WEBVTT 1 00:00:00.280 --> 00:00:03.240 Oh hey, it's your boyfriend's old roommate who always put 2 00:00:03.319 --> 00:00:06.080 pepsi's in the freezer and then forgot about them until 3 00:00:06.120 --> 00:00:09.800 they exploded. Ali would back with another episode of Ologies, 4 00:00:10.160 --> 00:00:13.560 So check in with your bod right now. Are you cold? 5 00:00:14.119 --> 00:00:16.079 Are you hot? How do you feel? Are you sweating? 6 00:00:16.280 --> 00:00:18.719 Is this too many personal questions? Okay, let's change the 7 00:00:18.760 --> 00:00:21.920 subject to me. Well, actually, te you. Thank you so much, 8 00:00:21.960 --> 00:00:25.480 as always to the patrons who support ologies at patrion 9 00:00:25.519 --> 00:00:28.079 dot com slash Ologies for everyone who gets themselves some 10 00:00:28.160 --> 00:00:31.800 ologies merch to put on their warm or their cold bodies, 11 00:00:32.240 --> 00:00:36.079 and of course everyone who subscribes rates, especially who reviews 12 00:00:36.079 --> 00:00:38.560 the podcast. You know, I read your reviews each week 13 00:00:38.880 --> 00:00:42.119 and it's creepy proof. Here's a fresh one. Baruerbird seventy 14 00:00:42.119 --> 00:00:44.920 seven wrote, I drive into work two days a week. 15 00:00:45.240 --> 00:00:47.119 Some days the thought of getting out of the house 16 00:00:47.320 --> 00:00:50.600 with a bra and mascara seem too much until I 17 00:00:50.640 --> 00:00:53.320 remember that a new episode awaits. I can't wait to 18 00:00:53.320 --> 00:00:55.000 hear what Old dow Ward has in store for my 19 00:00:55.039 --> 00:00:57.960 commute tomorrow. PS stay with me when you come to Philly. 20 00:00:58.000 --> 00:01:01.159 Open invitation. I'm mostly normal. How can I say no 21 00:01:01.280 --> 00:01:04.879 to that? Also? Keke and Colakookram left a sweet review 22 00:01:05.040 --> 00:01:07.480 that asked been listening for a while and I'm still 23 00:01:07.719 --> 00:01:10.200 not sure why Ali refers to herself as dad word. 24 00:01:10.359 --> 00:01:13.120 It's a great question. It started in a podcast Facebook 25 00:01:13.159 --> 00:01:17.319 group because i like hot dogs and bad puns, and 26 00:01:17.359 --> 00:01:20.280 I'm just very likely to lecture you about tire pressure 27 00:01:20.319 --> 00:01:22.760 safety because I love you. I just want you to 28 00:01:22.760 --> 00:01:25.640 be safe. Okay, So thermo physiology, let's get into it. 29 00:01:25.879 --> 00:01:29.519 Let's get it into us. Rather so thermo in ancient 30 00:01:29.519 --> 00:01:32.920 Greek means hot. Physio derives from the word for nature, 31 00:01:33.239 --> 00:01:37.239 so everything from hotness and nature to coldness in a 32 00:01:37.359 --> 00:01:41.519 lab as we will soon discuss. So this ologist is amazing. 33 00:01:41.640 --> 00:01:44.040 I met him over Thanksgiving at a dinner held by 34 00:01:44.040 --> 00:01:47.400 our mutual bud Karasanna Maria of the Tough Nerdy podcast 35 00:01:47.879 --> 00:01:51.079 and new to LA having just taken on the role 36 00:01:51.120 --> 00:01:54.680 of professor at UCLA. He mentioned some of the courses 37 00:01:54.760 --> 00:01:58.560 he teaches and his podcast, The Biology of Superheroes, and 38 00:01:58.640 --> 00:02:01.719 from there I gently begged him him to be on ologies. 39 00:02:01.959 --> 00:02:04.040 Then I found out we had more mutual friends, such 40 00:02:04.079 --> 00:02:07.719 as the Aaron's Welsh and Almond Updyke of the Epidemiology episode, 41 00:02:07.920 --> 00:02:11.439 and this podcast will kill you. Essentially, I was like, hello, sir, 42 00:02:11.599 --> 00:02:13.719 I regret to inform you that you will be my 43 00:02:13.759 --> 00:02:17.080 friend forever. So what a better time to talk about 44 00:02:17.120 --> 00:02:21.240 body heat issues than February when it's cold, heaters are cranked, 45 00:02:21.800 --> 00:02:25.919 nary a daffodil bulb has sprung from the slush, So 46 00:02:25.960 --> 00:02:28.319 we scheduled the time to record. I reached out to 47 00:02:28.360 --> 00:02:30.159 ask for a few more days, though, because I was 48 00:02:30.240 --> 00:02:34.039 so behind working on the aging episode that I literally 49 00:02:34.120 --> 00:02:37.039 cried that day. So this ologist kindly let me reschedule 50 00:02:37.080 --> 00:02:39.080 for a few days. Then I headed over to his 51 00:02:39.120 --> 00:02:41.960 brand new office at UCLA, where he was wearing normal 52 00:02:42.000 --> 00:02:45.039 person clothes and I was wearing four layers and a 53 00:02:45.080 --> 00:02:47.919 scarf because I'm at Chihuahua. So he showed me some 54 00:02:48.000 --> 00:02:51.000 fancy chambers in his lab and we settled in to 55 00:02:51.080 --> 00:02:55.680 have an absolutely wonderful and informative chat about how critters 56 00:02:55.719 --> 00:03:01.599 adapt to temperature changes, lizards, storms, dinosaur blood, hibernating bears, 57 00:03:01.919 --> 00:03:05.840 why you sweat in your sleep, maybe you specifically anti 58 00:03:05.919 --> 00:03:09.919 phrase frogs, miracle hamsters, why different people run at different temperatures, 59 00:03:10.120 --> 00:03:13.680 How comic books influence the way he sees science, learning 60 00:03:13.680 --> 00:03:17.000 how his brain works and sometime management hacks that he 61 00:03:17.120 --> 00:03:20.599 uses as a professor and host of the Biology of 62 00:03:20.639 --> 00:03:24.080 Superheroes podcast. So get ready to warm up to your 63 00:03:24.120 --> 00:03:29.360 new biology hero thermo physiologist doctor Shane Campbell Staton. 64 00:03:47.400 --> 00:03:50.159 And get every once in a while, or sometimes Stayton Camboy. 65 00:03:50.360 --> 00:03:54.280 It's a hyphenated names. It's a difficult life to live. 66 00:03:54.439 --> 00:03:57.360 Now, this is your first harsh Southern California winter. 67 00:03:57.759 --> 00:04:02.960 Oh so harsh? Yes, the yeah, I've notned. So I've 68 00:04:03.000 --> 00:04:05.479 spent my life sort of bumping around a bunch of 69 00:04:05.520 --> 00:04:11.280 different places. And before I moved here, I was in Montana. 70 00:04:11.840 --> 00:04:15.680 Before Montana, I was in Illinois, and then before that 71 00:04:15.759 --> 00:04:19.879 I was in Boston, all of which have pretty harsh winters. 72 00:04:20.000 --> 00:04:21.959 Before that, I was in Rochester, New York, which may 73 00:04:22.000 --> 00:04:25.279 actually be the snowiest place in the entire country. 74 00:04:25.480 --> 00:04:28.480 Oh so quick, aside. I look this up and Rochester 75 00:04:28.839 --> 00:04:32.560 is the fourth snowiest of the lower forty eight states, 76 00:04:32.639 --> 00:04:35.519 clocking in in about ninety nine inches of snow per year, 77 00:04:35.680 --> 00:04:38.839 which is just an injure to less than Anchorage, Alaska 78 00:04:38.879 --> 00:04:42.879 typically gets. Now, if you're listening in Syracuse, New York 79 00:04:42.959 --> 00:04:46.079 right now, you are screaming in your car or at 80 00:04:46.120 --> 00:04:50.319 your phone. You were saying, yes, bitch, Rochester is Florida 81 00:04:50.319 --> 00:04:53.879 compared to our one hundred and twenty three inches of snow, 82 00:04:54.199 --> 00:04:58.160 So yes, Syracuse, New York, you win for most snow 83 00:04:58.199 --> 00:05:01.199 related winter suffering. Also on the sunny side, if you're 84 00:05:01.240 --> 00:05:04.639 doing all that shoveling, you probably have pretty good core strength, 85 00:05:04.879 --> 00:05:07.079 pretty good abs. I don't know. That's all I got. 86 00:05:07.240 --> 00:05:09.480 And for the longest time I remember moving up from 87 00:05:09.519 --> 00:05:11.720 South Carolina, I was like, what is this lake effect 88 00:05:11.839 --> 00:05:15.120 that people keep talking about? And because the first time 89 00:05:15.120 --> 00:05:17.680 I'd ever heard of it, and then I realized the 90 00:05:17.720 --> 00:05:19.240 first winter came, I was like, Oh, it's like a 91 00:05:19.319 --> 00:05:23.720 hurricane but cold. Basically, it was a harsh reality to live. 92 00:05:23.839 --> 00:05:26.279 So luckily I bumped it over here to La. 93 00:05:26.759 --> 00:05:29.920 Good work on that. Okay, Now, what was it about 94 00:05:29.920 --> 00:05:33.720 your upbringing that you thought, I want to study biology. 95 00:05:33.759 --> 00:05:37.639 I want to study science, and particularly temperatures and cold. 96 00:05:37.839 --> 00:05:42.519 Oh man. So those things did not come along intentionally 97 00:05:42.759 --> 00:05:48.079 by any means. So when I was a kid, I 98 00:05:48.079 --> 00:05:52.240 got really obsessed with reptiles. I don't know what it 99 00:05:52.360 --> 00:05:55.240 was about the scalies that got me, but it was 100 00:05:55.279 --> 00:05:59.360 just a thing, and you know, and my mother, like 101 00:05:59.680 --> 00:06:03.360 blessed her heart. She was super supportive, but she you know, 102 00:06:03.439 --> 00:06:08.600 she was she just doesn't do that sort of stuff. Yeah, 103 00:06:08.680 --> 00:06:10.720 but she was really supportive. I remember in high school 104 00:06:10.720 --> 00:06:13.800 I had, you know, all sorts of creatures for a 105 00:06:13.839 --> 00:06:15.600 senior project I did, and you know, I had like 106 00:06:16.600 --> 00:06:22.120 a python and several different lizards, a giant green iguana, 107 00:06:22.360 --> 00:06:24.439 a breeding pair of corn snakes, like all this sort 108 00:06:24.439 --> 00:06:26.040 of stuff. I was obsessed with it. 109 00:06:26.519 --> 00:06:29.759 So Shane wound up getting his pH d in Organismic 110 00:06:29.920 --> 00:06:34.759 and evolutionary biology at Harvard University. But before that, as 111 00:06:34.839 --> 00:06:38.079 a young herp nerd, he figured biology would be the 112 00:06:38.079 --> 00:06:41.000 best course if he wanted to study his beloved reptiles, 113 00:06:41.360 --> 00:06:44.439 and he got his Bachelors of Science in ecology and 114 00:06:44.480 --> 00:06:47.879 evolutionary biology at the very snowy but yes, not as 115 00:06:47.920 --> 00:06:51.199 snowy as Syracuse, Syracuse University of Rochester. 116 00:06:52.319 --> 00:06:54.639 And so that's what I did. And I got this 117 00:06:54.839 --> 00:06:59.399 when I got introduced to anoles, because I love it. Yeah, 118 00:06:59.439 --> 00:07:03.839 they're so cool and actually so the one species of 119 00:07:04.279 --> 00:07:07.759 a knoll that is native to the United States. It's 120 00:07:07.759 --> 00:07:11.240 like the only there's like the very first animal I 121 00:07:11.279 --> 00:07:14.360 ever interacted with as a kid, because in South Carolina 122 00:07:14.399 --> 00:07:16.959 they're just like all over like the sides of houses 123 00:07:17.000 --> 00:07:17.839 and stuff. 124 00:07:17.639 --> 00:07:19.959 And aol is just a type of lizard, right. 125 00:07:19.879 --> 00:07:23.759 Yeah, yeah, So in AOL it's it's like this small lizard, 126 00:07:23.800 --> 00:07:26.680 typically small, that has like this little throat fan and 127 00:07:26.720 --> 00:07:29.040 they do a bunch of push ups and they like 128 00:07:29.120 --> 00:07:32.240 wave that little throat fan. But there are about four 129 00:07:32.319 --> 00:07:37.040 hundred species of aknole that are distributed across the neotropics, 130 00:07:37.040 --> 00:07:41.120 so like central South America, the islands of the Greater Antilles, 131 00:07:41.160 --> 00:07:44.639 and then our one special North American anol that's native 132 00:07:44.639 --> 00:07:46.480 to the US. There's a bunch of other species now 133 00:07:46.480 --> 00:07:49.759 that are invasive, but that's the one that's native. So 134 00:07:50.000 --> 00:07:52.040 that's and that's also the species I ended up studying 135 00:07:52.120 --> 00:07:52.920 for my dissertation. 136 00:07:53.279 --> 00:07:55.639 Oh wait, so you started liking them when you were 137 00:07:55.639 --> 00:07:57.519 a kid. You started them to get your beach? 138 00:07:57.800 --> 00:08:02.079 Yeah, I know, right, You're like, oh, that's amazing. 139 00:08:02.839 --> 00:08:05.040 Did you ever think when you were a kid with 140 00:08:05.160 --> 00:08:08.240 studying lizards and having corn stakes and having pythons, that 141 00:08:08.279 --> 00:08:10.639 you would get to do this for a living. 142 00:08:12.399 --> 00:08:15.399 I did not realize that this was a thing to 143 00:08:15.560 --> 00:08:20.439 do for a living. Generally speaking, it is interesting that, 144 00:08:21.040 --> 00:08:25.639 you know. So for me, you know, I was certain 145 00:08:25.680 --> 00:08:27.839 I think you know, when you asked most biologists how 146 00:08:27.839 --> 00:08:30.839 they got into science, they typically how it's like, Oh, 147 00:08:30.879 --> 00:08:32.600 when I was a kid, I was like walking through 148 00:08:32.639 --> 00:08:35.600 the woods, splashing in a tidal pool, and I just 149 00:08:35.679 --> 00:08:39.519 knew from that point on and that wasn't my life 150 00:08:39.679 --> 00:08:41.679 or you know, because my mom worked really long hours, 151 00:08:41.720 --> 00:08:43.039 I was like a latch key kid. I spent a 152 00:08:43.039 --> 00:08:47.600 lot of my time, you know, indoors. So my introduction 153 00:08:47.840 --> 00:08:52.600 to the outside world, to like nature and wildlife was 154 00:08:52.600 --> 00:08:55.200 through television like Jeff Corwin and Steve r and these 155 00:08:55.399 --> 00:08:57.799 these guys and then the little green lizards that you know, 156 00:08:57.840 --> 00:09:02.399 were around my house. And so to go from there 157 00:09:02.480 --> 00:09:06.320 to being able to do things like this, right, communicating science, 158 00:09:06.600 --> 00:09:09.840 you know, to people who you don't spend most of 159 00:09:09.879 --> 00:09:12.000 their lives doing this sort of stuff, I mean, it's 160 00:09:12.000 --> 00:09:14.399 sort of really special circle for me. 161 00:09:15.080 --> 00:09:17.960 Yeah, how great is that? For real? And so when 162 00:09:17.960 --> 00:09:20.480 you got your PhD, what exactly were you studying about 163 00:09:20.519 --> 00:09:21.039 these inoles? 164 00:09:21.200 --> 00:09:24.519 Yeah, so I was studying the evolution of cold tolerance 165 00:09:24.919 --> 00:09:32.679 in anoles, so trying to understand how geographic variation in temperature, 166 00:09:33.000 --> 00:09:38.279 influences patterns of like gene flow across space, and then 167 00:09:38.399 --> 00:09:41.159 how it influences physiology, you know, which ended up being 168 00:09:41.399 --> 00:09:44.519 a big question of mine because the green and ole 169 00:09:45.039 --> 00:09:49.840 came from Cuba originally, so sometime during the Miocene or Pliocene, 170 00:09:50.360 --> 00:09:54.519 it was transported from Cuba, most likely by storm. That's 171 00:09:54.559 --> 00:09:57.039 typically the way these sort of small things jumped from 172 00:09:57.039 --> 00:09:58.120 island to island. 173 00:09:58.320 --> 00:10:01.399 So just fay, yes, did have to look up how 174 00:10:01.480 --> 00:10:04.360 long ago was somewhere between the Miocene and Pliocene, and 175 00:10:04.399 --> 00:10:08.000 the Miocene was anywhere from twenty three to five million 176 00:10:08.080 --> 00:10:11.480 years ago. The Pliocene was two to five million years ago, 177 00:10:11.639 --> 00:10:14.519 so I think I think he's talking like five ish 178 00:10:14.639 --> 00:10:18.039 million years ago. These adorable little green lizards came over 179 00:10:18.080 --> 00:10:25.279 from Cuba, making things more enjoyable, kind of like living dackeries. Big, big, 180 00:10:25.279 --> 00:10:28.200 old stupid question. I'm just so glad that I asked. 181 00:10:28.440 --> 00:10:29.559 Do they go in the air? 182 00:10:30.759 --> 00:10:33.879 Yeah? Really, yeah, they can fly through the air sometimes, 183 00:10:33.919 --> 00:10:36.440 you know, it's like flocks. Them like drift like wood 184 00:10:36.519 --> 00:10:39.919 or leaves sometimes get you know, get blown across the water. 185 00:10:40.600 --> 00:10:44.080 But yeah, like a frog storm, yes, oh yeah, it 186 00:10:44.159 --> 00:10:48.159 gets it and get real biblical real fast you show 187 00:10:48.279 --> 00:10:52.120 see hail fall from a clear sky and burn his 188 00:10:52.320 --> 00:10:54.000 fire up on the ground. 189 00:10:54.440 --> 00:10:57.240 So they can just rain down Cuban and knoles in 190 00:10:57.320 --> 00:10:58.879 a different part of the world. 191 00:10:59.200 --> 00:11:00.000 Yeah, more or less. 192 00:11:00.080 --> 00:11:00.759 Oh that's awesome. 193 00:11:00.840 --> 00:11:03.320 More or less. Yeah, that's so cool. Yeah, I've never 194 00:11:03.399 --> 00:11:06.000 I don't. I have never heard of any reports that 195 00:11:06.000 --> 00:11:08.639 have actually, like you know, first hand reports of people 196 00:11:09.399 --> 00:11:12.360 like experiencing lizard rain ps. 197 00:11:12.399 --> 00:11:15.240 Allow me to read you an excerpt from the Sunbury 198 00:11:15.360 --> 00:11:22.159 American newspaper dated November twenty first, eighteen fifty seven, headline 199 00:11:22.759 --> 00:11:25.840 shower of lizards. The Leroy New York Gazette says that 200 00:11:25.919 --> 00:11:29.840 during the heavy rain of Sunday night last live lizards, 201 00:11:29.960 --> 00:11:33.200 some of them measuring four inches in length, came from 202 00:11:33.240 --> 00:11:37.440 the clouds like manna, though neither as plenty nor half 203 00:11:37.480 --> 00:11:40.840 as welcome. They were found crawling on the sidewalks and 204 00:11:40.960 --> 00:11:46.679 in the streets like fugitive infantile alligators, in places far 205 00:11:46.759 --> 00:11:50.960 removed from localities where they inhabit nature. Just when you 206 00:11:51.000 --> 00:11:53.919 think it's not a hallucination, it rains and knolls. 207 00:11:54.600 --> 00:11:59.919 Actually, I had a photo. I remember there's a sign 208 00:12:00.159 --> 00:12:04.559 test at ut Knoxville whose work actually inspired the work 209 00:12:04.559 --> 00:12:05.919 that I did with the green and ole. And he 210 00:12:05.960 --> 00:12:08.519 showed me this photo when I went and visited him 211 00:12:08.919 --> 00:12:12.240 of this male green and ole outside in the winter 212 00:12:12.879 --> 00:12:16.120 and there's this huge icicle on the side of the picture, 213 00:12:16.679 --> 00:12:19.240 and that's just such a really it's just a weird 214 00:12:19.320 --> 00:12:24.000 environment for like this tiny, little cold blooded subtropical animal 215 00:12:24.159 --> 00:12:26.200 to live in, and I just thought it was fascinating. 216 00:12:26.279 --> 00:12:29.080 So yeah, I got obsessed with how these animals were 217 00:12:29.080 --> 00:12:32.679 dealing with these these novel cold temperatures. How were they 218 00:12:32.919 --> 00:12:36.279 So yeah, so that's a it's actually it's a kind 219 00:12:36.279 --> 00:12:40.360 of a complicated question. But one of the things that 220 00:12:40.399 --> 00:12:44.879 we've found is that the farther north you go, essentially 221 00:12:44.879 --> 00:12:48.639 the more cold hardy the animals become. So we do 222 00:12:48.720 --> 00:12:52.720 these tests when we're looking at the limits of thermal tolerance. 223 00:12:52.799 --> 00:12:58.159 So for ectotherms like cold blooded animals, their internal body 224 00:12:58.200 --> 00:13:01.440 temperature is really tightly correlated with the external body temperature, 225 00:13:01.559 --> 00:13:05.240 and that means that their performance is really tightly tied 226 00:13:05.279 --> 00:13:07.320 to the external body temperature. 227 00:13:07.480 --> 00:13:11.480 How much beach volleyball would do you play in the snow? None? 228 00:13:11.519 --> 00:13:12.720 Because the answer is none. 229 00:13:13.000 --> 00:13:14.759 So what we would do is, you know, we go 230 00:13:14.840 --> 00:13:17.519 to a site and we take go into a population 231 00:13:17.679 --> 00:13:20.720 catch animals and we bring them into the laboratory and 232 00:13:20.759 --> 00:13:24.120 then we do these trials where we we goose them, 233 00:13:24.159 --> 00:13:28.799 so we put like a little thermometer in their cloaca, 234 00:13:28.080 --> 00:13:33.320 and then we cool them down very slowly by like 235 00:13:33.480 --> 00:13:37.080 one degree celsius per minute, and then we test for 236 00:13:37.200 --> 00:13:40.960 their ability to maintain a writing response, will like flip 237 00:13:41.000 --> 00:13:43.120 them onto their backs, and then we try to get 238 00:13:43.120 --> 00:13:45.720 them to flip themselves back over because a lizard always 239 00:13:45.759 --> 00:13:48.679 wants to be on its feet. And the temperature at 240 00:13:48.679 --> 00:13:51.159 which they can't do that anymore like that, we call 241 00:13:51.240 --> 00:13:55.639 that their lower thermal limit was called the critical thermal minimum. 242 00:13:55.840 --> 00:14:02.320 And so when we measured this across the the geographic range, 243 00:14:02.399 --> 00:14:06.879 we found that animals where the winter temperature or populations 244 00:14:06.879 --> 00:14:10.639 where the winter temperatures were coldest, had the animals that 245 00:14:10.679 --> 00:14:12.039 were the most cold hearted. 246 00:14:12.159 --> 00:14:14.759 Hello if your neutologies. A cloaca is a butt and 247 00:14:14.840 --> 00:14:18.000 reptiles and birds enjoy the convenience of a one stop 248 00:14:18.080 --> 00:14:23.639 shop for pooh pe sex and scientific spa treatments involving thermometers. 249 00:14:24.000 --> 00:14:28.039 So Shane says there's a lot of local adaptation. The 250 00:14:28.080 --> 00:14:31.200 lizards that can survive that cold have offspring they can 251 00:14:31.240 --> 00:14:34.639 also survive it, but they also just become heartier because 252 00:14:34.639 --> 00:14:37.840 they're like, been there, done that, walked two miles in 253 00:14:37.919 --> 00:14:42.120 the snow uphill. But unlike your friend's cranky grandpa, these 254 00:14:42.159 --> 00:14:45.120 lizards are doing it all this in the nude. Don't 255 00:14:45.120 --> 00:14:47.519 picture your friend's grandpa in the nude. Don't do it. 256 00:14:48.279 --> 00:14:51.759 Don't anyway in the wild. Natural selection, right. 257 00:14:52.039 --> 00:14:57.320 But but when we bring like gravid females into the 258 00:14:57.399 --> 00:15:00.799 lab and they lay eggs and those babies are born, 259 00:15:00.879 --> 00:15:04.679 we raise those babies under common laboratory conditions, so they've 260 00:15:04.720 --> 00:15:09.080 never seen a winter anywhere outside, and we do these 261 00:15:09.080 --> 00:15:14.320 same cold tolerance experiments. We find that the offspring have 262 00:15:14.440 --> 00:15:16.399 the same level of cold tolerance as their parents did. 263 00:15:16.399 --> 00:15:20.200 Would suggest that there's some heritable, genetically based component to 264 00:15:21.320 --> 00:15:22.120 cold tolerance. 265 00:15:22.440 --> 00:15:25.600 And then you and I are endotherms, Yes we are. 266 00:15:25.720 --> 00:15:28.480 How difficult was it not to apply some of your 267 00:15:28.519 --> 00:15:33.000 knowledge that you gained through studying nols to like yourself 268 00:15:33.039 --> 00:15:37.799 as an endotherm walking around freezing in Montana? Ps I 269 00:15:37.840 --> 00:15:41.000 got his timeline wrong, and Shane was studying anoles at 270 00:15:41.000 --> 00:15:44.960 Harvard and did his postdoc on very cold mice in Montana. 271 00:15:45.000 --> 00:15:48.440 But anyway, in those cold places, was he thinking about 272 00:15:48.440 --> 00:15:51.879 his own reactions to cold. I'm asking this as a 273 00:15:51.919 --> 00:15:54.399 person wearing a scarf in Los Angeles. 274 00:15:54.799 --> 00:15:57.159 I think it's pretty It was pretty easy for me 275 00:15:57.360 --> 00:16:02.080 because reptiles are just really different from mammals. The way 276 00:16:02.080 --> 00:16:05.600 that they experience temperature is very different from the way 277 00:16:05.639 --> 00:16:07.600 that mammals experience temperature. 278 00:16:08.120 --> 00:16:10.360 How do mammals experience temperature? 279 00:16:10.600 --> 00:16:14.279 Okay, so it's exciting. Yeah, so we're going to go 280 00:16:14.320 --> 00:16:16.879 We're going to go in right now. I'm going in 281 00:16:17.159 --> 00:16:21.360 when we're thinking about like the physiology, when we're talking 282 00:16:21.360 --> 00:16:26.360 about like thermal physiology, how animals experience temperature and how 283 00:16:26.399 --> 00:16:31.000 that temperature influences their function. There are four major categories, 284 00:16:31.960 --> 00:16:37.000 and yeah, they can sort of you can like sort 285 00:16:37.000 --> 00:16:40.279 of pick and choose the combination they're in, and you 286 00:16:40.320 --> 00:16:44.759 can find pretty much an organism that fits that that descriptions. 287 00:16:44.879 --> 00:16:48.320 Okay, here we go into a matrix of different combinations 288 00:16:48.399 --> 00:16:50.960 of body heat. You can have if you weren't already 289 00:16:51.039 --> 00:16:55.480 a hairy human, maybe you shave none of my business onward. 290 00:16:55.840 --> 00:17:03.759 So the first difference is being ectothermic or endothermic okay, right, 291 00:17:03.879 --> 00:17:08.079 So being endothermic, you can endothermic organisms can produce their 292 00:17:08.079 --> 00:17:14.599 own internal body heat. Ectothermic organisms cannot, and then we 293 00:17:14.759 --> 00:17:21.640 have basically homeothermic versus poikilothermic. WHOA, yeah, that's a good word. 294 00:17:21.400 --> 00:17:24.400 A word that is a scrabble word. It's a good 295 00:17:24.440 --> 00:17:27.000 podcast word. Yeah, poikilothermic. 296 00:17:27.400 --> 00:17:29.000 I know what that means. I'm not going to be 297 00:17:29.000 --> 00:17:31.240 looking that up and defining it in this side at all. 298 00:17:32.440 --> 00:17:35.440 That's gonna happen. Yeah, I did not know this word, pokilothermic, 299 00:17:35.480 --> 00:17:37.240 And yeah I got you covered with the death. So 300 00:17:37.359 --> 00:17:42.559 a pekuilotherm is an animal whose internal temperature varies considerably. 301 00:17:42.640 --> 00:17:45.519 It's all over the place, as opposed to homeotherm, which 302 00:17:45.559 --> 00:17:49.680 maintains homeostasis and keeps a temperature pretty constant like you 303 00:17:49.759 --> 00:17:52.720 and me. So Shane explains how this is not just 304 00:17:52.960 --> 00:17:57.079 ectothermic and endothermic. There's difference and thus a matrix. 305 00:17:57.519 --> 00:18:01.240 So homeotherms are able to maintain a constant body temperature 306 00:18:01.799 --> 00:18:07.720 and poikilotherms have fluctuating body temperature with respect to their 307 00:18:07.799 --> 00:18:11.680 external environment. So as their external environment fluctuates their internal 308 00:18:12.440 --> 00:18:15.240 and so you have a tendency I think generally speaking 309 00:18:15.279 --> 00:18:21.400 to group endotherm and homeotherm together, right, and ectotherm and 310 00:18:21.440 --> 00:18:22.640 poikilo therm. 311 00:18:22.400 --> 00:18:23.720 Together, That's what I would think. 312 00:18:23.839 --> 00:18:27.759 Yeah, but it's not always the case. Right. So for instance, 313 00:18:27.799 --> 00:18:34.319 you can have an endothermic poikilotherm. These are like mammals 314 00:18:34.319 --> 00:18:37.319 that hibernate. For animals that hibernate for really long periods 315 00:18:37.319 --> 00:18:40.839 of time, like weeks or months, their internal body temperature 316 00:18:40.920 --> 00:18:43.880 can actually drop to within about one degree celsius of 317 00:18:43.920 --> 00:18:47.920 ambient temperature. What even though they have these internal mechanisms 318 00:18:47.920 --> 00:18:52.799 of producing heat, and this is an energy saving mechanism. 319 00:18:52.839 --> 00:18:56.079 So these endo points, if you will, generate their own heat, 320 00:18:56.319 --> 00:18:58.960 but it can vary, kind of like a house with 321 00:18:59.039 --> 00:19:02.160 a furnace. But they set the dial depending on what 322 00:19:02.200 --> 00:19:04.240 they need. Now, in case you are on a first 323 00:19:04.359 --> 00:19:07.319 date or a job interview that's going badly, the only 324 00:19:07.359 --> 00:19:10.519 thing they can save it is naming some hibernating endothermic 325 00:19:10.559 --> 00:19:16.119 pekilo therms. Here is a list bears, gophers, bats, groundhogs, 326 00:19:16.400 --> 00:19:20.319 just to name a few. Now, let's say an ectotherm 327 00:19:20.640 --> 00:19:23.640 is like a house without a thermos, So the temperature 328 00:19:23.759 --> 00:19:26.599 could vary widely, but it doesn't mean it has to. 329 00:19:26.880 --> 00:19:30.880 On the flip side, you can have an ectotherm that 330 00:19:31.079 --> 00:19:37.799 is actually homeothermic. And this can happen by a couple 331 00:19:37.839 --> 00:19:41.240 of different ways. So the first way is just by 332 00:19:41.279 --> 00:19:44.160 being really large, all right. So this is what we 333 00:19:44.200 --> 00:19:46.799 call gigantothermy no. 334 00:19:47.160 --> 00:19:52.000 Word word gigantothermy. 335 00:19:52.279 --> 00:19:56.400 Yeah. So for instance, like the dinosaurs, okay, but also 336 00:19:56.519 --> 00:20:00.599 things like saltwater crocodiles, which are massive animals. The largest 337 00:20:00.599 --> 00:20:02.920 lizard on the planet, the Komodo dragon. 338 00:20:02.960 --> 00:20:04.079 Oh I was going to ask about them. 339 00:20:04.160 --> 00:20:09.319 Yeah, And this is essentially a byproduct of surface to volume, right, 340 00:20:09.400 --> 00:20:15.920 So if you are really large, your volume and with 341 00:20:16.079 --> 00:20:19.880 proportion to your surface area is very large, that means 342 00:20:19.880 --> 00:20:24.319 that you lose heat relatively slowly to the external environment. 343 00:20:24.880 --> 00:20:27.839 So for instance, if you went to Australia or if 344 00:20:27.839 --> 00:20:29.920 you went to the Nile, you would see really large 345 00:20:29.920 --> 00:20:33.519 crocodile early in the morning basking, just sitting in the 346 00:20:33.559 --> 00:20:39.440 sun with their mouths open, completely lifeless for hours. And 347 00:20:39.480 --> 00:20:41.319 then by the heat of the day they're up and 348 00:20:41.359 --> 00:20:45.039 moving and they're swimming around in pretty cold water. And 349 00:20:45.079 --> 00:20:47.480 they can maintain that function because they're so big. 350 00:20:47.599 --> 00:20:52.559 Okay, So that's an endothermic homeotherm like us endothermic pokeotherm 351 00:20:52.720 --> 00:20:56.799 bears groundhogs at all. And then we were talking about 352 00:20:56.960 --> 00:21:00.799 ectotherms that maintain constant body to but you're just by 353 00:21:00.839 --> 00:21:03.640 being huge. But that's not the only way to be 354 00:21:03.960 --> 00:21:07.920 an ecdothermic homeotherm. Did I say that right? 355 00:21:08.200 --> 00:21:15.079 Ectothermic homeotherm is through behavioral thermal regulation, all right, And 356 00:21:16.480 --> 00:21:20.559 you know, and basically this means, you know, paying really 357 00:21:20.599 --> 00:21:24.799 close attention to the micro environments, like the micro thermal 358 00:21:24.920 --> 00:21:28.400 environments that are available to you. Right, So if you 359 00:21:28.640 --> 00:21:33.200 are a small lizard, for instance, and it gets really 360 00:21:33.240 --> 00:21:36.200 hot outside, again, because you're so small, you're going to 361 00:21:36.240 --> 00:21:39.279 gain heat really quickly because of that same volume the 362 00:21:39.319 --> 00:21:43.960 surface area issue, except if you move into the shade, right, 363 00:21:44.039 --> 00:21:45.680 So if you move into the shade at the right 364 00:21:45.720 --> 00:21:47.880 time and you stay there for long enough, you can 365 00:21:47.920 --> 00:21:52.200 actually maintain a steady body temperature even though you're not 366 00:21:52.319 --> 00:21:54.200 producing internal body heat. 367 00:21:54.440 --> 00:21:56.000 Oh okay exactly. 368 00:21:56.119 --> 00:21:58.279 And then insects do it a whole different way. So 369 00:21:58.319 --> 00:22:05.160 things like bees are technically ectothermic homeotherms because they can 370 00:22:05.200 --> 00:22:07.880 actually use their flight muscles. They can decouple their flight 371 00:22:07.960 --> 00:22:12.039 muscles and vibrate them without moving their wings to generate heat. 372 00:22:12.160 --> 00:22:15.400 And why do some animals and humans have set body 373 00:22:15.440 --> 00:22:18.039 temperatures that they need to maintain in order to live, 374 00:22:18.640 --> 00:22:21.640 Like why why do humans have to be ninety eight 375 00:22:21.640 --> 00:22:24.920 point six? And why do and our dogs a different temperature? 376 00:22:24.960 --> 00:22:28.519 And do mice in Montana have to be a different 377 00:22:28.559 --> 00:22:31.000 temperature than the ones in New Mexico. 378 00:22:32.039 --> 00:22:36.000 That's a great question. So generally speaking, you know, it's 379 00:22:36.000 --> 00:22:41.200 all about strategy, like evolutionary strategy and life history strategy. 380 00:22:42.039 --> 00:22:47.480 So mammals benefit from being warm all the time in 381 00:22:47.519 --> 00:22:49.799 the sense that you know, I can get up and 382 00:22:49.839 --> 00:22:53.039 move regardless of you know what time of day it is, 383 00:22:53.279 --> 00:22:55.960 which means because I have that high metabolism, you know, 384 00:22:56.039 --> 00:22:58.599 I can you know, go run and you know, and 385 00:22:58.640 --> 00:23:02.559 do like really high intensity activities for a pretty sustained 386 00:23:02.559 --> 00:23:06.200 period of time, much more so than if I was 387 00:23:06.599 --> 00:23:10.559 an ectotherm. But also on the flip side of that, 388 00:23:10.640 --> 00:23:14.400 it also means that I have to take in much 389 00:23:14.440 --> 00:23:18.440 more energy in order to fuel that that internal furnace, 390 00:23:18.559 --> 00:23:21.240 right that defines that defines endo therms. 391 00:23:22.720 --> 00:23:25.039 So we have to be out grazing and hunting and 392 00:23:25.079 --> 00:23:27.480 finding food in order to have this like twenty four 393 00:23:27.519 --> 00:23:30.279 hour open supermarket of body heat. 394 00:23:30.400 --> 00:23:34.400 Kind of, yes, basically, So I do know that we've 395 00:23:34.799 --> 00:23:39.559 undergone like humans as a lineage, right, as we've sort 396 00:23:39.559 --> 00:23:42.960 of as we migrated out of Africa into the rest 397 00:23:43.000 --> 00:23:45.799 of the world. Temperature will played a huge part in 398 00:23:46.160 --> 00:23:48.279 that process, right, And we can actually see it in 399 00:23:48.920 --> 00:23:51.839 the diversity of body shapes that we see around the planet. 400 00:23:52.279 --> 00:23:56.359 So as we moved, So if we look within Africa, 401 00:23:56.440 --> 00:24:01.160