1 00:00:01,960 --> 00:00:04,360 Speaker 1: Welcome to brain Stuff, a production of I Heart Radio 2 00:00:06,519 --> 00:00:09,000 Speaker 1: Pay brain Stuff. I'm Lauren volk Baum and this is 3 00:00:09,000 --> 00:00:12,520 Speaker 1: a classic episode from our former host, Christian Sagar. We 4 00:00:12,800 --> 00:00:17,120 Speaker 1: usually think of evolution as being a near cosmically slow process, 5 00:00:17,400 --> 00:00:20,880 Speaker 1: and often it is. After all, living beings in our 6 00:00:20,920 --> 00:00:24,800 Speaker 1: relationships with our environments can be really complex, with dozens 7 00:00:24,800 --> 00:00:27,680 Speaker 1: of genes coming together to create the traits that help 8 00:00:27,840 --> 00:00:31,240 Speaker 1: or hurt our chances of survival. But you don't have 9 00:00:31,320 --> 00:00:33,400 Speaker 1: to be a germ, or a fruit fly or a 10 00:00:33,440 --> 00:00:36,920 Speaker 1: peace shoot to show change quickly. Today's episode is the 11 00:00:36,960 --> 00:00:44,560 Speaker 1: strange story of a particularly swift lizard evolution. Hey, brain Stuff, 12 00:00:44,560 --> 00:00:48,320 Speaker 1: it's Christian Sager here. So evolution takes time, but just 13 00:00:48,400 --> 00:00:51,560 Speaker 1: how much time it takes is the issue. How long, 14 00:00:51,640 --> 00:00:55,600 Speaker 1: for instance, did it take therapod dinosaurs to evolve into 15 00:00:55,640 --> 00:00:59,600 Speaker 1: modern birds tens, if not hundreds of millions of years. 16 00:01:00,040 --> 00:01:02,400 Speaker 1: But since the turn of the last century, when American 17 00:01:02,400 --> 00:01:07,040 Speaker 1: biologist Herman Bumpust noticed that individual sparrows in a population 18 00:01:07,120 --> 00:01:11,760 Speaker 1: became larger as the result of one huge snowstorm, scientists 19 00:01:11,760 --> 00:01:16,880 Speaker 1: have been observing instances of short bursts of evolutionary progress 20 00:01:16,880 --> 00:01:21,960 Speaker 1: over a significantly brief period of time. Definitive instances of 21 00:01:22,120 --> 00:01:25,280 Speaker 1: rapid evolution are tough to come by, though, even in 22 00:01:25,319 --> 00:01:29,319 Speaker 1: these days of advanced genetic testing, but a recent study 23 00:01:29,440 --> 00:01:33,360 Speaker 1: published in the journal Science finds that over the course 24 00:01:33,440 --> 00:01:37,840 Speaker 1: of just a few months, green annully lizards living in 25 00:01:37,840 --> 00:01:41,959 Speaker 1: the area of the Mexico Texas border evolved a rapid 26 00:01:42,040 --> 00:01:46,679 Speaker 1: genetic tolerance to cold weather after an unusually frigid winter. 27 00:01:47,360 --> 00:01:51,800 Speaker 1: Green Annullies are warm weather reptiles that evolved on the 28 00:01:51,840 --> 00:01:55,280 Speaker 1: Caribbean island of Cuba. They found their way to the 29 00:01:55,360 --> 00:01:59,680 Speaker 1: mainland long ago, but a prolonged and extreme cold snap 30 00:01:59,720 --> 00:02:03,080 Speaker 1: can really put the hurt on a population of annuls. 31 00:02:03,520 --> 00:02:09,119 Speaker 1: The winter of did just that before that year's famed 32 00:02:09,320 --> 00:02:14,160 Speaker 1: polar vortex hit. However, the research team collected annulis in 33 00:02:14,280 --> 00:02:17,720 Speaker 1: August to find out just how cold one of these 34 00:02:17,760 --> 00:02:22,280 Speaker 1: lizards could get before its motor function was compromised, specifically, 35 00:02:22,280 --> 00:02:25,079 Speaker 1: that is, when it couldn't right itself when it was 36 00:02:25,160 --> 00:02:29,799 Speaker 1: knocked over. They collected annuals from five different sites across 37 00:02:29,960 --> 00:02:33,760 Speaker 1: Texas and found that when gradually cooled in a chamber 38 00:02:33,760 --> 00:02:37,359 Speaker 1: in the lab, the individuals from the southernmost site became 39 00:02:37,560 --> 00:02:43,600 Speaker 1: uncoordinated at around fifty two degrees fahrenheit or eleven degrees celsius, 40 00:02:43,639 --> 00:02:48,440 Speaker 1: but the ones collected from the northernmost site became unable 41 00:02:48,480 --> 00:02:52,520 Speaker 1: to right themselves at around forty three degrees fahrenheit or 42 00:02:52,680 --> 00:02:57,919 Speaker 1: six degrees celsius. Because the scientists already had genetic samples 43 00:02:57,960 --> 00:03:01,160 Speaker 1: from the lizards in the first study, When a few 44 00:03:01,280 --> 00:03:05,280 Speaker 1: months later temperatures plummeted to lows that hadn't been seen 45 00:03:05,400 --> 00:03:09,600 Speaker 1: in fifteen years, the researchers went out and collected some 46 00:03:09,680 --> 00:03:14,000 Speaker 1: of the surviving lizards from all five sites. They placed 47 00:03:14,040 --> 00:03:17,959 Speaker 1: them in the same cooling chambers and found the southernmost 48 00:03:18,000 --> 00:03:22,480 Speaker 1: Annullies exhibited much more cold resistance than the ones that 49 00:03:22,520 --> 00:03:25,840 Speaker 1: had been collected back in the summer. They could now 50 00:03:25,919 --> 00:03:29,679 Speaker 1: stand strong in the face of forty three degrees fahrenheit 51 00:03:29,840 --> 00:03:34,720 Speaker 1: or six degrees celsius. RNA sequencing before and after the 52 00:03:34,720 --> 00:03:39,720 Speaker 1: cold front also revealed significant differences between individuals from the 53 00:03:39,920 --> 00:03:45,240 Speaker 1: southern genomic regions before and after the weather event. By 54 00:03:45,240 --> 00:03:48,680 Speaker 1: the way, did you know that Annulli's living in urban 55 00:03:48,760 --> 00:03:53,360 Speaker 1: areas have stickier feet than their country cousins. Apparently it's 56 00:03:53,360 --> 00:03:57,520 Speaker 1: an evolutionary adaptation to having to cling to class and metal. 57 00:03:58,040 --> 00:04:00,520 Speaker 1: Now I want to be bitten by a radioactive annually 58 00:04:00,720 --> 00:04:05,480 Speaker 1: so I can crawl waltz with them. Today's episode was 59 00:04:05,520 --> 00:04:08,720 Speaker 1: written by Jesselyn Shields and produced by Dylan Fagan, Little Berlante, 60 00:04:08,840 --> 00:04:11,120 Speaker 1: and Tyler Clang. For more on lit and lots of 61 00:04:11,120 --> 00:04:13,760 Speaker 1: other topics, visit how stuff works dot com. Brain Stuff 62 00:04:13,800 --> 00:04:16,040 Speaker 1: is a production of I Heart Radio. For more podcasts 63 00:04:16,080 --> 00:04:18,839 Speaker 1: my heart Radio, visit the iHeart Radio app, Apple Podcasts, 64 00:04:18,920 --> 00:04:20,640 Speaker 1: or wherever you listen to your favorite shows.