1 00:00:01,920 --> 00:00:04,320 Speaker 1: Welcome to brain Stuff, a production of I Heart Radio, 2 00:00:06,280 --> 00:00:10,360 Speaker 1: Hey brain Stuff, Lauren Vogelbaum. Here in nature, there's a 3 00:00:10,360 --> 00:00:13,600 Speaker 1: certain ethos of all scratch ere back if you scratch mine. 4 00:00:14,200 --> 00:00:17,720 Speaker 1: Living things never exist in isolation, and organisms of different 5 00:00:17,720 --> 00:00:21,439 Speaker 1: species occasionally need to cooperate in order to get stuff done, 6 00:00:22,120 --> 00:00:26,040 Speaker 1: And sometimes one organism takes the benefit from another while 7 00:00:26,120 --> 00:00:30,160 Speaker 1: that other one blithely lives its life unharmed but blissfully 8 00:00:30,200 --> 00:00:34,280 Speaker 1: unaware of the service it's performing. Collegists call this form 9 00:00:34,320 --> 00:00:37,640 Speaker 1: of half passive cooperation commence all is um, and it's 10 00:00:37,680 --> 00:00:40,320 Speaker 1: different from some other ways that members of an ecosystem 11 00:00:40,320 --> 00:00:44,120 Speaker 1: can interact. For instance, commence allism isn't the same thing 12 00:00:44,159 --> 00:00:47,839 Speaker 1: as parasiteis m, where one partner the parasite lives on 13 00:00:48,040 --> 00:00:50,200 Speaker 1: or in the body of a host and only one 14 00:00:50,240 --> 00:00:53,880 Speaker 1: partner actually benefits while the other is harmed. It's also 15 00:00:54,000 --> 00:00:57,600 Speaker 1: not exactly the same as mutualism, where both partners benefit 16 00:00:57,600 --> 00:01:00,640 Speaker 1: from the partnership. But think about the relationship between bees 17 00:01:00,680 --> 00:01:03,520 Speaker 1: and flowers. Of the bee gets food while the flower 18 00:01:03,560 --> 00:01:08,080 Speaker 1: accomplishes its reproductive goals. Commence ali is um involves one 19 00:01:08,160 --> 00:01:11,039 Speaker 1: organism just going about its business while one or more 20 00:01:11,080 --> 00:01:14,160 Speaker 1: others called commence als just sort of hang out and 21 00:01:14,240 --> 00:01:18,680 Speaker 1: benefit from that one guy's hard work. We spoke with 22 00:01:18,720 --> 00:01:23,080 Speaker 1: Amanda Hips, director of Communications and Development at wild Landscapes International. 23 00:01:23,720 --> 00:01:26,760 Speaker 1: She said, one of my favorite commensal relationships is the 24 00:01:26,800 --> 00:01:30,640 Speaker 1: one of Eastern screech owls and blind snakes. The owls 25 00:01:30,680 --> 00:01:33,560 Speaker 1: bring live blind snakes to their chicks, while some of 26 00:01:33,560 --> 00:01:35,760 Speaker 1: the snakes are eaten. The lucky ones burrow into the 27 00:01:35,840 --> 00:01:38,880 Speaker 1: nest and eat insect larva that they find there, lava 28 00:01:38,920 --> 00:01:42,680 Speaker 1: that would likely parasities the chicks. A study by scientists 29 00:01:42,680 --> 00:01:45,160 Speaker 1: from Baylor University found the chicks who grew up in 30 00:01:45,240 --> 00:01:49,000 Speaker 1: nests with blind snakes grew faster and experienced lower mortality 31 00:01:49,080 --> 00:01:53,400 Speaker 1: rates compared to nests without blind snakes. We can observe 32 00:01:53,560 --> 00:01:56,840 Speaker 1: three main types of commence all is um in Quillinism 33 00:01:57,120 --> 00:02:00,360 Speaker 1: is when one species lives on or inside of another species, 34 00:02:00,480 --> 00:02:02,840 Speaker 1: the way that our gut bacteria live inside us or 35 00:02:02,960 --> 00:02:06,280 Speaker 1: within a nest, burrow or dwelling created by another species. 36 00:02:06,880 --> 00:02:10,160 Speaker 1: For instance, gopher tortoises, which are native to the southeastern 37 00:02:10,240 --> 00:02:13,840 Speaker 1: United States, did long burrows for shelter, some of them 38 00:02:13,840 --> 00:02:17,400 Speaker 1: reaching forty feet or twelve meters in length. Hundreds of 39 00:02:17,400 --> 00:02:20,240 Speaker 1: other animals have been recorded using these burrows. Some of 40 00:02:20,280 --> 00:02:22,800 Speaker 1: them have even evolved to require the burrows of the 41 00:02:22,800 --> 00:02:26,120 Speaker 1: gopher tortoise in order to survive. Most of the commence 42 00:02:26,160 --> 00:02:29,200 Speaker 1: als are insects, but these burrows are also important to 43 00:02:29,240 --> 00:02:32,480 Speaker 1: a variety of species of snakes, frogs, and small mammals. 44 00:02:33,320 --> 00:02:37,120 Speaker 1: Hips said, there are fourteen recognized insects that are fully 45 00:02:37,240 --> 00:02:40,720 Speaker 1: reliant on gopher tortoises. One of these species is a 46 00:02:40,800 --> 00:02:44,320 Speaker 1: moth that feeds exclusively on the keratin of the shells 47 00:02:44,440 --> 00:02:48,000 Speaker 1: of dead gopher tortoises. Some of the remaining insects feed 48 00:02:48,000 --> 00:02:51,160 Speaker 1: on gopher tortoise doung Others feed on pest flies or 49 00:02:51,200 --> 00:02:54,400 Speaker 1: other organic matter inside the tortoise burrows. I like to 50 00:02:54,400 --> 00:02:57,079 Speaker 1: think of them as a housekeeping service to the gopher tortoise. 51 00:02:57,800 --> 00:03:00,440 Speaker 1: Although the impacts they have on gopher tortoises is not 52 00:03:00,520 --> 00:03:04,480 Speaker 1: yet understood, they likely lower parasite loads for tortoises and 53 00:03:04,600 --> 00:03:07,200 Speaker 1: the other vertebrates that also take advantage of the burrows. 54 00:03:08,520 --> 00:03:11,320 Speaker 1: Another kind of commence all is um is called metabiosis, 55 00:03:11,560 --> 00:03:15,240 Speaker 1: wherein one organism unintentionally forms a habitat for another while 56 00:03:15,440 --> 00:03:19,359 Speaker 1: just going about its normal business. For example, maggots need 57 00:03:19,440 --> 00:03:22,760 Speaker 1: to live somewhere, and it's often on or in the 58 00:03:22,800 --> 00:03:25,239 Speaker 1: carcass of a dead animal that, to be fair, wasn't 59 00:03:25,360 --> 00:03:29,520 Speaker 1: using that carcass anymore. Similarly, the gilo woodpecker makes its 60 00:03:29,520 --> 00:03:32,600 Speaker 1: nest in the cavity of the saara cactus, and hermit 61 00:03:32,639 --> 00:03:35,680 Speaker 1: crabs protect themselves and the discarded shells of snails and 62 00:03:35,760 --> 00:03:39,960 Speaker 1: other gastropods that have outground them. Meanwhile, for a c 63 00:03:40,360 --> 00:03:42,240 Speaker 1: is a type of commence ali is um when one 64 00:03:42,280 --> 00:03:45,040 Speaker 1: animal attaches to another in order to catch a ride 65 00:03:45,080 --> 00:03:48,480 Speaker 1: from one place to another. For instance, a nematode or 66 00:03:48,560 --> 00:03:51,200 Speaker 1: might can't really get very far on its own unless 67 00:03:51,200 --> 00:03:54,320 Speaker 1: it climbs on board a bee or a fly. The 68 00:03:54,480 --> 00:03:57,200 Speaker 1: might or nematode gets a huge benefit from the exchange, 69 00:03:57,440 --> 00:04:00,320 Speaker 1: whereas the bee or fly doesn't really benefit or suffer 70 00:04:00,360 --> 00:04:04,400 Speaker 1: from the interaction. While commence all um is a huge 71 00:04:04,440 --> 00:04:07,000 Speaker 1: benefit for some of the organisms in the deal, it 72 00:04:07,120 --> 00:04:12,000 Speaker 1: can be really tricky for an ecosystem under stress. Hips said, Ultimately, 73 00:04:12,160 --> 00:04:13,880 Speaker 1: I think having more commence ali is um in an 74 00:04:13,920 --> 00:04:17,520 Speaker 1: ecosystem could make an ecosystem more vulnerable if you lose 75 00:04:17,560 --> 00:04:21,200 Speaker 1: one species you could lose another If gopher tortoises went extinct, 76 00:04:21,440 --> 00:04:29,720 Speaker 1: we will undoubtedly lose other species along with it. Today's 77 00:04:29,720 --> 00:04:32,360 Speaker 1: episode was written by Jescelin Shields and produced by Tyler Klain. 78 00:04:32,839 --> 00:04:34,560 Speaker 1: For more on this and lots of other topics, visit 79 00:04:34,600 --> 00:04:37,120 Speaker 1: how stuff works dot com. Brain Stuff is production of 80 00:04:37,160 --> 00:04:39,719 Speaker 1: I Heart Radio. 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