Verbing Science! with Kristi Montooth
6. Kristi Montooth, “Fruit Flies, Fedoras, and Endless Forms Most Beautiful”
Consider the humble fruit fly. In your kitchen at home, it’s a pest. In a genetics research lab, however, it’s a hero! It’s all a matter of perspective. Science works best when scientists are flexible, willing and able to consider a problem from multiple different perspectives. Nowhere is this more evident than in the field of evolutionary genetics. In this episode, Dr. Kristi Montooth explains how the fruit fly became a cornerstone of this field, and how the synthesis of many different types and sources of information is key to understanding the beautiful and unfathomably complex phenomena of the living world.
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[00:00:00.000](bass guitar riffs)
[00:00:07.590]Consider the humble fruit fly.
[00:00:10.350]In your kitchen at home, it's a pest.
[00:00:13.320]In a genetics research lab, however, it's a hero.
[00:00:17.340]It's all a matter of perspective.
[00:00:20.100]Science works best when scientists are flexible,
[00:00:22.950]willing and able to consider a problem
[00:00:24.720]from multiple different perspectives.
[00:00:27.570]Nowhere is this more evident
[00:00:29.100]than in the field of evolutionary genetics.
[00:00:32.580]In this episode, Dr. Kristi Montooth explains
[00:00:35.040]how the fruit fly became a cornerstone
[00:00:37.440]of one of the most powerful and comprehensive
[00:00:39.600]explanatory frameworks in the history of science,
[00:00:43.230]and how the synthesis
[00:00:44.220]of many different types and sources of information
[00:00:46.680]is key to understanding
[00:00:47.880]the beautiful and unfathomably complex phenomena
[00:00:51.000]of the living world.
[00:00:52.710]I'm Jocelyn, and let's get verbing.
[00:01:06.975]I would say also though, that your offspring
[00:01:08.820]might actually enjoy working out just as much as you do
[00:01:11.760]because you pass on not only your genes,
[00:01:15.000]but you pass on your environment and your culture.
[00:01:18.510]And so it actually is one of the reasons
[00:01:21.570]that studying that portability of traits
[00:01:25.260]and also the evolution of traits
[00:01:26.610]is challenging because we know now
[00:01:29.640]that the relationship between a genotype and a trait
[00:01:35.130]is not simple.
[00:01:36.090]It's very complex.
[00:01:36.960]And part of that complexity comes
[00:01:38.880]because parents and offspring share a lot more
[00:01:41.310]than just our genomes.
[00:01:42.510]We share our environments and we share our culture
[00:01:45.450]and we know that those things can heavily influence traits.
[00:01:48.270]And so that's, you know,
[00:01:49.500]part of the challenge in evolutionary genetics
[00:01:51.450]is to, I think, embrace that complexity
[00:01:55.620]and don't just throw everything away
[00:01:58.470]and say it's too complex
[00:01:59.490]but try to embrace it and understand it.
[00:02:01.230]And so I would say my take on evolutionary genetics
[00:02:04.230]is trying to use physiology to really understand
[00:02:07.560]how genes and the environment interact with each other
[00:02:11.130]to affect traits.
[00:02:13.020]So you're looking at some epigenetics too, then?
[00:02:16.680]I haven't done much with epigenetics.
[00:02:19.740]I am interested in things called parental effects.
[00:02:23.580]So how mom may pass on things to her offspring
[00:02:29.190]that are in addition to her DNA.
[00:02:32.520]So things like in the early embryo,
[00:02:35.730]they're not making their own gene products yet,
[00:02:39.840]so they rely on the gene products that mom puts in the egg.
[00:02:43.410]And that can have a really big influence
[00:02:45.150]on that very early development.
[00:02:47.790]So we've studied that process a bit,
[00:02:50.226]but I haven't done too much with epigenetics.
[00:02:53.130]Flies don't have, it doesn't seem like fruit flies,
[00:02:56.760]which are model organism in genetics,
[00:02:58.620]it doesn't seem like they have
[00:02:59.700]the same types of methylation that's been studied in,
[00:03:03.930]you know, looking at human and mammalian epigenetics.
[00:03:06.360]So what's happening in flies there
[00:03:08.160]seems to be somewhat distinct
[00:03:09.900]from what's being studied in mammals and humans.
[00:03:13.800]Okay, so when you talk
[00:03:15.000]about the interaction between genes and environment,
[00:03:16.830]you're not necessarily talking about the sort of happening
[00:03:19.620]in a real-time interaction.
[00:03:21.600]I mean, I guess all time is real time, right?
[00:03:23.460]But, (laughs) or none of it's real.
[00:03:25.320]Are you the physicist that seems to-
[00:03:27.226]We can have a separate discussion about that,
[00:03:29.460]but we're not necessarily
One at a time.
[00:03:31.710]The DNA changes that are happening
[00:03:33.660]in an individual organism
[00:03:35.520]as they interact with the environment.
[00:03:37.200]We're talking about more of these longer scale changes
[00:03:40.440]and so not so much epigenetics,
[00:03:42.600]but the larger evolutionary changes
[00:03:44.580]that are acting on the genes.
[00:03:45.570]I, that makes sense.
[00:03:47.850]And also the, when I talk
[00:03:49.680]about how a gene interacts with the environment,
[00:03:52.380]you can have two individuals, individual flies, let's say,
[00:03:55.770]can have the exact same genotype,
[00:03:57.840]but if you develop them under different conditions,
[00:04:00.930]they can express a trait differently.
[00:04:02.610]And we call that plasticity.
[00:04:04.410]And that's an area that I study.
[00:04:06.420]And that is some self that can evolve
[00:04:09.090]and probably enables organisms
[00:04:11.280]to survive in variable environments.
[00:04:14.100]So if you think about the seasons,
[00:04:16.200]if you are a fruit fly or a butterfly
[00:04:18.810]or a snail or a paramecium,
[00:04:23.310]your biology runs at the temperature of your external world.
[00:04:28.500]And so that means in winter everything is really slow
[00:04:30.720]and in summer everything is really fast.
[00:04:32.790]And yet these species populate seasonal environments.
[00:04:37.530]And so I'm interested in how, you know,
[00:04:41.550]genetic information has influenced
[00:04:43.530]the expression of that information
[00:04:45.600]is influenced by the environment.
[00:04:47.880]And that in itself can be an adaptive process.
[00:04:50.640]So organisms may change their physiology
[00:04:53.599]in ways that enable them to do things like overwinter.
[00:04:57.480]Ooh, isn't there, is it a frog or is it a lizard?
[00:05:00.630]There's something that gets
[00:05:03.300]like super, super high blood sugar in the winter
[00:05:06.150]because basically it makes the blood,
[00:05:08.280]it's too saturated to freeze.
[00:05:10.890]It's like antifreeze.
[00:05:12.150]Yeah, yeah, yeah. Is that a frog?
[00:05:14.370]Yeah. So yeah, it's a, it.
[00:05:16.710]If you take a moment and think about
[00:05:20.880]how many organisms are ectotherm,
[00:05:24.090]meaning they're not mammals and they're not birds,
[00:05:26.640]they're not making their own body heat.
[00:05:27.960]It's a huge number of organisms
[00:05:30.450]and they are surviving winter in,
[00:05:34.440]you know, at higher latitudes.
[00:05:35.760]It's, if you haven't thought about that before
[00:05:38.040]and kind of embraced how amazing that is
[00:05:41.640]that you have organisms that are living
[00:05:44.070]in the summer here where it gets, you know,
[00:05:46.260]it can be a hundred degrees
[00:05:47.370]and then in the wintertime where it can be zero.
[00:05:50.160]And that's pretty phenomenal.
[00:05:51.690]And that all happens not through genetic changes.
[00:05:56.010]That happens through the expression of different genes
[00:05:59.310]under different conditions
[00:06:00.540]that allow those organisms to survive
[00:06:02.850]in those very different environments.
[00:06:05.370]Wow. And I don't know if this is anything
[00:06:08.940]that you look into at all,
[00:06:10.230]but another thing that I just, that blows my mind
[00:06:12.420]that I know is an area of ongoing research is the fact that,
[00:06:15.240]you know, every cell in our body has the same DNA in it,
[00:06:18.780]the same genes and yet we have all of these,
[00:06:20.783]we have tissue differentiations.
[00:06:22.740]So a skin cell is acting in a totally different way
[00:06:25.410]than a cardiac muscle cell is acting
[00:06:27.270]in a totally different way than a pancreas cell
[00:06:31.110]that's secreting certain products, you know?
[00:06:33.180]And so the fact that that all has to do
[00:06:34.590]with which genes are being activated
[00:06:36.270]and expressed and how and everything too, right?
[00:06:40.733]So there's a big, you know, one of the things
[00:06:42.300]that evolutionary biologists like to talk about
[00:06:44.610]is whether evolution at the molecular level
[00:06:47.940]or at the genetic level happens through changes
[00:06:51.000]that affect protein evolution
[00:06:53.220]or changes that affect the regulation of those proteins.
[00:06:57.630]And so that is an area where people are,
[00:07:01.650]and that's sort of what you're indicating there,
[00:07:03.840]is that you could have the same set of genes or proteins
[00:07:07.200]and what's really changing through evolutionary time
[00:07:09.540]is how and when those proteins get expressed or turned on.
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