:30:29.400 --> 00:30:32.259 for survival. But if she is fat enough, if she 00:30:32.259 --> 00:30:34.680 has enough reserves, her hormones send a signal, 00:30:34.759 --> 00:30:37.220 the egg implants and gestation finally begins. 00:30:37.539 --> 00:30:40.200 But because it starts so late in the year, the 00:30:40.200 --> 00:30:43.059 actual gestation is incredibly short. Only about 00:30:43.059 --> 00:30:45.650 six to eight weeks of real development. And that 00:30:45.650 --> 00:30:48.609 leads to the impossibly tiny babies. Absurdly 00:30:48.609 --> 00:30:51.509 tiny. A mother grizzly can weigh 700 pounds. 00:30:51.769 --> 00:30:54.849 Our newborn cub weighs less than one pound. It's 00:30:54.849 --> 00:30:58.049 the size of a chipmunk. It's born blind, virtually 00:30:58.049 --> 00:31:01.210 hairless, and completely helpless. It's the highest 00:31:01.210 --> 00:31:03.750 size ratio between mother and newborn in placental 00:31:03.750 --> 00:31:07.269 mammals, right? Aside from marsupials like kangaroos, 00:31:07.269 --> 00:31:10.809 yes. It only works because the den acts as a 00:31:10.809 --> 00:31:13.849 kind of external womb. The mother is hibernating, 00:31:13.849 --> 00:31:16.329 but her milk production is high. The cubs just 00:31:16.329 --> 00:31:18.710 latch on and grow in the dark, safe and warm, 00:31:18.829 --> 00:31:20.930 fueled by the fat she spent all summer storing. 00:31:21.130 --> 00:31:23.289 But safety is relative. The outline mentioned 00:31:23.289 --> 00:31:26.349 infanticide. This is the very dark side of bear 00:31:26.349 --> 00:31:28.990 behavior. It is brutal, but from a certain point 00:31:28.990 --> 00:31:32.269 of view, it's cold evolutionary math. Male bears 00:31:32.269 --> 00:31:34.890 will actively hunt and kill cubs that are not 00:31:34.890 --> 00:31:37.430 their own. Why? That seems so counterproductive 00:31:37.430 --> 00:31:39.890 for the species as a whole. Evolution doesn't 00:31:39.890 --> 00:31:42.109 care about the species. It cares about the individual's 00:31:42.109 --> 00:31:45.079 genes getting passed on. Here is the logic. A 00:31:45.079 --> 00:31:47.579 female bear with cubs will not mate. She is completely 00:31:47.579 --> 00:31:49.700 devoted to raising them for two to three years. 00:31:49.799 --> 00:31:52.789 She is off the market. So she's unavailable. 00:31:52.930 --> 00:31:56.170 Right. Now, if a new dominant male comes into 00:31:56.170 --> 00:31:59.089 the territory and kills those cubs, the female's 00:31:59.089 --> 00:32:01.990 lactation stops. Her hormones reset. And she 00:32:01.990 --> 00:32:04.369 goes back into estrus. She becomes ready to mate 00:32:04.369 --> 00:32:06.650 again, usually within just a few days. So by 00:32:06.650 --> 00:32:09.250 killing the cubs. By killing the cubs, the male 00:32:09.250 --> 00:32:11.630 gets a chance to father his own offspring immediately, 00:32:11.869 --> 00:32:14.049 rather than having to wait three years for her 00:32:14.049 --> 00:32:16.109 to be receptive again. That is just grim. It 00:32:16.109 --> 00:32:18.920 is nature red in tooth and claw. And this is 00:32:18.920 --> 00:32:21.880 why female bears with cubs are so terrifyingly 00:32:21.880 --> 00:32:25.059 aggressive. A mother bear knows that any strange 00:32:25.059 --> 00:32:27.880 male she encounters is a lethal threat to her 00:32:27.880 --> 00:32:30.180 genetic legacy. She isn't just protecting her 00:32:30.180 --> 00:32:32.579 babies in an abstract, affectionate way. She's 00:32:32.579 --> 00:32:35.079 protecting her entire lifetime reproductive success. 00:32:35.420 --> 00:32:38.359 She will fight a male twice her size to the death 00:32:38.359 --> 00:32:40.990 to protect them. That really changes the perspective 00:32:40.990 --> 00:32:43.569 on the whole mama bear trope. It's not just about 00:32:43.569 --> 00:32:45.690 affection. It's a desperate life or death defense 00:32:45.690 --> 00:32:48.730 against a very real biological threat. Exactly. 00:32:48.849 --> 00:32:50.609 Let's pivot now. We've looked at the biology, 00:32:50.730 --> 00:32:52.789 the history, the behavior. Now we're looking 00:32:52.789 --> 00:32:55.509 in the mirror at us, at the relationship between 00:32:55.509 --> 00:32:58.829 humans and bears. A relationship that is as old 00:32:58.829 --> 00:33:02.009 as humanity itself. We started with the linguistic 00:33:02.009 --> 00:33:05.230 taboo, but the connection goes so much deeper 00:33:05.230 --> 00:33:07.049 than that. It goes all the way to the stars. 00:33:07.289 --> 00:33:09.579 Bursa Major. The Great Bear. This is one of the 00:33:09.579 --> 00:33:12.019 few constellations that actually looks somewhat 00:33:12.019 --> 00:33:14.359 like what it's supposed to be. But the research 00:33:14.359 --> 00:33:16.740 suggests that seeing a bear in those stars isn't 00:33:16.740 --> 00:33:19.720 just some random coincidence. No, this is one 00:33:19.720 --> 00:33:21.700 of the most fascinating pieces of comparative 00:33:21.700 --> 00:33:24.740 anthropology. Cultures all across the Northern 00:33:24.740 --> 00:33:27.559 Hemisphere, from the ancient Greek poets to the 00:33:27.559 --> 00:33:29.920 Native American tribes of the Iroquois and the 00:33:29.920 --> 00:33:32.799 Algonquin, all looked at that same square of 00:33:32.799 --> 00:33:36.039 stars in the handle and said, that is a bear. 00:33:36.400 --> 00:33:39.319 How is that possible? Those cultures were separated 00:33:39.319 --> 00:33:41.599 by thousands of miles and thousands of years. 00:33:41.759 --> 00:33:44.480 The leading theory is that the story, the cosmic 00:33:44.480 --> 00:33:46.819 hunt myth, is older than the separation of those 00:33:46.819 --> 00:33:49.740 peoples. It likely dates back to the Paleolithic 00:33:49.740 --> 00:33:53.279 era, more than 13 ,000 years ago. When the first 00:33:53.279 --> 00:33:55.779 humans crossed the Bering land bridge from Asia 00:33:55.779 --> 00:33:57.819 into the Americas, they brought the story of 00:33:57.819 --> 00:34:00.109 the great bear in the sky with them. That gives 00:34:00.109 --> 00:34:02.390 me chills. So when you and I look up at the Big 00:34:02.390 --> 00:34:05.210 Dipper, we are seeing a story that our ancestors 00:34:05.210 --> 00:34:07.990 were telling each other in caves during the Ice 00:34:07.990 --> 00:34:11.429 Age. Exactly. And in most versions of the myth, 00:34:11.550 --> 00:34:14.429 the bowl of the Dipper is the bear itself. And 00:34:14.429 --> 00:34:16.789 the three stars of the handle are the hunters 00:34:16.789 --> 00:34:18.949 who are chasing it. And the chase has a purpose. 00:34:19.579 --> 00:34:22.619 It does. The myth says the hunt happens every 00:34:22.619 --> 00:34:25.300 year. In the autumn, the hunters finally catch 00:34:25.300 --> 00:34:28.039 the bear. Its blood falls to the earth and turns 00:34:28.039 --> 00:34:30.519 the leaves red and orange. That's the fall foliage. 00:34:30.719 --> 00:34:33.760 The bear then dies and goes into its den, which 00:34:33.760 --> 00:34:36.119 is hibernation, and then it is reborn in the 00:34:36.119 --> 00:34:38.869 spring. It's the cycle of the seasons, encoded 00:34:38.869 --> 00:34:41.489 in a story in the sky. And on the ground, that 00:34:41.489 --> 00:34:44.309 reverence was just as real. You had actual bear 00:34:44.309 --> 00:34:46.849 cults. The Ainu people of Japan, for instance, 00:34:47.070 --> 00:34:49.530 worshipped the bear as a powerful god that walked 00:34:49.530 --> 00:34:51.670 among them in the physical world. And in ancient 00:34:51.670 --> 00:34:54.050 Greece. The goddess of the hunt, Artemis, was 00:34:54.050 --> 00:34:56.909 deeply associated with bears. There was a famous 00:34:56.909 --> 00:34:58.929 cult where young Athenian girls had to go through 00:34:58.929 --> 00:35:01.469 a ritual called the Arctia. They would dress 00:35:01.469 --> 00:35:03.690 as bear's arctoi to mark their transition into 00:35:03.690 --> 00:35:06.530 womanhood. So we went from worshipping them as 00:35:06.530 --> 00:35:09.969 star gods and powerful spirits to the teddy bear. 00:35:10.090 --> 00:35:12.329 The ultimate domestication, isn't it? We took 00:35:12.329 --> 00:35:15.010 the most powerful and feared predator in our 00:35:15.010 --> 00:35:17.369 ancestral environment and we turned it into a 00:35:17.369 --> 00:35:20.289 child's toy. The story of the teddy bear is actually 00:35:20.289 --> 00:35:22.969 very specific, isn't it? It involves a U .S. 00:35:22.989 --> 00:35:26.170 president. Theodore Teddy Roosevelt. The year 00:35:26.170 --> 00:35:29.769 was 1902. He was on a bear hunting trip in Mississippi 00:35:29.769 --> 00:35:33.369 and he was having no luck. So his guys, trying 00:35:33.369 --> 00:35:35.590 to be helpful, went out and cornered an old American 00:35:35.590 --> 00:35:38.369 black bear. They beat it, tied it to a willow 00:35:38.369 --> 00:35:40.070 tree and then called the president over and said, 00:35:40.150 --> 00:35:43.429 here, Mr. President, shoot it. Talk about unsportsmanlike. 00:35:43.530 --> 00:35:45.949 That's exactly what Roosevelt said. He was disgusted. 00:35:45.949 --> 00:35:48.349 He refused to shoot an injured bound animal. 00:35:48.510 --> 00:35:51.190 He called it unsportsmanlike conduct and demanded 00:35:51.190 --> 00:35:53.639 they put the poor animal out of its misery. And 00:35:53.639 --> 00:35:56.159 the story got out. The story got out. A political 00:35:56.159 --> 00:35:58.300 cartoonist drew the seam for the newspapers, 00:35:58.539 --> 00:36:01.460 and a toy maker in Brooklyn, a man named Morris 00:36:01.460 --> 00:36:04.280 Mictum, saw the cartoon, made a little stuffed 00:36:04.280 --> 00:36:07.280 plush bear, and put it in his shop window. He 00:36:07.280 --> 00:36:10.139 asked for and received permission from the president 00:36:10.139 --> 00:36:13.619 to call it Teddy's Bear. And suddenly, the monster 00:36:13.619 --> 00:36:15.440 of the woods is something you tuck your kids 00:36:15.440 --> 00:36:17.739 in with at night. It completely softened the 00:36:17.739 --> 00:36:19.840 public image of the bear. It went from the brown 00:36:19.840 --> 00:36:22.340 one that summons death to Winnie the Pooh and 00:36:22.340 --> 00:36:24.760 Yogi Bear. But the reality of our interaction 00:36:24.760 --> 00:36:27.500 isn't always plush toys and cartoons. We have 00:36:27.500 --> 00:36:30.980 a long, dark history of exploiting these animals. 00:36:31.139 --> 00:36:34.099 We do. In Shakespeare's time, bear baiting was 00:36:34.099 --> 00:36:36.739 a huge public spectacle. You'd go to the theater 00:36:36.739 --> 00:36:38.880 to see Hamlet, or you could go next door to the 00:36:38.880 --> 00:36:41.599 bear garden to watch a bear chained to a post 00:36:41.599 --> 00:36:44.119 fighting off a pack of mastiffs for entertainment. 00:36:44.500 --> 00:36:47.219 And today, that exploitation has shifted to something 00:36:47.219 --> 00:36:51.679 more. Chemical. Bile farming. This is the hard 00:36:51.679 --> 00:36:54.059 part of the deep dive. In traditional Chinese 00:36:54.059 --> 00:36:56.860 medicine, bear bile has been used for thousands 00:36:56.860 --> 00:36:59.760 of years. The active ingredient is a compound 00:36:59.760 --> 00:37:03.500 called ursodeoxycholic acid, or UDCA. And what 00:37:03.500 --> 00:37:05.320 does it do? It can help dissolve certain kinds 00:37:05.320 --> 00:37:07.219 of gallstones and treat some liver diseases. 00:37:07.619 --> 00:37:10.539 So it works. Chemically, yes, the compound is 00:37:10.539 --> 00:37:12.800 effective. But here's the absolute tragedy of 00:37:12.800 --> 00:37:15.599 the situation. We do not need the bear. We make 00:37:15.599 --> 00:37:18.960 it in a lab. Easily. We have been able to synthesize 00:37:18.960 --> 00:37:23.119 UDCA for decades. It is cheap, it is pure, and 00:37:23.119 --> 00:37:26.619 it involves zero animal suffering. But the farms 00:37:26.619 --> 00:37:29.500 still exist. They do. In parts of Asia, thousands 00:37:29.500 --> 00:37:32.519 of bears, mostly moon bears or Asiatic black 00:37:32.519 --> 00:37:35.840 bears, are kept in tiny crush cages their entire 00:37:35.840 --> 00:37:37.800 lives, so small they can't even turn around. 00:37:38.000 --> 00:37:40.519 And bile is extracted from their gallbladders, 00:37:40.579 --> 00:37:43.239 often through a permanent catheter. It is a grueling, 00:37:43.239 --> 00:37:45.900 painful existence. Why does it persist if there's 00:37:45.900 --> 00:37:48.800 a synthetic version? It persists largely because 00:37:48.800 --> 00:37:51.679 of a deep -seated cultural belief that the wild 00:37:51.679 --> 00:37:54.500 or natural product is more potent than the synthetic 00:37:54.500 --> 00:37:56.940 one. It's the same kind of thinking that drives 00:37:56.940 --> 00:37:59.300 rhino poaching. That's heartbreaking. It is. 00:37:59.380 --> 00:38:02.219 But awareness is growing. There are amazing rescue 00:38:02.219 --> 00:38:04.639 sanctuaries now, and younger generations in those 00:38:04.639 --> 00:38:06.579 countries are moving away from these traditional 00:38:06.579 --> 00:38:09.579 remedies. But it is a very slow process. It really 00:38:09.579 --> 00:38:11.539 highlights the vulnerability of the bear family. 00:38:11.679 --> 00:38:14.159 We think of them as these invisible forces of 00:38:14.159 --> 00:38:16.840 nature, but they aren't. Not at all. Six out 00:38:16.840 --> 00:38:19.019 of the eight living bear species are listed as 00:38:19.019 --> 00:38:22.559 vulnerable by the IUCN. The sun bear, the sloth 00:38:22.559 --> 00:38:25.579 bear, the spectacled bear. They're all losing 00:38:25.579 --> 00:38:28.239 their forests to deforestation and facing pressure 00:38:28.239 --> 00:38:30.739 from poaching. But there is one major success 00:38:30.739 --> 00:38:34.000 story we have to mention. The panda. The panda 00:38:34.000 --> 00:38:36.519 is the poster child. Literally, it's the logo 00:38:36.519 --> 00:38:39.500 of the World Wildlife Fund for a reason. In the 00:38:39.500 --> 00:38:42.000 1980s, the panda was doomed. There were only 00:38:42.000 --> 00:38:44.480 a few hundred left in the wild. But the Chinese 00:38:44.480 --> 00:38:47.099 government launched a massive concerted conservation 00:38:47.099 --> 00:38:49.719 effort. What did they do? They created the Sichuan 00:38:49.719 --> 00:38:53.179 giant panda sanctuaries. They connected fragmented 00:38:53.179 --> 00:38:55.380 bamboo forests with corridors so populations 00:38:55.380 --> 00:38:58.340 could mix. They cracked down hard on poaching. 00:38:58.460 --> 00:39:00.800 And they invested heavily in captive breeding 00:39:00.800 --> 00:39:03.360 programs. And it worked. It worked. The wild 00:39:03.360 --> 00:39:06.079 population has rebounded significantly, so much 00:39:06.079 --> 00:39:07.920 so that a few years ago they were officially 00:39:07.920 --> 00:39:10.699 downgraded from endangered to vulnerable. It 00:39:10.699 --> 00:39:13.110 proves that if we actually care, if we put the 00:39:13.110 --> 00:39:15.210 resources and the political will behind it, we 00:39:15.210 --> 00:39:17.469 can save these species. We can find a way to 00:39:17.469 --> 00:39:19.630 coexist with the brown one. So we've covered 00:39:19.630 --> 00:39:22.469 the linguistic taboo, the surprising seal cousins, 00:39:22.710 --> 00:39:25.949 the nitrogen recycling sleep, and this long, 00:39:25.949 --> 00:39:28.789 complicated history with humans. It's a lot to 00:39:28.789 --> 00:39:32.369 process. It is. The bear is an animal that demands 00:39:32.369 --> 00:39:34.989 our respect, not just for its physical power, 00:39:35.130 --> 00:39:37.829 but for its incredible biological sophistication. 00:39:37.929 --> 00:39:40.210 As we wrap up this deep dive, is there one final 00:39:40.210 --> 00:39:41.809 thought you want to leave our listeners with? 00:39:42.269 --> 00:39:44.849 Something for them to chew on. I think so. We 00:39:44.849 --> 00:39:46.909 talk a lot about hibernation. I want you to go 00:39:46.909 --> 00:39:49.070 back to that nitrogen recycling trick for a minute. 00:39:49.269 --> 00:39:52.710 Okay. The muscle preservation. Right now, humanity 00:39:52.710 --> 00:39:56.030 is looking seriously at Mars. We want to be an 00:39:56.030 --> 00:39:59.489 interplanetary species. But one of the biggest 00:39:59.489 --> 00:40:02.130 hurdles for long -duration space travel isn't 00:40:02.130 --> 00:40:05.030 the rocket. It's the fragility of the human body. 00:40:05.210 --> 00:40:08.309 Muscle atrophy in zero -g. Exactly. If you put 00:40:08.309 --> 00:40:10.750 an astronaut in zero gravity for the six to nine 00:40:10.750 --> 00:40:12.650 months it takes to get to Mars, their muscles 00:40:12.650 --> 00:40:15.309 waste away, their bones weaken. They might arrive 00:40:15.309 --> 00:40:17.630 at Mars too weak to even put on their spacesuit 00:40:17.630 --> 00:40:19.309 and walk around. Right. We just aren't built 00:40:19.309 --> 00:40:22.429 for stasis. But bears are. Bears have cracked 00:40:22.429 --> 00:40:25.280 the code. They have figured out how to stay almost 00:40:25.280 --> 00:40:28.739 completely immobile for months on end and keep 00:40:28.739 --> 00:40:31.440 their muscle mass, their bone density, and their 00:40:31.440 --> 00:40:34.679 organ function perfectly intact. They hold the 00:40:34.679 --> 00:40:37.219 biological blueprint for a safe form of suspended 00:40:37.219 --> 00:40:39.380 animation. So you're saying? I'm saying that 00:40:39.380 --> 00:40:41.880 if medical science can fully unlock the bear's 00:40:41.880 --> 00:40:44.579 secret, if we can figure out how to trigger that 00:40:44.579 --> 00:40:48.019 super relaxed myosin state and that nitrogen 00:40:48.019 --> 00:40:51.199 recycling loop in humans, it changes everything. 00:40:51.480 --> 00:40:53.710 Not just for space travel. Not just for space. 00:40:53.909 --> 00:40:56.010 Think about coma patients not wasting away in 00:40:56.010 --> 00:40:58.510 a hospital bed. Think about the elderly maintaining 00:40:58.510 --> 00:41:00.469 their strength while they're bedridden after 00:41:00.469 --> 00:41:02.889 a fall. The potential applications for human 00:41:02.889 --> 00:41:05.650 health are staggering. The key to our future 00:41:05.650 --> 00:41:07.989 in the stars might be sleeping in a cave right 00:41:07.989 --> 00:41:09.789 now. We just have to be smart enough to learn 00:41:09.789 --> 00:41:11.769 from them rather than just fearing them or turning 00:41:11.769 --> 00:41:14.389 them into toys. That is a fascinating place to 00:41:14.389 --> 00:41:16.530 end. From the brown one to the astronaut's guide 00:41:16.530 --> 00:41:19.630 to the galaxy. Thank you for listening to this 00:41:19.630 --> 00:41:21.929 deep dive. We'll catch you on the next one. Keep 00:41:21.929 --> 00:41:25.829 exploring. Welcome to the debate. Today, we're 00:41:25.829 --> 00:41:27.869 looking at a creature that seems to hold this 00:41:27.869 --> 00:41:31.989 very specific, almost primal place in the human 00:41:31.989 --> 00:41:36.369 imagination. The bear. When you picture a grizzly 00:41:36.369 --> 00:41:39.130 standing on its hind legs, I mean, eight feet 00:41:39.130 --> 00:41:41.909 of muscle, claws the length of your fingers, 00:41:42.030 --> 00:41:44.869 a head the size of a boulder, you are looking 00:41:44.869 --> 00:41:47.210 at what appears to be the ultimate expression 00:41:47.210 --> 00:41:50.610 of biological power. To me, the family Ursidae 00:41:50.610 --> 00:41:53.590 is... It's the tank of the animal kingdom. It 00:41:53.590 --> 00:41:56.670 is the apex pinnacle of the order carnivora. 00:41:57.070 --> 00:42:01.769 But is that actually true? Or is the bear, as 00:42:01.769 --> 00:42:04.349 we're going to discuss, essentially a biological 00:42:04.349 --> 00:42:07.670 misunderstanding? Misunderstanding is a very 00:42:07.670 --> 00:42:10.829 polite way to put it. I look at that same grizzly 00:42:10.829 --> 00:42:14.010 and I don't see a tank at all. I see a creature 00:42:14.010 --> 00:42:16.610 that is frankly barely holding itself together. 00:42:17.280 --> 00:42:19.440 It's an animal that's trying to be three different 00:42:19.440 --> 00:42:22.619 things at once and while failing at most of them. 00:42:22.739 --> 00:42:25.460 To me, the bear isn't a masterpiece of evolution. 00:42:25.619 --> 00:42:28.699 It's a hack. It's an evolutionary improvisation 00:42:28.699 --> 00:42:31.280 that somehow manages to survive despite breaking 00:42:31.280 --> 00:42:34.219 every single rule in the book. That is a staggering 00:42:34.219 --> 00:42:36.619 claim for an animal that has conquered, I mean, 00:42:36.619 --> 00:42:39.179 pretty much the entire northern hemisphere. Is 00:42:39.179 --> 00:42:41.639 it, though? Think about how we even talk about 00:42:41.639 --> 00:42:45.440 them. The word bear itself is a clue. It comes 00:42:45.440 --> 00:42:48.269 from the Old English bara. which, you know, likely 00:42:48.269 --> 00:42:51.449 just means the brown one. It's a euphemism. The 00:42:51.449 --> 00:42:54.070 proto -dramatic tribes were apparently so terrified 00:42:54.070 --> 00:42:56.550 of this animal that they believed if you spoke 00:42:56.550 --> 00:42:59.949 its true name, Arcto, it would actually summon 00:42:59.949 --> 00:43:02.550 the beast out of the woods. So even our language 00:43:02.550 --> 00:43:05.070 is based on this deep -seated fear and avoidance. 00:43:05.130 --> 00:43:07.750 We treat it like a monster because we're scared 00:43:07.750 --> 00:43:10.070 of it. But when you strip away the fear and you 00:43:10.070 --> 00:43:12.530 look at the actual physiology, the quote -unquote 00:43:12.530 --> 00:43:17.159 monster is, well... See, I think that fear proves 00:43:17.159 --> 00:43:20.139 my point entirely. We don't create linguistic 00:43:20.139 --> 00:43:22.900 taboos around weak animals, we create them around 00:43:22.900 --> 00:43:25.420 forces of nature, and that is what a bear is. 00:43:25.599 --> 00:43:28.679 It is the most massive extant terrestrial member 00:43:28.679 --> 00:43:31.800 of the carnivora. That isn't an accident. Evolution 00:43:31.800 --> 00:43:34.800 favored mass and power because it works. And 00:43:34.800 --> 00:43:37.179 when you look at the skeletal morphology, you 00:43:37.179 --> 00:43:39.659 aren't seeing a hack. You are seeing a machine 00:43:39.659 --> 00:43:43.159 built for absolute leverage. massive skulls, 00:43:43.159 --> 00:43:46.380 thick, dense limb bones, just designed to support 00:43:46.380 --> 00:43:49.360 immense bulk. This is a creature built to dominate 00:43:49.360 --> 00:43:52.460 its environment through sheer brute force. Brute 00:43:52.460 --> 00:43:55.699 force is a great strategy if you're a rock falling 00:43:55.699 --> 00:43:58.820 down a hill. But for a complex mammal, it's just 00:43:58.820 --> 00:44:01.659 inefficient. And you call them the pinnacle of 00:44:01.659 --> 00:44:05.019 carnivora, but that label is incredibly misleading 00:44:05.019 --> 00:44:07.739 for how these animals actually live. I mean, 00:44:07.739 --> 00:44:10.280 if the bear is the perfect predator, Explain 00:44:10.280 --> 00:44:13.239 the giant panda to me. Here you have an animal 00:44:13.239 --> 00:44:15.760 with the digestive system of a wolf, a single 00:44:15.760 --> 00:44:18.780 stomach, short intestines, genes specifically 00:44:18.780 --> 00:44:21.679 coded for meat digestion, and yet it sits there 00:44:21.679 --> 00:44:25.440 eating 99 % bamboo. That is not a tank. That 00:44:25.440 --> 00:44:28.420 is a physiological paradox. It's a carnivore 00:44:28.420 --> 00:44:30.989 trying its best to be a cow. Okay, but the panda 00:44:30.989 --> 00:44:33.789 is the extreme outlier. You can't judge the whole 00:44:33.789 --> 00:44:36.090 family by its weirdest cousin. But the inefficiency 00:44:36.090 --> 00:44:39.309 is there across the entire family. It's not just 00:44:39.309 --> 00:44:42.789 the panda. Look at the sloth bear. It lost its 00:44:42.789 --> 00:44:45.929 two front upper teeth just so it can act like 00:44:45.929 --> 00:44:48.690 a vacuum cleaner for termites. And look at how 00:44:48.690 --> 00:44:51.130 they move. This, for me, is the smoking gun. 00:44:51.329 --> 00:44:54.429 Cats and dogs are digitigrade. They run on their 00:44:54.429 --> 00:44:57.070 toes. That's what gives a sprinter that explosive 00:44:57.070 --> 00:45:00.340 speed, right? It lengthens the leg lever. Bears, 00:45:00.500 --> 00:45:03.280 they are plantigrade. They walk flat -footed, 00:45:03.280 --> 00:45:06.139 on their heels, just like a human wearing snowshoes. 00:45:06.219 --> 00:45:08.639 It makes them lumbering. It makes them energy 00:45:08.639 --> 00:45:11.239 inefficient. My whole argument is that bears 00:45:11.239 --> 00:45:13.400 are successful not because they are perfect predators, 00:45:13.579 --> 00:45:16.119 but because they are generalist survivors. They're 00:45:16.119 --> 00:45:18.940 running herbivore software on carnivore hardware. 00:45:19.199 --> 00:45:21.659 I think you're confusing specialization with 00:45:21.659 --> 00:45:24.139 failure. But let's actually open up the hood, 00:45:24.239 --> 00:45:26.260 because I want to challenge you on this carnivore 00:45:26.260 --> 00:45:28.820 hardware point. You think their digestion is 00:45:28.820 --> 00:45:31.659 a mistake. I think it's a very calculated trade 00:45:31.659 --> 00:45:34.300 -off. It's hard to see the calculation when you 00:45:34.300 --> 00:45:36.780 look at the gut. I mean, let's get technical 00:45:36.780 --> 00:45:40.539 for a second. A true herbivore, like a cow or 00:45:40.539 --> 00:45:44.280 a deer, has a massive fermentation vat, a rumen, 00:45:44.280 --> 00:45:47.980 or a huge cecum, where bacteria spend days breaking 00:45:47.980 --> 00:45:50.760 down tough plant cellulose into usable energy. 00:45:51.340 --> 00:45:54.519 Bears don't have that. They have a sleek, simple 00:45:54.519 --> 00:45:58.539 carnivore gut. No cecum, short intestines, food 00:45:58.539 --> 00:46:01.940 goes in, and it shoots out in just a few hours. 00:46:02.800 --> 00:46:04.940 Evolutionarily speaking, a bear eating grass 00:46:04.940 --> 00:46:07.619 is like trying to fuel a Ferrari with lawn clippings. 00:46:07.659 --> 00:46:10.440 The engine just isn't built for the fuel. That's 00:46:10.440 --> 00:46:12.960 one way to view it. But here's the other perspective. 00:46:13.260 --> 00:46:16.380 Because they lack that fermentation vat, they 00:46:16.380 --> 00:46:19.099 aren't weighed down by it. A cow has to sit there 00:46:19.099 --> 00:46:22.800 and chew cud for hours on end. A bear is mobile. 00:46:23.210 --> 00:46:25.550 And because its gut is simple, it can process 00:46:25.550 --> 00:46:28.789 vast volumes of food very, very rapidly. It's 00:46:28.789 --> 00:46:31.750 a volume strategy. They are what we call low 00:46:31.750 --> 00:46:34.670 -protein macronutrient omnivores. They don't 00:46:34.670 --> 00:46:37.889 just graze mindlessly. They target high -value 00:46:37.889 --> 00:46:40.980 resources. They high -grade their food. But they 00:46:40.980 --> 00:46:42.880 have to high -grade because their system is so 00:46:42.880 --> 00:46:45.280 bad at extracting nutrients. The panda has to 00:46:45.280 --> 00:46:48.380 eat for 12 to 15 hours a day just to not starve 00:46:48.380 --> 00:46:51.119 to death. It relies on its gut microbiome to 00:46:51.119 --> 00:46:53.480 do work that its own body physically cannot do. 00:46:53.719 --> 00:46:57.019 And yet, look at the brown bear. It dominates 00:46:57.019 --> 00:46:59.820 the salmon runs. When a bear is eating salmon, 00:46:59.980 --> 00:47:02.920 it's not eating the whole fish. It's eating the 00:47:02.920 --> 00:47:07.059 skin, the brain, the eggs, the highest fat content, 00:47:07.139 --> 00:47:10.349 and just discarding the rest. That is intelligence. 00:47:10.610 --> 00:47:13.550 They use their massive size, that tank frame 00:47:13.550 --> 00:47:16.349 you talked about, to monopolize the best food 00:47:16.349 --> 00:47:19.849 sources so they don't need a complex gut. They 00:47:19.849 --> 00:47:22.869 substitute efficiency with dominance. When you 00:47:22.869 --> 00:47:25.789 see Asiatic blackbeers in Taiwan switching between 00:47:25.789 --> 00:47:28.809 acorns and hunting ungulates, they aren't confused. 00:47:28.989 --> 00:47:31.829 They are maximizing their caloric intake based 00:47:31.829 --> 00:47:35.019 on what's available. Maximizing implies they 00:47:35.019 --> 00:47:38.300 have a choice. I would argue they're in a constant 00:47:38.300 --> 00:47:41.860 state of nutritional panic. If the acorn crop 00:47:41.860 --> 00:47:44.500 fails, that bear is in big trouble because it 00:47:44.500 --> 00:47:47.179 can't simply switch to grazing on grass like 00:47:47.179 --> 00:47:49.760 a deer can, and it's not efficient enough to 00:47:49.760 --> 00:47:52.380 hunt mice like a fox. It's stuck in the middle. 00:47:52.500 --> 00:47:55.320 The only reason the system works at all is because 00:47:55.320 --> 00:47:57.619 they just throw massive amounts of food into 00:47:57.619 --> 00:47:59.559 the hopper. But let's go back to the movement. 00:47:59.639 --> 00:48:02.030 You mentioned the tank frame. Right, the dense 00:48:02.030 --> 00:48:05.750 bones, the power. But at what cost? You have 00:48:05.750 --> 00:48:08.550 this heavy, flat -footed animal. We establish 00:48:08.550 --> 00:48:10.929 they are plantigrade, walking on their heels. 00:48:11.389 --> 00:48:14.409 That provides stability, sure, but it sacrifices 00:48:14.409 --> 00:48:17.489 speed and endurance. A wolf can trot for miles 00:48:17.489 --> 00:48:20.429 without tiring. A bear has to expend significantly 00:48:20.429 --> 00:48:23.429 more energy just to move its own mass from point 00:48:23.429 --> 00:48:27.190 A to point B. They tire very quickly. And this 00:48:27.190 --> 00:48:29.590 forces them into a hunting style that relies 00:48:29.590 --> 00:48:32.269 on ambush or brute force because they physically 00:48:32.269 --> 00:48:35.070 cannot sustain a chase. They are chemically incapable 00:48:35.070 --> 00:48:38.690 of being a pursuit predator. I disagree that 00:48:38.690 --> 00:48:42.090 it's a disadvantage. The plantigrade foot allows 00:48:42.090 --> 00:48:45.869 for something a wolf can never do. Bipedalism. 00:48:46.070 --> 00:48:49.349 A bear can stand up, it can fight on two legs, 00:48:49.489 --> 00:48:52.230 it can reach fruit high in trees, and it frees 00:48:52.230 --> 00:48:55.559 up the front paws for manipulation. A wolf interacts 00:48:55.559 --> 00:48:58.300 with the world with its mouth. A bear interacts 00:48:58.300 --> 00:49:01.079 with its hands. You mentioned the panda earlier. 00:49:01.400 --> 00:49:04.599 It developed a pseudo -thumb, a bony extension 00:49:04.599 --> 00:49:08.340 of the wrist, just to strip bamboo. That is evolutionary 00:49:08.340 --> 00:49:11.380 brilliance. It's tool use without the tool. It's 00:49:11.380 --> 00:49:13.699 a wrist bone acting like a thumb because they 00:49:13.699 --> 00:49:16.119 don't have a real one. That's exactly what I 00:49:16.119 --> 00:49:18.960 mean by a hack. But look at the history here. 00:49:19.099 --> 00:49:22.210 The ancestors of bears, like Urcevas. were these 00:49:22.210 --> 00:49:25.550 small raccoon -sized things. As the lineage evolved, 00:49:25.849 --> 00:49:28.809 they just got bigger and heavier, but they kept 00:49:28.809 --> 00:49:31.769 the same basic body plan. The extinct short -faced 00:49:31.769 --> 00:49:35.070 bear, Arctodus, was a giant, but even it had 00:49:35.070 --> 00:49:37.769 to specialize to survive. And the cave bear, 00:49:37.969 --> 00:49:41.030 Ursus spileus? It evolved these massive teeth 00:49:41.030 --> 00:49:44.010 for grinding plants, got huge, and then went 00:49:44.010 --> 00:49:46.250 extinct the moment the climate shifted because 00:49:46.250 --> 00:49:48.949 it had painted itself into a corner. The tank 00:49:48.949 --> 00:49:51.809 strategy is risky. If you are big and slow, you 00:49:51.809 --> 00:49:54.369 need a lot of food. And if the food moves or 00:49:54.369 --> 00:49:57.590 disappears, you die. And yet the family Ursidae 00:49:57.590 --> 00:50:01.090 is still here. The cave bear is gone, yes, but 00:50:01.090 --> 00:50:03.489 the brown bear remains? The polar bear remains. 00:50:03.809 --> 00:50:06.909 And speaking of the polar bear, Ursus maritimus, 00:50:07.050 --> 00:50:09.750 this really is the checkmate to your bad design 00:50:09.750 --> 00:50:13.030 argument. Here is an animal that took that generalist 00:50:13.030 --> 00:50:15.429 frame and moved into the harshest environment 00:50:15.429 --> 00:50:18.909 on Earth. It returned to pure carnivory. It hunts 00:50:18.909 --> 00:50:21.610 seals on sea ice. It proves that the underlying 00:50:21.610 --> 00:50:24.469 machinery is predatory. When the environment 00:50:24.469 --> 00:50:26.570 demanded it, the bear didn't become a better 00:50:26.570 --> 00:50:29.070 herbivore. It became the ultimate carnivore. 00:50:29.150 --> 00:50:31.369 Or as it suggests, that the polar bear is the 00:50:31.369 --> 00:50:33.829 only one actually using the machinery for what 00:50:33.829 --> 00:50:36.349 it was designed for, while the rest of the family 00:50:36.349 --> 00:50:37.929 is just, you know, pretending to be vegetarian. 00:50:38.559 --> 00:50:40.579 But even the polar bear is struggling now that 00:50:40.579 --> 00:50:43.039 the ice is melting. It's hyper -specialized. 00:50:43.199 --> 00:50:45.599 But I want to talk about how they survive the 00:50:45.599 --> 00:50:47.980 times when there is no food, because this is 00:50:47.980 --> 00:50:50.659 usually the part where people say, but hibernation 00:50:50.659 --> 00:50:53.340 is a superpower. Because it is a superpower. 00:50:53.579 --> 00:50:56.559 You cannot just dismiss hibernation. It is a 00:50:56.559 --> 00:50:59.420 metabolic masterpiece. We're talking about an 00:50:59.420 --> 00:51:02.679 animal the size of a grand piano that can shut 00:51:02.679 --> 00:51:05.800 down its body for five to seven months. This 00:51:05.800 --> 00:51:08.980 isn't just a nap. It is a physiological state 00:51:08.980 --> 00:51:12.639 that frankly defies medical understanding. It's 00:51:12.639 --> 00:51:15.860 a desperate cope for caloric inefficiency. Hold 00:51:15.860 --> 00:51:18.440 on. Let me explain the mechanics before you dismiss 00:51:18.440 --> 00:51:21.480 it. Their heart rate drops from 55 beats per 00:51:21.480 --> 00:51:24.599 minute to as low as 9. But the real magic is 00:51:24.599 --> 00:51:26.960 the chemistry. They don't urinate or defecate 00:51:26.960 --> 00:51:29.559 for months. If a human did that, we would die 00:51:29.559 --> 00:51:32.349 of uremic poisoning in a week. The bear takes 00:51:32.349 --> 00:51:35.230 that toxic urea, breaks it down, and recycles 00:51:35.230 --> 00:51:37.250 the nitrogen back into protein to maintain its 00:51:37.250 --> 00:51:39.769 muscle mass. It is a closed -loop biological 00:51:39.769 --> 00:51:42.969 recycling plant. They use a super relaxed state 00:51:42.969 --> 00:51:45.409 of the protein myosin in their muscles so they 00:51:45.409 --> 00:51:47.809 don't atrophy. They wake up in spring almost 00:51:47.809 --> 00:51:50.090 as strong as when they went to sleep. No other 00:51:50.090 --> 00:51:52.690 large mammal can do this. I'll grant you, the 00:51:52.690 --> 00:51:55.190 chemistry is impressive. But you have to ask 00:51:55.190 --> 00:51:57.880 yourself why they have to do it. They have to 00:51:57.880 --> 00:52:01.079 do it because they are too big and too inefficient 00:52:01.079 --> 00:52:05.099 to survive the winter any other way. A wolf doesn't 00:52:05.099 --> 00:52:08.260 hibernate. A moose doesn't hibernate. They have 00:52:08.260 --> 00:52:11.219 strategies to find food in the snow. The bear's 00:52:11.219 --> 00:52:13.920 strategy is basically, I give up, I'm going to 00:52:13.920 --> 00:52:17.300 sleep until the salad bar opens again. And interestingly, 00:52:17.539 --> 00:52:20.400 that tank size you love so much is actually a 00:52:20.400 --> 00:52:23.219 problem here. Research shows that smaller bears 00:52:23.219 --> 00:52:25.900 can hibernate more efficiently than the massive 00:52:25.900 --> 00:52:28.909 ones. A grizzly has so much thermal inertia, 00:52:29.190 --> 00:52:32.250 it holds heat so well, that it actually struggles 00:52:32.250 --> 00:52:34.530 to lower its body temperature enough to get the 00:52:34.530 --> 00:52:37.230 full metabolic savings. It's like trying to cool 00:52:37.230 --> 00:52:39.929 down a nuclear reactor just to save fuel. It's 00:52:39.929 --> 00:52:42.710 hard work. But it works. They survive the season 00:52:42.710 --> 00:52:44.909 of death. And when they wake up, they navigate 00:52:44.909 --> 00:52:47.469 the world with a sensory apparatus that is just 00:52:47.469 --> 00:52:51.170 unparalleled. The bear's sense of smell is superior 00:52:51.170 --> 00:52:53.750 to that of a bloodhound. They can detect a carcass 00:52:53.750 --> 00:52:56.920 from kilometers away. Polar bears use scent tracks 00:52:56.920 --> 00:52:59.239 on the ice to find each other in a white void. 00:52:59.579 --> 00:53:01.980 You call them a hack, but they are operating 00:53:01.980 --> 00:53:04.960 with a guidance system that is military grade. 00:53:05.219 --> 00:53:09.360 They are operating with one good sensor. They 00:53:09.360 --> 00:53:12.960 are essentially a giant nose on four legs. Have 00:53:12.960 --> 00:53:15.099 you noticed they don't have whiskers? They are 00:53:15.099 --> 00:53:18.119 unique among carnivores in that regard. Their 00:53:18.119 --> 00:53:21.139 sight is poor. Their hearing is average. They 00:53:21.139 --> 00:53:23.860 sort of stumble through the world led by olfactory 00:53:23.860 --> 00:53:26.320 cues because their other senses just aren't sharp 00:53:26.320 --> 00:53:29.280 enough to hunt like a cat. A cougar uses sight 00:53:29.280 --> 00:53:32.659 and hearing to pinpoint prey. A bear sniffs around 00:53:32.659 --> 00:53:35.199 until it bumps into something edible. It's a 00:53:35.199 --> 00:53:38.480 brute force application of sensory input. A nose 00:53:38.480 --> 00:53:41.340 that can find a seal under a meter of hard -packed 00:53:41.340 --> 00:53:44.920 snow is not brute force. That is precision. But 00:53:44.920 --> 00:53:47.260 I want to pivot to their mind, their behavior. 00:53:47.869 --> 00:53:50.309 Because this is where the apex title is truly 00:53:50.309 --> 00:53:54.190 earned. They are solitary, powerful individualists. 00:53:54.889 --> 00:53:58.369 Asocial is the word I would probably use. Intelligent 00:53:58.369 --> 00:54:00.769 carnivores like wolves need a pack. They need 00:54:00.769 --> 00:54:03.829 a support system. A bear is a single unit of 00:54:03.829 --> 00:54:06.570 dominance. It doesn't need help. When two bears 00:54:06.570 --> 00:54:08.690 meet, they assert dominance through what's called 00:54:08.690 --> 00:54:11.889 frontal orientation, showing the canines, stretching 00:54:11.889 --> 00:54:14.849 the neck. It's honest signaling. They don't rely 00:54:14.849 --> 00:54:17.409 on the complexity of a hierarchy. They rely on 00:54:17.409 --> 00:54:20.010 the reality of their own strength. That solitary 00:54:20.010 --> 00:54:22.849 nature is a weakness, though. It limits what 00:54:22.849 --> 00:54:26.269 it can do. A pack of wolves can take down a bison. 00:54:26.449 --> 00:54:29.510 A single bear has to be much, much more careful. 00:54:29.789 --> 00:54:32.690 And it makes them fragile. If a wolf breaks a 00:54:32.690 --> 00:54:35.010 leg, the pack might feed it. If a bear breaks 00:54:35.010 --> 00:54:38.489 a leg, it dies. That solitude dictates a life 00:54:38.489 --> 00:54:41.719 of extreme caution. Most bear interactions are 00:54:41.719 --> 00:54:43.960 just avoidance. They spend their entire lives 00:54:43.960 --> 00:54:46.739 trying not to fight because a fight is just too 00:54:46.739 --> 00:54:50.380 expensive. And we should probably talk about 00:54:50.380 --> 00:54:53.679 the dark side of that individualism. Infanticide. 00:54:54.039 --> 00:54:56.980 It's a brutal topic, but it's biologically significant. 00:54:57.519 --> 00:55:00.099 Male brown and polar bears will kill cubs to 00:55:00.099 --> 00:55:03.099 bring the female back into estrus. It's horrific 00:55:03.099 --> 00:55:06.949 efficiency. It is evolutionary strategy. It shows 00:55:06.949 --> 00:55:09.389 a drive for genetic dominance that overrides 00:55:09.389 --> 00:55:12.690 any sort of social niceties. The male is ensuring 00:55:12.690 --> 00:55:16.050 his genes propagate. It's not nice, but nature 00:55:16.050 --> 00:55:19.989 isn't nice. It's effective. It's primitive. Social 00:55:19.989 --> 00:55:22.389 carnivores have moved past that. They raise young 00:55:22.389 --> 00:55:25.670 communally. But I will concede that bears aren't 00:55:25.670 --> 00:55:29.090 purely robotic monsters. We see spectacled bears 00:55:29.090 --> 00:55:31.670 in South America communicating with facial markings. 00:55:31.869 --> 00:55:34.210 We see aggregations at salmon runs where they 00:55:34.210 --> 00:55:36.420 tolerate each other. And obviously the mother 00:55:36.420 --> 00:55:39.280 -cub bond is fierce. But it's fleeting. Once 00:55:39.280 --> 00:55:41.980 those cubs are gone, they are back to being lonely 00:55:41.980 --> 00:55:45.260 wanderers. They are wanderers because they require 00:55:45.260 --> 00:55:48.260 vast territories to fuel that massive engine. 00:55:48.639 --> 00:55:50.940 Which brings us right back to the central question. 00:55:51.360 --> 00:55:53.480 You see collection of parts that don't quite 00:55:53.480 --> 00:55:57.000 fit. A carnivore gut. A herbivore diet. Flat 00:55:57.000 --> 00:56:01.340 feet. A solitary life. I see a synthesis. I see 00:56:01.340 --> 00:56:04.039 an animal that took a different path. It diverged 00:56:04.039 --> 00:56:06.199 from the dog -like ancestors 20 million years 00:56:06.199 --> 00:56:08.699 ago and just decided to maximize size and durability 00:56:08.699 --> 00:56:12.139 over speed. And I still maintain they are evolutionary 00:56:12.139 --> 00:56:15.559 tinkerers. They are the jack of all trades, master 00:56:15.559 --> 00:56:18.260 of none. They can climb, but not like a monkey. 00:56:18.519 --> 00:56:21.239 They can swim, but not like a seal. They can 00:56:21.239 --> 00:56:23.619 hunt, but not like a wolf. And they can eat grass, 00:56:23.800 --> 00:56:26.920 but not like a cow. They are successful because 00:56:26.920 --> 00:56:29.820 they are stubborn, not because they are perfected. 00:56:30.019 --> 00:56:32.380 Well, maybe stubbornness is just another word 00:56:32.380 --> 00:56:35.320 for resilience. Whether it is the polar bear 00:56:35.320 --> 00:56:38.099 on the ice or the sloth bear sucking up termites, 00:56:38.239 --> 00:56:41.639 the family Ursidae finds a way to impose its 00:56:41.639 --> 00:56:44.659 bulk on the world. They are the heavyweights. 00:56:44.659 --> 00:56:48.500 They are the great bears. They are certainly 00:56:48.500 --> 00:56:51.440 unique. I mean, there is nothing else quite like 00:56:51.440 --> 00:56:54.250 them on Earth. And that uniqueness, I think, 00:56:54.269 --> 00:56:57.969 we have to note, is fragile. We should say that 00:56:57.969 --> 00:57:01.190 despite being these tanks, six of the eight bear 00:57:01.190 --> 00:57:04.429 species are listed as vulnerable. Even the brown 00:57:04.429 --> 00:57:06.550 bear faces extinction in parts of its range. 00:57:06.769 --> 00:57:10.050 It is a sobering reality. The great bear, Ursa 00:57:10.050 --> 00:57:13.369 Major, has been in our mists for 13 ,000 years. 00:57:13.889 --> 00:57:16.570 The cosmic hunt mists appear on both sides of 00:57:16.570 --> 00:57:18.750 the Bering land bridge. We have looked up at 00:57:18.750 --> 00:57:20.969 the stars and seen a bear for as long as we have 00:57:20.969 --> 00:57:23.820 been human. That myth might outlast the animal 00:57:23.820 --> 00:57:26.519 if we aren't careful. Habitat loss, the trade 00:57:26.519 --> 00:57:29.079 in bear bile, climate change, these are threats 00:57:29.079 --> 00:57:31.380 that brute force cannot solve. The tank armor 00:57:31.380 --> 00:57:33.780 doesn't stop a bullet or a shrinking ice cap. 00:57:34.000 --> 00:57:37.219 A tragedy we must work to prevent. I hope this 00:57:37.219 --> 00:57:39.920 debate has shifted your perspective, even slightly, 00:57:40.139 --> 00:57:42.699 on what is happening inside that massive frame. 00:57:43.059 --> 00:57:45.360 It has. And for those listeners who want to see 00:57:45.360 --> 00:57:47.440 what a perfect predator bear might have looked 00:57:47.440 --> 00:57:50.340 like, one that actually followed the rules, I 00:57:50.340 --> 00:57:53.539 really encourage you to look up the extinct Hemisoninae, 00:57:53.659 --> 00:57:56.219 the running bears. These were bears that stayed 00:57:56.219 --> 00:57:58.599 on their toes. They chased prey like wolves. 00:57:58.699 --> 00:58:00.980 It's a fascinating glimpse of the road not taken. 00:58:01.139 --> 00:58:04.099 The bear that could have been. Thank you for 00:58:04.099 --> 00:58:06.019 listening. Welcome to the debate.