1 00:00:01,920 --> 00:00:06,560 Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey 2 00:00:06,600 --> 00:00:10,119 Speaker 1: brain Stuff, Lauren vogebam here. If you've ever swatted it 3 00:00:10,200 --> 00:00:12,600 Speaker 1: fruit flies hovering over the fruit bowl on your kitchen 4 00:00:12,640 --> 00:00:16,760 Speaker 1: counter and wondered what purpose they could ever possibly serve humanity, 5 00:00:17,160 --> 00:00:20,960 Speaker 1: You're not alone. They are small, and they are annoying, 6 00:00:21,320 --> 00:00:23,799 Speaker 1: but humans owe them a huge debt of gratitude for 7 00:00:23,800 --> 00:00:27,560 Speaker 1: their contributions to the science of modern genetics. One species, 8 00:00:27,600 --> 00:00:32,360 Speaker 1: in particular, Drosophila melanogaster, is a superstar of tiny, annoying 9 00:00:32,479 --> 00:00:36,519 Speaker 1: winged things. At least five Nobel Prizes have been awarded 10 00:00:36,520 --> 00:00:39,920 Speaker 1: to scientists for their work on fruit flies. Yes, the 11 00:00:40,000 --> 00:00:44,159 Speaker 1: lowly fruit fly and the larger, glorious er human have 12 00:00:44,360 --> 00:00:47,159 Speaker 1: together tackle genetics and done a lot of cool stuff. 13 00:00:48,000 --> 00:00:51,720 Speaker 1: But like why fruit flies? And how do you keep 14 00:00:51,800 --> 00:00:54,200 Speaker 1: them out of your kitchen? And do we need to 15 00:00:54,200 --> 00:00:56,880 Speaker 1: blame scientists for them being in your kitchen? To begin with, 16 00:00:58,280 --> 00:01:00,760 Speaker 1: fruit flies have been used in biological studies for a 17 00:01:00,840 --> 00:01:03,800 Speaker 1: long time, which means there are a lot of tools 18 00:01:03,840 --> 00:01:08,680 Speaker 1: and resources for scientists using Drosophila melanogaster to ask interesting questions. 19 00:01:09,280 --> 00:01:12,520 Speaker 1: But there are some specific reasons. The species has always 20 00:01:12,520 --> 00:01:16,720 Speaker 1: been a Darling of geneticists. For starters in genetics, it's 21 00:01:16,720 --> 00:01:19,920 Speaker 1: helpful to have research subjects that can cycle through generations 22 00:01:20,040 --> 00:01:23,880 Speaker 1: rather quickly, and fruit flies are great at that. We 23 00:01:23,920 --> 00:01:26,880 Speaker 1: spoke via email with Thomas Merritt, PhD, Professor in the 24 00:01:26,920 --> 00:01:31,399 Speaker 1: Department of Chemistry and Biochemistry at Laurentian University in Ontario, Canada. 25 00:01:32,280 --> 00:01:35,280 Speaker 1: He said fruit flies create a new generation in about 26 00:01:35,319 --> 00:01:38,920 Speaker 1: two weeks, making breeding them in the lab simple. They're 27 00:01:38,959 --> 00:01:41,760 Speaker 1: also small and easy to rear and care for, and 28 00:01:41,800 --> 00:01:43,520 Speaker 1: it's easy to house as many of them as you 29 00:01:43,600 --> 00:01:47,640 Speaker 1: need in a single lab at one time. Also, fruit 30 00:01:47,640 --> 00:01:52,080 Speaker 1: flies are surprisingly similar to humans and other vertebrates. Drosophila 31 00:01:52,080 --> 00:01:55,760 Speaker 1: melanogaster has fourteen thousand genes, and we humans have somewhere 32 00:01:55,760 --> 00:01:59,040 Speaker 1: between twenty thousand and twenty five thousand, and about eight 33 00:01:59,080 --> 00:02:03,120 Speaker 1: thousand of those vans are analogous. Similarly, most fruit fly 34 00:02:03,200 --> 00:02:07,600 Speaker 1: biochemistry is the same or similar to ours. Merritt said 35 00:02:08,000 --> 00:02:10,360 Speaker 1: fruit flies are great to work on if you're interested 36 00:02:10,400 --> 00:02:14,280 Speaker 1: in variation between individuals or genetic lineages. They are also 37 00:02:14,320 --> 00:02:18,000 Speaker 1: a great system if you're interested in experimentally altering the environment. 38 00:02:18,600 --> 00:02:20,799 Speaker 1: They are so small we can do things like keep 39 00:02:20,840 --> 00:02:24,000 Speaker 1: thousands of flies at different temperatures to see how temperature 40 00:02:24,040 --> 00:02:28,040 Speaker 1: changes metabolism or gene activity. In one study in my lab, 41 00:02:28,280 --> 00:02:30,799 Speaker 1: we used a small conveyor belt to slowly turn the 42 00:02:30,880 --> 00:02:34,160 Speaker 1: vials we keep the flies in. This simple instrument is 43 00:02:34,240 --> 00:02:37,560 Speaker 1: essentially a fly treadmill, and we can get literally hundreds 44 00:02:37,560 --> 00:02:42,440 Speaker 1: of flies exercising on a small desktop. But fruit flies 45 00:02:42,520 --> 00:02:44,960 Speaker 1: can be annoying in a lab, just as they can 46 00:02:45,000 --> 00:02:48,600 Speaker 1: in your kitchen, to begin with their small and it's 47 00:02:48,840 --> 00:02:51,280 Speaker 1: very difficult to dissect a fruit fly in case you 48 00:02:51,320 --> 00:02:54,560 Speaker 1: were wondering. And although we share many of the same 49 00:02:54,639 --> 00:02:58,120 Speaker 1: genes and genetic networks, were separated from them by hundreds 50 00:02:58,120 --> 00:03:00,920 Speaker 1: of millions of years of evolution. So it's hard to 51 00:03:00,919 --> 00:03:03,600 Speaker 1: make assumptions about ourselves based on what we find in 52 00:03:03,680 --> 00:03:07,960 Speaker 1: these little insects because there are substantial biological differences between us. 53 00:03:09,000 --> 00:03:11,919 Speaker 1: Merritt said, there are certainly questions that are better asked 54 00:03:11,960 --> 00:03:16,120 Speaker 1: in larger or evolutionarily more closely related species like rats 55 00:03:16,120 --> 00:03:20,160 Speaker 1: and mice. Similarly, there are questions, for example, changes in 56 00:03:20,280 --> 00:03:23,280 Speaker 1: genes through evolution that are better asked in organisms that 57 00:03:23,320 --> 00:03:26,399 Speaker 1: are even smaller, can be kept in even larger numbers, 58 00:03:26,480 --> 00:03:31,040 Speaker 1: and with even shorter lifespans like bacteria or fungi. But 59 00:03:31,360 --> 00:03:34,720 Speaker 1: we can't blame scientists for the proliferation of fruit flies 60 00:03:34,800 --> 00:03:38,760 Speaker 1: in the world. They would have been there regardless, Merrett explained. 61 00:03:39,000 --> 00:03:43,760 Speaker 1: Drosophalo melanogaster is a cosmopolitan species, meaning it's found essentially 62 00:03:43,840 --> 00:03:48,240 Speaker 1: almost anywhere we find humans. A fruit fly has pretty 63 00:03:48,240 --> 00:03:51,280 Speaker 1: simple needs in order to prosper and multiply, and those 64 00:03:51,320 --> 00:03:54,760 Speaker 1: needs are usually met in our homes, moderate temperatures and 65 00:03:54,840 --> 00:03:57,680 Speaker 1: a source of fresh produce that's on the overripe side. 66 00:03:58,320 --> 00:04:00,680 Speaker 1: This is why fruit flies live i on the hug 67 00:04:00,720 --> 00:04:05,200 Speaker 1: in places like dumpsters, compost tapes, and kitchens. Marrett said. 68 00:04:05,720 --> 00:04:08,880 Speaker 1: One interesting thing is we seem to see more flies 69 00:04:08,960 --> 00:04:12,520 Speaker 1: inside in the early fall. I think that's from flies 70 00:04:12,560 --> 00:04:15,520 Speaker 1: that have been happily breeding and multiplying outside all summer 71 00:04:15,800 --> 00:04:19,200 Speaker 1: moving into the warmer inside spaces as the weather cools. 72 00:04:20,600 --> 00:04:23,000 Speaker 1: The good news is that fruit flies aren't dangerous in 73 00:04:23,040 --> 00:04:26,760 Speaker 1: any way. Merritt said. They don't carry disease, and they 74 00:04:26,800 --> 00:04:30,320 Speaker 1: don't cause fruit to spoil or rot. At least Drosophila 75 00:04:30,360 --> 00:04:34,080 Speaker 1: melano gaster doesn't, although there is at least one invasive species, 76 00:04:34,120 --> 00:04:37,360 Speaker 1: the spotted wing fruit fly that actually damages fruit crops, 77 00:04:37,400 --> 00:04:40,880 Speaker 1: and it's a growing agricultural concern. In my lab and 78 00:04:40,920 --> 00:04:44,279 Speaker 1: in my house, we use a simple vinegar trap kenning 79 00:04:44,320 --> 00:04:46,320 Speaker 1: jar with some vinegar in the bottom and a top 80 00:04:46,360 --> 00:04:48,560 Speaker 1: of plastic wrap with a few holes punched in it 81 00:04:48,600 --> 00:04:57,039 Speaker 1: to trap and remove flies. Today's episode was written by 82 00:04:57,120 --> 00:04:59,760 Speaker 1: Joceline Shields and produced by Tyler Clang. For more on 83 00:04:59,800 --> 00:05:02,239 Speaker 1: this and lots of other tiny topics with a huge impact, 84 00:05:02,320 --> 00:05:05,120 Speaker 1: visit how stuff works dot com. 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