1 00:00:07,840 --> 00:00:11,360 Speaker 1: The fungus known as Ohio cortceps may be the most 2 00:00:11,480 --> 00:00:14,400 Speaker 1: famous fungus in pop culture right now. I know it's 3 00:00:14,440 --> 00:00:17,000 Speaker 1: a lobar, but still it's pretty cool. The Girl with 4 00:00:17,040 --> 00:00:19,919 Speaker 1: All the Gifts, The Last of Us and a host 5 00:00:20,720 --> 00:00:24,640 Speaker 1: of other books, movies, and video games feature this behavior 6 00:00:24,760 --> 00:00:29,120 Speaker 1: manipulating fungal pathogen. But what does it really do? How 7 00:00:29,120 --> 00:00:32,720 Speaker 1: do the zombie ants behave? And what do we know 8 00:00:32,800 --> 00:00:36,239 Speaker 1: about how the fungus hijacks ant behavior? And Yes, at 9 00:00:36,280 --> 00:00:38,960 Speaker 1: the end of the episode, I'll speculate on whether Ofio 10 00:00:39,000 --> 00:00:42,120 Speaker 1: coort aceps could jump from ants to humans hijacking or 11 00:00:42,159 --> 00:00:46,839 Speaker 1: behavior along the way. Welcome to Daniel and Kelly's Manipulated Universe. 12 00:01:00,160 --> 00:01:02,960 Speaker 2: Hi. I'm Daniel. I'm a particle physicist, and I like 13 00:01:03,000 --> 00:01:04,640 Speaker 2: to think of myself as a fun guy. 14 00:01:05,480 --> 00:01:07,479 Speaker 1: You know, Daniel, you have made that joke before. 15 00:01:08,080 --> 00:01:08,959 Speaker 2: It's too good? 16 00:01:09,640 --> 00:01:12,880 Speaker 1: It is, It is good, It's good. I'm Kelly Wider Smith, 17 00:01:12,959 --> 00:01:14,039 Speaker 1: and I'm a fun gal. 18 00:01:18,319 --> 00:01:21,400 Speaker 2: And today we're talking about how funguses make us friends, 19 00:01:21,680 --> 00:01:26,280 Speaker 2: or make us more fun no, or make us whact 20 00:01:26,319 --> 00:01:27,840 Speaker 2: weird and climbed to the tops of. 21 00:01:27,800 --> 00:01:32,640 Speaker 1: Things or something else entirely Yes, how ants get manipulated 22 00:01:32,680 --> 00:01:36,000 Speaker 1: by a fungal pathogen, but probably well, wait till the end, 23 00:01:36,040 --> 00:01:37,319 Speaker 1: we'll see what we think about people. 24 00:01:37,440 --> 00:01:39,959 Speaker 2: I do like the idea that some of our weird 25 00:01:40,000 --> 00:01:42,600 Speaker 2: behavior can be attributed to some part of us that's 26 00:01:42,680 --> 00:01:45,360 Speaker 2: not really part of us. You know, that you can say, oh, 27 00:01:45,400 --> 00:01:47,040 Speaker 2: that's just the fungus in my brain. 28 00:01:47,360 --> 00:01:49,760 Speaker 1: Yeah. Absolutely. So. When I started my PhD, I was 29 00:01:49,800 --> 00:01:53,000 Speaker 1: studying why organisms behave the way they do, so I 30 00:01:53,040 --> 00:01:56,360 Speaker 1: was into animal behavior and I came across the Toxoplasma 31 00:01:56,400 --> 00:01:59,600 Speaker 1: Gandhi literature, where that parasite that lives in our brains 32 00:01:59,640 --> 00:02:02,920 Speaker 1: is a sociated with weird behaviors. And I got absolutely 33 00:02:02,960 --> 00:02:06,040 Speaker 1: hooked on this idea that not all of our behaviors 34 00:02:06,080 --> 00:02:09,320 Speaker 1: are attributable to our decisions, that maybe it's like a 35 00:02:09,320 --> 00:02:12,560 Speaker 1: group effort the person who we end up being, and 36 00:02:12,560 --> 00:02:15,120 Speaker 1: that you know, the microbes in our gut influence our 37 00:02:15,160 --> 00:02:18,240 Speaker 1: behavior and the parasites in our brain influence our behavior. 38 00:02:18,280 --> 00:02:20,360 Speaker 1: And I find this topic totally fascinating. 39 00:02:20,440 --> 00:02:23,079 Speaker 2: But in some sense that's frame because it tells you, oh, 40 00:02:23,080 --> 00:02:25,519 Speaker 2: it don't make all my decisions. In another sense that's 41 00:02:25,600 --> 00:02:27,400 Speaker 2: terrifying because it's like, oh my gosh, I don't make 42 00:02:27,400 --> 00:02:30,359 Speaker 2: all my decisions, and Katrina would probably be like, no, 43 00:02:30,480 --> 00:02:33,080 Speaker 2: that is who you are. Your microbes are part of you. 44 00:02:33,800 --> 00:02:35,720 Speaker 1: Yeah, No, I tind of agree with that take. But 45 00:02:35,760 --> 00:02:37,360 Speaker 1: one thing that I think is fun is that one 46 00:02:37,400 --> 00:02:40,160 Speaker 1: of the big names in the field that studies how 47 00:02:40,200 --> 00:02:44,320 Speaker 1: Toxoplasma gandhia impacts human behavior, his name is Yaroslav Flagger. 48 00:02:44,560 --> 00:02:48,000 Speaker 1: Apologies for my you know, forever bad pronunciations. He got 49 00:02:48,040 --> 00:02:51,120 Speaker 1: into this because he was like, you know, I act 50 00:02:51,240 --> 00:02:54,600 Speaker 1: kind of weird, sort of like not like other people. 51 00:02:54,680 --> 00:02:57,680 Speaker 1: I wonder if I have a brain infecting parasite. And 52 00:02:57,720 --> 00:02:59,880 Speaker 1: he gave himself a test and he did, and this 53 00:03:00,080 --> 00:03:02,920 Speaker 1: set him off on the path of like wondering about 54 00:03:03,040 --> 00:03:07,240 Speaker 1: how toxoplasmosis is associated with human behavior. It's an interesting question. 55 00:03:07,480 --> 00:03:09,280 Speaker 2: Is it possible to have a fungus in your brain 56 00:03:09,360 --> 00:03:13,680 Speaker 2: that makes you eat cookies too late at night? Can 57 00:03:13,720 --> 00:03:14,800 Speaker 2: I blame that on somebody? 58 00:03:15,480 --> 00:03:18,400 Speaker 1: Daniel? That is you? No, that's you, Daniel, that's you. 59 00:03:18,800 --> 00:03:22,000 Speaker 1: And just for clarification, Toxoplasma gandhia is not a fungus, 60 00:03:22,040 --> 00:03:24,760 Speaker 1: but there are a variety of different parasites that can 61 00:03:24,760 --> 00:03:25,560 Speaker 1: live in human brains. 62 00:03:25,600 --> 00:03:28,360 Speaker 2: Unfortunately, so if I do have a parasite, it's probably, 63 00:03:28,360 --> 00:03:30,520 Speaker 2: like Daniel, stop eating cookies. Those are bad for you 64 00:03:30,560 --> 00:03:31,360 Speaker 2: and bad for us. 65 00:03:31,560 --> 00:03:31,960 Speaker 1: Yeah. 66 00:03:32,000 --> 00:03:34,400 Speaker 2: Maybe, Wow, I'm overruling them. 67 00:03:34,440 --> 00:03:38,240 Speaker 1: I don't know that cookie consumption as an implication of 68 00:03:38,440 --> 00:03:41,200 Speaker 1: brain parasites has been studied thoroughly, So I don't want 69 00:03:41,200 --> 00:03:41,960 Speaker 1: to go on the record. 70 00:03:42,800 --> 00:03:45,000 Speaker 2: It's so easy to get to the edge of knowledge 71 00:03:45,000 --> 00:03:45,920 Speaker 2: in biology. Wow. 72 00:03:46,680 --> 00:03:48,760 Speaker 1: Yeah, we're not asking the right questions. 73 00:03:50,320 --> 00:03:52,880 Speaker 2: Why does mainstream biology want to shut this question down? 74 00:03:53,000 --> 00:03:53,720 Speaker 2: Kelly hmm. 75 00:03:55,400 --> 00:03:58,800 Speaker 1: Yeah, I don't know, Daniel, not a great question, But 76 00:03:58,880 --> 00:04:00,000 Speaker 1: you know, what is a great question? 77 00:04:00,320 --> 00:04:01,200 Speaker 2: Give us a transition? 78 00:04:01,680 --> 00:04:04,280 Speaker 1: Yeah, what is a great question is the question we 79 00:04:04,320 --> 00:04:05,240 Speaker 1: asked our listeners. 80 00:04:05,680 --> 00:04:06,440 Speaker 2: What was that? 81 00:04:06,440 --> 00:04:11,520 Speaker 1: That was? What is summit disease? And if you would 82 00:04:11,600 --> 00:04:13,600 Speaker 1: like to answer questions for us, send us at an 83 00:04:13,640 --> 00:04:16,840 Speaker 1: email at questions at Danielinkelly dot org and we'll add 84 00:04:16,880 --> 00:04:19,479 Speaker 1: you to our list. So let's hear what our listeners 85 00:04:19,520 --> 00:04:22,720 Speaker 1: had to say in response to what is summit disease? 86 00:04:23,320 --> 00:04:27,560 Speaker 2: Summit disease is an affliction that occurs when you can't 87 00:04:27,600 --> 00:04:31,040 Speaker 2: stop hiking to the top of mountains, and it causes 88 00:04:31,080 --> 00:04:33,320 Speaker 2: you to neglect the rest of your life. I think 89 00:04:33,360 --> 00:04:35,360 Speaker 2: it's a brain disorder that makes you way at dead 90 00:04:35,360 --> 00:04:39,960 Speaker 2: bodies on the way up Nepalese mountains. The sickness individuals 91 00:04:40,160 --> 00:04:45,520 Speaker 2: get when they are at a high altitude and climbing mountains, 92 00:04:45,560 --> 00:04:46,880 Speaker 2: for example. 93 00:04:46,839 --> 00:04:50,240 Speaker 3: I think you're referring to high altitude sickness. Mountain climbers, 94 00:04:50,400 --> 00:04:52,800 Speaker 3: when they go up above a certain elevation, can get 95 00:04:53,320 --> 00:04:57,960 Speaker 3: lack of oxygen, pulmonary edema, cerebral edema, et cetera. No bueno, 96 00:04:58,360 --> 00:05:02,080 Speaker 3: this is a disease a similar to OCD. You have 97 00:05:02,160 --> 00:05:04,440 Speaker 3: to walk around adding things together. 98 00:05:04,800 --> 00:05:07,880 Speaker 2: I could be mistaken, but I believe it is when 99 00:05:08,040 --> 00:05:12,039 Speaker 2: an avid climber gets the impulsive need to tell the 100 00:05:12,080 --> 00:05:15,080 Speaker 2: people around them all of the mountains that they have summitted. 101 00:05:15,400 --> 00:05:18,080 Speaker 3: It seems like summer disease could be when I go 102 00:05:18,320 --> 00:05:20,360 Speaker 3: on top of a mountain and my fingers swell up 103 00:05:20,800 --> 00:05:21,520 Speaker 3: and I get tired. 104 00:05:21,560 --> 00:05:23,359 Speaker 2: Easier except for way way worse. 105 00:05:23,720 --> 00:05:27,360 Speaker 3: Summit disease is when you, after a really long climb, 106 00:05:27,360 --> 00:05:30,280 Speaker 3: get to the summit, and then the mountain gods invade 107 00:05:30,320 --> 00:05:31,760 Speaker 3: your brain make you do bad stuff. 108 00:05:31,920 --> 00:05:32,279 Speaker 2: I don't know. 109 00:05:32,680 --> 00:05:36,080 Speaker 3: When you reach the summit of a mountain and you 110 00:05:36,160 --> 00:05:40,200 Speaker 3: can't stop throwing up because you're so sick of looking 111 00:05:40,279 --> 00:05:40,880 Speaker 3: at mountains. 112 00:05:41,160 --> 00:05:42,960 Speaker 2: I think that's when you're hiking and you've each an 113 00:05:42,960 --> 00:05:45,640 Speaker 2: altitude or an elevation where the air gets dinner and 114 00:05:45,720 --> 00:05:48,560 Speaker 2: you start to get headaches and funauseous and stuff like that. 115 00:05:49,000 --> 00:05:51,400 Speaker 2: So I also would have guessed something that happens to 116 00:05:51,440 --> 00:05:53,000 Speaker 2: you at the top of Mount Everest. 117 00:05:53,240 --> 00:05:56,279 Speaker 1: Yeah, that is a totally reasonable answer. We have a 118 00:05:56,400 --> 00:05:59,760 Speaker 1: very smart audience, but actually this is something that happens 119 00:05:59,760 --> 00:06:02,880 Speaker 1: to insects and not to humans. And I'll also note 120 00:06:02,880 --> 00:06:05,039 Speaker 1: that I laughed out loud at the uh you have 121 00:06:05,080 --> 00:06:07,120 Speaker 1: to walk around adding things together. It took me a 122 00:06:07,120 --> 00:06:09,520 Speaker 1: second to put that together and be like, oh, some 123 00:06:10,120 --> 00:06:14,080 Speaker 1: it some it adding, and I laughed out loud. So anyway, 124 00:06:14,160 --> 00:06:17,000 Speaker 1: thank you for that moment of revelation there. 125 00:06:17,279 --> 00:06:19,559 Speaker 2: Well, I love this opportunity to dig into the real 126 00:06:19,680 --> 00:06:23,880 Speaker 2: science that's sort of underlying some Hollywood myths. You know, 127 00:06:23,920 --> 00:06:26,680 Speaker 2: there are these fun stories you hear sometimes in science fiction, 128 00:06:27,160 --> 00:06:30,800 Speaker 2: but often these are inspired by actual and really fascinating 129 00:06:30,920 --> 00:06:34,000 Speaker 2: on their own stories of what's going on out there 130 00:06:34,040 --> 00:06:37,760 Speaker 2: in nature. So tell us, Kelly, what is the story 131 00:06:37,839 --> 00:06:40,400 Speaker 2: that inspires all these Hollywood tropes? 132 00:06:40,640 --> 00:06:43,320 Speaker 1: Well, So let's start with what is summit disease. And 133 00:06:43,440 --> 00:06:45,880 Speaker 1: Summit disease is a thing that happens to a lot 134 00:06:45,920 --> 00:06:49,000 Speaker 1: of different insects that are infected by fungus or by viruses. 135 00:06:49,080 --> 00:06:51,560 Speaker 1: And the deal is that either the fungus or the 136 00:06:51,640 --> 00:06:54,320 Speaker 1: virus gets an insect to climb high, and then it 137 00:06:54,360 --> 00:06:56,599 Speaker 1: gets the insect to stay there instead of like coming 138 00:06:56,600 --> 00:06:59,279 Speaker 1: down for the night. And then they like cling in 139 00:06:59,320 --> 00:07:02,479 Speaker 1: some way and they stay up high and from that 140 00:07:02,600 --> 00:07:07,080 Speaker 1: location they then die and they rain infectious particles down 141 00:07:07,279 --> 00:07:09,320 Speaker 1: on their other insects below. 142 00:07:09,400 --> 00:07:10,480 Speaker 2: They like explode. 143 00:07:10,840 --> 00:07:14,160 Speaker 1: Uh you know, explode might be over selling it a little, 144 00:07:14,360 --> 00:07:17,720 Speaker 1: but like, so, for example, there's a virus that infects caterpillars, 145 00:07:17,720 --> 00:07:20,280 Speaker 1: and caterpillars go up during the day to like eat leaves, 146 00:07:20,520 --> 00:07:22,520 Speaker 1: and then at night they usually come down and they 147 00:07:22,600 --> 00:07:25,160 Speaker 1: like hide. But this when they're infected by this virus, 148 00:07:25,160 --> 00:07:27,320 Speaker 1: they climb up and they stay there and then they 149 00:07:27,360 --> 00:07:30,320 Speaker 1: die and they sort of liquefy and they rain virus 150 00:07:30,360 --> 00:07:32,680 Speaker 1: particles down on the caterpillars that are below. 151 00:07:34,640 --> 00:07:37,840 Speaker 2: They drip guey infected caterpillar down they do. 152 00:07:38,000 --> 00:07:40,920 Speaker 1: Yeah, what a weather forecast that's oh yeah, cloudy with 153 00:07:40,960 --> 00:07:46,200 Speaker 1: the chance of virus soup caterpillar bits. That's right, gross, 154 00:07:47,200 --> 00:07:50,000 Speaker 1: But this also happens. There are like quote unquote zombie 155 00:07:50,000 --> 00:07:52,680 Speaker 1: flies that are infected by a fungus and they'll climb 156 00:07:52,800 --> 00:07:55,000 Speaker 1: up and they'll even like they'll climb up and then 157 00:07:55,000 --> 00:07:57,360 Speaker 1: they'll spread their wings out to the side so that 158 00:07:57,400 --> 00:08:00,480 Speaker 1: when they die, the fungus can come out of their 159 00:08:00,480 --> 00:08:02,200 Speaker 1: back and their wings don't get in the way. And 160 00:08:02,240 --> 00:08:05,000 Speaker 1: that one does it sort of like shoots like cannonballs 161 00:08:05,000 --> 00:08:07,760 Speaker 1: out of their back down at the like flies below. 162 00:08:07,880 --> 00:08:10,240 Speaker 1: And so, oh my gosh, this is a pretty common 163 00:08:10,280 --> 00:08:14,560 Speaker 1: strategy you see in viruses and fungus that infect insects 164 00:08:14,560 --> 00:08:16,720 Speaker 1: that want to go on to infect more insects. 165 00:08:16,920 --> 00:08:20,280 Speaker 2: It's fascinating because you say it does this so that 166 00:08:20,400 --> 00:08:22,880 Speaker 2: this other thing happens, which implies that there's some sort 167 00:08:22,880 --> 00:08:25,080 Speaker 2: of high level decision making. But I know it's all 168 00:08:25,160 --> 00:08:30,600 Speaker 2: like low level mechanistic blind evolution. So I'm curious to 169 00:08:30,640 --> 00:08:33,000 Speaker 2: hear how all that comes together and how the whole 170 00:08:33,040 --> 00:08:35,920 Speaker 2: process comes together. You know, it's one of these examples 171 00:08:35,920 --> 00:08:38,360 Speaker 2: of like a complicated thing where you need lots of 172 00:08:38,400 --> 00:08:41,760 Speaker 2: pieces all together to accrue the benefit, which always makes 173 00:08:41,760 --> 00:08:44,680 Speaker 2: me wonder how it came together in the intermediate stages. 174 00:08:44,880 --> 00:08:47,040 Speaker 1: Yeah, and this is why the zombie ant system is 175 00:08:47,080 --> 00:08:50,200 Speaker 1: one of my favorite systems to study. So this phenomenon 176 00:08:50,240 --> 00:08:54,640 Speaker 1: where some parasite or pathogen hijacks the behavior of its 177 00:08:54,679 --> 00:08:57,480 Speaker 1: host so that the host is doing something that benefits 178 00:08:57,480 --> 00:09:02,520 Speaker 1: the parasite, we call this manipulation, and it's really tempting, 179 00:09:02,520 --> 00:09:04,520 Speaker 1: and we've talked about this in other episodes. It's really 180 00:09:04,600 --> 00:09:07,160 Speaker 1: tempting when you see a host behaving weirdly to be like, oh, 181 00:09:07,200 --> 00:09:10,040 Speaker 1: that's a manipulation that must benefit the parasite in some way. 182 00:09:10,520 --> 00:09:12,920 Speaker 1: But while it's easy to come up with a story, 183 00:09:12,960 --> 00:09:14,839 Speaker 1: it's harder to test that. And every once in a 184 00:09:14,920 --> 00:09:16,840 Speaker 1: while we'll have a story where it sounds like the 185 00:09:16,880 --> 00:09:19,480 Speaker 1: pathogen was benefiting, but when you look into it, it's 186 00:09:19,520 --> 00:09:23,199 Speaker 1: not so. Mosquitos when they're infected by malaria, right after 187 00:09:23,200 --> 00:09:26,600 Speaker 1: they get infected by malaria, they bite less, and there's 188 00:09:26,720 --> 00:09:29,760 Speaker 1: a period where after the mosquito takes a blood meal 189 00:09:29,800 --> 00:09:33,520 Speaker 1: that has malaria, that malaria is sort of maturing and 190 00:09:33,600 --> 00:09:36,520 Speaker 1: can't transmit yet. So if the mosquito took a blood 191 00:09:36,559 --> 00:09:40,920 Speaker 1: meal and got slept by a hand, then the malaria 192 00:09:40,960 --> 00:09:42,960 Speaker 1: would die, and so that wouldn't be good. You know, 193 00:09:43,000 --> 00:09:45,640 Speaker 1: in a very anthropomorphic way, the malaria quote unquote doesn't 194 00:09:45,679 --> 00:09:48,520 Speaker 1: want the mosquito to get killed or to take blood 195 00:09:48,520 --> 00:09:49,640 Speaker 1: meals at that point. 196 00:09:49,480 --> 00:09:51,840 Speaker 2: While it's still developing and preparing. 197 00:09:51,520 --> 00:09:53,720 Speaker 1: That's right. But once it's ready, once it's in the 198 00:09:53,760 --> 00:09:57,240 Speaker 1: mosquito salivary glands and could transmit to a human, those 199 00:09:57,280 --> 00:10:01,040 Speaker 1: mosquitos start biting even more. So this was thought of 200 00:10:01,200 --> 00:10:05,840 Speaker 1: as manipulation. The parasite is protecting the mosquito and itself 201 00:10:06,120 --> 00:10:08,640 Speaker 1: until it can transmit, and then once it transmits, it 202 00:10:08,679 --> 00:10:11,079 Speaker 1: gets the mosquito to bite a lot more. And that 203 00:10:11,280 --> 00:10:13,080 Speaker 1: really sounds like it would be good for the mosquito. 204 00:10:13,320 --> 00:10:15,440 Speaker 1: It's a good story, it's a great story. But it 205 00:10:15,520 --> 00:10:19,400 Speaker 1: turns out that if you activate the mosquito's immune response 206 00:10:19,480 --> 00:10:23,360 Speaker 1: by for example, killing bacteria and then putting those dead 207 00:10:23,440 --> 00:10:27,200 Speaker 1: bacteria into the mosquito, it will do the same thing. 208 00:10:27,320 --> 00:10:29,360 Speaker 2: Even though it doesn't benefit that bacteria. 209 00:10:29,400 --> 00:10:31,760 Speaker 1: That's right. Where Yeah, the bacteria are dead, they're just 210 00:10:31,920 --> 00:10:35,720 Speaker 1: making the mosquito's immune system activate, and this is what 211 00:10:35,760 --> 00:10:38,080 Speaker 1: the mosquito does. So it could be like when the 212 00:10:38,080 --> 00:10:40,680 Speaker 1: mosquito's immune system is activated, it just kind of wants 213 00:10:40,679 --> 00:10:42,959 Speaker 1: to hunker down. It's not as fast, it's feeling kind 214 00:10:43,000 --> 00:10:45,760 Speaker 1: of crummy. It's just taking a nap before it's ready 215 00:10:45,760 --> 00:10:49,240 Speaker 1: to go again. And so that's probably not manipulation. It 216 00:10:49,280 --> 00:10:51,320 Speaker 1: doesn't look like the malaria is doing that. That's something 217 00:10:51,320 --> 00:10:52,520 Speaker 1: that's driven by the mosquito. 218 00:10:52,720 --> 00:10:54,880 Speaker 2: Could still be in response to the malaria. Right when 219 00:10:54,880 --> 00:10:57,400 Speaker 2: it gets infected, it does this, and the malaria can 220 00:10:57,480 --> 00:11:00,200 Speaker 2: benefit from it. You're just saying it's not something that 221 00:11:00,240 --> 00:11:03,679 Speaker 2: the malaria has specifically engineered to benefit itself. It's something 222 00:11:03,720 --> 00:11:06,520 Speaker 2: the mosquito is already doing or would otherwise have done. 223 00:11:06,920 --> 00:11:08,040 Speaker 2: Fascinating exactly. 224 00:11:08,080 --> 00:11:10,160 Speaker 1: Yeah, So trying to figure out who's driving the change 225 00:11:10,160 --> 00:11:13,280 Speaker 1: in the behavior and how it actually benefits is much 226 00:11:13,320 --> 00:11:15,640 Speaker 1: harder than coming up with the initial story. Yeah, and 227 00:11:15,679 --> 00:11:17,760 Speaker 1: so what I love about the zombie ants is that 228 00:11:17,840 --> 00:11:20,160 Speaker 1: this system has been studied in quite a bit of detail, 229 00:11:20,200 --> 00:11:22,720 Speaker 1: and so we're actually starting to nail down the various 230 00:11:22,760 --> 00:11:23,920 Speaker 1: pieces of what's happening here. 231 00:11:24,040 --> 00:11:26,280 Speaker 2: Well, that reminds me of our conversation with Capo hen 232 00:11:26,320 --> 00:11:28,720 Speaker 2: and when we were talking about science and storytelling and 233 00:11:28,760 --> 00:11:32,320 Speaker 2: how much of science is storytelling is saying this happens 234 00:11:32,400 --> 00:11:35,240 Speaker 2: because of that, because of this other thing, and sometimes 235 00:11:35,280 --> 00:11:38,920 Speaker 2: the statistics or the mechanics of it don't always support that. 236 00:11:38,960 --> 00:11:42,280 Speaker 2: It's just we are trying to extract stories because stories 237 00:11:42,320 --> 00:11:43,160 Speaker 2: make sense to us. 238 00:11:43,440 --> 00:11:45,200 Speaker 1: Yeah, and I think sometimes we get a little carried 239 00:11:45,240 --> 00:11:47,680 Speaker 1: away with our stories and we don't necessarily have facts 240 00:11:47,679 --> 00:11:52,000 Speaker 1: to support every piece of the story. And so this 241 00:11:52,080 --> 00:11:54,760 Speaker 1: system is nice because almost every piece of the story 242 00:11:55,000 --> 00:11:57,120 Speaker 1: has been dug into to some degree. 243 00:11:57,240 --> 00:11:59,480 Speaker 2: All right, then carry us away to a story, Kelly 244 00:11:59,520 --> 00:12:01,960 Speaker 2: tell us about manipulation of ants. 245 00:12:02,320 --> 00:12:06,560 Speaker 1: Okay, you are a little ant walking around on the 246 00:12:06,600 --> 00:12:09,880 Speaker 1: forest floor. Unbeknownst to you, you have stepped on a 247 00:12:09,880 --> 00:12:14,440 Speaker 1: fungal spore. The fungus gets in between the cuticles and 248 00:12:14,720 --> 00:12:15,600 Speaker 1: invades the body. 249 00:12:15,679 --> 00:12:18,880 Speaker 2: Wait, I'm a little ant and I have cuticles still exoskeleton. 250 00:12:19,040 --> 00:12:21,160 Speaker 1: I think they call that cuticle. I don't study ants. 251 00:12:21,200 --> 00:12:24,280 Speaker 2: Man. What's the name of my aunt? Am I Dantiel? 252 00:12:27,360 --> 00:12:29,679 Speaker 1: Yes, yes, you're Danchel. 253 00:12:29,440 --> 00:12:31,559 Speaker 2: Walking around the forest with my little cuticles. 254 00:12:31,559 --> 00:12:36,640 Speaker 1: Okay, so poor Danchel has picked up a fungus. Danchel 255 00:12:36,720 --> 00:12:40,720 Speaker 1: doesn't realize that he's infected. Actually, if you're a forger, 256 00:12:40,760 --> 00:12:42,880 Speaker 1: you're probably a female. So this anyway, this is not 257 00:12:42,920 --> 00:12:45,240 Speaker 1: working great. But anyway, so the little ants, the little 258 00:12:45,280 --> 00:12:48,440 Speaker 1: ant has gotten infected, doesn't realize it. It goes back 259 00:12:48,480 --> 00:12:51,040 Speaker 1: to its nest. The nest mates don't seem to realize 260 00:12:51,040 --> 00:12:54,600 Speaker 1: that it's infected either. But a couple weeks after it 261 00:12:54,640 --> 00:12:57,640 Speaker 1: initially gets infected, it starts walking out of the nest. 262 00:12:57,720 --> 00:12:59,400 Speaker 1: And this nest is up in a tree, and it 263 00:12:59,440 --> 00:13:02,200 Speaker 1: starts rumbling down. We call it a drunk walk. So 264 00:13:02,280 --> 00:13:04,360 Speaker 1: it sort of starts stumbling down the tree and then 265 00:13:04,360 --> 00:13:07,320 Speaker 1: it walks along the forest floor and it climbs up 266 00:13:07,400 --> 00:13:09,720 Speaker 1: a stalk and this is in the tropics. It climbs 267 00:13:09,840 --> 00:13:12,840 Speaker 1: up a stalk or a stem of something to about 268 00:13:12,920 --> 00:13:16,679 Speaker 1: twenty plus or minus two centimeters. This is happening at 269 00:13:16,679 --> 00:13:19,720 Speaker 1: solar noon and on the north northwest side of the plant. 270 00:13:19,960 --> 00:13:23,520 Speaker 1: It goes underneath a leaf, bites down with its mandibles. 271 00:13:23,559 --> 00:13:25,840 Speaker 1: These are like the pinsy mouth parts it has, and 272 00:13:25,880 --> 00:13:28,240 Speaker 1: then it will never move again and it dies. 273 00:13:28,520 --> 00:13:30,040 Speaker 2: Wow. So it has to go all the way down 274 00:13:30,080 --> 00:13:32,600 Speaker 2: the tree just to find the stalk to climb up. 275 00:13:32,679 --> 00:13:34,640 Speaker 1: Yes, yep, just to find the stock to climb up. 276 00:13:34,720 --> 00:13:35,200 Speaker 2: Fascinating. 277 00:13:35,280 --> 00:13:38,760 Speaker 1: And then the ant dies and a stalk comes out 278 00:13:38,760 --> 00:13:41,280 Speaker 1: of the side of its neck and it forms a 279 00:13:41,520 --> 00:13:44,160 Speaker 1: ball at the sort of like top ish part of 280 00:13:44,200 --> 00:13:46,760 Speaker 1: the stalk, and then fungal spores rained down on the 281 00:13:46,760 --> 00:13:48,760 Speaker 1: forest floor and the cycle starts again. 282 00:13:48,880 --> 00:13:50,680 Speaker 2: The stalk is not from the plant, it's some like 283 00:13:50,760 --> 00:13:51,719 Speaker 2: weird fungal thing. 284 00:13:52,120 --> 00:13:54,160 Speaker 1: Yeah, it's the fungus makes it so the fungus, now 285 00:13:54,160 --> 00:13:56,080 Speaker 1: that the ant is dead, it starts using all of 286 00:13:56,080 --> 00:13:59,520 Speaker 1: the ant's internal body parts and converting it into fungus 287 00:13:59,760 --> 00:14:02,720 Speaker 1: and makes this stalk that rains fungal spores down, and 288 00:14:02,760 --> 00:14:03,800 Speaker 1: the cycle starts again. 289 00:14:03,960 --> 00:14:06,440 Speaker 2: This sounds like a science fiction horror movie. You're telling 290 00:14:06,480 --> 00:14:08,439 Speaker 2: me this is happening on our planet all the time. 291 00:14:08,600 --> 00:14:10,920 Speaker 1: Oh my it is. And okay, so what blows my 292 00:14:11,000 --> 00:14:13,600 Speaker 1: mind is that that is so specific. Like one of 293 00:14:14,080 --> 00:14:16,880 Speaker 1: one of Zach's gripes about me as a human being 294 00:14:17,200 --> 00:14:21,160 Speaker 1: is that I am really bad at estimating distances, and 295 00:14:21,400 --> 00:14:22,840 Speaker 1: like He'll be like, well, what's you know? Do it 296 00:14:22,840 --> 00:14:24,360 Speaker 1: about two feet from here, and I'll be like, I 297 00:14:24,400 --> 00:14:26,320 Speaker 1: have no idea what you mean, Like, I just I 298 00:14:26,360 --> 00:14:30,600 Speaker 1: can't do that. Whereas this fungus by remote control is 299 00:14:30,640 --> 00:14:34,080 Speaker 1: getting the ant to about twenty five centimeters plus or 300 00:14:34,080 --> 00:14:37,080 Speaker 1: minus like two and a half centimeters. I think earlier 301 00:14:37,120 --> 00:14:39,160 Speaker 1: I said it was twenty but it's more like twenty five, 302 00:14:39,240 --> 00:14:41,280 Speaker 1: which is very specific. And so how does that happen. 303 00:14:41,360 --> 00:14:43,280 Speaker 1: We're gonna get to our best guess right now at 304 00:14:43,320 --> 00:14:45,640 Speaker 1: how that happens a little bit later in the show. 305 00:14:45,880 --> 00:14:47,640 Speaker 1: But it's amazingly specific. 306 00:14:47,800 --> 00:14:48,080 Speaker 2: Wow. 307 00:14:48,280 --> 00:14:50,640 Speaker 1: But now it's worth mentioning that. Okay, that is a 308 00:14:50,680 --> 00:14:54,560 Speaker 1: story from O fio cordus steps unilateralis And just to 309 00:14:54,680 --> 00:14:55,160 Speaker 1: complete the. 310 00:14:55,200 --> 00:14:57,280 Speaker 2: Loop, it rains it down on the forest floor and 311 00:14:57,360 --> 00:14:59,360 Speaker 2: then the next ant can come along and pick it 312 00:14:59,480 --> 00:15:02,000 Speaker 2: up in there goals and that's how it completes the cycle. 313 00:15:02,440 --> 00:15:06,840 Speaker 1: Danchel, the she ants does pick up dante l Yeah, Dantel, 314 00:15:06,920 --> 00:15:09,400 Speaker 1: that's right, picks up the fungus and the cycle starts again. 315 00:15:09,600 --> 00:15:11,400 Speaker 2: Wow, all right, okay, And so the name of this 316 00:15:11,520 --> 00:15:13,680 Speaker 2: fungus is some crazy Latin phrase. Yeah. 317 00:15:13,720 --> 00:15:17,440 Speaker 1: So Ofio cordyceps unilateralis. The unilaterallysis refers to the fact 318 00:15:17,520 --> 00:15:20,480 Speaker 1: that the stalk comes out of one side of the 319 00:15:20,520 --> 00:15:24,280 Speaker 1: ant's head. And so opio coortceps is a genus. So 320 00:15:24,320 --> 00:15:27,000 Speaker 1: there's a lot of different fungus species that are very 321 00:15:27,040 --> 00:15:31,040 Speaker 1: closely related, and they infect different ant species, so they 322 00:15:31,080 --> 00:15:34,040 Speaker 1: seem to specialize on different species. So there's actually a 323 00:15:34,240 --> 00:15:37,200 Speaker 1: bunch of ants all over the world that are infected 324 00:15:37,240 --> 00:15:40,680 Speaker 1: by this fungus in slightly different ways. So the story 325 00:15:40,720 --> 00:15:42,400 Speaker 1: isn't the same for all of them. The story I 326 00:15:42,480 --> 00:15:45,120 Speaker 1: gave you is a story that I'd initially read for 327 00:15:45,640 --> 00:15:49,680 Speaker 1: Ophagio Cordyceps unilateralis infecting an ant species in the tropics. 328 00:15:50,160 --> 00:15:52,760 Speaker 1: But yeah, there's a lot of this happening in our world, and. 329 00:15:52,880 --> 00:15:55,560 Speaker 2: Within this species of ant and this species of fungus. 330 00:15:56,000 --> 00:15:58,080 Speaker 2: You're saying, there's not a lot of variation in the 331 00:15:58,160 --> 00:16:00,720 Speaker 2: behavior of ants. They like basically all do the same 332 00:16:01,040 --> 00:16:02,680 Speaker 2: march to death and then brain. 333 00:16:02,480 --> 00:16:04,880 Speaker 1: Explosion, brain explosion or you. 334 00:16:04,880 --> 00:16:06,720 Speaker 2: Know, fungal stock extrusion or what. 335 00:16:06,960 --> 00:16:08,880 Speaker 1: Yeah. Yeah, So we are going to talk about how 336 00:16:08,920 --> 00:16:11,480 Speaker 1: they differ a little bit. The details can differ depending 337 00:16:11,520 --> 00:16:14,320 Speaker 1: on where you are, but the story is generally the same. 338 00:16:14,400 --> 00:16:17,920 Speaker 1: That they find a way to be up above the 339 00:16:18,200 --> 00:16:20,400 Speaker 1: areas where the foragers usually go so that they can 340 00:16:20,520 --> 00:16:21,560 Speaker 1: rain the spores back down. 341 00:16:21,600 --> 00:16:24,200 Speaker 2: Again. Wow, amazing, So tell us how it works. 342 00:16:24,360 --> 00:16:27,520 Speaker 1: So first, I want to note we call these zombie ants, 343 00:16:27,800 --> 00:16:31,000 Speaker 1: and I often get people in the field grumpy with 344 00:16:31,160 --> 00:16:33,240 Speaker 1: me for calling them zombies because they're like people are 345 00:16:33,280 --> 00:16:35,960 Speaker 1: gonna think they come back from the dead. Dear listener, 346 00:16:36,040 --> 00:16:38,280 Speaker 1: I don't think that you think that ants come back 347 00:16:38,320 --> 00:16:41,200 Speaker 1: from the dead. But just to be clear, the zombie 348 00:16:41,240 --> 00:16:44,120 Speaker 1: ants do not come back from the dead. They are 349 00:16:44,200 --> 00:16:46,560 Speaker 1: their behavior is getting hijacked while they're alive, and then 350 00:16:46,600 --> 00:16:49,560 Speaker 1: they die in a very particular position that benefits the fungus. 351 00:16:49,880 --> 00:16:53,480 Speaker 2: So you're saying they're not zombies because the ants haven't died. 352 00:16:53,640 --> 00:16:57,400 Speaker 2: They're just in some sort of like controlled state where 353 00:16:57,400 --> 00:16:59,240 Speaker 2: they're not really acting the way they would if they 354 00:16:59,280 --> 00:17:02,880 Speaker 2: were normal ants. They're like drunk or they're hallucinating or something. 355 00:17:03,000 --> 00:17:05,320 Speaker 1: Something like that, and yet it looks like their circadian 356 00:17:05,400 --> 00:17:07,840 Speaker 1: rhythms are getting messed with. So Terarissa de Becker's lab 357 00:17:08,000 --> 00:17:10,520 Speaker 1: has looked at how a big part of the manipulation 358 00:17:10,680 --> 00:17:13,920 Speaker 1: seems to be them doing kind of normal behaviors but 359 00:17:14,040 --> 00:17:15,360 Speaker 1: at abnormal times. 360 00:17:15,720 --> 00:17:18,159 Speaker 2: So that seems to me a very technical definition of zombie. 361 00:17:18,200 --> 00:17:21,359 Speaker 2: I mean, if humans, for example, were infected by something 362 00:17:21,400 --> 00:17:24,359 Speaker 2: which made them stagger around and want to eat brains, 363 00:17:24,440 --> 00:17:26,680 Speaker 2: but weren't technically dead, would you be there being like, 364 00:17:26,760 --> 00:17:28,560 Speaker 2: excuse me, you're not a zombie. 365 00:17:28,280 --> 00:17:32,919 Speaker 1: Sir, No, Because I love fiction in all of its forms, 366 00:17:32,960 --> 00:17:35,840 Speaker 1: and as long as the rules are consistent in the 367 00:17:35,880 --> 00:17:38,520 Speaker 1: world that's created, I don't care. So when I use 368 00:17:38,520 --> 00:17:41,320 Speaker 1: the word zombie, I basically just mean an organism where 369 00:17:41,960 --> 00:17:44,880 Speaker 1: a significant amount of its behaviors seem to be under 370 00:17:44,880 --> 00:17:48,400 Speaker 1: the control of another critter, and those behaviors are good 371 00:17:48,520 --> 00:17:51,400 Speaker 1: for the parasite but usually bad for the host. 372 00:17:51,720 --> 00:17:54,399 Speaker 2: All right, well, let's take a break because I definitely 373 00:17:54,480 --> 00:17:57,159 Speaker 2: need one, and come back and hear all about the 374 00:17:57,240 --> 00:18:20,840 Speaker 2: details of how this fungus controls this an. Okay, we're back, 375 00:18:20,880 --> 00:18:22,760 Speaker 2: and we're talking about the name of a fungus that 376 00:18:22,840 --> 00:18:27,000 Speaker 2: I cannot pronounce but is amazingly adept at manipulating ants. 377 00:18:27,400 --> 00:18:29,680 Speaker 1: This is a really nice like turn of the tables. 378 00:18:29,760 --> 00:18:32,359 Speaker 1: Usually I'm the one who can't pronounce things. We've got 379 00:18:32,480 --> 00:18:36,920 Speaker 1: to do more episodes with like complex latinate names. But okay, 380 00:18:37,480 --> 00:18:39,200 Speaker 1: So one of the first things I think is so 381 00:18:39,359 --> 00:18:44,479 Speaker 1: amazing about this system is that it evades the social 382 00:18:44,600 --> 00:18:49,240 Speaker 1: immune system that ants have. So ants are very genetically 383 00:18:49,520 --> 00:18:51,560 Speaker 1: related to one another, and they work together for this 384 00:18:51,720 --> 00:18:55,040 Speaker 1: common goal of like helping the queen create more offspring 385 00:18:55,119 --> 00:18:55,639 Speaker 1: and stuff like that. 386 00:18:55,920 --> 00:18:58,560 Speaker 2: And they have complex fractional relationships, right, It's not just 387 00:18:58,680 --> 00:19:01,040 Speaker 2: like you have kids that are half you. You're like 388 00:19:01,480 --> 00:19:03,440 Speaker 2: related by a quarter or a sixth or a third 389 00:19:03,560 --> 00:19:04,760 Speaker 2: or something complicated. Right. 390 00:19:04,880 --> 00:19:07,200 Speaker 1: I think it's like three quarters. Like you're way more 391 00:19:07,240 --> 00:19:09,520 Speaker 1: closely related than like, you know, my brother and I 392 00:19:09,600 --> 00:19:12,879 Speaker 1: would be, for example, typical siblings, and so they're like, 393 00:19:13,000 --> 00:19:16,359 Speaker 1: you know, pretty close to you genetically. And so this 394 00:19:16,560 --> 00:19:19,840 Speaker 1: tends to result in what look like ultruistic behaviors. And 395 00:19:20,080 --> 00:19:22,280 Speaker 1: so if one of the ants comes into the colony 396 00:19:23,040 --> 00:19:26,879 Speaker 1: and is clearly infected with something, the nest has a 397 00:19:27,040 --> 00:19:30,240 Speaker 1: like social immune response where other nestmates will be like, oh, 398 00:19:30,680 --> 00:19:33,400 Speaker 1: you can't bring that in here, man, and they will 399 00:19:33,560 --> 00:19:36,200 Speaker 1: in some cases kill that ant and then go put 400 00:19:36,240 --> 00:19:39,440 Speaker 1: it in like a graveyard somewhere far away from the 401 00:19:39,520 --> 00:19:41,439 Speaker 1: nest so that it can't infect the rest of the. 402 00:19:41,480 --> 00:19:43,760 Speaker 2: Nest based just on the behavior. It's not like it's 403 00:19:43,800 --> 00:19:45,320 Speaker 2: giving off some pheromones or something. 404 00:19:45,600 --> 00:19:46,840 Speaker 1: I think in a lot of cases we don't know 405 00:19:46,920 --> 00:19:49,080 Speaker 1: exactly how the nest mats can tell. It's probably some 406 00:19:49,160 --> 00:19:51,760 Speaker 1: combination of behaviors. And then ants are a species that 407 00:19:51,840 --> 00:19:54,480 Speaker 1: in particular tends to communicate a lot with chemical cues. 408 00:19:54,840 --> 00:19:57,119 Speaker 1: So it could be that they sort of smell or 409 00:19:57,200 --> 00:20:00,400 Speaker 1: whatever taste and nestmate and they're like, no, that's it's weird. 410 00:20:00,960 --> 00:20:03,639 Speaker 1: We're kicking you out, Daniel. 411 00:20:03,680 --> 00:20:04,920 Speaker 2: You taste funny. We're killing you. 412 00:20:05,080 --> 00:20:06,879 Speaker 1: Yeah, that's right, that's right, Daniel. It's not how your 413 00:20:06,920 --> 00:20:09,159 Speaker 1: forehead is supposed to taste. And I licked it and 414 00:20:09,280 --> 00:20:13,560 Speaker 1: now you can't live here anymore. Danchel, danchel. And so anyway, 415 00:20:13,720 --> 00:20:18,200 Speaker 1: so usually when an infected nest mate comes back, it 416 00:20:18,280 --> 00:20:21,480 Speaker 1: gets picked up on and they get killed and kicked out. 417 00:20:21,680 --> 00:20:22,480 Speaker 2: Brutal but fair. 418 00:20:22,760 --> 00:20:24,760 Speaker 1: Brutal but fair. And this is a pathogen that you 419 00:20:24,880 --> 00:20:26,760 Speaker 1: would want to put a stop to. So you know, 420 00:20:27,440 --> 00:20:30,240 Speaker 1: if they don't capture this individual and kill it, it 421 00:20:30,400 --> 00:20:34,200 Speaker 1: is going to create essentially like a stock of infectious 422 00:20:34,240 --> 00:20:37,760 Speaker 1: propagules nearby. So anyway, there should be selective pressure for 423 00:20:37,920 --> 00:20:38,240 Speaker 1: this part. 424 00:20:38,240 --> 00:20:41,120 Speaker 2: And so how does it evade this selective pressure? Why 425 00:20:41,200 --> 00:20:42,240 Speaker 2: can't the other ants tell? 426 00:20:42,520 --> 00:20:44,840 Speaker 1: So we don't have a great handle on why the 427 00:20:44,920 --> 00:20:47,000 Speaker 1: other ants can't tell. Part of it seems to be 428 00:20:47,280 --> 00:20:49,639 Speaker 1: that in at least some systems. So I'm going to 429 00:20:49,720 --> 00:20:52,280 Speaker 1: be talking about this system like every system acts the 430 00:20:52,320 --> 00:20:54,560 Speaker 1: same way, but just sort of like with the tartar grades. 431 00:20:54,960 --> 00:20:58,479 Speaker 1: Some questions have been asked in one ophiocordycep species infecting 432 00:20:58,560 --> 00:21:01,200 Speaker 1: one ant species. Some questions been asked in other systems, 433 00:21:01,560 --> 00:21:03,080 Speaker 1: but we're going to mix and match for the purpose 434 00:21:03,119 --> 00:21:06,119 Speaker 1: of this show. But there's the disclaimer. So some ants, 435 00:21:06,359 --> 00:21:09,159 Speaker 1: the timing of their behavior changes and they interact with 436 00:21:09,320 --> 00:21:12,560 Speaker 1: nestmates less often, and so part of the story might 437 00:21:12,640 --> 00:21:15,119 Speaker 1: be that instead of just like blindly going into the 438 00:21:15,240 --> 00:21:18,760 Speaker 1: nest and then getting found out, these ants that are 439 00:21:18,800 --> 00:21:21,720 Speaker 1: infected are avoiding nest mates so they never get found out, 440 00:21:21,800 --> 00:21:25,040 Speaker 1: they never get their forehead licked, and so so they're 441 00:21:25,080 --> 00:21:27,040 Speaker 1: able to escape in that way. It could also be 442 00:21:27,480 --> 00:21:30,200 Speaker 1: like the scent of the fungus is being masked in 443 00:21:30,280 --> 00:21:33,200 Speaker 1: some way, but through mechanisms we don't understand, it manages 444 00:21:33,320 --> 00:21:35,440 Speaker 1: to evade the social immunity of the nest. 445 00:21:35,760 --> 00:21:36,000 Speaker 2: Wow. 446 00:21:36,280 --> 00:21:38,639 Speaker 1: Amazing, Yeah, pretty cool. All right, So now you've got 447 00:21:38,720 --> 00:21:41,639 Speaker 1: this ant that's infected. It's nest mates haven't killed it 448 00:21:41,720 --> 00:21:44,400 Speaker 1: like they probably should have, and then at some point 449 00:21:44,920 --> 00:21:48,400 Speaker 1: it's does that Drunkard's walk, and we don't really understand 450 00:21:48,560 --> 00:21:52,240 Speaker 1: why that drunkard's walk happens. But there is a chemical 451 00:21:52,440 --> 00:21:57,359 Speaker 1: that's produced by the ant that is associated with something 452 00:21:57,400 --> 00:22:01,480 Speaker 1: that causes like staggering and seizures and other insects. And 453 00:22:01,640 --> 00:22:03,600 Speaker 1: so we think that it's going out there and it's 454 00:22:03,600 --> 00:22:05,880 Speaker 1: starting to do this staggering thing because of some chemicals 455 00:22:05,920 --> 00:22:08,440 Speaker 1: produced by the fungus. It gets down to the forest floor, 456 00:22:09,040 --> 00:22:11,639 Speaker 1: and now the interesting question is how does it know 457 00:22:11,760 --> 00:22:13,920 Speaker 1: where to go? So this is the Summit disease part. 458 00:22:14,000 --> 00:22:16,920 Speaker 1: It starts climbing up, but we're trying to figure out 459 00:22:17,000 --> 00:22:18,680 Speaker 1: how does it know where to stop? How does it 460 00:22:18,800 --> 00:22:20,320 Speaker 1: know where a good spot is. 461 00:22:20,800 --> 00:22:23,280 Speaker 2: Well, it's very confusing to me that the behavior is 462 00:22:23,320 --> 00:22:26,879 Speaker 2: so complex that it includes climbing down and then climbing up, 463 00:22:27,400 --> 00:22:29,680 Speaker 2: Like I could see it somehow is pulling on some 464 00:22:30,359 --> 00:22:32,520 Speaker 2: lever inside the brain to make it go up, to 465 00:22:32,560 --> 00:22:34,160 Speaker 2: make it go down, but to make it go down 466 00:22:34,280 --> 00:22:37,480 Speaker 2: and then up like that's really amazing. 467 00:22:37,840 --> 00:22:39,680 Speaker 1: That is really amazing. I mean, I think part of 468 00:22:39,800 --> 00:22:42,520 Speaker 1: the selection pressure there. And this is just me telling 469 00:22:42,560 --> 00:22:44,920 Speaker 1: a story. I haven't I don't know that we've tested this, 470 00:22:45,040 --> 00:22:48,360 Speaker 1: but if the ant had gone down, it's probably one 471 00:22:48,440 --> 00:22:51,199 Speaker 1: going down a big trunk, and they tend to attach 472 00:22:51,320 --> 00:22:53,200 Speaker 1: to like thin stems, and we'll get into that in 473 00:22:53,240 --> 00:22:55,879 Speaker 1: a second. But also if it just kind of clung 474 00:22:56,000 --> 00:22:58,399 Speaker 1: in an area where foraging ants would be going up 475 00:22:58,440 --> 00:23:01,480 Speaker 1: and down. Anyway, if a four ant sees a dead 476 00:23:01,560 --> 00:23:03,760 Speaker 1: ant with a stalk coming out of its neck, that 477 00:23:04,000 --> 00:23:06,640 Speaker 1: it is going to throw over into the trash can, 478 00:23:06,880 --> 00:23:08,800 Speaker 1: and so that would be the end for the fungus too. 479 00:23:09,160 --> 00:23:12,160 Speaker 2: So that tells us why that strategy, the simpler strategy 480 00:23:12,200 --> 00:23:15,359 Speaker 2: wouldn't work of just like clinging to the tree. But 481 00:23:15,480 --> 00:23:18,159 Speaker 2: it leaves us still impressed with this complex strategy of 482 00:23:18,200 --> 00:23:19,840 Speaker 2: climbing down and then climbing up. 483 00:23:19,960 --> 00:23:22,560 Speaker 1: Right, And so let me go ahead and jump ahead 484 00:23:22,640 --> 00:23:25,480 Speaker 1: a little bit to the benefit of climbing back up again. 485 00:23:25,600 --> 00:23:28,600 Speaker 1: So there's been an experiment done where they took ants 486 00:23:28,720 --> 00:23:31,240 Speaker 1: that had like settled in at a particular location and 487 00:23:31,359 --> 00:23:33,040 Speaker 1: they cut the leaf off that the ant was on 488 00:23:33,160 --> 00:23:35,760 Speaker 1: and they moved it up. And when you move it up, 489 00:23:36,600 --> 00:23:39,399 Speaker 1: the temperature and the humidity are no longer good for 490 00:23:39,440 --> 00:23:41,840 Speaker 1: the fungus, and the fungus can't make that stalk and 491 00:23:41,920 --> 00:23:45,040 Speaker 1: it can't make the infectious propagules that rain down on 492 00:23:45,160 --> 00:23:48,440 Speaker 1: the other foragers, and so there is this like kind 493 00:23:48,480 --> 00:23:50,720 Speaker 1: of narrow band that the fungus needs to be in 494 00:23:50,960 --> 00:23:53,879 Speaker 1: in order to complete its development. And so you know, 495 00:23:54,000 --> 00:23:56,040 Speaker 1: it takes some work to find exactly the right spot. 496 00:23:56,440 --> 00:23:59,520 Speaker 2: And it's fascinating to me to imagine all the evolutionary 497 00:23:59,560 --> 00:24:01,840 Speaker 2: dead ends. You know, ants that just went down and 498 00:24:01,920 --> 00:24:04,560 Speaker 2: never climbed up, ants that climbed up the tree instead 499 00:24:04,720 --> 00:24:08,720 Speaker 2: and didn't propagate. It's incredible that this whole thing came together. 500 00:24:09,040 --> 00:24:11,399 Speaker 1: Yeah, yeah, it really is well, and I'm sure that 501 00:24:11,480 --> 00:24:14,320 Speaker 1: a lot of times when researchers go out to study 502 00:24:14,840 --> 00:24:16,680 Speaker 1: this kind of stuff, like you know, if you're too low, 503 00:24:16,800 --> 00:24:19,640 Speaker 1: then spiders and other scavengers come along and they'll eat 504 00:24:20,000 --> 00:24:23,680 Speaker 1: the zombie ant. And so there's probably some instances where 505 00:24:23,840 --> 00:24:26,800 Speaker 1: the ant dies and the wrong spot, but the researchers 506 00:24:26,880 --> 00:24:29,000 Speaker 1: never find it because something is eating it and it's gone. 507 00:24:29,160 --> 00:24:31,040 Speaker 1: So you know, you do the best you can with 508 00:24:31,119 --> 00:24:31,880 Speaker 1: the data you've got. 509 00:24:32,160 --> 00:24:34,200 Speaker 2: So tell us about this climbing up. How does it 510 00:24:34,400 --> 00:24:38,560 Speaker 2: know where to stop that it gets this right height? Like, 511 00:24:38,640 --> 00:24:40,840 Speaker 2: do we understand the mechanisms for how it knows how 512 00:24:40,920 --> 00:24:43,000 Speaker 2: high it is. It's not like doing GPS or something. 513 00:24:43,960 --> 00:24:47,440 Speaker 1: So we think it's queuing in on light, which is 514 00:24:47,480 --> 00:24:50,000 Speaker 1: amazing to me because it's inside the body of an ant, 515 00:24:50,080 --> 00:24:52,399 Speaker 1: and so how is it getting information about light? So 516 00:24:52,720 --> 00:24:55,520 Speaker 1: what they did was they found what's called ant graveyards, 517 00:24:55,680 --> 00:24:59,760 Speaker 1: So the ants tend to accumulate in certain areas of 518 00:24:59,760 --> 00:25:01,920 Speaker 1: the and so they're like, Okay, we know this is 519 00:25:01,960 --> 00:25:04,359 Speaker 1: an area that's good because the fungus have chosen to 520 00:25:04,400 --> 00:25:06,879 Speaker 1: be here before. And then they put a little bit 521 00:25:06,920 --> 00:25:10,240 Speaker 1: of a light shade over the zombie graveyard and so 522 00:25:10,320 --> 00:25:12,119 Speaker 1: now that area is getting a little bit less light 523 00:25:12,160 --> 00:25:14,440 Speaker 1: than it was getting before. And what they found was 524 00:25:14,440 --> 00:25:17,040 Speaker 1: that if you go back in future weeks, that area 525 00:25:17,160 --> 00:25:20,760 Speaker 1: doesn't get as many new ants as nearby areas that 526 00:25:20,920 --> 00:25:23,720 Speaker 1: have more light. So it looks like the fungus is 527 00:25:23,800 --> 00:25:26,960 Speaker 1: driving the ants towards areas that have certain amounts of light. 528 00:25:27,640 --> 00:25:30,680 Speaker 1: And then they looked there were still some newly infected 529 00:25:30,760 --> 00:25:33,639 Speaker 1: ants that went into the areas with the shades, and 530 00:25:33,720 --> 00:25:36,160 Speaker 1: if you followed what was happening with that fungus, overtime, 531 00:25:36,280 --> 00:25:39,399 Speaker 1: the fungus was less able to produce those stalks and 532 00:25:39,520 --> 00:25:41,680 Speaker 1: produce I'm just gonna call them baby fungus because no 533 00:25:41,720 --> 00:25:44,119 Speaker 1: one wants to hear me try to say propagule again. 534 00:25:44,640 --> 00:25:48,360 Speaker 1: So less baby fungus gets made in areas where you've 535 00:25:48,359 --> 00:25:50,000 Speaker 1: got these shades, I see. 536 00:25:50,160 --> 00:25:52,680 Speaker 2: And so the ants are using the light as a 537 00:25:52,760 --> 00:25:55,680 Speaker 2: queue for where to go. Is the light important in 538 00:25:55,800 --> 00:25:57,879 Speaker 2: making the baby funguses or is it just like a 539 00:25:57,960 --> 00:26:00,280 Speaker 2: signal to the fungus of when the ant has crawled 540 00:26:00,320 --> 00:26:01,040 Speaker 2: up to the right height. 541 00:26:01,520 --> 00:26:04,440 Speaker 1: I think that the light is used as a proxy 542 00:26:04,520 --> 00:26:07,680 Speaker 1: for information about temperature and humidity. And it could be 543 00:26:07,760 --> 00:26:09,560 Speaker 1: that the light is important for some way too. I 544 00:26:09,560 --> 00:26:13,200 Speaker 1: don't a fungus. I don't know, but nature's complicated, but 545 00:26:13,359 --> 00:26:15,760 Speaker 1: it does look like things like temperature and humidity and 546 00:26:15,920 --> 00:26:18,560 Speaker 1: light are all important for the way the fungus is 547 00:26:18,600 --> 00:26:19,240 Speaker 1: able to develop. 548 00:26:19,280 --> 00:26:20,600 Speaker 2: Wow. Fascinating. 549 00:26:20,840 --> 00:26:22,919 Speaker 1: And this is the part that you see another insects too. 550 00:26:22,920 --> 00:26:25,960 Speaker 1: We I talked about those zombie flies and those caterpillars. 551 00:26:26,359 --> 00:26:30,000 Speaker 1: This climbing up thing happens in a lot of insects systems. 552 00:26:30,240 --> 00:26:32,359 Speaker 2: And then you said they also bite down, they like 553 00:26:32,560 --> 00:26:35,440 Speaker 2: clamp onto this plant. Why is that part important? Is 554 00:26:35,480 --> 00:26:37,000 Speaker 2: it because the ant's going to die and you want 555 00:26:37,040 --> 00:26:37,600 Speaker 2: it to stay there. 556 00:26:37,960 --> 00:26:39,800 Speaker 1: Yeah, so you want the ant to stay put. And 557 00:26:39,960 --> 00:26:42,760 Speaker 1: so in the tropics, what happens is they find a leaf, 558 00:26:43,160 --> 00:26:46,040 Speaker 1: they crawl along the bottom of the leaf, along the 559 00:26:46,119 --> 00:26:49,320 Speaker 1: major leaf veanes, and the ants will clamp down with 560 00:26:49,440 --> 00:26:52,640 Speaker 1: their mandibles. They've got these pincers and their muscles will 561 00:26:52,760 --> 00:26:56,680 Speaker 1: like hyper contract, so though like really strongly bite down, 562 00:26:57,119 --> 00:26:59,200 Speaker 1: and then the ants will never be able to open 563 00:26:59,240 --> 00:27:01,360 Speaker 1: their mandibles again and they will die there. 564 00:27:01,560 --> 00:27:01,760 Speaker 3: Wow. 565 00:27:02,000 --> 00:27:04,800 Speaker 1: And so that's how they hold on. And this is 566 00:27:04,880 --> 00:27:07,560 Speaker 1: called the death grip. And one of the things that's 567 00:27:07,640 --> 00:27:10,040 Speaker 1: interesting is that depending on where you are in the world, 568 00:27:10,520 --> 00:27:12,800 Speaker 1: the death grip will look a little bit different. So 569 00:27:13,000 --> 00:27:15,480 Speaker 1: in the tropics they tend to bite down on leaves, 570 00:27:15,960 --> 00:27:18,880 Speaker 1: but if you go to like North Carolina, for example, 571 00:27:19,160 --> 00:27:22,960 Speaker 1: instead of biting down on leaves, they'll bite down on stems, 572 00:27:23,600 --> 00:27:26,800 Speaker 1: and they'll also wrap their legs around them, and so 573 00:27:26,920 --> 00:27:30,119 Speaker 1: they'll hold on with their legs and with their pincy parts. 574 00:27:30,600 --> 00:27:32,880 Speaker 1: And we think that the reason that they hang out 575 00:27:32,960 --> 00:27:36,000 Speaker 1: on stems instead of leaves in areas that are farther 576 00:27:36,119 --> 00:27:40,159 Speaker 1: north like North Carolina, is because in the tropics, leaves 577 00:27:40,200 --> 00:27:42,680 Speaker 1: really never fall off the trees, or they at least 578 00:27:42,680 --> 00:27:44,800 Speaker 1: don't have a seasonal pattern of falling off in the winter, 579 00:27:45,359 --> 00:27:49,120 Speaker 1: whereas farther north, if you bite down on a leaf, 580 00:27:49,240 --> 00:27:51,680 Speaker 1: you've got until like I don't know, August, September, or 581 00:27:51,720 --> 00:27:54,199 Speaker 1: October before those leaves start to fall off. But if 582 00:27:54,240 --> 00:27:56,399 Speaker 1: you're on the stem, then you can stay up there 583 00:27:56,480 --> 00:28:01,960 Speaker 1: for longer, raining fire down upon the other ants. And 584 00:28:02,040 --> 00:28:04,240 Speaker 1: so it looks like there have been four different instances 585 00:28:04,320 --> 00:28:07,560 Speaker 1: where you've gotten this evolutionary transition from biting down on 586 00:28:07,720 --> 00:28:09,880 Speaker 1: leaves to biting down on things like stems. 587 00:28:10,280 --> 00:28:13,320 Speaker 2: This is fascinating. I love these moments in science when 588 00:28:13,400 --> 00:28:15,879 Speaker 2: you can look at what's going on and unravel it 589 00:28:16,080 --> 00:28:19,760 Speaker 2: and tell a story. I remember Hazel summarizing all of 590 00:28:19,880 --> 00:28:22,920 Speaker 2: science once. She says, like, stuff happened and we figured 591 00:28:22,960 --> 00:28:25,879 Speaker 2: out why, And I'm like, yeah, that's pretty much the 592 00:28:26,160 --> 00:28:30,280 Speaker 2: whole idea. Yes, So by looking at this pattern of 593 00:28:30,359 --> 00:28:33,200 Speaker 2: how things evolve differently in different parts of the world 594 00:28:33,320 --> 00:28:35,719 Speaker 2: where the conditions are slightly different, we start to get 595 00:28:35,760 --> 00:28:38,440 Speaker 2: a sense for how this all came together. That's incredible. 596 00:28:38,560 --> 00:28:41,440 Speaker 1: Yeah, it's really incredible. And I got to see one 597 00:28:41,520 --> 00:28:43,959 Speaker 1: in North Carolina. I'll put a picture on this online 598 00:28:44,000 --> 00:28:46,680 Speaker 1: when it comes out. But we found one in North Carolina, 599 00:28:46,840 --> 00:28:49,960 Speaker 1: and Andrew Turner found it. I was out looking for 600 00:28:50,200 --> 00:28:54,040 Speaker 1: snakes and salamanders. And Andrew Turner, a friend of mine, 601 00:28:54,560 --> 00:28:57,480 Speaker 1: was like, is that a zombie at And I freaked out. 602 00:28:57,880 --> 00:29:00,200 Speaker 1: Anyone in like a one mile radius probably her me 603 00:29:00,240 --> 00:29:02,040 Speaker 1: screamed because I didn't think I was going to get 604 00:29:02,040 --> 00:29:04,000 Speaker 1: to see a zombie ant. So anyway, I've seen them 605 00:29:04,000 --> 00:29:06,280 Speaker 1: in North Carolina. And then Andrew Turner put one in 606 00:29:06,480 --> 00:29:08,600 Speaker 1: like a resin for me, and so I've got it 607 00:29:08,680 --> 00:29:10,280 Speaker 1: on my desk and it is my favorite. 608 00:29:10,360 --> 00:29:11,120 Speaker 2: And what are we looking at? 609 00:29:11,200 --> 00:29:14,120 Speaker 1: We are looking at this is a bit of stem 610 00:29:14,800 --> 00:29:17,320 Speaker 1: and on the bottom there's an ant that's got its 611 00:29:17,440 --> 00:29:20,520 Speaker 1: legs wrapped around the stem. It's biting down with its mandibles. 612 00:29:20,560 --> 00:29:22,560 Speaker 1: You can see it's got a big stalk coming out 613 00:29:22,560 --> 00:29:25,120 Speaker 1: of the side of its head. The spore that the 614 00:29:26,080 --> 00:29:28,239 Speaker 1: fungus would come out of is kind of small. It's 615 00:29:28,280 --> 00:29:30,840 Speaker 1: hard to see, but it's about maybe three quarters of 616 00:29:30,880 --> 00:29:33,240 Speaker 1: the way up the stem. Best thing I own. 617 00:29:35,480 --> 00:29:36,880 Speaker 2: You have children too, don't for care. 618 00:29:37,080 --> 00:29:41,000 Speaker 1: I don't own them. You know, they could choose to 619 00:29:41,080 --> 00:29:43,320 Speaker 1: leave at one point, but this will never leave. 620 00:29:46,440 --> 00:29:49,160 Speaker 2: It's a special place in your heart. It is all right. 621 00:29:49,400 --> 00:29:52,640 Speaker 1: So the ant bites down. And one of the cool 622 00:29:52,680 --> 00:29:54,720 Speaker 1: things about this, what we call a death grip, is 623 00:29:54,800 --> 00:29:58,280 Speaker 1: that it leaves a very distinctive mark. So if you 624 00:29:58,400 --> 00:30:01,160 Speaker 1: find leaves, you'll see the they've got. It looks like, 625 00:30:01,240 --> 00:30:04,959 Speaker 1: you know, like scissors cut on either side of the veins. 626 00:30:05,520 --> 00:30:09,320 Speaker 1: And there are forty eight million year old leaf fossils 627 00:30:09,680 --> 00:30:13,240 Speaker 1: from Germany that have these little scissor cuts in them, 628 00:30:13,600 --> 00:30:17,440 Speaker 1: and we think that these are like essentially fossil records 629 00:30:17,480 --> 00:30:20,520 Speaker 1: of behavior showing that like around the time a bunch 630 00:30:20,560 --> 00:30:24,280 Speaker 1: of the different mammalian species we're sort of evolving into existence, 631 00:30:25,000 --> 00:30:27,480 Speaker 1: this manipulation was already happening. And you know, you can't 632 00:30:27,480 --> 00:30:29,520 Speaker 1: be one hundred percent sure the ants weren't still attached 633 00:30:29,560 --> 00:30:31,960 Speaker 1: or anything like that, but it's indirect evidence that this 634 00:30:32,080 --> 00:30:35,040 Speaker 1: is sort of an ancient association and a manipulation that's 635 00:30:35,080 --> 00:30:37,280 Speaker 1: been going on for longer than humans have been on 636 00:30:37,320 --> 00:30:37,800 Speaker 1: this planet. 637 00:30:38,040 --> 00:30:40,960 Speaker 2: And so when the ant mandibles do this hyper contraction, 638 00:30:41,120 --> 00:30:43,160 Speaker 2: they make a special sort of pattern that they can't 639 00:30:43,280 --> 00:30:45,960 Speaker 2: otherwise make because it's just the ant mandible, right, It's 640 00:30:45,960 --> 00:30:48,640 Speaker 2: not like, how is this pattern different from a normal 641 00:30:48,760 --> 00:30:49,360 Speaker 2: ant chomp. 642 00:30:49,800 --> 00:30:51,680 Speaker 1: So, first of all, a lot of ants don't chomp 643 00:30:51,880 --> 00:30:53,760 Speaker 1: around leaf veans like this, So you might be thinking 644 00:30:53,760 --> 00:30:57,320 Speaker 1: about leaf cutter ants, and leaf cutter ants will cut 645 00:30:57,400 --> 00:30:59,560 Speaker 1: out like chunks of leaves and bring them back to 646 00:30:59,640 --> 00:31:02,400 Speaker 1: their net so that they can they feed them to fungus, 647 00:31:02,440 --> 00:31:05,640 Speaker 1: and that they're sort of like a farming situation. But anyway, 648 00:31:06,000 --> 00:31:10,320 Speaker 1: ants don't usually just go and like chomp down on 649 00:31:10,560 --> 00:31:13,480 Speaker 1: leafs around the veins and then do nothing else with it. 650 00:31:14,440 --> 00:31:16,560 Speaker 2: I see. So it's also the location of the chump. 651 00:31:16,800 --> 00:31:19,880 Speaker 1: Yeah, it's also the location of the chump. Wow, amazing, Yeah, 652 00:31:19,920 --> 00:31:22,360 Speaker 1: pretty cool. And so you tend to get aggregations in 653 00:31:22,440 --> 00:31:25,520 Speaker 1: these good parts of the forest where the conditions are 654 00:31:25,560 --> 00:31:27,560 Speaker 1: good for fungal growth, and so you end up with 655 00:31:27,680 --> 00:31:30,000 Speaker 1: these ant graveyards where you've got a bunch of these 656 00:31:30,120 --> 00:31:33,880 Speaker 1: zombified ants hanging on the underside of stems or leaves, 657 00:31:34,280 --> 00:31:37,600 Speaker 1: raining fungal spores down on their nest mates below. 658 00:31:38,040 --> 00:31:40,920 Speaker 2: And does the fungus actually kill the ant or does 659 00:31:41,000 --> 00:31:43,880 Speaker 2: this sort of death march end up exhausting the ant 660 00:31:44,000 --> 00:31:44,960 Speaker 2: or why does the ant die? 661 00:31:45,200 --> 00:31:47,440 Speaker 1: I don't know if the ant dies, because once it 662 00:31:47,560 --> 00:31:49,960 Speaker 1: bites down, it can't use its mandibles again. I don't 663 00:31:49,960 --> 00:31:52,320 Speaker 1: know if it just eventually dies because it runs out 664 00:31:52,320 --> 00:31:54,760 Speaker 1: of energy, or if the fungus kills it, but I 665 00:31:54,840 --> 00:31:57,160 Speaker 1: do know that pretty soon after it bites down, the 666 00:31:57,280 --> 00:32:00,800 Speaker 1: fungus starts consuming the inside of the ant to make 667 00:32:00,880 --> 00:32:02,160 Speaker 1: more fungal tissue instead. 668 00:32:02,400 --> 00:32:05,440 Speaker 2: And how long is it like spraying propagules. 669 00:32:04,840 --> 00:32:07,480 Speaker 1: For That really depends on where you are. I think 670 00:32:07,640 --> 00:32:09,680 Speaker 1: in some parts of the world it happens for like 671 00:32:09,960 --> 00:32:12,680 Speaker 1: just a couple months. I think in some areas, I 672 00:32:12,760 --> 00:32:15,440 Speaker 1: think it can happen for like a year. That really 673 00:32:15,480 --> 00:32:16,920 Speaker 1: depends on the environment that you're in. 674 00:32:17,320 --> 00:32:19,080 Speaker 2: All Right, and let's take a break, and when we 675 00:32:19,200 --> 00:32:21,560 Speaker 2: come back, we'll hear about how this benefits the fungus 676 00:32:21,640 --> 00:32:45,240 Speaker 2: and how the ant manages to pull this all off. Okay, 677 00:32:45,280 --> 00:32:47,360 Speaker 2: we're back, and we're talking about the death march of 678 00:32:47,560 --> 00:32:51,840 Speaker 2: zombie ants. Kelly, tell us why the fungus makes this happen. 679 00:32:52,000 --> 00:32:55,080 Speaker 2: Why can't the fungus just find some other friendlier way 680 00:32:55,200 --> 00:32:56,040 Speaker 2: to spread itself. 681 00:32:57,720 --> 00:32:59,600 Speaker 1: I don't know why it doesn't find a friendlier way 682 00:32:59,640 --> 00:33:01,360 Speaker 1: to do it, but we do know that this method 683 00:33:01,440 --> 00:33:03,520 Speaker 1: seems to work for the fungus. As we sort of 684 00:33:03,640 --> 00:33:06,960 Speaker 1: hinted at earlier. It's actually pretty easy to move these 685 00:33:07,080 --> 00:33:09,920 Speaker 1: ants to different places to test out, like where would 686 00:33:09,960 --> 00:33:12,560 Speaker 1: the best place be for these ants to have settled down, 687 00:33:12,920 --> 00:33:14,680 Speaker 1: so you can cut off a leaf, And if you 688 00:33:14,800 --> 00:33:17,280 Speaker 1: move it up too high, as we mentioned earlier, the 689 00:33:17,400 --> 00:33:20,840 Speaker 1: temperature and humidity and lightning conditions are just not good 690 00:33:20,920 --> 00:33:23,880 Speaker 1: and the fungus will essentially never be able to produce 691 00:33:24,040 --> 00:33:26,360 Speaker 1: that stock that makes the spores. And so that's the 692 00:33:26,480 --> 00:33:29,000 Speaker 1: end of the line for the fungus. Not great. And 693 00:33:29,240 --> 00:33:31,080 Speaker 1: if you move it down too low, it gets found 694 00:33:31,160 --> 00:33:34,160 Speaker 1: by scavengers. And so unlike a lot of other examples 695 00:33:34,200 --> 00:33:36,440 Speaker 1: where we have a nice story, here we've been able 696 00:33:36,480 --> 00:33:39,200 Speaker 1: to manipulate the system a little bit and say, you know, look, 697 00:33:39,240 --> 00:33:41,600 Speaker 1: if you do something different than what we're seeing, the 698 00:33:41,680 --> 00:33:44,360 Speaker 1: fungus is quite clearly doing less well. The fungus either 699 00:33:44,400 --> 00:33:46,600 Speaker 1: gets eaten and killed or it can't make babies. 700 00:33:46,800 --> 00:33:49,120 Speaker 2: I'm still sort of amazed that this whole thing works, 701 00:33:49,200 --> 00:33:52,240 Speaker 2: Like I can imagine a fungus infecting an and and 702 00:33:52,360 --> 00:33:54,800 Speaker 2: it makes a small change in the ant's behavior, and 703 00:33:54,960 --> 00:33:57,600 Speaker 2: maybe that benefits it a little bit, But this benefit 704 00:33:57,680 --> 00:34:00,880 Speaker 2: requires such complex behavior for the antigodam and then across 705 00:34:00,960 --> 00:34:02,840 Speaker 2: and then up and then bite and all this stuff. 706 00:34:03,160 --> 00:34:05,959 Speaker 2: All these pieces have to basically fall into place due 707 00:34:06,000 --> 00:34:08,640 Speaker 2: to random mutation. So how do you get all the 708 00:34:08,680 --> 00:34:11,400 Speaker 2: way to this complex behavior when none of the individual 709 00:34:11,440 --> 00:34:13,840 Speaker 2: pieces on their own are going to benefit the fungus. 710 00:34:14,200 --> 00:34:16,759 Speaker 1: Yeah, that's a great question. So one thing that's worth 711 00:34:16,840 --> 00:34:18,960 Speaker 1: noting is that, you know, as we've mentioned earlier, this 712 00:34:19,040 --> 00:34:22,719 Speaker 1: summoning disease thing happens pretty often. So it suggests that 713 00:34:22,800 --> 00:34:26,320 Speaker 1: there's something about insects where it's not too hard to 714 00:34:26,400 --> 00:34:29,560 Speaker 1: manipulate their ability to go up or stay up. And 715 00:34:29,719 --> 00:34:32,200 Speaker 1: so a number of different kinds of parasites and pathogens 716 00:34:32,239 --> 00:34:34,560 Speaker 1: have found the switch. I can't say I'm an expert 717 00:34:34,640 --> 00:34:36,080 Speaker 1: on what that switch is, but there's a couple of 718 00:34:36,080 --> 00:34:39,239 Speaker 1: different routes to up and stay there. But you can 719 00:34:39,360 --> 00:34:42,360 Speaker 1: imagine that this happened, you know, step by step. So 720 00:34:42,440 --> 00:34:45,520 Speaker 1: maybe the first thing that happened was that ants that 721 00:34:45,560 --> 00:34:47,560 Speaker 1: were starting to show signs of being infected by the 722 00:34:47,600 --> 00:34:50,560 Speaker 1: fungus left the nest so that the nestmates didn't kill them, 723 00:34:50,760 --> 00:34:53,239 Speaker 1: and maybe they died on the forest floor. And then 724 00:34:53,280 --> 00:34:56,120 Speaker 1: there happens to be an ant that climbed up a 725 00:34:56,200 --> 00:34:59,160 Speaker 1: little bit before it died, and that helped the fungus 726 00:34:59,560 --> 00:35:01,560 Speaker 1: relative just dying on the floor. And so you can, 727 00:35:01,640 --> 00:35:04,800 Speaker 1: you know, imagine how each step could have happened first 728 00:35:04,960 --> 00:35:08,920 Speaker 1: and then been honed over time. But this is definitely 729 00:35:08,960 --> 00:35:10,320 Speaker 1: one of those things where we have to tell a 730 00:35:10,400 --> 00:35:13,640 Speaker 1: story and we can't be exactly sure what happened in 731 00:35:13,680 --> 00:35:16,239 Speaker 1: what order. I mean, maybe what happened first is that 732 00:35:16,640 --> 00:35:18,759 Speaker 1: the ants that are infected by a fungus would die 733 00:35:18,880 --> 00:35:21,120 Speaker 1: high up and they'd never go back to their nest. 734 00:35:21,600 --> 00:35:24,200 Speaker 1: And maybe the nest stuff came later by some ant 735 00:35:24,239 --> 00:35:27,480 Speaker 1: that happened to wander back but wasn't discovered for whatever reason. 736 00:35:28,120 --> 00:35:30,120 Speaker 1: And so you know, each step there's selective pressure for 737 00:35:30,239 --> 00:35:34,040 Speaker 1: whatever benefits the fungus more. But the exact path that 738 00:35:34,160 --> 00:35:36,560 Speaker 1: this took. I think the best we can do is speculate. 739 00:35:36,440 --> 00:35:39,040 Speaker 2: I see. But it's plausible to string these complex behaviors 740 00:35:39,080 --> 00:35:43,360 Speaker 2: together because each individual one already does benefit the fungus. 741 00:35:43,680 --> 00:35:46,400 Speaker 2: So that, yeah, that makes sense. I wonder what in 742 00:35:46,480 --> 00:35:49,440 Speaker 2: one hundred million years, this fungus will have this ants doing, like, oh, 743 00:35:49,480 --> 00:35:51,719 Speaker 2: it turns out if they do the macarena before they 744 00:35:51,840 --> 00:35:52,359 Speaker 2: bite down. 745 00:35:55,040 --> 00:35:57,320 Speaker 1: Yeah, yeah, it could be. I mean I would imagine that, like, 746 00:35:57,440 --> 00:36:00,640 Speaker 1: as climate is changing across the planet, the exact location 747 00:36:00,760 --> 00:36:03,920 Speaker 1: where biting down is the most beneficial might change. So 748 00:36:04,000 --> 00:36:06,879 Speaker 1: there might be selection to like tinker with exactly where 749 00:36:06,880 --> 00:36:08,680 Speaker 1: the ants end up so you keep getting the right 750 00:36:08,760 --> 00:36:11,239 Speaker 1: temperature in humidity, and maybe that will be like you know, 751 00:36:11,280 --> 00:36:13,560 Speaker 1: you should go to areas with even less light because 752 00:36:13,560 --> 00:36:15,960 Speaker 1: everything is getting too warm and too hot, and so 753 00:36:16,120 --> 00:36:18,120 Speaker 1: less light will be a little cooler and the temperatures 754 00:36:18,120 --> 00:36:20,840 Speaker 1: will be right anyway, So I can imagine that happening. 755 00:36:21,160 --> 00:36:26,640 Speaker 1: But part of understanding the steps is probably understanding the mechanisms, 756 00:36:26,880 --> 00:36:28,320 Speaker 1: because that gives you some insights. 757 00:36:28,520 --> 00:36:31,439 Speaker 2: Yeah, like what's going on inside the ant that lets 758 00:36:31,480 --> 00:36:34,440 Speaker 2: the fungus? What are these levers that the fungus is pushing? 759 00:36:34,640 --> 00:36:37,120 Speaker 1: Yeah, so first let me just talk briefly about how 760 00:36:37,160 --> 00:36:40,959 Speaker 1: we start answering these questions. So, as we've discussed, there's 761 00:36:41,040 --> 00:36:43,480 Speaker 1: a bunch of different steps here that the fungus is doing, 762 00:36:43,560 --> 00:36:47,040 Speaker 1: and so the answer for how does the fungus manipulate 763 00:36:47,080 --> 00:36:50,960 Speaker 1: behavior probably differs depending on what step you're talking. 764 00:36:50,719 --> 00:36:53,399 Speaker 2: About different ants, different answer. 765 00:36:56,880 --> 00:36:58,719 Speaker 1: Do I tell you often enough? How much I like 766 00:36:58,800 --> 00:37:01,320 Speaker 1: working with you, Daniel, because I really do. 767 00:37:01,560 --> 00:37:03,680 Speaker 2: I'm just going for the easy puns because somebody has to. 768 00:37:03,920 --> 00:37:07,360 Speaker 1: I know, the dad jokes, the amazing dad jokes. So 769 00:37:07,760 --> 00:37:09,359 Speaker 1: the way that you know, for example, if you're trying 770 00:37:09,400 --> 00:37:12,319 Speaker 1: to figure out what differs between an ant that gets 771 00:37:12,360 --> 00:37:15,760 Speaker 1: ignored by its nest mates and an ant that gets dumped, 772 00:37:16,200 --> 00:37:19,480 Speaker 1: well you can, for example, infect some ants with ofio 773 00:37:19,560 --> 00:37:22,480 Speaker 1: cordyceps and other ants with a different kind of fungus 774 00:37:22,840 --> 00:37:25,879 Speaker 1: and send them both into a nest and see how 775 00:37:26,040 --> 00:37:29,239 Speaker 1: they interact differently with their nest mates, how the nestmates 776 00:37:29,280 --> 00:37:32,480 Speaker 1: interact differently with them, And then you can look at 777 00:37:32,520 --> 00:37:35,759 Speaker 1: the different chemical profiles and say, like this one is 778 00:37:35,920 --> 00:37:38,920 Speaker 1: emitting these chemicals and this one is emitting these chemicals, 779 00:37:38,960 --> 00:37:40,840 Speaker 1: and then try to figure out, you know, is the 780 00:37:41,400 --> 00:37:44,680 Speaker 1: fungus is ofio cord aceps producing some chemicals that the 781 00:37:44,760 --> 00:37:47,719 Speaker 1: other fungus doesn't produce, and then start looking into those 782 00:37:47,800 --> 00:37:49,359 Speaker 1: as candidates for what's happening there. 783 00:37:49,560 --> 00:37:51,960 Speaker 2: Do you need an IRB for these kinds of experiments 784 00:37:52,160 --> 00:37:54,880 Speaker 2: or can we just experiment willy nilly on ants? Do 785 00:37:55,000 --> 00:37:55,879 Speaker 2: ants have any rights? 786 00:37:56,000 --> 00:37:58,880 Speaker 1: That's a good question. So IRBs are almost exclusively for humans, 787 00:37:59,000 --> 00:38:00,759 Speaker 1: so you don't need an You. 788 00:38:00,760 --> 00:38:03,719 Speaker 2: Can't just experiment on dogs and chimps and rats, right, 789 00:38:03,840 --> 00:38:05,440 Speaker 2: there's some ethics there, yep. 790 00:38:05,520 --> 00:38:07,799 Speaker 1: For dogs and chimps and rats, you need an institutional 791 00:38:07,880 --> 00:38:10,759 Speaker 1: Animal Care and Use Committee protocol and you have to 792 00:38:10,880 --> 00:38:12,960 Speaker 1: jump through many hoops to make that happen, which which 793 00:38:13,000 --> 00:38:17,040 Speaker 1: we'll talk about on another episode. But for invertebrates like ants, 794 00:38:17,480 --> 00:38:20,320 Speaker 1: you don't need to do those kinds of protocols. But 795 00:38:20,480 --> 00:38:22,440 Speaker 1: I will say that everyone who I've ever talked to 796 00:38:22,560 --> 00:38:27,120 Speaker 1: who works with animals, even just little ants, gets pretty 797 00:38:27,160 --> 00:38:29,880 Speaker 1: emotionally attached to them, and they do worry about, like 798 00:38:29,960 --> 00:38:32,160 Speaker 1: how do I euthanize this ant to get my data 799 00:38:32,320 --> 00:38:35,400 Speaker 1: in the way that will like make it fastest. And 800 00:38:35,800 --> 00:38:37,120 Speaker 1: you know, I don't think we really know if ants 801 00:38:37,160 --> 00:38:40,080 Speaker 1: feel pain or not, but like, if they do, how 802 00:38:40,239 --> 00:38:41,719 Speaker 1: could we do it so that they'll feel the least 803 00:38:41,760 --> 00:38:42,399 Speaker 1: amount of pain? 804 00:38:42,640 --> 00:38:45,800 Speaker 2: So nobody's just callously grinding up ants. They're like shedding 805 00:38:45,840 --> 00:38:47,959 Speaker 2: a tear while grinding up ants. That's nice. 806 00:38:48,880 --> 00:38:51,160 Speaker 1: Yeah, let's move on. 807 00:38:53,400 --> 00:38:55,600 Speaker 2: All right, No, but I mean jokes aside. You're saying 808 00:38:55,680 --> 00:38:58,920 Speaker 2: that scientists involved understand the costs here in terms of 809 00:38:59,360 --> 00:39:01,920 Speaker 2: lives and the appearances even of the little ants, and 810 00:39:02,040 --> 00:39:02,560 Speaker 2: that's nice. 811 00:39:02,840 --> 00:39:04,560 Speaker 1: Yes, no, they do, and I think they try to 812 00:39:04,600 --> 00:39:06,960 Speaker 1: make the ants lives as natural and as nice as 813 00:39:07,000 --> 00:39:10,120 Speaker 1: possible before these experiments happen. But so mostly the point 814 00:39:10,120 --> 00:39:12,360 Speaker 1: I wanted to make was how we do these different 815 00:39:12,400 --> 00:39:15,320 Speaker 1: comparisons to get a handle on what might be happening. 816 00:39:15,400 --> 00:39:18,040 Speaker 1: And the answer is, you know, at very similar time points, 817 00:39:18,120 --> 00:39:20,680 Speaker 1: you look at ants that are uninfected, ants that are 818 00:39:20,719 --> 00:39:24,120 Speaker 1: infected by opiel cordyceps, and ants that are infected by 819 00:39:24,280 --> 00:39:26,960 Speaker 1: other fungus that are bad for the ant, but we 820 00:39:27,040 --> 00:39:29,839 Speaker 1: don't think they manipulate behavior in any way. And by 821 00:39:29,920 --> 00:39:32,759 Speaker 1: looking to see what's happening differently in the bodies and 822 00:39:32,840 --> 00:39:35,719 Speaker 1: the behavior of the ants in those three different categories, 823 00:39:36,040 --> 00:39:39,040 Speaker 1: we can start getting some like candidate molecules for you know, 824 00:39:39,239 --> 00:39:42,000 Speaker 1: this might be the thing that's getting produced by the 825 00:39:42,040 --> 00:39:46,680 Speaker 1: fungus to change the behavior. And so they found a 826 00:39:46,800 --> 00:39:50,480 Speaker 1: lot of stuff that differs, and that's not too surprising 827 00:39:50,680 --> 00:39:53,560 Speaker 1: because the ants are doing complicated behaviors. There's a lot 828 00:39:53,600 --> 00:39:55,680 Speaker 1: of behaviors. I feel like what we really want as 829 00:39:55,760 --> 00:39:59,400 Speaker 1: humans is that the answer is there's this one molecule 830 00:40:00,040 --> 00:40:02,719 Speaker 1: that tells you everything, and that's fascinating, but really it 831 00:40:02,800 --> 00:40:05,440 Speaker 1: ends up being like hundreds of molecules that are being 832 00:40:05,480 --> 00:40:08,160 Speaker 1: produced that we think are important in every single different step. 833 00:40:08,280 --> 00:40:10,840 Speaker 1: So there's not like a really nice, easy to tell story. 834 00:40:11,280 --> 00:40:13,680 Speaker 1: But a couple things that pop out is that interra 835 00:40:13,800 --> 00:40:17,640 Speaker 1: toxins seem like they're important. These are toxins that are 836 00:40:17,680 --> 00:40:20,920 Speaker 1: released by things like bacteria like E. Coli. We're not 837 00:40:21,080 --> 00:40:23,680 Speaker 1: totally sure what the toxin is doing to the ants, 838 00:40:24,239 --> 00:40:26,680 Speaker 1: but it might be playing a role in breaking down 839 00:40:26,800 --> 00:40:30,319 Speaker 1: ant muscles at particular times. So maybe after the ant 840 00:40:30,440 --> 00:40:33,120 Speaker 1: bites down, those muscles get broken down so the ant 841 00:40:33,239 --> 00:40:35,840 Speaker 1: can't leave, and that might be what the toxin is 842 00:40:35,960 --> 00:40:37,439 Speaker 1: doing when it's released at that point. 843 00:40:37,880 --> 00:40:40,160 Speaker 2: I think it's great to try to dig into the 844 00:40:40,239 --> 00:40:43,520 Speaker 2: details and understand the mechanisms to make sure the story 845 00:40:43,560 --> 00:40:46,399 Speaker 2: that we're telling is the real story, and also because 846 00:40:46,440 --> 00:40:50,320 Speaker 2: you could discover surprising things when you dig into the details. 847 00:40:50,800 --> 00:40:52,560 Speaker 2: But what else could we learn by doing this. Is 848 00:40:52,600 --> 00:40:55,440 Speaker 2: there the possibility here of a surprise that we discover, Oh, 849 00:40:55,520 --> 00:40:57,800 Speaker 2: it's not actually working the way that we expected. 850 00:40:58,000 --> 00:41:00,840 Speaker 1: Yeah, So a lot of people think of the behavior 851 00:41:01,000 --> 00:41:06,319 Speaker 1: manipulating parasites and pathogens as like evolutionary neuroscientists. So they've 852 00:41:06,320 --> 00:41:09,239 Speaker 1: been interacting with their host for you know, in this case, 853 00:41:09,320 --> 00:41:11,640 Speaker 1: it looks like more than forty eight million years, and 854 00:41:11,719 --> 00:41:14,520 Speaker 1: through the process of natural selection, they've maybe happened upon 855 00:41:15,560 --> 00:41:19,120 Speaker 1: solutions for changing the ants behavior. And so by looking 856 00:41:19,200 --> 00:41:21,520 Speaker 1: to see what is the fungus making, if it's a 857 00:41:21,560 --> 00:41:24,799 Speaker 1: compound we've never seen before, maybe we've unlocked some tiny 858 00:41:24,840 --> 00:41:26,799 Speaker 1: piece of the puzzle for how brains work and how 859 00:41:26,840 --> 00:41:29,040 Speaker 1: you can modify behavior. And you know, you could imagine 860 00:41:29,400 --> 00:41:31,680 Speaker 1: maybe if you've got some pest in a field, if 861 00:41:31,719 --> 00:41:33,920 Speaker 1: you make them all like you know, climb up and 862 00:41:34,040 --> 00:41:37,400 Speaker 1: stay up and then die, they'll like stop messing with 863 00:41:37,480 --> 00:41:40,359 Speaker 1: your field. And so like, whenever we can understand even 864 00:41:40,440 --> 00:41:43,280 Speaker 1: how insect behavior works, it gives you some extra tools 865 00:41:43,360 --> 00:41:45,759 Speaker 1: to not just you know, understand how your world works, 866 00:41:45,800 --> 00:41:47,600 Speaker 1: but also to maybe sort of control some of the 867 00:41:47,719 --> 00:41:50,120 Speaker 1: negative aspects of like pest organisms. 868 00:41:50,360 --> 00:41:53,160 Speaker 2: Wow, so the fungus has been doing neuroscience experiments on 869 00:41:53,280 --> 00:41:56,760 Speaker 2: the ants for forty eight million years without ever writing 870 00:41:56,800 --> 00:41:59,120 Speaker 2: a paper and getting their PhD. That's got to set 871 00:41:59,160 --> 00:41:59,800 Speaker 2: some kind of record. 872 00:42:00,000 --> 00:42:01,680 Speaker 1: They don't have to worry about tenure. They don't have 873 00:42:01,760 --> 00:42:04,400 Speaker 1: to get brands, they don't have to write permits and protocols. 874 00:42:04,520 --> 00:42:06,800 Speaker 1: It really seems unfair the head start that they've gotten. 875 00:42:07,200 --> 00:42:09,200 Speaker 1: But if we study them, then we can sort of 876 00:42:09,280 --> 00:42:11,480 Speaker 1: extract their secrets and maybe this will help us like 877 00:42:11,600 --> 00:42:16,120 Speaker 1: jump ahead in our you know, study of neuroscience, which 878 00:42:16,120 --> 00:42:17,560 Speaker 1: I think is a cool idea. And so they also 879 00:42:17,640 --> 00:42:21,000 Speaker 1: found what they call a bioactive compound where they've they've 880 00:42:21,040 --> 00:42:23,000 Speaker 1: never sort of seen this before, but it looks like 881 00:42:23,080 --> 00:42:26,360 Speaker 1: another compound that, as we talked about earlier, causes insects 882 00:42:26,440 --> 00:42:28,920 Speaker 1: to stagger, and so this might explain why they sort 883 00:42:28,960 --> 00:42:31,160 Speaker 1: of like walk down the tree like they're drunk. But 884 00:42:31,239 --> 00:42:33,719 Speaker 1: we think, and this is this is just hypothesizing at 885 00:42:33,760 --> 00:42:36,399 Speaker 1: this point, we think it might be important in those 886 00:42:36,480 --> 00:42:39,360 Speaker 1: systems where the ants are clinging to the bottom of stems. 887 00:42:39,920 --> 00:42:42,440 Speaker 1: If the ants are feeling like all sort of wobbly 888 00:42:42,880 --> 00:42:47,160 Speaker 1: and uneven, they might hug down on the stem to 889 00:42:47,320 --> 00:42:49,840 Speaker 1: hold themselves so they don't fall off of it, and 890 00:42:50,239 --> 00:42:52,080 Speaker 1: that could be sort of the moment that the fungus 891 00:42:52,200 --> 00:42:54,600 Speaker 1: kills them, so that they will be really clinging hard 892 00:42:54,640 --> 00:42:56,520 Speaker 1: to the stem. And at this point. This is just 893 00:42:56,560 --> 00:42:58,560 Speaker 1: a story, and we know that we need to dig 894 00:42:58,640 --> 00:43:00,759 Speaker 1: into it more. But that's where we are right now. 895 00:43:01,320 --> 00:43:02,160 Speaker 1: So it's complicated. 896 00:43:02,360 --> 00:43:04,560 Speaker 2: And do we know like where in the ant the 897 00:43:04,680 --> 00:43:06,799 Speaker 2: fungus ends up, Like does the ant have a little 898 00:43:06,840 --> 00:43:09,040 Speaker 2: ant brain and the fungus is sitting on top of it, 899 00:43:09,239 --> 00:43:11,560 Speaker 2: like cackling maniacally and pulling levers. 900 00:43:12,080 --> 00:43:13,600 Speaker 1: Yeah, so this is really neat. So you know, I've 901 00:43:13,640 --> 00:43:16,520 Speaker 1: already mentioned that Terissa de Becker's lab has been doing 902 00:43:16,560 --> 00:43:19,000 Speaker 1: some important work on timing, and they've been working on 903 00:43:19,200 --> 00:43:22,520 Speaker 1: like chemicals that are produced by the fungus. David Hughes 904 00:43:23,160 --> 00:43:27,600 Speaker 1: did some work with collaborators where they scanned ants with 905 00:43:27,680 --> 00:43:31,360 Speaker 1: an electron microscope, so like very very detailed scans, and 906 00:43:31,400 --> 00:43:33,759 Speaker 1: they put all of the scans together and what they 907 00:43:33,840 --> 00:43:36,719 Speaker 1: found was that the fungus is forming a network and 908 00:43:36,840 --> 00:43:40,320 Speaker 1: it's invading a bunch of different muscles. And so the 909 00:43:40,400 --> 00:43:42,279 Speaker 1: way it was described in the popular press was that 910 00:43:42,320 --> 00:43:44,560 Speaker 1: you could think of it as like the fungus essentially 911 00:43:44,640 --> 00:43:47,600 Speaker 1: having strings on a puppet, where it could be like 912 00:43:47,719 --> 00:43:50,160 Speaker 1: pulling up and down, and that might be over selling 913 00:43:50,200 --> 00:43:52,120 Speaker 1: it a little bit, but one of the things that 914 00:43:52,200 --> 00:43:54,840 Speaker 1: they thought was interesting was that it doesn't seem to 915 00:43:54,920 --> 00:43:58,120 Speaker 1: be invading the brain tissue, so it's touching the brain 916 00:43:58,200 --> 00:44:01,080 Speaker 1: but not going into the brain tissue. This was made 917 00:44:01,440 --> 00:44:04,719 Speaker 1: a pretty big deal in the POPSI articles at the time. 918 00:44:04,920 --> 00:44:07,439 Speaker 1: I wasn't as impressed with that. So, like the brain 919 00:44:07,520 --> 00:44:10,080 Speaker 1: infecting parasite that I studied on fish for my PhD 920 00:44:10,760 --> 00:44:13,080 Speaker 1: also sat on top of the brain and not inside 921 00:44:13,120 --> 00:44:15,680 Speaker 1: of it. And there's some other evidence in the zombieant 922 00:44:15,800 --> 00:44:19,120 Speaker 1: system that the fungus is kind of protecting the brain. 923 00:44:19,520 --> 00:44:21,360 Speaker 1: So you can imagine that, like if you're inside of 924 00:44:21,400 --> 00:44:24,319 Speaker 1: the brain, you might just like totally screw up your ride, 925 00:44:24,640 --> 00:44:26,960 Speaker 1: like it's not gonna do what you want, because you've 926 00:44:27,040 --> 00:44:29,440 Speaker 1: just totally debilitated it. And now it's obvious and the 927 00:44:29,480 --> 00:44:32,000 Speaker 1: other ants can tell. And so it looks like it's 928 00:44:32,040 --> 00:44:35,200 Speaker 1: sort of tinkering with the brain without actually like sticking 929 00:44:35,239 --> 00:44:37,800 Speaker 1: its hands in there. But it does have its you know, 930 00:44:38,239 --> 00:44:42,440 Speaker 1: hipha which are like fungal fingers inside the other muscles. 931 00:44:42,680 --> 00:44:45,920 Speaker 2: Wow, amazing, and I see something amazing here in the outline. 932 00:44:46,000 --> 00:44:49,759 Speaker 2: Tell me about hyper parasites. Are these like the superhero 933 00:44:49,880 --> 00:44:53,279 Speaker 2: version of parasites? Kind of were they bitten by a 934 00:44:53,360 --> 00:44:54,280 Speaker 2: radioactive spider. 935 00:44:54,440 --> 00:44:57,400 Speaker 1: No no, no, no, no, you've watched too many movies, Daniel. 936 00:44:58,520 --> 00:44:59,120 Speaker 2: This is true. 937 00:44:59,239 --> 00:45:01,800 Speaker 1: Yeah, this is cool. So you know, you've got this 938 00:45:01,920 --> 00:45:05,560 Speaker 1: fungus that manipulates ant behavior. But there are other fungal 939 00:45:05,680 --> 00:45:10,320 Speaker 1: species that infect opio cordyceps. So the ant will be like, 940 00:45:10,400 --> 00:45:13,880 Speaker 1: you know, clinging to a stem, and you'll find fungus 941 00:45:14,120 --> 00:45:16,680 Speaker 1: that is living on top of Ofio cordyceps and is 942 00:45:16,719 --> 00:45:18,680 Speaker 1: sapping the o fio cortaceps energy. 943 00:45:18,880 --> 00:45:21,719 Speaker 2: It's like fungus inception. Wait, fungus antception. 944 00:45:23,200 --> 00:45:27,359 Speaker 1: Whoa dead jokes galore. This might be our most dead 945 00:45:27,480 --> 00:45:29,560 Speaker 1: jokey episode. Yet I didn't see it coming. 946 00:45:29,920 --> 00:45:32,240 Speaker 2: Wow. So this fungus thought I was pulling the strings, 947 00:45:32,280 --> 00:45:34,399 Speaker 2: but its strings were being pulled the whole time. 948 00:45:34,800 --> 00:45:37,600 Speaker 1: There are so many levels in nature. I am so 949 00:45:37,840 --> 00:45:41,440 Speaker 1: glad to be uh where I am so okay. So 950 00:45:41,880 --> 00:45:44,239 Speaker 1: I promised at the beginning of the episode that I 951 00:45:44,280 --> 00:45:47,160 Speaker 1: would answer if Ofio cordyceps could jump to humans and 952 00:45:47,280 --> 00:45:50,279 Speaker 1: manipulate us, Daniel. So now I'm going to ask you 953 00:45:50,400 --> 00:45:54,399 Speaker 1: what is your favorite representation of a fungus that jumps 954 00:45:54,440 --> 00:45:57,200 Speaker 1: to humans and the ant. You could just say I 955 00:45:57,239 --> 00:45:59,040 Speaker 1: don't watch the same shows as 'di Kelly. 956 00:46:00,440 --> 00:46:03,120 Speaker 2: I'm not a fan of the zombie genre in general, 957 00:46:03,840 --> 00:46:06,600 Speaker 2: the violence and the goo and like not a fan. 958 00:46:06,840 --> 00:46:09,080 Speaker 1: So yeah, I'm gonna have to leave it to you, 959 00:46:09,360 --> 00:46:11,480 Speaker 1: all right, Well, okay, I've been really liking The Last 960 00:46:11,520 --> 00:46:15,200 Speaker 1: of Us lately, but not necessarily because it like hues 961 00:46:15,440 --> 00:46:19,359 Speaker 1: so closely to what happens in nature, so that one 962 00:46:19,520 --> 00:46:22,480 Speaker 1: starts by saying, like, yes, I know it seems unlikely 963 00:46:22,640 --> 00:46:24,960 Speaker 1: that I think they call it cort aceps. The genus 964 00:46:25,040 --> 00:46:27,680 Speaker 1: name has changed a little bit, but anyway, yes, it 965 00:46:27,680 --> 00:46:29,680 Speaker 1: seems unlikely that it could jump to humans, but the 966 00:46:29,760 --> 00:46:32,440 Speaker 1: way our environment is changing, we can't rule it out 967 00:46:32,560 --> 00:46:34,840 Speaker 1: or something like that. And then fast forward decades and 968 00:46:35,160 --> 00:46:38,440 Speaker 1: humans are infected by the fungus. I think it is 969 00:46:38,560 --> 00:46:39,320 Speaker 1: highly unlikely. 970 00:46:39,800 --> 00:46:40,160 Speaker 2: Why is that? 971 00:46:40,600 --> 00:46:43,279 Speaker 1: Well, okay, so even in nature we talked about at 972 00:46:43,280 --> 00:46:46,080 Speaker 1: the beginning of the show that each opio cort Aceps 973 00:46:46,160 --> 00:46:51,000 Speaker 1: species tends to infect and manipulate specific ant species, so 974 00:46:51,120 --> 00:46:54,840 Speaker 1: they are so specialized that they can't even like manipulate 975 00:46:55,239 --> 00:46:58,319 Speaker 1: closely related ants. Like that's too much of a jump. 976 00:46:58,560 --> 00:47:01,000 Speaker 2: So maybe like, if you you know how to fly 977 00:47:01,160 --> 00:47:03,840 Speaker 2: a Sessana. That doesn't mean that if somebody drops you 978 00:47:04,040 --> 00:47:06,239 Speaker 2: into like a seven forty seven, you're going to know 979 00:47:06,320 --> 00:47:07,200 Speaker 2: how to land that thing. 980 00:47:07,560 --> 00:47:11,480 Speaker 1: Yes, exactly right, And human brains are so incredibly different 981 00:47:11,560 --> 00:47:15,560 Speaker 1: than ant brains. I suppose it's possible that a fungus 982 00:47:15,960 --> 00:47:18,480 Speaker 1: might be able to eke out an existence in us, 983 00:47:18,560 --> 00:47:20,279 Speaker 1: but I even think that would be quite a jump. 984 00:47:20,360 --> 00:47:23,040 Speaker 1: But if it could, the probability that it would be 985 00:47:23,080 --> 00:47:25,239 Speaker 1: able to control our behavior in a way that would 986 00:47:25,239 --> 00:47:28,799 Speaker 1: benefit the fungus seems pretty close to zero. And I'm 987 00:47:28,880 --> 00:47:32,200 Speaker 1: not being negative about the movies and TV shows and 988 00:47:32,280 --> 00:47:35,920 Speaker 1: books that are great and Daniel's missing out. I think 989 00:47:35,960 --> 00:47:38,359 Speaker 1: it's great that they created these worlds, and if they're 990 00:47:38,360 --> 00:47:41,120 Speaker 1: consistent with their rules, I'm on board. But I'm a 991 00:47:41,160 --> 00:47:44,719 Speaker 1: person with massive anxiety and it doesn't keep me up 992 00:47:44,719 --> 00:47:46,960 Speaker 1: at night worrying that ofiocordyceps is going to jump to 993 00:47:47,000 --> 00:47:47,600 Speaker 1: me or my kids. 994 00:47:47,960 --> 00:47:50,200 Speaker 2: Well, I have a theory for how this fungus can 995 00:47:50,280 --> 00:47:52,920 Speaker 2: jump to humans and benefit itself. Okay, if you think 996 00:47:52,920 --> 00:47:55,680 Speaker 2: of this fungus as little neuroscientists, then what you to 997 00:47:55,760 --> 00:47:58,719 Speaker 2: do It should get humans to help it out. So 998 00:47:59,320 --> 00:48:02,640 Speaker 2: if it infects human brains and makes those humans interested 999 00:48:02,800 --> 00:48:05,680 Speaker 2: in this and puzzle. So they come along basically acting 1000 00:48:05,760 --> 00:48:08,160 Speaker 2: like colleagues and figuring out like, hey, how does this 1001 00:48:08,239 --> 00:48:10,680 Speaker 2: actually work? And maybe you can help, like you know, 1002 00:48:11,200 --> 00:48:13,760 Speaker 2: super engineer this fungus to be even more efficient. 1003 00:48:14,040 --> 00:48:15,840 Speaker 1: I feel like you're in a roundabout way trying to 1004 00:48:15,880 --> 00:48:17,520 Speaker 1: get back to the like it's okay that I eat 1005 00:48:17,600 --> 00:48:20,680 Speaker 1: cookies at night thing, like you know, if the if 1006 00:48:20,719 --> 00:48:24,080 Speaker 1: the fungus benefits from me eating cookies. But you know 1007 00:48:24,160 --> 00:48:29,840 Speaker 1: what is interesting, So ofio cord accepts Senensis infects I 1008 00:48:29,920 --> 00:48:33,520 Speaker 1: think it's caterpillars, but it infects craters, but instead of 1009 00:48:33,520 --> 00:48:35,759 Speaker 1: having them climb up, it has them burrow into the 1010 00:48:35,800 --> 00:48:38,239 Speaker 1: ground and then the fungal stalk grows out of the 1011 00:48:38,320 --> 00:48:42,280 Speaker 1: ground and like pops up. Okay, and humans have decided 1012 00:48:42,320 --> 00:48:45,480 Speaker 1: that this is amazing in tea, and so people will 1013 00:48:45,560 --> 00:48:48,120 Speaker 1: actually go out in search of this and they can 1014 00:48:48,239 --> 00:48:50,920 Speaker 1: sell it for a lot of money. And I think 1015 00:48:50,960 --> 00:48:53,080 Speaker 1: you can even buy this in the United States, like 1016 00:48:53,160 --> 00:48:55,840 Speaker 1: tea with ofio cord accepts senensus in it, and so 1017 00:48:55,960 --> 00:48:58,840 Speaker 1: you know, I don't maybe ofio cordceps senensus jumps to 1018 00:48:59,040 --> 00:49:01,759 Speaker 1: us and makes us want the tea, and so then 1019 00:49:01,840 --> 00:49:05,960 Speaker 1: we'll start big farms where we sort of seed their 1020 00:49:06,080 --> 00:49:08,640 Speaker 1: hosts with the fungus so that they can start growing 1021 00:49:08,719 --> 00:49:11,120 Speaker 1: up and then we can replicate it. So maybe that'll 1022 00:49:11,120 --> 00:49:11,840 Speaker 1: be the route. 1023 00:49:11,960 --> 00:49:15,359 Speaker 2: Or maybe that'll just be the story in your Netflix show. 1024 00:49:15,760 --> 00:49:17,600 Speaker 2: Netflix call us We're ready. 1025 00:49:17,960 --> 00:49:20,879 Speaker 1: Yeah, you know, I wrote fiction once and I kind 1026 00:49:20,920 --> 00:49:24,279 Speaker 1: of think it was a disaster. So I don't see 1027 00:49:24,360 --> 00:49:27,200 Speaker 1: me starting a new fictional series. But if anybody would 1028 00:49:27,320 --> 00:49:31,440 Speaker 1: like scientific input on their own series, I am available. 1029 00:49:34,040 --> 00:49:36,800 Speaker 2: And she promises not to be completely a wet blanket. 1030 00:49:37,280 --> 00:49:39,480 Speaker 1: I you know, I don't like to make promises I 1031 00:49:39,560 --> 00:49:45,239 Speaker 1: can't keep. I'll try to play along, all right, So, 1032 00:49:45,800 --> 00:49:48,279 Speaker 1: just to sort of reiterate, I love this system because 1033 00:49:48,400 --> 00:49:50,400 Speaker 1: we've dug into more of the different pieces in this 1034 00:49:50,480 --> 00:49:52,600 Speaker 1: system than a bunch of other systems. But there's so 1035 00:49:52,840 --> 00:49:55,280 Speaker 1: much we have left to learn. And as we mentioned earlier, 1036 00:49:55,440 --> 00:49:59,080 Speaker 1: like we're discovering molecules that we've never seen before. This 1037 00:49:59,280 --> 00:50:01,640 Speaker 1: might be a way to help us understand how brains 1038 00:50:01,760 --> 00:50:03,960 Speaker 1: work and how we can sort of tinker with behavior. 1039 00:50:04,000 --> 00:50:06,040 Speaker 1: It might give us some inputs on how to control 1040 00:50:06,160 --> 00:50:09,480 Speaker 1: insect populations. There's so much cool stuff we might have 1041 00:50:09,600 --> 00:50:11,960 Speaker 1: left to learn as we continue digging into the system. 1042 00:50:12,560 --> 00:50:15,520 Speaker 2: Amazing and it's incredible what we can learn from like 1043 00:50:15,719 --> 00:50:18,760 Speaker 2: ants and fungus, and sometimes that tells us something deeper 1044 00:50:18,880 --> 00:50:21,800 Speaker 2: about the way brains work. And so you never know 1045 00:50:21,920 --> 00:50:24,920 Speaker 2: where the next great scientific discovery will come from and 1046 00:50:25,080 --> 00:50:26,960 Speaker 2: who's really pulling your strings? 1047 00:50:27,239 --> 00:50:29,560 Speaker 1: That's right, But the next great scientific discovery is probably 1048 00:50:29,600 --> 00:50:32,759 Speaker 1: coming from biology. That's what I think. 1049 00:50:33,880 --> 00:50:35,560 Speaker 2: As long as it gets into people's heads and makes 1050 00:50:35,600 --> 00:50:37,560 Speaker 2: them listen to the podcast, I'm all for it. 1051 00:50:37,640 --> 00:50:39,480 Speaker 1: Or it gives Daniel an excuse for eating cookies in 1052 00:50:39,520 --> 00:50:40,160 Speaker 1: the middle of the night. 1053 00:50:42,520 --> 00:50:43,439 Speaker 2: Chomp, chomp, chomp. 1054 00:50:51,560 --> 00:50:55,360 Speaker 1: Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio. We 1055 00:50:55,440 --> 00:50:56,680 Speaker 1: would love to hear from you. 1056 00:50:56,960 --> 00:50:59,800 Speaker 2: We really would. We want to know what questions you 1057 00:51:00,200 --> 00:51:02,720 Speaker 2: have about this Extraordinary Universe. 1058 00:51:02,880 --> 00:51:05,759 Speaker 1: You want to know your thoughts on recent shows, suggestions 1059 00:51:05,800 --> 00:51:08,759 Speaker 1: for future shows. If you contact us, we will get 1060 00:51:08,840 --> 00:51:09,200 Speaker 1: back to you. 1061 00:51:09,520 --> 00:51:12,960 Speaker 2: We really mean it. We answer every message. Email us 1062 00:51:13,080 --> 00:51:16,200 Speaker 2: at Questions at Danielandkelly. 1063 00:51:15,360 --> 00:51:17,399 Speaker 1: Dot org, or you can find us on social media. 1064 00:51:17,520 --> 00:51:21,239 Speaker 1: We have accounts on x, Instagram, Blue Sky and on 1065 00:51:21,400 --> 00:51:23,320 Speaker 1: all of those platforms. You can find us at D 1066 00:51:23,800 --> 00:51:25,320 Speaker 1: and K universe. 1067 00:51:25,520 --> 00:51:27,040 Speaker 2: Don't be shy, write to us.