WEBVTT - Cat Parasites Conquer the World 0:00:03.800 --> 0:00:06.680 Welcome to Stuff to Blow your Mind from how Stuff 0:00:06.680 --> 0:00:13.440 Works dot com. Hey, you're welcot the Stuff to Blow 0:00:13.440 --> 0:00:16.240 your Mind. Mym is Robert Lamb, and I'm Julie Douglas. Julie. 0:00:16.239 --> 0:00:19.239 The more we discuss the world and the way it 0:00:19.320 --> 0:00:22.880 works and the way we perceive it, the more labyrinthine 0:00:22.920 --> 0:00:26.439 it confused. Yeah. Yeah, the more layers that you feel away, 0:00:26.480 --> 0:00:29.040 the more layers you find underneath. Right, right, you look 0:00:29.080 --> 0:00:30.760 back on a time pretty much like the post War 0:00:30.800 --> 0:00:32.600 War two era, Like that was the time when it 0:00:32.760 --> 0:00:35.000 was all this optimism that we had things more or 0:00:35.080 --> 0:00:37.360 less figured out, that we were venturing into this age 0:00:37.360 --> 0:00:40.879 where everything's gonna make sense. Diseases, we're going to defeat space, 0:00:40.960 --> 0:00:44.440 we're going to travel. Everything was within our grasp. And 0:00:44.479 --> 0:00:47.640 then we started learning more and more and things become 0:00:47.720 --> 0:00:50.120 just more and more complicated. I mean, that's kind of 0:00:50.120 --> 0:00:53.440 a simplification, but but that's kind of the the story 0:00:53.479 --> 0:00:56.560 shaped version of it. And yeah, it seemed like science 0:00:56.720 --> 0:00:59.279 was emerging to the degree where we could really get 0:00:59.280 --> 0:01:02.760 a handle on things. And you know, psychologically we had 0:01:02.800 --> 0:01:06.360 Freud and Young and we're really trying to be introspective 0:01:06.360 --> 0:01:10.080 and say, ah, yes, this is what drives human beings, right, 0:01:10.280 --> 0:01:12.880 and it seems that humans were the lords of the Earth, 0:01:12.920 --> 0:01:15.280 that we this was our planet, we had it not, 0:01:15.680 --> 0:01:18.280 and we were going to be the poster children of 0:01:18.360 --> 0:01:21.880 this planet moving forward. But the topic we're going to 0:01:21.920 --> 0:01:24.160 talk about today really sheds a light on just one 0:01:24.160 --> 0:01:27.440 of the areas where humans are not the top dogs. 0:01:27.520 --> 0:01:30.800 The topic that really illuminates how the organisms that operate 0:01:31.240 --> 0:01:33.480 in the shadows, and at a much smaller level, it 0:01:33.600 --> 0:01:36.680 may just be the rulers of the planet, right, the 0:01:37.200 --> 0:01:40.679 organisms inside of us. And we've actually talked about this before, 0:01:40.840 --> 0:01:43.440 whether or not we actually have free will, And we've 0:01:43.440 --> 0:01:46.399 talked about this from a psychological perspective like, oh, did 0:01:46.440 --> 0:01:48.840 you know that a lot of people who are named 0:01:49.120 --> 0:01:52.720 Denise tend to be dentists or Dennists tend to be dentists. 0:01:52.760 --> 0:01:57.000 And this was in David Eagleman's book, right recent book Incognito, 0:01:57.080 --> 0:02:00.240 that talked about all these sort of subtle machination is 0:02:00.240 --> 0:02:03.480 going on that really informed our worldview and the decisions 0:02:03.480 --> 0:02:06.880 we make. But we've also talked about little critters and 0:02:07.040 --> 0:02:10.080 how how we may actually just be you know, walking 0:02:10.240 --> 0:02:13.880 transportation for these guys, so that we we can just 0:02:13.919 --> 0:02:17.880 spread critters among the earth. And this has become even 0:02:17.919 --> 0:02:21.440 more apparent recently with a recent article that's been in 0:02:21.480 --> 0:02:25.359 the news. I believe that the the name of it 0:02:25.400 --> 0:02:28.760 is how your cat is Making You Crazy? And this 0:02:28.800 --> 0:02:32.000 is by Kathleen Mcaliffe and this was in the March 0:02:32.840 --> 0:02:35.720 edition of The Atlantic. Yeah, this of course deals with 0:02:35.880 --> 0:02:42.480 good old taxo taxo plasma gandhi taxo plasmosis being the infestation. Okay, well, 0:02:42.800 --> 0:02:44.680 and this comes out up every year or two. I 0:02:44.680 --> 0:02:47.239 wrote a bunch about it for Animal Planet a couple 0:02:47.280 --> 0:02:49.560 of years back. Yeah, you you have actually talked about 0:02:49.560 --> 0:02:53.640 this before, but yeah, definitely, there's there's a driving force 0:02:53.840 --> 0:02:56.520 now though around the topic, because there are so many 0:02:56.600 --> 0:02:59.560 different studies that are beginning to support this idea that 0:02:59.680 --> 0:03:03.160 this our side is doing some really crazy Shenanigan stuff 0:03:03.200 --> 0:03:07.000 with not just animals but perhaps even humans. Right, there's 0:03:07.040 --> 0:03:09.400 a simplistic way to think of parasites, and I think 0:03:09.400 --> 0:03:10.840 this is a new way we often think. We we 0:03:10.880 --> 0:03:13.200 think in terms of oh, I have a leech on me, 0:03:13.240 --> 0:03:15.079 Oh I have a mosquito on me, or a gear 0:03:15.120 --> 0:03:18.519 tick or something, and and these are external parasites. But 0:03:18.600 --> 0:03:21.040 the model is simple. There's a weakness in my defense 0:03:21.160 --> 0:03:25.080 is something is stealing energy from me and then moving on. 0:03:25.240 --> 0:03:27.480 It's a blood sucker. Um And that's a that's a 0:03:27.520 --> 0:03:31.440 pretty straightforward con. But something like ke Gandhi. Here T 0:03:31.560 --> 0:03:34.880 Gandhi is playing the long con and and has and 0:03:34.920 --> 0:03:37.320 it's so intricate. I mean, this is like what was 0:03:37.360 --> 0:03:42.080 the Kaiser so say movie, Oh the Unsuspected really usual, 0:03:42.600 --> 0:03:45.800 you know, it's it's like that level of complex plot 0:03:45.840 --> 0:03:48.680 going on where when you begin to see the full 0:03:48.760 --> 0:03:52.200 life cycle of this organism and see the full scheme 0:03:52.400 --> 0:03:54.920 as much of it as we can understand, you really 0:03:54.920 --> 0:03:57.160 odd because it's not just a matter of something, Oh 0:03:57.800 --> 0:03:59.480 you've got a little room for me to live inside you. 0:03:59.520 --> 0:04:01.560 I'm gonna inside you where it's warm. No, it's it's 0:04:01.600 --> 0:04:04.880 it's far more. You're right. If T Gandhi was plain Vegas, 0:04:04.920 --> 0:04:07.600 it would be like the ultimate grifter move what we're 0:04:07.600 --> 0:04:10.920 about to describe. There would be a parasites. Oh yeah, 0:04:10.920 --> 0:04:13.920 well here we go. Okay, So let's talk about T. 0:04:14.080 --> 0:04:18.719 Gandhi Texi Plasmosa Gandhi, and let's talk about what it 0:04:18.960 --> 0:04:22.640 actually is and why it is so fierce. Yes, so 0:04:22.839 --> 0:04:27.440 Toxoplasmosa gandhi is a protozoan parasite and the only known 0:04:27.480 --> 0:04:30.440 definitive hosts for T. Gandhi. That's what we're gonna call 0:04:30.480 --> 0:04:33.640 it from here on out. Our domestic cats in their relatives, 0:04:33.800 --> 0:04:35.680 and that's that's why our feline friends have been in 0:04:35.720 --> 0:04:39.000 the news lately too, and a little bit demonized, which 0:04:39.000 --> 0:04:41.800 we'll talk about later. The cats. Cats, Yeah, yeah, well 0:04:41.839 --> 0:04:44.880 in general they're kind of demon They steal your breath, right, 0:04:45.279 --> 0:04:48.880 that's what they say. But old T. Gandhi here makes 0:04:48.920 --> 0:04:52.800 the cat, the feline. It's primary host. This is where 0:04:52.839 --> 0:04:57.279 it reproduces. This is the the mothership for T. Gandhi, 0:04:57.640 --> 0:05:00.159 but it's life cycle takes it to other creek is 0:05:00.200 --> 0:05:05.080 as well. So this fantastic journey begins inside spaceship cat 0:05:05.839 --> 0:05:09.320 inside the mothership, all right, the new toxoplasma they multiply 0:05:09.560 --> 0:05:11.880 in the lining of an infected cats and testing. Right, 0:05:11.880 --> 0:05:14.480 so the cat eats something, picks up the parasite, right, 0:05:14.720 --> 0:05:17.880 get in the tummy. It reproduces in the cat. It's 0:05:17.880 --> 0:05:20.120 the primary host again, So that's what goes on here. 0:05:20.520 --> 0:05:24.240 And then the toxoplasma young, which are called ship out 0:05:24.640 --> 0:05:28.760 on the feces, okay, um, right, and this is a 0:05:28.839 --> 0:05:34.320 common practice among parasites. That's the outgoing highway from most organisms. 0:05:34.360 --> 0:05:36.599 And that's so if you need to get out, that's 0:05:36.600 --> 0:05:38.640 the way you gotta go. And this is shed for 0:05:38.760 --> 0:05:40.880 like one to two weeks or so, you know, in 0:05:40.920 --> 0:05:43.640 the feces of the cat. In any creature that encounters 0:05:43.880 --> 0:05:49.400 this stowaway laden waist is susceptible to accidental infection. Okay. 0:05:49.560 --> 0:05:52.240 So this means you know, everything from touching a litter box, 0:05:52.440 --> 0:05:56.880 walking around on barefoot, on infected soil, infected water, infected 0:05:56.920 --> 0:06:00.400 garden veggies, where there's poop, there's a way, right. And 0:06:00.440 --> 0:06:02.600 so if you think of a bird or a rodent 0:06:02.680 --> 0:06:06.440 trapesing across a pile of fresh cat poo, then obviously 0:06:06.520 --> 0:06:09.280 that that's a great way for the parasite to hit 0:06:09.360 --> 0:06:12.599 a ride now on say a rat, right, because that's 0:06:12.600 --> 0:06:15.880 what it needs to do. Ultimately, this parasite needs to 0:06:15.920 --> 0:06:19.000 return to a cat, all right, And it really like 0:06:19.080 --> 0:06:21.719 that the rat is very important here. This parasite loves 0:06:21.720 --> 0:06:24.880 the rat. Yes, so the rat also you know some 0:06:24.880 --> 0:06:27.680 some birds things that cats eat. That is it's it's 0:06:27.800 --> 0:06:31.360 ticket back aboard a cat. Somewhere. So now it's aboard 0:06:31.400 --> 0:06:35.400 the rat, the bird, whatever the intermediate host may be. 0:06:35.760 --> 0:06:40.240 And eventually what happens your pet cat corners this intermediate 0:06:40.240 --> 0:06:44.360 host um you know, in your cellar, in your backyard, 0:06:44.440 --> 0:06:48.400 in the neighbor's yard, wherever it happens to do. It's hunting. 0:06:48.960 --> 0:06:50.719 And if you've ever seen your cat with one of 0:06:50.720 --> 0:06:53.320 these animals, you know what happens next. It gobbles it down, 0:06:53.400 --> 0:06:55.240 or gobbles half of it down, and then leaves the 0:06:55.279 --> 0:06:58.360 other half for you to find on your computer day. Yeah. Yeah, 0:06:58.440 --> 0:07:00.200 puts its head on a steak. It says, like what 0:07:00.279 --> 0:07:02.960 I did. But when the cat eats this intermediate host, 0:07:03.360 --> 0:07:07.320 the cycle continues. Now the taxoplasma is in its system anew, 0:07:07.640 --> 0:07:11.040 it is returned to a primary host. Yeah, and so 0:07:11.160 --> 0:07:14.080 this is the coolest thing about this or frightening or 0:07:14.200 --> 0:07:16.680 whatever your perspective is, is that it returns back to 0:07:17.080 --> 0:07:21.880 the cat where those ussis transform into taki a z o. 0:07:22.040 --> 0:07:26.160 It's after ingestion, and that's where it becomes the adult 0:07:26.320 --> 0:07:29.280 version of the parasite. And it's really the only way 0:07:29.280 --> 0:07:31.880 that it can fulfill this life cycle again through the 0:07:31.920 --> 0:07:34.200 cat right just on its own. I mean, the cycle 0:07:34.240 --> 0:07:36.720 is kind of cool, but it's not completely mind blowing 0:07:36.760 --> 0:07:41.320 because obviously cats eat mice and birds, so the circle 0:07:41.400 --> 0:07:46.280 is pretty simple. It's not completely crazy until you start 0:07:46.280 --> 0:07:49.160 getting into the times subtle manipulations that are going on 0:07:49.560 --> 0:07:52.120 inside the intermediate hosts. So when the cycle begins a 0:07:52.160 --> 0:07:54.800 new it's important though, to stress that more than birds 0:07:55.040 --> 0:07:58.120 and and mice are susceptible to this parasite will end 0:07:58.160 --> 0:08:00.800 up in humans. Little does the parasite. There's probably a 0:08:00.840 --> 0:08:02.720 little chance that once it ends up in a human 0:08:03.080 --> 0:08:06.960 that a cat will eat that human. I mean, it 0:08:07.280 --> 0:08:10.480 happens sometimes, but for the most part, feral cat hordes 0:08:10.480 --> 0:08:12.880 are not overwhelming humans on the train as far as 0:08:12.920 --> 0:08:14.440 we know. I don't know this because this could be 0:08:14.480 --> 0:08:16.480 a plot by the cats, you know, to infect a 0:08:16.520 --> 0:08:18.880 subtle defends out through they are, I guess. But but 0:08:18.960 --> 0:08:21.560 for the most part, this is kind of collateral damage. 0:08:21.680 --> 0:08:24.440 The parasite needs to return to the cat. It needs 0:08:24.480 --> 0:08:26.600 to get in a bird or a rat to do so, 0:08:26.960 --> 0:08:30.000 but it'll try pretty much anything. Yeah, So think about 0:08:30.000 --> 0:08:32.720 this parasite it's now taken up you know, home, and 0:08:32.800 --> 0:08:35.720 say like an animal um and the and the tissues 0:08:35.760 --> 0:08:38.320 of an animal usually in the muscle tissues, and these 0:08:38.360 --> 0:08:41.400 little cysts are there, So how can it infect a human? 0:08:41.600 --> 0:08:43.960 You will you could eat undercooked meat of an animal 0:08:44.040 --> 0:08:46.640 that has those those cysts in it. Because I mentioned 0:08:46.679 --> 0:08:49.600 the litter box thing is is an obvious but yeah, yeah, 0:08:49.640 --> 0:08:51.840 there are more subtle ways to yet yet litter box 0:08:51.920 --> 0:08:56.080 even just say stepping on people contaminated soil and then 0:08:56.120 --> 0:08:58.800 accionally like swiping your finger on it and then dipping 0:08:58.800 --> 0:09:00.319 it in your mouth. Right, so think about that. The 0:09:00.360 --> 0:09:02.319 next thing you see children running around barefoot in the 0:09:02.400 --> 0:09:05.320 yard actually kind of creepy. Right. Blood transfusion or organ 0:09:05.360 --> 0:09:09.600 transplantation and transplants centrally from mother to fetus. Now, I'm 0:09:09.600 --> 0:09:12.360 sure that a lot of people have heard about toxoplasmosis 0:09:12.400 --> 0:09:14.880 in terms of pregnant women because that really is a 0:09:14.920 --> 0:09:18.000 concern in the medical community because if a to be 0:09:18.160 --> 0:09:23.160 mother actually were to have toxoplasmosis, she could then transport 0:09:23.200 --> 0:09:27.640 that via the placenta to the fetus, and that really 0:09:27.640 --> 0:09:30.240 can cause a lot of problems, anything from blindness to 0:09:31.080 --> 0:09:34.640 mental disabilities to brain damage. So it's that that's usually 0:09:34.679 --> 0:09:37.240 how people know of this. But okay, let's say that 0:09:37.679 --> 0:09:40.920 it does occupy the brains of a human who is 0:09:41.040 --> 0:09:43.960 not pregnant. And by the way, this is not as 0:09:44.040 --> 0:09:46.439 uncommon as you would think. And actually it is just 0:09:46.480 --> 0:09:48.200 going to hang out there for the rest of your 0:09:48.240 --> 0:09:50.440 life in your body, all right, it's kind of dead 0:09:50.520 --> 0:09:54.720 ended in spaceship human, but it's going to stick around 0:09:55.320 --> 0:09:58.920 very chance that a cat may eat you one day 0:09:58.960 --> 0:10:01.920 exactly that they they finally get the world dominancy that 0:10:01.960 --> 0:10:03.920 they are looking for. Yeah, it is buried in your 0:10:04.000 --> 0:10:06.320 muscle and nerve tissue. And this is not We're not 0:10:06.400 --> 0:10:08.640 talking about like a rare circumstance where oh, they just 0:10:08.679 --> 0:10:10.880 happen to have a cat parasite, because you do have 0:10:10.960 --> 0:10:14.959 some situations where a parasitic infestation in a human is 0:10:15.000 --> 0:10:17.360 kind of a rare occurrence and causes all these problems. 0:10:17.559 --> 0:10:20.160 But the U S inert for Disease Control Prevention estimates 0:10:20.200 --> 0:10:24.600 that twenty two point five of the United States twelve 0:10:24.640 --> 0:10:28.560 and older population currently carries the TOXO parasite and estimates 0:10:28.640 --> 0:10:31.760 run is high as nine in some parts of the world. 0:10:31.960 --> 0:10:36.120 So between thirty and sixty percent of the global population 0:10:36.480 --> 0:10:41.040 is infested. That is an incredible amount of humans infested 0:10:41.080 --> 0:10:45.040 with us, right and you know, just for comparisons sake, 0:10:45.240 --> 0:10:47.440 let me look at France and that's upward to like 0:10:47.520 --> 0:10:51.080 fifty five percent. And again it's a thought because in 0:10:51.200 --> 0:10:53.880 France it's much more common to have uncooked meat or 0:10:53.960 --> 0:10:58.080 you know, still uncooked the uncooked. But that makes it 0:10:58.120 --> 0:11:01.079 sound like they're the frenchmen are running through the fields 0:11:01.080 --> 0:11:05.240 like pulling down cows and horses and deer. Yeah, with 0:11:05.240 --> 0:11:08.040 with big fancy curly mustaches. But no, I mean, you know, 0:11:08.040 --> 0:11:10.199 state tartar are some of the ways that the meat 0:11:10.280 --> 0:11:13.280 is prepared wherever there's a tradition of rare to raw 0:11:13.360 --> 0:11:16.599 meat consumption. So of stick tatar is big in a 0:11:16.720 --> 0:11:19.640 region and domestic cats are around, there's a chance that 0:11:19.640 --> 0:11:22.040 that's going to be higher, right, Or if you live 0:11:22.080 --> 0:11:25.240 in conditions where you're the soil is contaminated quite a 0:11:25.280 --> 0:11:27.560 bit and you don't have say the means to have 0:11:27.600 --> 0:11:31.160 access to clean water, of course, and infanstation rates would 0:11:31.200 --> 0:11:34.480 be much higher. Um. But okay, so there's all this 0:11:34.720 --> 0:11:37.760 data swirling around. Now you know the life cycle of 0:11:38.120 --> 0:11:43.400 texoplasmas gandhi, and do you understand that us humans are 0:11:43.760 --> 0:11:46.200 far more infected than we probably ever knew, Right, So 0:11:46.240 --> 0:11:49.200 what's the big deal. Well, the big deal is that, again, 0:11:49.240 --> 0:11:53.280 the cycle itself, the ideal cycle of cat to rat, 0:11:53.360 --> 0:11:56.880 the cat is pretty straightforward. But these guys trying to 0:11:56.920 --> 0:12:01.200 gain the process because they really once they're in spaceship rat, 0:12:01.720 --> 0:12:04.160 they really want to dock with the mothership again. So 0:12:04.200 --> 0:12:06.839 they essentially pilot this mothership a little and they don't 0:12:06.880 --> 0:12:09.480 completely take the controls. It's not the sort of a 0:12:09.559 --> 0:12:12.920 zombie thing, though, You'll definitely see that situation play out 0:12:12.960 --> 0:12:15.880 in some parasitic infestations, but in this one, it's more 0:12:15.880 --> 0:12:20.520 of a subtle tweaking of the design functions in the rat. Well, 0:12:20.559 --> 0:12:23.319 it actually changes the behavior of the rat. And we're 0:12:23.320 --> 0:12:27.760 talking about here's the rats fear response specifically to cats. Yeah, 0:12:27.880 --> 0:12:29.760 so the rat needs to return to the cats. So 0:12:29.880 --> 0:12:33.880 what can I do as a parasite to to set 0:12:34.000 --> 0:12:38.120 up this encounter to encourage my rat host to wind 0:12:38.200 --> 0:12:40.160 up in the belly of a cat. And indeed, the 0:12:40.200 --> 0:12:43.199 easiest thing is too, well, let's make this prey animal 0:12:43.679 --> 0:12:47.199 less afraid of its number one predator. Yeah, and actually 0:12:47.280 --> 0:12:51.280 let's take up residents and the rats and magdala where 0:12:51.280 --> 0:12:54.160 we know that you know, motions like fear are hanging 0:12:54.160 --> 0:12:57.440 out and let's do a little neural rewiring. Right, So 0:12:57.520 --> 0:13:02.440 this is like oceans eleven um parasites eleven. The they're 0:13:02.440 --> 0:13:06.120 sneaking into the into the control mainframe to try and 0:13:06.440 --> 0:13:08.480 mess with the security system. Okay, And so if you 0:13:08.520 --> 0:13:10.640 think that, we're completely nuts, so we just made all 0:13:10.640 --> 0:13:14.000 this up again that the article in the Atlantic is 0:13:14.040 --> 0:13:16.400 great in talking about this more specifically. And there are 0:13:16.440 --> 0:13:18.840 a ton of studies, one of which was conducted by 0:13:18.920 --> 0:13:24.440 Joanne Webster. She's a parasitologist at Imperial College, London, and 0:13:24.559 --> 0:13:27.240 she took it an enclosure with rats, and she treated 0:13:27.280 --> 0:13:30.800 one corner of each enclosure with the animal's own order 0:13:30.920 --> 0:13:33.800 odor excuse me, a second with water, a third with 0:13:33.880 --> 0:13:36.200 cat urine, in the last corner with the urine of 0:13:36.200 --> 0:13:38.679 a rabbit. Okay, so this is not a creature that 0:13:38.720 --> 0:13:41.560 prays on rodents, right. She said, we thought the parasite 0:13:41.640 --> 0:13:44.720 might reduce the rats aversion to cat odor. Not only 0:13:44.760 --> 0:13:47.920 did do that, but it actually increased their attraction. They 0:13:47.960 --> 0:13:50.560 spent more time in the cat treated areas, the cat 0:13:50.679 --> 0:13:53.840 urine areas, okay, And naturally they would have gotten one 0:13:53.840 --> 0:13:56.000 whiff of that and been out of there, right, so 0:13:56.080 --> 0:13:59.199 she and other scientists have repeated this experiment with the 0:13:59.320 --> 0:14:02.720 urin of dog and minks, which also prey on rodents, 0:14:03.040 --> 0:14:05.439 and the effect was so specific to cat her and 0:14:05.520 --> 0:14:08.600 she says that they call it the fatal feline attraction. 0:14:09.559 --> 0:14:12.959 In a sense, the parasite makes the rats sexually attracted 0:14:13.360 --> 0:14:17.320 to death by cat. Yes, they're creating suicide rats really, 0:14:17.440 --> 0:14:21.040 and again this is all pointing back to this disconnection 0:14:21.360 --> 0:14:26.000 of fear circuits, and neuroscientists Robert Sapulski and his colleagues 0:14:26.000 --> 0:14:29.040 found that T GANDHI disconnects these fear circuits in the brain. 0:14:29.720 --> 0:14:33.920 And again that's this isn't somewhat of an explanation for 0:14:34.600 --> 0:14:37.960 these rats losing their aversion to cat odor. Okay, now, 0:14:38.000 --> 0:14:40.360 if I if I might return to the parasites eleven 0:14:40.400 --> 0:14:43.160 analogy here, let's say we want to gain the process 0:14:43.240 --> 0:14:45.520 even further. Al Right, Okay, so we've sort of shut 0:14:45.560 --> 0:14:48.560 down security. But the rat is and or a bird. 0:14:48.720 --> 0:14:50.640 These are creatures that have evolved over millions and millions 0:14:50.640 --> 0:14:53.960 of years to effectively evade the predators that want to 0:14:54.000 --> 0:14:56.560 eat them. All right, so we tweet things so that 0:14:56.600 --> 0:15:00.040 they're attracted to the urine of their predator. But I 0:15:00.040 --> 0:15:01.800 wonder if we could do more. What have we made 0:15:01.840 --> 0:15:04.800 them clumsy? What if we messed with their motor skills? 0:15:05.360 --> 0:15:07.680 Their studies that suggested that this is exactly what happens. 0:15:07.720 --> 0:15:10.960 A little parasitic reprogramming of the brain, and they're able 0:15:11.000 --> 0:15:14.960 to impair the host motor controls. So the parasite cuts 0:15:14.960 --> 0:15:18.040 the host chances of avoiding the cat's jaws and claws 0:15:18.080 --> 0:15:19.800 and winding up in the belly, just gains it a 0:15:19.840 --> 0:15:22.320 little more. And only that, let's add to the mix 0:15:22.400 --> 0:15:25.040 that not only do you lose your fear response and 0:15:25.160 --> 0:15:28.280 your motor control slows down, but let's let's say that 0:15:28.320 --> 0:15:30.080 when you do get a whiff of that good time 0:15:30.200 --> 0:15:33.240 cat you're in, that your dopamine center in your brain 0:15:33.280 --> 0:15:36.240 starts to go nuts. It's like you've released something into 0:15:36.280 --> 0:15:41.000 the air events to sort of pacify the security patrol 0:15:41.480 --> 0:15:45.160 at this hypothetical casino. There you go and you're attracted 0:15:45.200 --> 0:15:46.720 to it, and what do you do? You walk right 0:15:46.800 --> 0:15:49.760 up to a cat and say, I just I just 0:15:49.800 --> 0:15:52.280 had a whiff of your cat. Peek, I like what 0:15:52.360 --> 0:15:54.640 you've got going on there? Why don't we hang out? 0:15:54.720 --> 0:15:57.160 And then the cat, of course, eats it because because 0:15:57.160 --> 0:15:59.160 the cat. In a little bit we'll discuss some possible 0:15:59.160 --> 0:16:01.920 sort of side effects for the cat of the taxo 0:16:02.080 --> 0:16:03.680 infesting it, but for the most part of the cat 0:16:04.080 --> 0:16:06.680 is unaffected. The cat knows what it's doing when it 0:16:06.720 --> 0:16:10.240 comes to killing things and then pooping things. So there's 0:16:10.280 --> 0:16:13.120 not really any need to tinker with that model because 0:16:13.240 --> 0:16:14.640 because if you have a cat, you know that it 0:16:14.680 --> 0:16:16.880 eats and poops very well. So we're too about cats, 0:16:16.880 --> 0:16:18.480 but they've got those two things down. It's like the 0:16:18.720 --> 0:16:21.680 four things they dig, but it's the prey animals, uh, 0:16:22.080 --> 0:16:25.320 in the cycle that they tweak. Yeah, that's right. And 0:16:25.360 --> 0:16:27.600 so as soon as that rat, who has lost all 0:16:27.680 --> 0:16:30.760 sense of fear, presents him or herself to the cat, 0:16:30.920 --> 0:16:33.800 then you know, the t gandhi inside are going. You know, Booya, 0:16:34.840 --> 0:16:36.880 is exactly what we wanted you to do. But what's 0:16:36.880 --> 0:16:40.120 fascinating about that is that that that parasite is in 0:16:40.200 --> 0:16:44.400 the rat's brain really tinkering with it so specifically you know, 0:16:44.520 --> 0:16:47.800 to cat urine and another animal urine that it's attracted to, 0:16:48.280 --> 0:16:51.000 or you know, losing the motor coordination. I mean that 0:16:51.120 --> 0:16:53.160 all of that is fascinating to me. Yeah, and it 0:16:53.200 --> 0:16:57.240 turns our previous understandings of how the world works on 0:16:57.280 --> 0:16:59.680 its head, like the idea that at this small level, 0:16:59.760 --> 0:17:02.280 the creatures that we don't even think of as having 0:17:02.280 --> 0:17:06.119 intelligence are manipulating the whole show. You know. They're like 0:17:06.200 --> 0:17:10.919 they're like tiny gods, right, And now the situation is unfolding, 0:17:11.080 --> 0:17:14.440 and there's there's just one researcher, this one scientist who 0:17:14.720 --> 0:17:16.720 looks at this. It looks all these different cases of 0:17:16.720 --> 0:17:20.560 parasites changing behavior in insects and animals and says, m hm, 0:17:21.200 --> 0:17:23.679 you know, but I've been acting kind of strange lately. 0:17:24.680 --> 0:17:28.920 I wonder if I could be infested with something that's 0:17:29.000 --> 0:17:32.160 changing my behavior. And we're gonna take a quick break, 0:17:32.160 --> 0:17:33.600 but when we get back, we're going to talk about 0:17:33.600 --> 0:17:38.120 whether or not we are also controlled by unseen forces 0:17:38.359 --> 0:17:46.240 aka parasites. We're back, and like we mentioned before that 0:17:46.320 --> 0:17:49.439 the parasite he guaranty, wants to get inside a cat again, 0:17:49.480 --> 0:17:51.159 and it wants to do that by getting inside a 0:17:51.240 --> 0:17:53.680 rat or a bird. That's the cycle cat, the rat, 0:17:53.960 --> 0:17:57.520 the cat. But this journey will often lead it into humans, 0:17:57.680 --> 0:17:59.920 which generally is a dead end journey. But it is 0:18:00.040 --> 0:18:02.680 still going to use all of its skills to try 0:18:02.720 --> 0:18:05.200 and get that right and into the belly of a cat. 0:18:05.400 --> 0:18:08.800 It's still programmed to change the host and to manipulate 0:18:08.880 --> 0:18:13.200 the host towards its ultimate goal again the digestive system 0:18:13.440 --> 0:18:18.080 of a feline. So human infestation by T. Gandhi also 0:18:18.119 --> 0:18:22.560 appears to result in some mind puppeting. It appears, you know, 0:18:22.680 --> 0:18:25.199 the jury is still somewhat out, and there's quite a 0:18:25.240 --> 0:18:28.240 kerfuffle about it, but it seems to be some some 0:18:28.359 --> 0:18:31.320 pretty serious evidence that there's tinkering going on in the 0:18:31.440 --> 0:18:34.960 human mind. In fact, biologist Yaroslav Flagger in the n 0:18:35.960 --> 0:18:38.159 as I said before he had begun to suspect that 0:18:38.160 --> 0:18:42.840 a parasite was subtly manipulating his personality. For instance, he 0:18:42.880 --> 0:18:45.040 would cross the road in the middle of trafficked weapon 0:18:45.119 --> 0:18:48.800 without any fear, and in moments of panic he observed 0:18:48.840 --> 0:18:53.440 others freaking out while he remained oddly calm. He realized 0:18:53.480 --> 0:18:55.919 that he also didn't have much of an investment in 0:18:56.000 --> 0:19:00.520 his appearance. He seemed sort of unkempt, introverted, and and uh. 0:19:00.880 --> 0:19:05.320 He remembered learning about reckless ants whose nervous systems had 0:19:05.320 --> 0:19:09.680 been reprogrammed by flatworms, so he remembered this this instance 0:19:09.680 --> 0:19:13.080 in which instead of heading underground, which ants should do 0:19:13.720 --> 0:19:16.240 when the temperature drops, these ants would actually scale a 0:19:16.280 --> 0:19:19.399 blade of grass and chomp down on the top and 0:19:19.440 --> 0:19:22.240 just hang there in the wind until it was gulped 0:19:22.280 --> 0:19:24.040 down by a predator. And this was of course the 0:19:24.080 --> 0:19:27.919 tapeworm um the tapeworms doing so. He'd heard of a 0:19:27.960 --> 0:19:31.760 similar con job in the parasite world, and suddenly he realized, 0:19:32.000 --> 0:19:34.640 what if I'm being con What if the parasites are 0:19:34.640 --> 0:19:39.000 working through me uh in their their master plan? Yep, 0:19:39.119 --> 0:19:42.280 and so on a whim. In at Charles University, where 0:19:42.320 --> 0:19:45.160 his colleagues were searching for infected individuals to test out 0:19:45.160 --> 0:19:47.560 some new kits to see how fancy they were, they 0:19:47.560 --> 0:19:51.639 found that Flagger tested positive for the parasite. So his 0:19:51.800 --> 0:19:54.880 hunch was right. What that led to is this guy 0:19:55.160 --> 0:19:58.320 like doggedly trying to understand this parasite and how it 0:19:58.400 --> 0:20:02.040 behaves in humans, and a bunch of other people of 0:20:02.119 --> 0:20:04.120 late have you know, jumped on the ship to try 0:20:04.119 --> 0:20:06.840 to figure out what's going on as well. So he 0:20:06.920 --> 0:20:08.919 was a man with no fear, he was, Yeah, he 0:20:08.960 --> 0:20:10.760 was a man with no fear. And so again, and 0:20:10.840 --> 0:20:12.760 you know looking at rats, and he he looked at 0:20:12.840 --> 0:20:15.720 rats too, and was looking at the same thing. This, 0:20:15.920 --> 0:20:19.560 this disconnecting of the fear center and wondering if his 0:20:19.600 --> 0:20:21.520 own crazy behavior and walking out in the middle of 0:20:21.600 --> 0:20:26.159 traffic was related. And he found in one of his 0:20:26.240 --> 0:20:29.639 studies that this had a direct correlation to people in 0:20:29.680 --> 0:20:32.880 traffic accidents. Yes, according to a two thousand and nine 0:20:32.880 --> 0:20:37.280 study from Charles University in Prague, toxoplasmosis infection could make 0:20:37.359 --> 0:20:39.800 one two point five times more likely to wind up 0:20:39.800 --> 0:20:43.440 in an automobile accident, specifically if you happen to have 0:20:43.600 --> 0:20:46.480 Reese's negative blood, which means you're missing a protein on 0:20:46.520 --> 0:20:48.960 the surface of your blood cells. And this comes around 0:20:48.960 --> 0:20:51.720 to the tinkering we were talking about earlier, that motor 0:20:51.760 --> 0:20:56.000 skills have been adjusted, the fear of death has been adjusted, 0:20:56.440 --> 0:21:00.639 and combine those two out on the road and you 0:21:00.640 --> 0:21:02.400 can make I feel like you can make a definite 0:21:02.400 --> 0:21:07.400 case that you're more susceptible to an automobile wreck. Yeah, 0:21:07.440 --> 0:21:11.280 that's right. And the two Turkish studies have replicated his studies. Again, 0:21:11.440 --> 0:21:14.280 these are people who have been involved in traffic accidents 0:21:14.440 --> 0:21:18.840 and the accident victims blood was taken and again, it 0:21:18.880 --> 0:21:20.639 was found two and a half times more likely to 0:21:20.680 --> 0:21:24.119 be in traffic accident if you are infested with this parasite. Yeah, 0:21:24.240 --> 0:21:27.479 amazingly enough, the prog studies suggests that between four hundred 0:21:27.480 --> 0:21:30.160 thousand and a million of the world's annual road deaths 0:21:30.480 --> 0:21:34.560