WEBVTT - Why Are Fruit Flies Science Superstars? 0:00:01.920 --> 0:00:06.560 Welcome to brain Stuff production of I Heart Radio. Hey 0:00:06.600 --> 0:00:10.119 brain Stuff, Lauren vogebam here. If you've ever swatted it 0:00:10.200 --> 0:00:12.600 fruit flies hovering over the fruit bowl on your kitchen 0:00:12.640 --> 0:00:16.760 counter and wondered what purpose they could ever possibly serve humanity, 0:00:17.160 --> 0:00:20.960 You're not alone. They are small, and they are annoying, 0:00:21.320 --> 0:00:23.799 but humans owe them a huge debt of gratitude for 0:00:23.800 --> 0:00:27.560 their contributions to the science of modern genetics. One species, 0:00:27.600 --> 0:00:32.360 in particular, Drosophila melanogaster, is a superstar of tiny, annoying 0:00:32.479 --> 0:00:36.519 winged things. At least five Nobel Prizes have been awarded 0:00:36.520 --> 0:00:39.920 to scientists for their work on fruit flies. Yes, the 0:00:40.000 --> 0:00:44.159 lowly fruit fly and the larger, glorious er human have 0:00:44.360 --> 0:00:47.159 together tackle genetics and done a lot of cool stuff. 0:00:48.000 --> 0:00:51.720 But like why fruit flies? And how do you keep 0:00:51.800 --> 0:00:54.200 them out of your kitchen? And do we need to 0:00:54.200 --> 0:00:56.880 blame scientists for them being in your kitchen? To begin with, 0:00:58.280 --> 0:01:00.760 fruit flies have been used in biological studies for a 0:01:00.840 --> 0:01:03.800 long time, which means there are a lot of tools 0:01:03.840 --> 0:01:08.680 and resources for scientists using Drosophila melanogaster to ask interesting questions. 0:01:09.280 --> 0:01:12.520 But there are some specific reasons. The species has always 0:01:12.520 --> 0:01:16.720 been a Darling of geneticists. For starters in genetics, it's 0:01:16.720 --> 0:01:19.920 helpful to have research subjects that can cycle through generations 0:01:20.040 --> 0:01:23.880 rather quickly, and fruit flies are great at that. We 0:01:23.920 --> 0:01:26.880 spoke via email with Thomas Merritt, PhD, Professor in the 0:01:26.920 --> 0:01:31.399 Department of Chemistry and Biochemistry at Laurentian University in Ontario, Canada. 0:01:32.280 --> 0:01:35.280 He said fruit flies create a new generation in about 0:01:35.319 --> 0:01:38.920 two weeks, making breeding them in the lab simple. They're 0:01:38.959 --> 0:01:41.760 also small and easy to rear and care for, and 0:01:41.800 --> 0:01:43.520 it's easy to house as many of them as you 0:01:43.600 --> 0:01:47.640 need in a single lab at one time. Also, fruit 0:01:47.640 --> 0:01:52.080 flies are surprisingly similar to humans and other vertebrates. Drosophila 0:01:52.080 --> 0:01:55.760 melanogaster has fourteen thousand genes, and we humans have somewhere 0:01:55.760 --> 0:01:59.040 between twenty thousand and twenty five thousand, and about eight 0:01:59.080 --> 0:02:03.120 thousand of those vans are analogous. Similarly, most fruit fly 0:02:03.200 --> 0:02:07.600 biochemistry is the same or similar to ours. Merritt said 0:02:08.000 --> 0:02:10.360 fruit flies are great to work on if you're interested 0:02:10.400 --> 0:02:14.280 in variation between individuals or genetic lineages. They are also 0:02:14.320 --> 0:02:18.000 a great system if you're interested in experimentally altering the environment. 0:02:18.600 --> 0:02:20.799 They are so small we can do things like keep 0:02:20.840 --> 0:02:24.000 thousands of flies at different temperatures to see how temperature 0:02:24.040 --> 0:02:28.040 changes metabolism or gene activity. In one study in my lab, 0:02:28.280 --> 0:02:30.799 we used a small conveyor belt to slowly turn the 0:02:30.880 --> 0:02:34.160 vials we keep the flies in. This simple instrument is 0:02:34.240 --> 0:02:37.560 essentially a fly treadmill, and we can get literally hundreds 0:02:37.560 --> 0:02:42.440 of flies exercising on a small desktop. But fruit flies 0:02:42.520 --> 0:02:44.960 can be annoying in a lab, just as they can 0:02:45.000 --> 0:02:48.600 in your kitchen, to begin with their small and it's 0:02:48.840 --> 0:02:51.280 very difficult to dissect a fruit fly in case you 0:02:51.320 --> 0:02:54.560 were wondering. And although we share many of the same 0:02:54.639 --> 0:02:58.120 genes and genetic networks, were separated from them by hundreds 0:02:58.120 --> 0:03:00.920 of millions of years of evolution. So it's hard to 0:03:00.919 --> 0:03:03.600 make assumptions about ourselves based on what we find in 0:03:03.680 --> 0:03:07.960 these little insects because there are substantial biological differences between us. 0:03:09.000 --> 0:03:11.919 Merritt said, there are certainly questions that are better asked 0:03:11.960 --> 0:03:16.120 in larger or evolutionarily more closely related species like rats 0:03:16.120 --> 0:03:20.160 and mice. Similarly, there are questions, for example, changes in 0:03:20.280 --> 0:03:23.280 genes through evolution that are better asked in organisms that 0:03:23.320 --> 0:03:26.399 are even smaller, can be kept in even larger numbers, 0:03:26.480 --> 0:03:31.040 and with even shorter lifespans like bacteria or fungi. But 0:03:31.360 --> 0:03:34.720 we can't blame scientists for the proliferation of fruit flies 0:03:34.800 --> 0:03:38.760 in the world. They would have been there regardless, Merrett explained. 0:03:39.000 --> 0:03:43.760 Drosophalo melanogaster is a cosmopolitan species, meaning it's found essentially 0:03:43.840 --> 0:03:48.240 almost anywhere we find humans. A fruit fly has pretty 0:03:48.240 --> 0:03:51.280 simple needs in order to prosper and multiply, and those 0:03:51.320 --> 0:03:54.760 needs are usually met in our homes, moderate temperatures and 0:03:54.840 --> 0:03:57.680 a source of fresh produce that's on the overripe side. 0:03:58.320 --> 0:04:00.680 This is why fruit flies live i on the hug 0:04:00.720 --> 0:04:05.200 in places like dumpsters, compost tapes, and kitchens. Marrett said. 0:04:05.720 --> 0:04:08.880 One interesting thing is we seem to see more flies 0:04:08.960 --> 0:04:12.520 inside in the early fall. I think that's from flies 0:04:12.560 --> 0:04:15.520 that have been happily breeding and multiplying outside all summer 0:04:15.800 --> 0:04:19.200 moving into the warmer inside spaces as the weather cools. 0:04:20.600 --> 0:04:23.000 The good news is that fruit flies aren't dangerous in 0:04:23.040 --> 0:04:26.760 any way. Merritt said. They don't carry disease, and they 0:04:26.800 --> 0:04:30.320 don't cause fruit to spoil or rot. At least Drosophila 0:04:30.360 --> 0:04:34.080 melano gaster doesn't, although there is at least one invasive species, 0:04:34.120 --> 0:04:37.360 the spotted wing fruit fly that actually damages fruit crops, 0:04:37.400 --> 0:04:40.880 and it's a growing agricultural concern. In my lab and 0:04:40.920 --> 0:04:44.279 in my house, we use a simple vinegar trap kenning 0:04:44.320 --> 0:04:46.320 jar with some vinegar in the bottom and a top 0:04:46.360 --> 0:04:48.560 of plastic wrap with a few holes punched in it 0:04:48.600 --> 0:04:57.039 to trap and remove flies. Today's episode was written by 0:04:57.120 --> 0:04:59.760 Joceline Shields and produced by Tyler Clang. For more on 0:04:59.800 --> 0:05:02.239 this and lots of other tiny topics with a huge impact, 0:05:02.320 --> 0:05:05.120 visit how stuff works dot com. Brain Stuff is production 0:05:05.160 --> 0:05:07.760 of iHeart Radio. For more podcasts for my heart Radio, 0:05:07.960 --> 0:05:10.640 visit the iHeart Radio app, Apple Podcasts, or wherever you 0:05:10.680 --> 0:05:11.880 listen to your favorite shows.