WEBVTT 00:00:11.279 --> 00:00:16.879 lost in the fog of a cosmic storm floating on 00:00:16.879 --> 00:00:21.120 whimsical wavelengths is the norm dancing through 00:00:21.120 --> 00:00:27.379 the stars chasing spectrums of light riding the 00:00:27.379 --> 00:00:31.149 waves that are just out So one of the things 00:00:31.149 --> 00:00:33.130 that I've noticed is that I don't introduce myself 00:00:33.130 --> 00:00:36.409 very often. And for all those new listeners out 00:00:36.409 --> 00:00:38.950 there that show up from time to time, my name's 00:00:38.950 --> 00:00:40.969 Dr. Jeffrey Zurich. I'm the host of Whimsical 00:00:40.969 --> 00:00:43.570 Wavelengths. And today is all about the white 00:00:43.570 --> 00:00:46.009 sturgeon. Because, you know, I've spent the vast 00:00:46.009 --> 00:00:48.609 majority of my life living along the major rivers 00:00:48.609 --> 00:00:51.590 in southern British Columbia, Canada. The Kootenai 00:00:51.590 --> 00:00:53.990 and the Columbia Rivers and now the Fraser River. 00:00:54.229 --> 00:00:56.590 These rivers have a lot in common from the ecology 00:00:56.590 --> 00:00:59.530 standpoint with respect to salmon and the subject 00:00:59.530 --> 00:01:02.770 of today's episode, the white sturgeon. And these 00:01:02.770 --> 00:01:05.989 fish are amazing. I've spent a lot of time fishing 00:01:05.989 --> 00:01:08.849 the Columbia for trout and walleye, also known 00:01:08.849 --> 00:01:11.650 as pickerel in other parts of Canada. But I've 00:01:11.650 --> 00:01:14.209 never interacted with a sturgeon. To me, they've 00:01:14.209 --> 00:01:18.510 always been mysterious fish of the river. I know 00:01:18.510 --> 00:01:22.469 they are there, but I've never seen them. The 00:01:22.469 --> 00:01:24.989 Loch Ness of the Columbia and the Fraser River. 00:01:25.370 --> 00:01:27.569 And I've always wanted to learn more about these 00:01:27.569 --> 00:01:31.989 creatures. You know, this group, sturgeon, and 00:01:31.989 --> 00:01:34.849 their family group, they first appeared in the 00:01:34.849 --> 00:01:38.189 late Cretaceous, with the oldest seen in the 00:01:38.189 --> 00:01:42.170 fossil record at 100 million years ago, found 00:01:42.170 --> 00:01:46.359 in Alberta. canada in fact they look today very 00:01:46.359 --> 00:01:48.819 similar to what they looked in the late cretaceous 00:01:48.819 --> 00:01:51.760 they join a short list of creatures that have 00:01:51.760 --> 00:01:55.299 not at least outwardly significantly changed 00:01:55.299 --> 00:01:58.959 their body shapes or their large scale building 00:01:58.959 --> 00:02:01.859 blocks in a very long time like the crocodile 00:02:01.859 --> 00:02:04.900 whose modern body shape came together 80 to 90 00:02:04.900 --> 00:02:08.139 million years ago or the horseshoe crab which 00:02:08.139 --> 00:02:10.960 has been around a lot longer nearly 400 million 00:02:10.960 --> 00:02:15.539 years Besides being what some term a living dinosaur, 00:02:15.939 --> 00:02:19.860 they're also polyploidy, meaning they can have 00:02:19.860 --> 00:02:23.960 different numbers of chromosomes. This whole 00:02:23.960 --> 00:02:25.759 part of it actually makes my head hurt. Give 00:02:25.759 --> 00:02:28.960 me the simplicity of a wave equation. Thankfully, 00:02:29.060 --> 00:02:32.139 in a few minutes, I have a guest to help me understand 00:02:32.139 --> 00:02:36.110 it. But let me attempt to set this up. So they, 00:02:36.270 --> 00:02:38.009 the white sturgeon, are scientifically amazing 00:02:38.009 --> 00:02:40.849 already. And we haven't even gotten into what 00:02:40.849 --> 00:02:44.909 the species do. Above and beyond what the local 00:02:44.909 --> 00:02:47.509 rivers mean to us. There are culturally important 00:02:47.509 --> 00:02:51.150 food for First Nations of North America and harvested 00:02:51.150 --> 00:02:54.349 for caviar in other places. The caviar can go 00:02:54.349 --> 00:03:01.550 for $1 ,000 to $5 ,000 Canadian per pound. A 00:03:01.550 --> 00:03:06.060 true luxury item. that starts its history almost 00:03:06.060 --> 00:03:11.319 2500 years ago when the persians ate them in 00:03:11.319 --> 00:03:15.199 a belief that it provided strength later becoming 00:03:15.199 --> 00:03:19.120 a prized delicacy of european nobility sturgeon 00:03:19.120 --> 00:03:22.659 are predators and scavengers using barbells or 00:03:22.659 --> 00:03:26.280 whisker -like sensory organs that smell and taste 00:03:26.280 --> 00:03:29.900 to detect on the riverbed things like salmon 00:03:29.900 --> 00:03:33.120 carcasses eggs lamprey crayfish clams and worms 00:03:33.120 --> 00:03:37.900 some might call them a keystone scavenger aiding 00:03:37.900 --> 00:03:40.340 in keeping riverbeds healthy for other species 00:03:40.340 --> 00:03:43.060 now we have the geologic time perspective and 00:03:43.060 --> 00:03:45.740 the culture perspective and how they are important 00:03:45.740 --> 00:03:49.080 to the river systems they inhabit what about 00:03:49.080 --> 00:03:52.719 their population i can anecdotally attest to 00:03:52.719 --> 00:03:55.719 these fish being rare In fact, they're threatened 00:03:55.719 --> 00:03:59.439 as a species due to overfishing and habitat modification. 00:04:00.460 --> 00:04:03.539 The Columbia River has many, many dams along 00:04:03.539 --> 00:04:07.419 it due to the Columbia River Treaty. All right, 00:04:07.500 --> 00:04:09.740 time to bring in the guest. To help us understand 00:04:09.740 --> 00:04:12.439 about these enigmatic fish, their populations, 00:04:12.439 --> 00:04:14.879 and their genetics, please welcome a fisheries 00:04:14.879 --> 00:04:18.620 geneticist with the Hagerman Genetics Lab, Dr. 00:04:18.720 --> 00:04:21.879 Stuart Willis. Hi, Jeff. Always excited to talk 00:04:21.879 --> 00:04:25.069 about sturgeon. Yay. Before jumping into the 00:04:25.069 --> 00:04:26.449 science, I always think it's important to like 00:04:26.449 --> 00:04:28.470 see how someone comes by their chosen subject. 00:04:28.629 --> 00:04:31.490 I mean, careers in STEM, we need to make them 00:04:31.490 --> 00:04:33.769 less scary in general. And science is always 00:04:33.769 --> 00:04:38.050 a human endeavor. I grew up living beside a river. 00:04:38.509 --> 00:04:41.149 But what about you? Was there a river, a body 00:04:41.149 --> 00:04:43.410 of water? Was it fishing? What brought you to 00:04:43.410 --> 00:04:46.290 studying fish and their ecosystems? Yeah, so 00:04:46.290 --> 00:04:49.189 I did a lot of fishing with my dad as a kid back 00:04:49.189 --> 00:04:52.189 in Texas, except I always wanted to bring our 00:04:52.189 --> 00:04:54.670 catch home and keep them in an aquarium to learn 00:04:54.670 --> 00:04:57.709 more about them. So as a teenager, I did keep 00:04:57.709 --> 00:05:00.230 a lot of aquarium, but mostly South American 00:05:00.230 --> 00:05:03.170 river fishes, not our North American native fishes. 00:05:03.709 --> 00:05:06.009 And so then when I went to college, I got hooked 00:05:06.009 --> 00:05:08.170 up with a professor who had a graduate student 00:05:08.170 --> 00:05:11.189 doing phylogenetic and evolutionary ecology work 00:05:11.189 --> 00:05:15.100 on South American fishes, and I was hooked. And 00:05:15.100 --> 00:05:17.600 so I did my graduate work on phylogenetics and 00:05:17.600 --> 00:05:19.720 population genetics of South American fishes. 00:05:20.079 --> 00:05:22.819 But in academia, as you know, you sort of have 00:05:22.819 --> 00:05:25.399 to go where the money is. And so that eventually 00:05:25.399 --> 00:05:28.579 led into the work that I do today for a consortium 00:05:28.579 --> 00:05:30.939 of tribal nations for whom fish, and particularly 00:05:30.939 --> 00:05:33.740 salmon, are an integral part of their culture. 00:05:33.819 --> 00:05:35.899 They've taken a lead role in managing the natural 00:05:35.899 --> 00:05:38.459 resources within their ancestral territories 00:05:38.459 --> 00:05:41.160 in the Columbia River Basin. And as a part of 00:05:41.160 --> 00:05:43.740 that work, I manage our genetic investigations 00:05:43.740 --> 00:05:46.899 of white sturgeons, which are the largest freshwater 00:05:46.899 --> 00:05:51.209 fish in North America. Okay. So, I mean... I 00:05:51.209 --> 00:05:53.290 grew up next to the Columbia. I fully support 00:05:53.290 --> 00:05:55.870 this sort of research and keeping those ecosystems 00:05:55.870 --> 00:05:57.889 at least understandable, what's happening to 00:05:57.889 --> 00:05:59.850 them, monitor them and make sure they're there 00:05:59.850 --> 00:06:02.189 for the next generation. But are you also looking 00:06:02.189 --> 00:06:05.029 at different opportunities to do other research 00:06:05.029 --> 00:06:07.970 outside of those drainage catchments as well? 00:06:08.189 --> 00:06:10.209 I mean, yes, you follow the money, but, you know, 00:06:10.230 --> 00:06:13.949 I also want to go back one day and do some volcano 00:06:13.949 --> 00:06:16.670 research that might take years and years and 00:06:16.670 --> 00:06:18.750 years and years to actually come to fruition. 00:06:18.870 --> 00:06:21.040 I mean, that's the nature. of sometimes playing 00:06:21.040 --> 00:06:24.560 science. It's a long game. Yeah, I still do collaborate 00:06:24.560 --> 00:06:27.819 on occasion with people from my past. I still 00:06:27.819 --> 00:06:30.379 have a project that I'm working on looking at 00:06:30.379 --> 00:06:34.540 photosensory evolution in shallow and deep walling 00:06:34.540 --> 00:06:37.819 reef fishes and things like that. But for the 00:06:37.819 --> 00:06:40.899 most part, I stay within what the tribes need 00:06:40.899 --> 00:06:43.399 and the tribes are focused on fisheries in the 00:06:43.399 --> 00:06:46.459 Columbia River Basin. A lot of what I do day 00:06:46.459 --> 00:06:50.329 to day is... salmon genomics. And there's a huge 00:06:50.329 --> 00:06:52.350 community of people, as you can imagine, that 00:06:52.350 --> 00:06:54.709 are interested in all things salmon, everything 00:06:54.709 --> 00:06:57.689 we find out about salmon. White sturgeon is a 00:06:57.689 --> 00:06:59.730 little bit smaller of a community, but to me, 00:06:59.750 --> 00:07:02.230 because there's so much less known about white 00:07:02.230 --> 00:07:04.250 sturgeon, it sort of feels more like a voyage 00:07:04.250 --> 00:07:05.990 of discovery, much more like the things that 00:07:05.990 --> 00:07:08.410 I did as a graduate student, where I was going 00:07:08.410 --> 00:07:11.829 out into the Amazon and finding things for the 00:07:11.829 --> 00:07:14.350 first time, seeing places that no scientist had 00:07:14.350 --> 00:07:17.759 collected fish before, at least. A lot of new 00:07:17.759 --> 00:07:22.600 stuff. Hard, difficult, but new. Right. And I 00:07:22.600 --> 00:07:25.879 will get into how you managed to find these fish, 00:07:25.939 --> 00:07:28.360 hopefully eventually here. But I want to pivot 00:07:28.360 --> 00:07:31.240 a little bit to the rivers themselves that are 00:07:31.240 --> 00:07:33.720 kind of the focus of this study and your work 00:07:33.720 --> 00:07:36.379 in general. The mighty Fraser and the Columbia, 00:07:36.519 --> 00:07:38.959 two rivers here on the west coast of North America. 00:07:39.879 --> 00:07:42.620 I really felt like I needed to add a little bit 00:07:42.620 --> 00:07:45.040 Canadian content from the political past. It's 00:07:45.040 --> 00:07:47.300 kind of a fun little tidbit. The two rivers are 00:07:47.300 --> 00:07:49.879 separated by only about 45 meters of elevation. 00:07:50.100 --> 00:07:51.819 Like there's a divide right near Vail Mount, 00:07:51.980 --> 00:07:55.160 British Columbia. In the 1960s, British Columbia 00:07:55.160 --> 00:07:58.459 actually made a public threat in taking the Columbia's 00:07:58.459 --> 00:08:00.680 water in a negotiating tactic for the Columbia 00:08:00.680 --> 00:08:03.920 Basin River Treaty. In a geographic sense, the 00:08:03.920 --> 00:08:07.889 rivers are very similar. Yet today... are very 00:08:07.889 --> 00:08:10.189 different. Perhaps let's start there. What is 00:08:10.189 --> 00:08:12.689 kind of like the state of the two rivers? Yeah. 00:08:13.089 --> 00:08:16.029 So both the Fraser and Columbia basins face increasing 00:08:16.029 --> 00:08:19.149 pressure from urbanization and other intentional 00:08:19.149 --> 00:08:22.490 and unintentional modifications, as well as changing 00:08:22.490 --> 00:08:24.610 precipitation and temperature patterns that make 00:08:24.610 --> 00:08:27.829 life as an aquatic organism exponentially harder. 00:08:28.310 --> 00:08:30.790 The Fraser, fortunately, doesn't have the same 00:08:30.790 --> 00:08:33.289 level of damming that Columbia does, particularly 00:08:33.289 --> 00:08:35.929 the main channels. Thanks, and going back to 00:08:35.929 --> 00:08:39.230 your... comment on Canadian politics, as I understand 00:08:39.230 --> 00:08:41.769 it, to push back from the public about the effects 00:08:41.769 --> 00:08:44.110 that would have on aquatic species and the people 00:08:44.110 --> 00:08:46.289 that depend on them. Which is not to say that 00:08:46.289 --> 00:08:49.070 Fraser is in pristine shape. Channel modification 00:08:49.070 --> 00:08:52.730 and pollution are a big issue and anagimous fisheries 00:08:52.730 --> 00:08:55.690 have been on the decline for a number of years. 00:08:55.909 --> 00:08:58.690 Some of the factors for that are local and some 00:08:58.690 --> 00:09:01.789 of them probably regional. The Columbia, on the 00:09:01.789 --> 00:09:04.850 other hand, is strongly segmented by hydroelectric 00:09:04.850 --> 00:09:07.710 facilities from the tributaries through the main 00:09:07.710 --> 00:09:10.870 channel. And on top of that, as well as urbanization 00:09:10.870 --> 00:09:12.850 and other habitat degradation, not to mention 00:09:12.850 --> 00:09:15.690 climate change, invasive species have really 00:09:15.690 --> 00:09:18.629 started chasing their toll. Some intentionally 00:09:18.629 --> 00:09:20.970 introduced by well -meaning but short -sighted 00:09:20.970 --> 00:09:23.809 state agencies like Channel Catfish and Chad. 00:09:23.889 --> 00:09:26.269 Some introduced by well -meaning but ignorant 00:09:26.269 --> 00:09:30.320 bucket biologists like walleye. And some completely 00:09:30.320 --> 00:09:33.120 unintentional hitchhikers, like quagga mussels 00:09:33.120 --> 00:09:36.320 and Siberian ponds. So the answer to your question, 00:09:36.419 --> 00:09:38.620 the state of the rivers is probably middling 00:09:38.620 --> 00:09:43.519 to struggling, respectively. Right. But maybe 00:09:43.519 --> 00:09:46.419 where I was kind of wondering is like, what's 00:09:46.419 --> 00:09:48.620 the effect of those dams? Because that's like, 00:09:48.700 --> 00:09:52.299 all things being equal, they have, I mean, yeah, 00:09:52.340 --> 00:09:54.039 I could say that Columbia, at least in its lower 00:09:54.039 --> 00:09:58.129 reaches, has more population pressure. And they're 00:09:58.129 --> 00:10:00.850 very similar in their geographic and everything 00:10:00.850 --> 00:10:03.370 else, but the Fraser's dirty. It has a lot of 00:10:03.370 --> 00:10:05.409 sediment. I wouldn't say dirty. Dirty is the 00:10:05.409 --> 00:10:07.289 wrong word necessarily because it's not like 00:10:07.289 --> 00:10:10.389 it's polluted or anything, but you have all these 00:10:10.389 --> 00:10:14.149 dams in the Columbia that are causing all that 00:10:14.149 --> 00:10:16.610 sediment to settle out. And that's, you know, 00:10:16.629 --> 00:10:20.789 I've heard it said that a dam gives a river a 00:10:20.789 --> 00:10:24.070 stroke. You can partially recover from that stroke, 00:10:24.129 --> 00:10:25.570 but you're never going to get all the way back. 00:10:26.480 --> 00:10:30.519 Right. So there are great diversity of dams on 00:10:30.519 --> 00:10:33.379 the Columbia. Sort of the two main types are 00:10:33.379 --> 00:10:37.960 run of river dams that sort of don't have a big 00:10:37.960 --> 00:10:41.679 difference in elevation. And then dams that have 00:10:41.679 --> 00:10:45.539 a large body of water that are held behind them. 00:10:45.600 --> 00:10:48.899 And those in particular have major effects on 00:10:48.899 --> 00:10:52.320 the river ecosystems because. Not only do they 00:10:52.320 --> 00:10:54.720 slow down their water, which means that fish 00:10:54.720 --> 00:10:57.200 now have to swim rather than just being in the 00:10:57.200 --> 00:10:58.899 current, but they also allow the water to heat. 00:10:59.519 --> 00:11:02.279 And that hot water is really hard for these very 00:11:02.279 --> 00:11:05.519 cold -specific species, cold -adapted species, 00:11:05.779 --> 00:11:08.740 because they get in hot water, their retazolums 00:11:08.740 --> 00:11:11.279 ramp up, their parasite load is more difficult 00:11:11.279 --> 00:11:14.600 to manage. And so they're very different, both 00:11:14.600 --> 00:11:18.700 at a very small -scale endocrine level and then 00:11:18.700 --> 00:11:21.419 at a major ecological level. And then, of course, 00:11:21.500 --> 00:11:22.600 there are a number of dams that don't even have 00:11:22.600 --> 00:11:24.919 fish passage at all. So it's hard to be an anagimous 00:11:24.919 --> 00:11:26.620 fish when you can't even get over the dam in 00:11:26.620 --> 00:11:28.960 the first place. Okay. I was going to move on 00:11:28.960 --> 00:11:30.279 to the next question, but I need to check the 00:11:30.279 --> 00:11:36.799 word. Anagimous? So anagimous is a term that 00:11:36.799 --> 00:11:39.220 just means fish that start out in freshwater, 00:11:39.460 --> 00:11:41.500 go and live part of their life in saltwater, 00:11:41.679 --> 00:11:45.399 and then come back to spawn in saltwater. It's 00:11:45.399 --> 00:11:48.279 a subset of what we call diadromous fish, so 00:11:48.279 --> 00:11:50.120 fish that have sort of two different parts to 00:11:50.120 --> 00:11:53.480 their life history strategy or life cycle. The 00:11:53.480 --> 00:11:56.659 alternative is catadromous fish that live in 00:11:56.659 --> 00:11:59.720 saltwater as adults, spawn, they're young, go 00:11:59.720 --> 00:12:01.220 into freshwater for some period of time, and 00:12:01.220 --> 00:12:04.019 then return back to saltwater response. I think 00:12:04.019 --> 00:12:06.299 the American eel is a catadromous fish. They 00:12:06.299 --> 00:12:08.559 all spawn out in the ocean. They're young, spend 00:12:08.559 --> 00:12:12.779 most of their life in freshwater. So then what 00:12:12.779 --> 00:12:15.360 would salmon be? Salmon are anadromous fish. 00:12:15.539 --> 00:12:19.419 They spawn in fresh water. The young go out to 00:12:19.419 --> 00:12:22.340 the ocean, grow up, and then come back to adults. 00:12:22.580 --> 00:12:25.620 And this is sort of getting off on a tangent. 00:12:25.860 --> 00:12:29.139 There are some salmon that don't, right? Like 00:12:29.139 --> 00:12:32.139 rainbow trout. Anything we call a trout is because 00:12:32.139 --> 00:12:34.940 they can't complete their life cycle in fresh 00:12:34.940 --> 00:12:37.639 water. The reason that they go to the ocean is 00:12:37.639 --> 00:12:39.600 because there are so much more nutrients in the 00:12:39.600 --> 00:12:41.820 ocean. So there's an advantage to going out to 00:12:41.820 --> 00:12:45.139 the ocean. to be able to grow faster or have 00:12:45.139 --> 00:12:48.299 greater access to nutrients. And so all of that 00:12:48.299 --> 00:12:51.440 life history differences are adaptations that 00:12:51.440 --> 00:12:54.379 these fish sort of manage across time as environments 00:12:54.379 --> 00:12:59.419 changed. Right. Okay, well, to pivot to the topic 00:12:59.419 --> 00:13:02.440 of the day, the white sturgeon. Who are they 00:13:02.440 --> 00:13:04.659 and what role do they fill in the ecosystem of 00:13:04.659 --> 00:13:07.940 these two rivers? Yeah, sturgeon are very charismatic 00:13:07.940 --> 00:13:10.240 fishes for those who are lucky enough to live 00:13:10.240 --> 00:13:12.799 where they do. As you mentioned in your intro, 00:13:13.000 --> 00:13:16.159 they look very prehistoric. And indeed, as a 00:13:16.159 --> 00:13:18.639 group, the order as a pincer of forms, which 00:13:18.639 --> 00:13:21.720 includes sturgeons and paddlefish, had been around 00:13:21.720 --> 00:13:24.279 for a long time, being one of the earliest groups 00:13:24.279 --> 00:13:27.659 of bony fishes to break off at least 300 million 00:13:27.659 --> 00:13:30.440 years ago. So before the divergence of the dinosaurs 00:13:30.440 --> 00:13:33.659 from other reptiles. But I personally don't like 00:13:33.659 --> 00:13:36.730 the term. living fossil or living dinosaur that 00:13:36.730 --> 00:13:39.230 sometimes gets applied because they are, in fact, 00:13:39.370 --> 00:13:42.870 highly modified both from other fishes and from 00:13:42.870 --> 00:13:45.649 their own ancestors. For example, they have a 00:13:45.649 --> 00:13:48.950 mostly cartilaginous skeleton, like sharks, but 00:13:48.950 --> 00:13:51.509 that's a feature that they evolved after diverging 00:13:51.509 --> 00:13:53.389 from other fishes. It's a secondary characteristic. 00:13:54.169 --> 00:13:57.529 Similarly, while fish recognizable as asapensirthons 00:13:57.529 --> 00:14:00.190 have existed since at least the early Jurassic, 00:14:00.840 --> 00:14:03.620 Modern sturgeon and paddlefish were as different 00:14:03.620 --> 00:14:06.279 from those forms as sturgeon and paddlefish are 00:14:06.279 --> 00:14:09.460 from each other today. But, you know, as you 00:14:09.460 --> 00:14:11.279 say, they have been around for a long time, and 00:14:11.279 --> 00:14:14.039 they have some neat features beyond their unique 00:14:14.039 --> 00:14:17.860 appearance. For example, they still retain electrosensory 00:14:17.860 --> 00:14:21.240 organs on their head called ampullae of Lorenzini. 00:14:21.820 --> 00:14:24.740 that allow them to sense the weak electric field 00:14:24.740 --> 00:14:27.399 emitted by other aquatic organisms, a feature 00:14:27.399 --> 00:14:29.860 that they share with sharks and rays and one 00:14:29.860 --> 00:14:31.820 of the group of early diverging fawny fishes. 00:14:32.279 --> 00:14:35.159 And you can imagine that feature helps them to 00:14:35.159 --> 00:14:38.320 find fish in the deepest, darkest parts of large 00:14:38.320 --> 00:14:41.100 rivers where they're found. And that leads into 00:14:41.100 --> 00:14:43.620 their ecological roles, which change depending 00:14:43.620 --> 00:14:46.899 on their life stage. As eggs, larvae, and fry, 00:14:47.000 --> 00:14:50.250 they are food for a lot of other creatures. But 00:14:50.250 --> 00:14:51.950 they grow really fast in the first couple of 00:14:51.950 --> 00:14:54.549 years of life, usually reaching 30 to 40 centimeters 00:14:54.549 --> 00:14:57.889 in the first year and a meter within three to 00:14:57.889 --> 00:15:01.090 five years. And after that, especially as adults 00:15:01.090 --> 00:15:04.009 that reach three or four or even more meters 00:15:04.009 --> 00:15:06.769 long, they don't have a lot of natural predators. 00:15:07.190 --> 00:15:09.649 So they can sit at the top of the aquatic food 00:15:09.649 --> 00:15:12.230 chain, eating basically anything that can hoover 00:15:12.230 --> 00:15:14.370 up into their mouth that smells good, which could 00:15:14.370 --> 00:15:17.330 be live or dead. And so they are both top predators 00:15:17.330 --> 00:15:22.860 and scavengers. All right, so I guess they're 00:15:22.860 --> 00:15:25.259 kind of like a keystone species to some extent 00:15:25.259 --> 00:15:29.279 for these two rivers. You know, it's hard to 00:15:29.279 --> 00:15:30.899 say keystone species because that sort of depends 00:15:30.899 --> 00:15:32.539 on your perspective. I mean, you could say that 00:15:32.539 --> 00:15:34.539 salmon are a keystone species for these ecosystems 00:15:34.539 --> 00:15:38.539 because they bring all of those marine direct 00:15:38.539 --> 00:15:43.440 nutrients. They're an apex species, right? They 00:15:43.440 --> 00:15:45.039 sit at the top of the food chain, and certainly 00:15:45.039 --> 00:15:48.289 they have effects on the ecosystem. You know, 00:15:48.289 --> 00:15:51.169 Keystone is sort of an amorphous concept. So 00:15:51.169 --> 00:15:54.610 I'd be cautious to venture out and say that for 00:15:54.610 --> 00:15:57.289 sure. Well, how long does it take for them to 00:15:57.289 --> 00:15:59.710 get to adulthood? Because I know that they're 00:15:59.710 --> 00:16:03.110 long living. And generally speaking, those species 00:16:03.110 --> 00:16:06.450 who are long living, you know, they take a long 00:16:06.450 --> 00:16:08.370 time to reach adulthood. They take a long time 00:16:08.370 --> 00:16:10.809 to reproduce. Is that the same for this species 00:16:10.809 --> 00:16:15.240 as well? It is. As a survival strategy, you avoid 00:16:15.240 --> 00:16:18.159 being prey yourself. White sturgeons grow as 00:16:18.159 --> 00:16:21.879 fast as they can to get into a size so that they're 00:16:21.879 --> 00:16:24.500 less likely to be eaten. But once they do, they 00:16:24.500 --> 00:16:26.320 slow down their growth and just sort of chill. 00:16:26.679 --> 00:16:29.779 Since prehistorically, at least, mortality amongst 00:16:29.779 --> 00:16:33.059 sub -adults and adults was really low. While 00:16:33.059 --> 00:16:35.940 conversely, finding food to maintain such large 00:16:35.940 --> 00:16:40.740 bodies is a full -time job. So they are a type 00:16:40.740 --> 00:16:42.799 of fish that exhibit what we call a periodic 00:16:42.799 --> 00:16:45.379 life history strategy, which means that they 00:16:45.379 --> 00:16:48.120 reproduce at regular intervals, usually in the 00:16:48.120 --> 00:16:50.559 late spring when snow melt is high but the water 00:16:50.559 --> 00:16:53.519 is warming. But the local conditions that help 00:16:53.519 --> 00:16:57.440 their young to survive can be unpredictable spatially. 00:16:57.779 --> 00:17:00.340 And so it's really advantageous to produce a 00:17:00.340 --> 00:17:03.360 ton of eggs that get spread out across space 00:17:03.360 --> 00:17:06.720 to mitigate risk. And for organisms like that, 00:17:06.759 --> 00:17:10.460 for which egg number or secondity is a determining 00:17:10.460 --> 00:17:14.200 factor in reproductive success, size at reproduction, 00:17:14.460 --> 00:17:17.000 which generally also means age, also becomes 00:17:17.000 --> 00:17:19.819 a determining factor, which explains why sturgeon 00:17:19.819 --> 00:17:22.660 males, for whom size is slightly less of a constraining 00:17:22.660 --> 00:17:26.000 factor, don't mature to around 12 to 20 years 00:17:26.000 --> 00:17:29.019 of age, while sturgeon females don't usually 00:17:29.019 --> 00:17:32.220 start to mature around at least 15, usually 18, 00:17:32.259 --> 00:17:35.779 but can hit the 30 years. to mature and then 00:17:35.779 --> 00:17:39.400 once they do because that kind of pulse reproductive 00:17:39.400 --> 00:17:42.599 effort is so taxing females in the wild will 00:17:42.599 --> 00:17:45.420 usually only reproduce every three to six years 00:17:45.420 --> 00:17:48.500 or so and some of those years would be good recruitment 00:17:48.500 --> 00:17:52.480 years and some will be bad and based on prevailing 00:17:52.480 --> 00:17:55.240 environmental conditions so the reason why they 00:17:55.240 --> 00:17:58.859 succeed is because they can live so long Long 00:17:58.859 --> 00:18:02.660 enough for a few fry to survive from a few of 00:18:02.660 --> 00:18:05.799 the 70, even 100 years that they're going to 00:18:05.799 --> 00:18:09.319 live. But that's in natural conditions and rivers 00:18:09.319 --> 00:18:12.380 unaltered by dams and dredging and pollution, 00:18:12.460 --> 00:18:14.859 invasive species, et cetera, et cetera. So how 00:18:14.859 --> 00:18:17.619 that continues to function in our modern river 00:18:17.619 --> 00:18:20.799 ecosystems is something we are actively studying. 00:18:21.920 --> 00:18:23.940 I have a feeling I'm about to jump the shark 00:18:23.940 --> 00:18:25.720 here with this question because you kind of brought 00:18:25.720 --> 00:18:31.210 it up. take decades to like humans have a couple 00:18:31.210 --> 00:18:34.130 of years and we you know sexually mature like 00:18:34.130 --> 00:18:36.849 it's it's it's a standard window it's not exactly 00:18:36.849 --> 00:18:39.769 the same between individuals but it's pretty 00:18:39.769 --> 00:18:43.630 close like it's not decades and you just gave 00:18:43.630 --> 00:18:47.609 a range that were potentially decades long that 00:18:47.609 --> 00:18:52.490 it takes to mature like that seems Could you 00:18:52.490 --> 00:18:56.009 imagine being a teenager for decades? And one 00:18:56.009 --> 00:18:58.809 person or one fish goes through that in 12 years. 00:18:58.869 --> 00:19:03.049 The next one takes 20 years. We make jokes about 00:19:03.049 --> 00:19:05.250 us men taking a lot longer to mature, but this 00:19:05.250 --> 00:19:07.609 is taking it to the whole next level, right? 00:19:08.069 --> 00:19:12.390 It is. Yeah. And so some of that is probably 00:19:12.390 --> 00:19:15.549 environmental conditions. If you grow quickly, 00:19:15.690 --> 00:19:17.829 you're more likely to mature quickly if your 00:19:17.829 --> 00:19:20.460 growth rate is sort of... set at an early age 00:19:20.460 --> 00:19:22.500 to be slow. You're going to take longer to reproduce. 00:19:22.759 --> 00:19:26.460 But sometimes that can be an advantage. You know, 00:19:26.480 --> 00:19:28.680 we talk about keeping it back to salmon because 00:19:28.680 --> 00:19:30.200 that's one of the other things that I work on. 00:19:30.259 --> 00:19:34.460 Salmon have very distinct peaks in age at maturity, 00:19:34.579 --> 00:19:38.019 but larger fish have larger precondities. They 00:19:38.019 --> 00:19:39.920 produce more eggs. And so it can actually be 00:19:39.920 --> 00:19:43.299 an advantage to become sexually mature later. 00:19:43.829 --> 00:19:46.309 And so it's entirely possible that's true for 00:19:46.309 --> 00:19:48.690 sturgeon as well, that it can be an advantage 00:19:48.690 --> 00:19:51.650 to wait to become sexually mature because you're 00:19:51.650 --> 00:19:54.849 larger, you end up having a greater fecundity, 00:19:55.069 --> 00:19:57.829 maybe you weathered out a time period of which 00:19:57.829 --> 00:19:59.690 you wouldn't have been successful reproducing 00:19:59.690 --> 00:20:01.829 anyway because there were cruddy conditions for 00:20:01.829 --> 00:20:04.569 offspring. And so, yeah, that range certainly 00:20:04.569 --> 00:20:07.549 has implications for population dynamics, but 00:20:07.549 --> 00:20:10.309 at an individual level can actually be an advantage. 00:20:11.069 --> 00:20:15.130 And not to get too hard, to jump too far ahead 00:20:15.130 --> 00:20:17.990 into talking about, you know, sort of state of 00:20:17.990 --> 00:20:20.349 the population. One of the things that we're 00:20:20.349 --> 00:20:23.289 seeing in looking at some of these river segments, 00:20:23.390 --> 00:20:25.329 the ones that are sectioned off by dams and that 00:20:25.329 --> 00:20:27.170 kind of thing, is that fish are taking longer 00:20:27.170 --> 00:20:30.230 to mature. And so basically that's probably because 00:20:30.230 --> 00:20:32.750 the ecosystems are not as productive or the fish 00:20:32.750 --> 00:20:35.430 don't have access to the areas where they historically 00:20:35.430 --> 00:20:37.880 would have been able to. get enough for me to 00:20:37.880 --> 00:20:41.680 be able to reproduce at younger ages. So let's 00:20:41.680 --> 00:20:44.019 pivot towards the actual paper, the reason I 00:20:44.019 --> 00:20:46.240 got you onto the show. And to be honest, I really 00:20:46.240 --> 00:20:48.440 struggled with it to understand it. I mean, I 00:20:48.440 --> 00:20:50.220 guess I'm a volcanologist, this to be expected, 00:20:50.339 --> 00:20:52.339 but even the more I learned, the more I was blown 00:20:52.339 --> 00:20:56.220 away. The paper, Genome Assembly and Diagnostic 00:20:56.220 --> 00:20:59.799 DNA Markers for Sex of the Largest Freshwater 00:20:59.799 --> 00:21:04.079 Fish in North America, the White Sturgeon Assenpenser 00:21:04.079 --> 00:21:07.890 Transmountainous. I know I did the terrible job 00:21:07.890 --> 00:21:10.470 of pronouncing that, but that's okay. So I guess 00:21:10.470 --> 00:21:13.329 let's start with the hardest thing that I had 00:21:13.329 --> 00:21:15.650 wrapping my head around and I made a joke. Give 00:21:15.650 --> 00:21:20.130 me wave equations instead. What exactly is ploidy? 00:21:20.730 --> 00:21:25.369 Yeah. So this paper is our first attempt at reconstructing 00:21:25.369 --> 00:21:27.789 the genome of white sturgeon so that we could 00:21:27.789 --> 00:21:30.390 develop new genomic tools for their conservation. 00:21:30.390 --> 00:21:33.130 But we really couldn't do that without confronting 00:21:33.130 --> 00:21:37.339 the issue of ploidy. And so hopefully I can explain 00:21:37.339 --> 00:21:39.180 that without getting too much into the weeds 00:21:39.180 --> 00:21:42.119 and feel free to jump in if I'm getting entirely 00:21:42.119 --> 00:21:46.019 too nerdy and esoteric. But we fully embrace. 00:21:46.519 --> 00:21:49.900 Don't worry about that. Esoteric. Well, to a 00:21:49.900 --> 00:21:51.740 point, because we have to understand it, too. 00:21:51.859 --> 00:21:54.160 Well, that's my that's my wife's euphemistic 00:21:54.160 --> 00:21:57.440 term for me. So, you know, that's just how I. 00:21:57.500 --> 00:22:03.519 Yeah. But ploidy refers to the number of complete. 00:22:04.190 --> 00:22:07.829 sets of chromosomes in a cell, whatever complete 00:22:07.829 --> 00:22:10.789 is for that species. And I'm using air quotes 00:22:10.789 --> 00:22:13.470 when I say complete. My voice does not convey 00:22:13.470 --> 00:22:16.130 that. And I'll come back to that in a moment. 00:22:16.190 --> 00:22:18.210 But to give you an example you're familiar with, 00:22:18.269 --> 00:22:21.130 humans, like most multicellular organisms, are 00:22:21.130 --> 00:22:24.650 diploid, diploid, di meaning two. That is, we 00:22:24.650 --> 00:22:27.329 get one complete set of chromosomes from mom 00:22:27.329 --> 00:22:30.309 and one from dad. So the final set contains pairs 00:22:30.309 --> 00:22:35.400 of each unique or homologous. chromosome, meaning 00:22:35.400 --> 00:22:38.299 what each mom and dad contributes, eggs and sperm, 00:22:38.599 --> 00:22:42.119 are, in this case, monoploid, mono meaning one, 00:22:42.220 --> 00:22:46.380 one complete cell. Now, technically, we use the 00:22:46.380 --> 00:22:50.519 term haploid to refer to the complement of chromosome 00:22:50.519 --> 00:22:55.240 in a gamete, an egg or a sperm, meaning half. 00:22:55.440 --> 00:22:59.240 And what the combined gametes produce, somatic 00:22:59.240 --> 00:23:03.450 cells, are called duploid. The root U, meaning 00:23:03.450 --> 00:23:07.289 true or even. And then we call instances where 00:23:07.289 --> 00:23:10.390 there are incomplete sets of chromosomes aneuploid 00:23:10.390 --> 00:23:14.490 or not even. For example, in humans, we may be 00:23:14.490 --> 00:23:17.089 familiar with trisomy, where there are three 00:23:17.089 --> 00:23:24.170 copies of a chromosome. And the trisomy, three 00:23:24.170 --> 00:23:28.450 bodies of chromatome or chromosome, which creates 00:23:28.450 --> 00:23:31.690 uneven sets of chromosome or even. aneuploidy. 00:23:31.710 --> 00:23:33.869 And this is usually a problem developmentally, 00:23:33.930 --> 00:23:37.069 like trypsin via chromosome 21 in humans produces 00:23:37.069 --> 00:23:40.789 Down syndrome, because gene regulation, as it 00:23:40.789 --> 00:23:44.730 turns out, is frequently dosage dependent, meaning 00:23:44.730 --> 00:23:47.609 the regulation and expression of genes has evolved 00:23:47.609 --> 00:23:51.569 to be balanced in a copy number dependent manner, 00:23:51.690 --> 00:23:54.849 and aneuploidy messes up the typical dosage. 00:23:55.650 --> 00:23:58.369 But going back to the air quotes, complete... 00:23:58.970 --> 00:24:01.309 set of chromosomes, when we look across animal 00:24:01.309 --> 00:24:04.430 and plant species, we see wildly different numbers 00:24:04.430 --> 00:24:08.029 of chromosomes and genome sizes. Some of these 00:24:08.029 --> 00:24:10.849 differences are because chromosomes have expanded 00:24:10.849 --> 00:24:13.910 or contracted individually, or some chromosomes 00:24:13.910 --> 00:24:17.089 have split or combined. And so we see relatively 00:24:17.089 --> 00:24:19.950 moderate changes in chromosome numbers among 00:24:19.950 --> 00:24:22.910 related species. But those changes don't affect 00:24:22.910 --> 00:24:25.720 the ploidy. because it's not changing how many 00:24:25.720 --> 00:24:28.640 sets of chromosomes are in each cell, rather 00:24:28.640 --> 00:24:32.880 just the numbers that make up each set. But sometimes 00:24:32.880 --> 00:24:36.200 the genome sizes changes because of polypoidization, 00:24:36.420 --> 00:24:39.640 poly meaning many, in this case many sets, where 00:24:39.640 --> 00:24:42.619 the number of chromosomes goes up by entire sets 00:24:42.619 --> 00:24:46.119 all at once. And there are two main ways this 00:24:46.119 --> 00:24:50.460 can happen. In allopolypoidization, allo meaning 00:24:50.460 --> 00:24:54.150 different, in this case different species, Two 00:24:54.150 --> 00:24:57.049 moderately divergent species hybridize, and through 00:24:57.049 --> 00:24:59.970 some cell developmental magic, the progeny end 00:24:59.970 --> 00:25:02.509 up with twice the combined set of chromosomes 00:25:02.509 --> 00:25:05.930 from both parental species. And this form of 00:25:05.930 --> 00:25:08.230 polyploidy is fairly rare in animals, though 00:25:08.230 --> 00:25:11.029 there's at least one group of fishes, the Catastomidae, 00:25:11.029 --> 00:25:14.769 or suckers, that are thought to be allopolyploids. 00:25:15.529 --> 00:25:17.710 But it's actually fairly common in plants, including 00:25:17.710 --> 00:25:20.109 some you might know, like wheat. Wheat is an 00:25:20.109 --> 00:25:23.900 allopolyploid. If, on the other hand, polyploidization 00:25:23.900 --> 00:25:27.519 happens without hybridization, by the doubling 00:25:27.519 --> 00:25:32.019 of a genome within a species, we call that autopolyploidization. 00:25:32.440 --> 00:25:36.259 Auto meaning cell. And autopolyploidization has 00:25:36.259 --> 00:25:38.599 happened repeatedly, not only in plants, but 00:25:38.599 --> 00:25:40.940 also in vertebrates, especially in fishes, and 00:25:40.940 --> 00:25:46.650 in particular in sturgeons. So based on mapping 00:25:46.650 --> 00:25:48.589 of chromosome counts across the phylogenetic 00:25:48.589 --> 00:25:50.730 tree of fishes, that is the relationships among 00:25:50.730 --> 00:25:54.450 species of fish, we can estimate the ancestor 00:25:54.450 --> 00:25:57.150 of the Acipensia reforms, that was sturgeons 00:25:57.150 --> 00:26:00.970 and paddlefish, had a euploid or complete number 00:26:00.970 --> 00:26:05.650 of chromosomes around 60. But all modern Acipensia 00:26:05.650 --> 00:26:08.750 reforms have at least 120 chromosomes in their 00:26:08.750 --> 00:26:11.029 genome. And many sturgeons, like the white sturgeon, 00:26:11.529 --> 00:26:15.069 normally have at least 240 chromosomes in themselves. 00:26:15.329 --> 00:26:18.869 So approximately double to quadruple the ancestral 00:26:18.869 --> 00:26:23.069 number. So if we presume that that ancestor with 00:26:23.069 --> 00:26:25.910 60 chromosomes was diploid, which is a reasonably 00:26:25.910 --> 00:26:28.710 safe bet for a reason we can talk about, then 00:26:28.710 --> 00:26:32.369 the species with around 120 chromosomes would 00:26:32.369 --> 00:26:36.369 be evolutionary or ancestral tetraploids. That 00:26:36.369 --> 00:26:40.170 is relative for complete sets to that ancestor 00:26:40.170 --> 00:26:43.170 that had two. And species with 240 or so chromosomes 00:26:43.170 --> 00:26:47.109 would be ancestral octoploids, the eight complete 00:26:47.109 --> 00:26:51.730 sets. And so the haploid number for those organisms, 00:26:51.930 --> 00:26:54.670 what's found in an egg or a sperm, and what's 00:26:54.670 --> 00:26:57.609 half the euploid number, and all of that, is 00:26:57.609 --> 00:27:02.230 multiple complete sets relative to the ancestors. 00:27:02.809 --> 00:27:07.529 And big jumps like that from 60 to 120 to 240 00:27:07.529 --> 00:27:10.730 as the euploid number are the hallmark of... 00:27:11.119 --> 00:27:16.059 polyp organization. Okay. To be honest, I had 00:27:16.059 --> 00:27:19.059 a hard time following. I think it's just because 00:27:19.059 --> 00:27:22.279 it's like, there's not enough numbers. No. And 00:27:22.279 --> 00:27:26.339 I also couldn't spell any of those words. Like, 00:27:26.420 --> 00:27:28.859 I just come back to like the human idea here. 00:27:28.980 --> 00:27:31.339 And we talk about human genetics when we end 00:27:31.339 --> 00:27:35.380 up with, like, it seems like the more you have, 00:27:35.440 --> 00:27:37.680 the more things that can go wrong. Or is it the 00:27:37.680 --> 00:27:42.599 more you have, the more Fail safes you have like 00:27:42.599 --> 00:27:48.859 Yeah, how does that work? So it's what's really 00:27:48.859 --> 00:27:51.700 interesting is that in most of the ancestor polyploids 00:27:51.700 --> 00:27:54.279 we know in both plants and animals the genome 00:27:54.279 --> 00:27:58.480 actually acts as functional diploids made the 00:27:58.480 --> 00:28:02.319 same two pairs of chromosomes Pair up and split 00:28:02.319 --> 00:28:04.920 for distribution in gametes rather than in sets 00:28:04.920 --> 00:28:07.279 of multiples on random parable the original multiple 00:28:08.109 --> 00:28:12.170 We call this process redeploytization. And although 00:28:12.170 --> 00:28:14.430 the reasons for why this seemed to inevitably 00:28:14.430 --> 00:28:18.470 happen are an active area of research, we think 00:28:18.470 --> 00:28:22.230 that it's some combination of fixing what dosage 00:28:22.230 --> 00:28:25.769 problems were created by polypoidization, particularly 00:28:25.769 --> 00:28:29.349 around sex regeneration, and the redeployment 00:28:29.349 --> 00:28:32.390 of what duplicated genes are retained for distinct 00:28:32.390 --> 00:28:36.130 purposes. And indeed, in an ancestral tetrapoid 00:28:36.130 --> 00:28:38.450 European sturgeon called the sterlet, for which 00:28:38.450 --> 00:28:40.269 we have a pretty good genome sequence, there's 00:28:40.269 --> 00:28:42.269 pretty clear evidence that most of the genome 00:28:42.269 --> 00:28:46.970 has at least redeployed that. But white sturgeon, 00:28:47.009 --> 00:28:49.990 the subject of our paper, to get to be an ancestral 00:28:49.990 --> 00:28:52.710 octopoid has probably undergone two polyphoretization 00:28:52.710 --> 00:28:56.410 events. The first prior to its split its sterlet, 00:28:56.470 --> 00:28:58.369 so a shared one, and then one that's more recent 00:28:58.369 --> 00:29:02.910 and exclusive to Pacific sturgeon. But if sterlet 00:29:02.910 --> 00:29:06.670 are ancestral tetraploids, functional diploids, 00:29:06.829 --> 00:29:10.910 what does that make white sturgeon? So what we've 00:29:10.910 --> 00:29:12.950 gained from our genome assembly from white sturgeon 00:29:12.950 --> 00:29:15.190 is that there's evidence both that the majority 00:29:15.190 --> 00:29:19.309 of the genome seems to exist in four copies or 00:29:19.309 --> 00:29:23.789 relative to the sterlet sturgeon, that's a template, 00:29:23.930 --> 00:29:27.230 your diploid number, which makes white sturgeon 00:29:27.230 --> 00:29:31.119 technically tetraploid. There's also evidence 00:29:31.119 --> 00:29:36.200 that four ancestral chromosomes don't recombine 00:29:36.200 --> 00:29:38.900 much during meiosis, suggesting that enough of 00:29:38.900 --> 00:29:42.700 the genome has rediploidized for the machinery 00:29:42.700 --> 00:29:45.299 of cell division to treat them as two pair rather 00:29:45.299 --> 00:29:48.400 than four of a kind. So notwithstanding that 00:29:48.400 --> 00:29:51.559 there's ambiguity in our results, because shockingly, 00:29:51.599 --> 00:29:54.859 it's really hard to assemble an octoploid genome. 00:29:55.500 --> 00:29:57.599 It looks like the white sturgeon genome is in 00:29:57.599 --> 00:29:59.720 sort of an intermediate phase of rediploidizing 00:29:59.720 --> 00:30:02.940 from being functionally petroploid to the most 00:30:02.940 --> 00:30:06.819 recent autopletoplasmic event. So I guess what 00:30:06.819 --> 00:30:08.039 I'm trying to say in answering your question 00:30:08.039 --> 00:30:11.359 is that it's hard and it creates problems, but 00:30:11.359 --> 00:30:14.339 it seems that most of the time genomes go back 00:30:14.339 --> 00:30:20.859 to being diploid across time. polyploidy is an 00:30:20.859 --> 00:30:24.319 important factor. Evolutionary is sort of a different 00:30:24.319 --> 00:30:29.599 question, but in terms of how it sort of rejiggers 00:30:29.599 --> 00:30:32.859 the machinery, it does that by becoming rediploid, 00:30:32.980 --> 00:30:37.259 going back to being diploid over time. So it 00:30:37.259 --> 00:30:40.920 tries to simplify over time genetically. Right, 00:30:40.940 --> 00:30:46.160 yeah. In the, what's the word, I guess the background 00:30:46.160 --> 00:30:48.670 research that I tried to do in I don't pretend 00:30:48.670 --> 00:30:50.390 to understand it. They made the case that perhaps 00:30:50.390 --> 00:30:56.869 this sort of branching ploidy is to deal with 00:30:56.869 --> 00:31:01.509 evolutionary or environmental conditions. So 00:31:01.509 --> 00:31:05.450 I guess the argument is plants began that process 00:31:05.450 --> 00:31:08.869 when they came onto land. Is that kind of where 00:31:08.869 --> 00:31:11.089 we're going here? The environment changes so 00:31:11.089 --> 00:31:13.390 much that the genetics had to change really quickly. 00:31:13.509 --> 00:31:16.670 And one way to do that is to have more chromosomes 00:31:16.670 --> 00:31:20.059 that can drift and change with the environment? 00:31:20.200 --> 00:31:25.880 Yeah. And I, the broad answer to your question 00:31:25.880 --> 00:31:29.180 is maybe, um, I don't want to get into what one 00:31:29.180 --> 00:31:32.839 might call, um, an adaptationist or selection 00:31:32.839 --> 00:31:36.619 paradigm, um, because not every trait that an 00:31:36.619 --> 00:31:40.440 organism has is necessarily adaptive. Sometimes 00:31:40.440 --> 00:31:44.859 it's just neutral. Um, or maybe even disadvantageous, 00:31:44.859 --> 00:31:46.920 but developmentally connected to a trait that 00:31:46.920 --> 00:31:50.640 is advantageous. In addition, for any trait to 00:31:50.640 --> 00:31:53.920 actually being adapted, it has to be advantageous 00:31:53.920 --> 00:31:58.200 at an individual level. That is, it has to give 00:31:58.200 --> 00:32:01.339 that individual an edge over competitors within 00:32:01.339 --> 00:32:05.420 its own species. So that trait can't just appear 00:32:05.420 --> 00:32:08.819 to be beneficial for the population as a whole. 00:32:09.359 --> 00:32:11.859 And the same here goes with coity. It's likely 00:32:11.859 --> 00:32:15.079 that in most cases, these kinds of genomic changes 00:32:15.079 --> 00:32:17.880 are ultimately lethal. And it's only when the 00:32:17.880 --> 00:32:20.859 stars align that a polycoidization event happens. 00:32:21.000 --> 00:32:25.079 That genome is developmentally viable. The phenotype 00:32:25.079 --> 00:32:27.500 it creates is relatively neutral or even has 00:32:27.500 --> 00:32:30.700 some advantage in some environments. And then 00:32:30.700 --> 00:32:33.500 that that individual is fertile and able to reproduce 00:32:33.500 --> 00:32:36.480 either with normal coity individuals or that 00:32:36.480 --> 00:32:39.269 there are enough. other polypoids around that 00:32:39.269 --> 00:32:41.529 tend to reproduce. And those are pretty exceptional 00:32:41.529 --> 00:32:46.069 circumstances. But the answer to the broader 00:32:46.069 --> 00:32:48.329 question of why would this ever possibly work 00:32:48.329 --> 00:32:51.529 out is really the same answer to why we have 00:32:51.529 --> 00:32:53.170 sexual reproduction in the first place, which 00:32:53.170 --> 00:32:54.910 I think is part of what you're talking about. 00:32:55.069 --> 00:32:58.130 And the answer to that is novelty. The most salient 00:32:58.130 --> 00:33:01.309 theory for why we have sexual reproduction, which 00:33:01.309 --> 00:33:04.190 creates generally diploid offspring using material 00:33:04.190 --> 00:33:06.940 from two parents, Why it evolved in the first 00:33:06.940 --> 00:33:09.599 place is because of a race between organisms 00:33:09.599 --> 00:33:13.319 and their generally clonally reproducing parasites 00:33:13.319 --> 00:33:16.799 and pathogens. Combining DNA from two individuals 00:33:16.799 --> 00:33:19.519 creates new variants a lot faster than having 00:33:19.519 --> 00:33:22.759 to mutate them from scratch. And the same is 00:33:22.759 --> 00:33:25.559 true for polypoids. When we look across environments, 00:33:25.740 --> 00:33:28.039 polypoids are associated with two things. As 00:33:28.039 --> 00:33:30.619 you say, extreme environments and also humans. 00:33:31.400 --> 00:33:33.539 Humans, and this is mostly true for agricultural 00:33:33.539 --> 00:33:35.960 species like the wheat that I mentioned, because 00:33:35.960 --> 00:33:38.460 when we find weirdos that have traits that we 00:33:38.460 --> 00:33:40.960 like, even if those traits would have put them 00:33:40.960 --> 00:33:43.859 at a disadvantage out in the wild, we baby them 00:33:43.859 --> 00:33:46.460 and we breed them a bunch. So like with wheat, 00:33:46.559 --> 00:33:49.539 most grasses have tiny dinky little seeds, and 00:33:49.539 --> 00:33:52.519 most of what's adaptive about them is their ability 00:33:52.519 --> 00:33:55.900 to delay germination, to resist being eaten or 00:33:55.900 --> 00:33:58.200 resist digestion if they are eaten, or to spread 00:33:58.200 --> 00:34:01.150 as far as possible. But wheat, on the other hand, 00:34:01.250 --> 00:34:03.750 has these giant honking brains that we love, 00:34:03.869 --> 00:34:06.069 but are pretty terrible for avoiding being eaten 00:34:06.069 --> 00:34:09.670 or dispersed. And it turns out the same goes 00:34:09.670 --> 00:34:12.650 in extreme environments. A lot of polypoids, 00:34:12.769 --> 00:34:15.610 where they are viable, have exaggerated characteristics 00:34:15.610 --> 00:34:18.070 compared to those normal voiding individuals 00:34:18.070 --> 00:34:20.730 in their next seasons. So think like wheat with 00:34:20.730 --> 00:34:23.789 the giant seeds. They're often what Stephen Jay 00:34:23.789 --> 00:34:27.110 Gould once called hopeful monsters, obvious mutants 00:34:27.110 --> 00:34:28.789 that are just looking for the right environment. 00:34:29.469 --> 00:34:31.769 And in places where you're competing with normal 00:34:31.769 --> 00:34:33.670 -point individuals in an ancestral environment, 00:34:33.829 --> 00:34:36.369 you may be at a disadvantage. But if you happen 00:34:36.369 --> 00:34:39.650 to disperse into an extreme environment, extreme 00:34:39.650 --> 00:34:42.429 here simply meaning beyond the normal environmental 00:34:42.429 --> 00:34:45.369 tolerances for that species, immediately you've 00:34:45.369 --> 00:34:47.610 got less competition than the normal -point individuals. 00:34:47.989 --> 00:34:50.409 And if those exaggerated characteristics make 00:34:50.409 --> 00:34:52.889 you better suited for that environment than normal 00:34:52.889 --> 00:34:55.010 -point individuals, then you're off to the races. 00:34:55.550 --> 00:34:57.429 Ecologists would say you're exploiting a new 00:34:57.429 --> 00:35:00.849 niche. But to bring it home to Sturgeon, why 00:35:00.849 --> 00:35:03.429 Sturgeon specifically exhibit this kind of ploidy 00:35:03.429 --> 00:35:07.349 variation, my guess is that this is genomic flexibility. 00:35:07.389 --> 00:35:10.510 It has more to do with a slow mutation rate and 00:35:10.510 --> 00:35:13.929 a compound history of polyploidy than an adaptively 00:35:13.929 --> 00:35:16.889 retained ability to tolerate or utilize changes. 00:35:17.349 --> 00:35:20.070 Though, sort of to your broader point, whether 00:35:20.070 --> 00:35:23.150 that has given them an advantage to weather the 00:35:23.150 --> 00:35:25.530 many changes that they have seen over 300 million 00:35:25.530 --> 00:35:27.929 years, that's an open question. Yeah, I don't 00:35:27.929 --> 00:35:29.230 think we really have the answer for that yet. 00:35:29.730 --> 00:35:32.570 Okay, I'm going to go on a short tangent because 00:35:32.570 --> 00:35:34.369 I don't know if you have the answer. You mentioned 00:35:34.369 --> 00:35:37.349 extreme environments and environments where you 00:35:37.349 --> 00:35:41.309 can change quickly, where you have less, you 00:35:41.309 --> 00:35:44.989 know, other animals and plants being in competition 00:35:44.989 --> 00:35:48.130 with you. What about things like ocean islands 00:35:48.130 --> 00:35:51.070 that, you know, volcanic, they're wiped clean. 00:35:51.389 --> 00:35:54.250 Is this another type of environment where Ploody 00:35:54.250 --> 00:35:58.019 can take it? So I'm thinking Galapagos, I'm thinking 00:35:58.019 --> 00:36:01.880 Hawaii, I'm thinking those sorts of really extreme 00:36:01.880 --> 00:36:05.420 but yet isolated environments. Yeah, so islands 00:36:05.420 --> 00:36:07.780 have always been sort of a natural laboratory 00:36:07.780 --> 00:36:13.179 for evolutionary diversification and adaptation. 00:36:13.559 --> 00:36:15.960 And there are a number of reasons for that. Islands, 00:36:16.199 --> 00:36:19.059 as you say... They often have less competition 00:36:19.059 --> 00:36:20.960 because there are so many fewer species, which 00:36:20.960 --> 00:36:24.000 means that there are a lot of unoccupied niches. 00:36:24.039 --> 00:36:26.260 They tend to be very isolated, so there's not 00:36:26.260 --> 00:36:28.840 a lot of input from other populations that would 00:36:28.840 --> 00:36:31.239 prevent you from adapting to those new environments. 00:36:31.699 --> 00:36:34.599 And they often have very small population sizes. 00:36:34.800 --> 00:36:37.599 And so you have, it's technically inbreeding, 00:36:37.659 --> 00:36:39.679 but essentially what's happening in populations, 00:36:39.679 --> 00:36:42.969 you always have a balance between. Things that 00:36:42.969 --> 00:36:44.769 are happening because of genetic drift. So these 00:36:44.769 --> 00:36:47.250 are just numerical things that gene frequencies 00:36:47.250 --> 00:36:50.070 change because they're just a limited number 00:36:50.070 --> 00:36:52.969 of individuals and natural selection. Natural 00:36:52.969 --> 00:36:56.349 selection is creating adaptation. And so those 00:36:56.349 --> 00:37:00.489 factors are often in conflict with one another 00:37:00.489 --> 00:37:04.110 because a drift will often sort of accidentally 00:37:04.110 --> 00:37:09.550 take you away from the adaptive. field that you're 00:37:09.550 --> 00:37:11.650 looking for. I don't want to anthropomorphize 00:37:11.650 --> 00:37:17.449 it. That is optimal. And so in large populations, 00:37:17.869 --> 00:37:21.510 natural selection is less opposed by drift, and 00:37:21.510 --> 00:37:23.670 therefore it can be more effective. And in small 00:37:23.670 --> 00:37:25.809 populations, drift is a much bigger force. And 00:37:25.809 --> 00:37:28.190 what that can sometimes mean is you can drift 00:37:28.190 --> 00:37:31.829 over into different phenotypes that are actually 00:37:31.829 --> 00:37:35.750 better for niches, unoccupied niches that you 00:37:35.750 --> 00:37:38.119 wouldn't have been able to exploit before. And 00:37:38.119 --> 00:37:41.559 that can be true for polyploidy as well. Think 00:37:41.559 --> 00:37:44.860 of polyploidy as being sort of the oddballs that 00:37:44.860 --> 00:37:46.719 normally they would get selected out. But when 00:37:46.719 --> 00:37:48.699 you're in these isolated environments where you're 00:37:48.699 --> 00:37:51.300 not getting input from a lot of nomoploidy individuals, 00:37:51.639 --> 00:37:54.460 it doesn't take that many polyploid individuals 00:37:54.460 --> 00:37:57.860 to start an entire new population. So that combined 00:37:57.860 --> 00:38:00.280 with the unoccupied niches, with the isolation, 00:38:00.719 --> 00:38:03.380 all those kinds of things, gives them an opportunity 00:38:03.380 --> 00:38:06.159 that they wouldn't normally have in mainland 00:38:06.159 --> 00:38:10.449 environments. Cool. All right. So we know they 00:38:10.449 --> 00:38:13.889 have complex genetics and I don't really want 00:38:13.889 --> 00:38:15.969 to get into it, but I will just kind of drop 00:38:15.969 --> 00:38:17.969 it. We have a society that has gotten confused 00:38:17.969 --> 00:38:20.409 when talking about the rare cases in human genetics 00:38:20.409 --> 00:38:25.829 when it comes to sex. But with four or six different 00:38:25.829 --> 00:38:32.940 pairs or chromosome groups like. Can they switch 00:38:32.940 --> 00:38:35.820 sexes like other species? Is there some combination 00:38:35.820 --> 00:38:38.139 of chromosomes that kind of try to determine 00:38:38.139 --> 00:38:39.900 this? Like, it's got to be way more complicated 00:38:39.900 --> 00:38:44.420 for them than it is for us. It is. I mean, it's 00:38:44.420 --> 00:38:47.139 also in some ways sort of fundamentally different 00:38:47.139 --> 00:38:49.400 because, as I alluded to, sex is one of the primary 00:38:49.400 --> 00:38:52.360 reasons that genomes are forced to restructure 00:38:52.360 --> 00:38:56.030 after a polyploidization event. So, for example, 00:38:56.050 --> 00:38:59.110 in mammal species, which have an XY sex chromosome 00:38:59.110 --> 00:39:02.570 system like humans, females, which of course 00:39:02.570 --> 00:39:05.809 have two X chromosomes, one of them is generally 00:39:05.809 --> 00:39:09.110 completely turned off during development or silent 00:39:09.110 --> 00:39:12.309 to maintain the same dosage as in males, which 00:39:12.309 --> 00:39:14.789 only have a single act, right? And an interesting 00:39:14.789 --> 00:39:17.070 manifestation of this, if you've ever seen a 00:39:17.070 --> 00:39:19.329 tortoiseshell cat, which have that attractive 00:39:19.329 --> 00:39:22.170 black and orange spotting. It's because of that 00:39:22.170 --> 00:39:26.469 gene or colors on the X chromosome in cats. And 00:39:26.469 --> 00:39:30.250 which X chromosome is silenced can vary across 00:39:30.250 --> 00:39:32.769 the body in early development in females, which 00:39:32.769 --> 00:39:35.710 leads to different versions of the gene being 00:39:35.710 --> 00:39:38.929 expressed in different patches of skin. But to 00:39:38.929 --> 00:39:41.070 your question, part of the reason why it's very 00:39:41.070 --> 00:39:43.409 different in sturgeons to a degree is because 00:39:43.409 --> 00:39:48.320 they show a ZW sex determination system. Birds 00:39:48.320 --> 00:39:50.760 generally have a ZW sex determination system, 00:39:50.920 --> 00:39:54.380 and that's where the female is the sex with the 00:39:54.380 --> 00:39:57.539 two different sex chromosomes rather than the 00:39:57.539 --> 00:40:00.019 male. And so just to be obvious about that, we 00:40:00.019 --> 00:40:03.940 say ZW instead of XY in these female heterogametic 00:40:03.940 --> 00:40:07.460 species. And we know that that's true, that sturgeons 00:40:07.460 --> 00:40:10.280 have a ZW sex determination system because you 00:40:10.280 --> 00:40:14.239 can actually feminize or masculinize fish using 00:40:14.239 --> 00:40:18.280 hormones. So when feminized males are used, so 00:40:18.280 --> 00:40:21.079 this would be a fish that only has the ZZ chromosome, 00:40:21.360 --> 00:40:23.940 they produce all male offspring because there 00:40:23.940 --> 00:40:27.360 are no W chromosomes amongst them. Whereas if 00:40:27.360 --> 00:40:31.659 you masculinize females and make ZW females be 00:40:31.659 --> 00:40:35.480 male, they produce both male and female offspring, 00:40:35.619 --> 00:40:37.500 although the ratio is messed up because there 00:40:37.500 --> 00:40:40.619 are now more W chromosomes than there would usually 00:40:40.619 --> 00:40:44.039 be. And indeed, in the sterlet sturgeon, that 00:40:44.039 --> 00:40:46.820 diploid European sturgeon that I may have mentioned 00:40:46.820 --> 00:40:50.360 before, there is a region on one chromosome that's 00:40:50.360 --> 00:40:54.079 only present in females, as expected. And it 00:40:54.079 --> 00:40:55.900 happens to be a gene that's strongly expressed 00:40:55.900 --> 00:40:59.739 in the sex organs of some other fishes. And then 00:40:59.739 --> 00:41:02.079 we found the same region present in white sturgeon, 00:41:02.099 --> 00:41:05.119 too. And it seems to predict sex pretty well, 00:41:05.199 --> 00:41:07.119 depending on which population you're looking 00:41:07.119 --> 00:41:10.000 at. But all of that being said... It's true. 00:41:10.099 --> 00:41:13.280 We don't know how much environment may play a 00:41:13.280 --> 00:41:16.360 role in determining sex of sturgeon. It is possible 00:41:16.360 --> 00:41:18.559 that this genomic region that we found, both 00:41:18.559 --> 00:41:22.139 in these two seasons of sturgeon, can be mediated 00:41:22.139 --> 00:41:25.619 or completely overridden in certain environments. 00:41:25.860 --> 00:41:29.199 And that could cause some noise around what the 00:41:29.199 --> 00:41:31.900 markers that we develop from this predict in 00:41:31.900 --> 00:41:36.599 terms of sex. Interesting. All that to say is 00:41:36.599 --> 00:41:40.639 it's possible, but we don't know. It is possible. 00:41:40.820 --> 00:41:44.960 So as I thought this earlier and didn't get a 00:41:44.960 --> 00:41:48.820 chance, the other wonky thing about sturgeon 00:41:48.820 --> 00:41:53.139 is that not only are they probably functional 00:41:53.139 --> 00:41:55.579 tetraploids themselves, they also show spontaneous 00:41:55.579 --> 00:41:58.420 autopolyploids. So these are the fish with the 00:41:58.420 --> 00:42:01.119 six N chromosomes that you were talking about. 00:42:01.639 --> 00:42:05.079 And these spontaneous autopoly, what we know 00:42:05.079 --> 00:42:07.760 is that they have one and a half times. the normal 00:42:07.760 --> 00:42:10.579 amount of dna normal for white turkish which 00:42:10.579 --> 00:42:13.920 is of course a sort of a more of this concept 00:42:13.920 --> 00:42:16.960 but these individuals then one and a half times 00:42:16.960 --> 00:42:19.960 would either be um hexaploid the six in you mentioned 00:42:19.960 --> 00:42:21.880 or if you're talking ancestrally they could be 00:42:21.880 --> 00:42:24.340 dodecaploid 12n or if you consider that white 00:42:24.340 --> 00:42:27.280 spirits are normally diploid they are triploid 00:42:27.280 --> 00:42:30.659 but and i can i can talk about how we think that 00:42:30.659 --> 00:42:32.820 actually happens is spontaneous auto polyploidy 00:42:32.820 --> 00:42:36.780 but the weirder part is as a rule triploid fish 00:42:36.780 --> 00:42:39.480 are sterile right in fact triploid fish you may 00:42:39.480 --> 00:42:41.860 have heard of these rainbow trout brass carp 00:42:41.860 --> 00:42:44.900 atlantic salmon are often stocked in the wild 00:42:44.900 --> 00:42:47.400 specifically because they're sterile because 00:42:47.400 --> 00:42:50.000 they won't invade habitats or interbreed with 00:42:50.000 --> 00:42:52.599 wild fish and they're sterile because having 00:42:52.599 --> 00:42:54.760 three sets of chromosomes when they go to make 00:42:54.760 --> 00:42:57.119 their haploid gametes the chromosomes get all 00:42:57.119 --> 00:42:59.519 shuffled up in unpredictable ways and their gametes 00:42:59.519 --> 00:43:02.539 end up having uneven set that is their aneuploid 00:43:03.019 --> 00:43:05.320 But I guess nobody told white sturgeon, because 00:43:05.320 --> 00:43:08.179 while we've found that these one and a half times 00:43:08.179 --> 00:43:11.179 variants are rare in the wild, they're still 00:43:11.179 --> 00:43:13.880 present, but they're rare. They're pretty common 00:43:13.880 --> 00:43:16.619 in hatcheries, common enough that they've been 00:43:16.619 --> 00:43:19.699 unintentionally crossed with normal ploidy sturgeon. 00:43:19.820 --> 00:43:22.179 And lo and behold, they produce five offspring 00:43:22.179 --> 00:43:24.360 with an intermediate ploidy, which is probably 00:43:24.360 --> 00:43:28.159 safest to call pentaploid, I guess, which is 00:43:28.159 --> 00:43:30.119 five sets of chromosome. And we don't really 00:43:30.119 --> 00:43:32.940 know a lot about these pentaploids except that 00:43:32.940 --> 00:43:35.800 they're viable. So it's sort of an open question 00:43:35.800 --> 00:43:37.880 as to whether or not they could be important 00:43:37.880 --> 00:43:41.119 evolutionarily if they were created out in the 00:43:41.119 --> 00:43:43.460 wild and half the population. But the point, 00:43:43.539 --> 00:43:46.639 you know, to your point is that those spontaneous 00:43:46.639 --> 00:43:49.880 autopolyploids, the one and a half times fish, 00:43:50.059 --> 00:43:53.019 that are hexaploid, dodecaploid, triploid, whatever 00:43:53.019 --> 00:43:56.019 you call them. are at least viable and partly 00:43:56.019 --> 00:43:59.059 fertile. And you can sort of imagine that there 00:43:59.059 --> 00:44:02.480 are situations where enough of them were accumulating 00:44:02.480 --> 00:44:04.579 out there in sort of an isolated environment 00:44:04.579 --> 00:44:06.980 that they actually could create an entirely new 00:44:06.980 --> 00:44:10.860 population. And so that sort of gives you a bridge 00:44:10.860 --> 00:44:14.119 or a window to how these higher ploidies could 00:44:14.119 --> 00:44:16.300 have formed in the first place. And you have 00:44:16.300 --> 00:44:18.619 these sort of strange cellular developmental 00:44:18.619 --> 00:44:23.340 things going on that result from sort of... breakdowns 00:44:23.340 --> 00:44:25.960 in environmental conditions and just create this 00:44:25.960 --> 00:44:29.639 sort of convergence of conditions where new set 00:44:29.639 --> 00:44:32.900 of OED variants happen to start reproducing and 00:44:32.900 --> 00:44:38.119 diverge from the original population. Okay, so 00:44:38.119 --> 00:44:40.880 let's go back to the paper. You're using DNA 00:44:40.880 --> 00:44:44.559 markers to figure out whether or not individuals 00:44:44.559 --> 00:44:48.960 are male or female. And according to this, you're 00:44:48.960 --> 00:44:51.730 like, you can't. see, I would imagine, a fish, 00:44:51.769 --> 00:44:53.269 whether it's male or female, just by looking 00:44:53.269 --> 00:44:56.369 at it. And so you're using genetics and you're 00:44:56.369 --> 00:44:59.989 96 % accurate for females, but only 81 % for 00:44:59.989 --> 00:45:03.250 males. Why is it easier to spot the female genetically? 00:45:03.409 --> 00:45:06.530 And is it a null result sometimes instead of 00:45:06.530 --> 00:45:09.309 like, say, a false positive or false negative? 00:45:09.769 --> 00:45:12.489 Yeah, it's certainly possible that some cases 00:45:12.489 --> 00:45:15.710 where our sex markers aren't 100 % accurate could 00:45:15.710 --> 00:45:19.699 be. because of the failure of the molecular assay, 00:45:19.699 --> 00:45:22.900 something that we call a null allele, where the 00:45:22.900 --> 00:45:25.519 genomic region is there in that individual, but 00:45:25.519 --> 00:45:29.239 our assay simply fails to pick it up. And that 00:45:29.239 --> 00:45:33.000 would explain why some females were predicted 00:45:33.000 --> 00:45:36.739 to be males, but not why males would be predicted 00:45:36.739 --> 00:45:40.119 to be females. In those cases, it's not the assay 00:45:40.119 --> 00:45:42.239 that's failing, since we can clearly see that 00:45:42.239 --> 00:45:46.190 the genomic region is present. but rather a failed 00:45:46.190 --> 00:45:50.530 association of the genomic region with phenotypic 00:45:50.530 --> 00:45:53.489 sex. And I think what's actually going on is 00:45:53.489 --> 00:45:58.030 any or all of three things. One, it's possible 00:45:58.030 --> 00:46:00.829 that the sex data for our samples are wrong for 00:46:00.829 --> 00:46:02.730 some populations. That is, which are males and 00:46:02.730 --> 00:46:04.489 which are females was just misrecorded. As a 00:46:04.489 --> 00:46:06.349 scientist, you have to be upfront about the fact 00:46:06.349 --> 00:46:08.869 that your data may just be flawed in some cases. 00:46:09.010 --> 00:46:12.519 And the fact that our markers are... 100 % accurate 00:46:12.519 --> 00:46:15.260 for fish whose sex I have personally confirmed, 00:46:15.579 --> 00:46:18.300 not by looking under the hood, but through offspring 00:46:18.300 --> 00:46:21.460 of known crosses, sort of indicates that in some 00:46:21.460 --> 00:46:25.260 cases. But two, as we said earlier, it's possible 00:46:25.260 --> 00:46:28.179 that in some cases environment may play more 00:46:28.179 --> 00:46:30.760 of a role in determining sex than we understand. 00:46:31.239 --> 00:46:33.619 But three, and this is my preferred hypothesis, 00:46:33.920 --> 00:46:36.159 or at least the one I'm most interested in pursuing, 00:46:36.400 --> 00:46:40.380 that how far down the process of re -diploidization 00:46:40.989 --> 00:46:43.170 and specifically how much exchange between those 00:46:43.170 --> 00:46:46.829 ancestral sex chromosomes there still is, varies 00:46:46.829 --> 00:46:50.110 from one population to another. And so the association 00:46:50.110 --> 00:46:53.710 of our markers and perhaps even how that genomic 00:46:53.710 --> 00:46:58.469 region mediates sex may vary from one sturgeon 00:46:58.469 --> 00:47:01.230 population to another. And indeed, some of the 00:47:01.230 --> 00:47:03.710 data that we use to make our genome assembly 00:47:03.710 --> 00:47:06.550 indicate that at least in the Middle Snake River 00:47:06.550 --> 00:47:09.099 in Idaho, which is one of the places where our 00:47:09.099 --> 00:47:11.840 sex markers aren't 100 % accurate. There is still 00:47:11.840 --> 00:47:14.739 some recombination between those ancestral sex 00:47:14.739 --> 00:47:17.980 chromosomes. Okay, well, let's try to give this 00:47:17.980 --> 00:47:22.559 a little bit more real world heft to it now. 00:47:23.860 --> 00:47:26.480 How does this, I guess I'm going to add something 00:47:26.480 --> 00:47:28.980 to my original question is like, how does this 00:47:28.980 --> 00:47:32.300 further our understanding of genetics in the 00:47:32.300 --> 00:47:35.719 animal kingdom? And how do we use this to like 00:47:35.719 --> 00:47:39.079 help? conservation of the species like how do 00:47:39.079 --> 00:47:42.500 we how do we use this information in practice 00:47:42.500 --> 00:47:47.179 yeah it's you know been a few decades now since 00:47:47.179 --> 00:47:51.800 we sequenced the human genome and we know a lot 00:47:51.800 --> 00:47:54.260 more than we did then but every day we sort of 00:47:54.260 --> 00:47:56.679 find out that our understanding of what genomes 00:47:56.679 --> 00:48:00.639 are how they work what's wrong and that's science 00:48:00.639 --> 00:48:02.820 that's how that's supposed to work you know so 00:48:02.820 --> 00:48:06.650 for example these days we're interested in structural 00:48:06.650 --> 00:48:08.710 variation. So structural variation of genomes 00:48:08.710 --> 00:48:12.929 is entire sections of the genome that are present 00:48:12.929 --> 00:48:15.969 in one individual or missing in another, or regions 00:48:15.969 --> 00:48:18.429 that are, you know, reversed so that they're 00:48:18.429 --> 00:48:21.210 in the opposite direction from one individual 00:48:21.210 --> 00:48:23.829 to another. We sort of originally thought that 00:48:23.829 --> 00:48:26.050 genomes were basically the same, except, you 00:48:26.050 --> 00:48:29.030 know, I've got an A and you've got a T, and over 00:48:29.030 --> 00:48:31.309 here you've got a G and I've got a C, that they're 00:48:31.309 --> 00:48:33.730 very small differences. It turns out that even 00:48:33.730 --> 00:48:35.469 among individuals of some species, there can 00:48:35.469 --> 00:48:39.090 be huge, very big differences in the chromosomes 00:48:39.090 --> 00:48:42.050 between individuals. And so that is particularly 00:48:42.050 --> 00:48:45.110 true for polypoids, where not only is that happening 00:48:45.110 --> 00:48:48.630 between just very small homologous chromosomes, 00:48:48.769 --> 00:48:52.070 but chromosomes that have a much larger ancestral 00:48:52.070 --> 00:48:55.949 relationship. And so the way the genomes evolve 00:48:55.949 --> 00:49:00.610 or redepoidize following polypoidization provides 00:49:00.610 --> 00:49:03.420 a good window into understanding that. But as 00:49:03.420 --> 00:49:05.800 to the conservation of this species, which, of 00:49:05.800 --> 00:49:08.239 course, is what I'm interested in on behalf of 00:49:08.239 --> 00:49:10.980 the tribe, it's easier to imagine that folks 00:49:10.980 --> 00:49:12.920 running commercial caviar farms would like to 00:49:12.920 --> 00:49:16.239 know which fish are female as early as possible 00:49:16.239 --> 00:49:18.820 so they can maximize their root hormone on investment. 00:49:19.039 --> 00:49:21.559 But that's not really our target audience. On 00:49:21.559 --> 00:49:23.260 behalf of the tribes, we're focused on trying 00:49:23.260 --> 00:49:25.880 to maintain or rebuild the fisheries of these 00:49:25.880 --> 00:49:28.610 species and understanding. Population dynamics 00:49:28.610 --> 00:49:31.230 is a critical part of that, like the sex ratio 00:49:31.230 --> 00:49:34.409 of wild populations or how many females reproduce 00:49:34.409 --> 00:49:37.449 in a year and with how many males. And being 00:49:37.449 --> 00:49:39.869 able to take a thin clip and predict sex rather 00:49:39.869 --> 00:49:42.969 than having to do an abdominal biopsy makes that 00:49:42.969 --> 00:49:45.449 data a lot more accessible. But beyond that, 00:49:45.530 --> 00:49:47.590 because there are a lot of populations that are 00:49:47.590 --> 00:49:50.269 slowly declining because of a lack of consistent 00:49:50.269 --> 00:49:53.969 recruitment and reproduction, a number of conservation 00:49:53.969 --> 00:49:57.739 aquaculture programs. hatcheries that are specifically 00:49:57.739 --> 00:50:01.099 focused on rebuilding wild populations have been 00:50:01.099 --> 00:50:03.219 developed to supplement those wild populations. 00:50:03.420 --> 00:50:05.639 And while they have become very adept at producing 00:50:05.639 --> 00:50:08.019 many young sturgeons, they're very effective. 00:50:08.400 --> 00:50:11.659 We don't know whether those aquaculture practices 00:50:11.659 --> 00:50:15.000 bias the resulting offspring towards one sex 00:50:15.000 --> 00:50:17.679 or another. For example, it's possible that male 00:50:17.679 --> 00:50:20.289 sturgeon grow faster than female. And at high 00:50:20.289 --> 00:50:22.650 densities, like there are atrophied males, may 00:50:22.650 --> 00:50:24.750 out -compete females and produce, therefore, 00:50:24.869 --> 00:50:26.710 a male -biased population. You don't want to 00:50:26.710 --> 00:50:28.969 dump a whole bunch of males back into the wild 00:50:28.969 --> 00:50:32.489 because that screws up the population. So since 00:50:32.489 --> 00:50:34.909 you can't sex young sturgeon until they're basically 00:50:34.909 --> 00:50:37.630 begun to mature, having a molecular assay, like 00:50:37.630 --> 00:50:40.610 we've developed from this marker, is a much more 00:50:40.610 --> 00:50:42.610 effective way of doing that at earlier life stages. 00:50:43.750 --> 00:50:46.329 Okay, so you're providing the information needed 00:50:46.329 --> 00:50:49.349 for those that are making the policy decisions 00:50:49.349 --> 00:50:51.889 about how to do the conservation. You're giving 00:50:51.889 --> 00:50:54.460 them the tools to make those decisions. Yeah, 00:50:54.559 --> 00:50:57.820 we're much more focused on sort of the state 00:50:57.820 --> 00:50:59.940 agencies that are putting into action policies, 00:50:59.940 --> 00:51:02.019 something that we need to be people who have, 00:51:02.099 --> 00:51:04.639 you know, in a higher pay grade. Right. But you're 00:51:04.639 --> 00:51:06.739 giving them the information to make those policy 00:51:06.739 --> 00:51:09.139 decisions. I mean, in a volcanology sense, a 00:51:09.139 --> 00:51:11.119 volcanologist isn't the one telling people to 00:51:11.119 --> 00:51:13.500 evacuate. The volcanologist is telling them, 00:51:13.539 --> 00:51:15.460 OK, this is what's happening. This is the likely 00:51:15.460 --> 00:51:18.219 outcome. And then the policy people who make 00:51:18.219 --> 00:51:20.239 a lot more money typically, not always, but typically 00:51:20.239 --> 00:51:22.420 make the decision whether or not you need to 00:51:22.420 --> 00:51:26.099 get out of town. Yes, yes, exactly. We provide 00:51:26.099 --> 00:51:28.559 as much information as we can, and what they 00:51:28.559 --> 00:51:31.280 choose to do with it is beyond our purview, unfortunately. 00:51:31.780 --> 00:51:36.199 Exactly, exactly. Okay, so I'm kind of glad to 00:51:36.199 --> 00:51:38.980 see that it's working similarly in two completely 00:51:38.980 --> 00:51:41.699 different disciplines, actually. That's science, 00:51:41.840 --> 00:51:46.199 yes. For better or worse. It goes both ways. 00:51:46.340 --> 00:51:48.260 Sometimes you really don't want the scientists 00:51:48.260 --> 00:51:50.480 making the decision for people sometimes, and 00:51:50.480 --> 00:51:54.840 sometimes it would actually be better. I'm biased 00:51:54.840 --> 00:51:57.579 there, I guess. Yeah, no, having everybody at 00:51:57.579 --> 00:51:59.320 the table is not the right way to do it. It's 00:51:59.320 --> 00:52:01.539 just being able to respect everyone's opinions 00:52:01.539 --> 00:52:07.860 is sometimes the challenge. Yeah. On that note, 00:52:08.000 --> 00:52:11.699 I'm going to skip one of my questions because 00:52:11.699 --> 00:52:14.019 I think it's kind of wrapped up here in the same. 00:52:14.360 --> 00:52:16.659 So the Fraser River, it's a river that connects 00:52:16.659 --> 00:52:19.559 my home turf and more broadly for my local river. 00:52:20.119 --> 00:52:21.699 What is the future for this species? Because 00:52:21.699 --> 00:52:24.239 you've mentioned the Snake River already being 00:52:24.239 --> 00:52:27.639 already quite different. But I know you're focused 00:52:27.639 --> 00:52:30.239 more on the Columbia and its tributaries. But 00:52:30.239 --> 00:52:33.300 what can you say about the Fraser and what needs 00:52:33.300 --> 00:52:37.719 to happen to protect it? Yeah. So as we said, 00:52:37.840 --> 00:52:40.079 the Columbia has a major challenge of having 00:52:40.079 --> 00:52:43.199 all of these dams. And you can imagine that. 00:52:43.900 --> 00:52:46.000 prehistorically a five meter fish could go basically 00:52:46.000 --> 00:52:49.079 anywhere it wanted in in the basin you know if 00:52:49.079 --> 00:52:50.860 there are different sections of the river basin 00:52:50.860 --> 00:52:54.639 that are better for reproduction for growth or 00:52:54.639 --> 00:52:57.139 you know hanging out in hot summer temperatures 00:52:57.139 --> 00:52:59.159 that kind of thing you could choose that and 00:52:59.159 --> 00:53:01.059 you put in dams in the way well now you just 00:53:01.059 --> 00:53:03.519 got to deal with whatever is available and unfortunately 00:53:03.519 --> 00:53:06.360 in many of these sections there's not enough 00:53:06.360 --> 00:53:09.630 good habitat for rearing in the early life stages, 00:53:09.849 --> 00:53:11.690 that they're getting a lot of recruitment. And 00:53:11.690 --> 00:53:13.710 so what is there is getting older and older, 00:53:14.210 --> 00:53:16.710 and as a result, the populations diminish over 00:53:16.710 --> 00:53:20.170 time. The Frasier does not have that problem 00:53:20.170 --> 00:53:23.010 of damming. From my understanding, the biggest 00:53:23.010 --> 00:53:25.650 threats to the Frasier white sturgeon are habitat 00:53:25.650 --> 00:53:29.170 degradation and the diminishing runs of the naturalist 00:53:29.170 --> 00:53:31.949 fish, particularly chum, phantom, and eucalon. 00:53:32.480 --> 00:53:35.320 It may be strange to think of a freshwater fish 00:53:35.320 --> 00:53:38.860 as being dependent on marine species, but these 00:53:38.860 --> 00:53:41.820 interior Pacific ecosystems have evolved with 00:53:41.820 --> 00:53:44.800 that regular influx of marine -derived nutrients. 00:53:45.079 --> 00:53:46.820 And that's especially true for white sturgeon, 00:53:46.940 --> 00:53:50.300 which depend on those returning fish, their carcasses, 00:53:50.420 --> 00:53:53.639 their eggs, their offspring for food. And as 00:53:53.639 --> 00:53:58.099 those runs diminish, it's likely that sturgeon 00:53:58.099 --> 00:54:01.139 will continue to do so too, unfortunately. And 00:54:01.139 --> 00:54:06.980 we're already hearing reports of, and I should 00:54:06.980 --> 00:54:09.420 say, that's not something that conservation aquaculture 00:54:09.420 --> 00:54:11.940 can overcome. You can dump a bunch of young fish 00:54:11.940 --> 00:54:13.940 in the river, but if there's nothing for them 00:54:13.940 --> 00:54:17.900 to eat, then you're just spinning your wheels. 00:54:18.119 --> 00:54:20.599 And we're already hearing reports this year of 00:54:20.599 --> 00:54:24.239 another warm water blob developing off of California 00:54:24.239 --> 00:54:27.679 and the prediction of a super El Nino later this 00:54:27.679 --> 00:54:31.679 year. So it seems to be that while there are 00:54:31.679 --> 00:54:34.059 things that we can do to give the Fraser River 00:54:34.059 --> 00:54:37.219 or the Columbia River sturgeon the best chance 00:54:37.219 --> 00:54:40.719 we can, their fate, like the fate of so many 00:54:40.719 --> 00:54:42.699 other species, is going to depend on whether 00:54:42.699 --> 00:54:46.119 we humans can get our act together as a species 00:54:46.119 --> 00:54:48.619 and realize that we're not entitled to be the 00:54:48.619 --> 00:54:50.440 center of the universe and start acting like 00:54:50.440 --> 00:54:55.099 good stewards, like we should be. So we could 00:54:55.099 --> 00:54:57.260 sum it up with essentially climate change. Yeah. 00:54:57.599 --> 00:54:59.940 I mean, that's certainly the train coming down 00:54:59.940 --> 00:55:02.679 the tracks, right? It's how long do we need to 00:55:02.679 --> 00:55:04.239 see the train before we decide that we're going 00:55:04.239 --> 00:55:08.579 to get off of it, off the tracks. And I'm actually 00:55:08.579 --> 00:55:10.460 more of an optimist than a doomsayer because 00:55:10.460 --> 00:55:15.739 I think being a doomsayer paralyzes action. We 00:55:15.739 --> 00:55:17.840 are doing stuff. Things are changing. It's just 00:55:17.840 --> 00:55:20.079 changing too slowly, to be fair. Yeah. Well, 00:55:20.239 --> 00:55:22.500 I mean, the science is there and it's really 00:55:22.500 --> 00:55:24.460 just a matter of political will when it comes 00:55:24.460 --> 00:55:27.260 down to it, which is both. promising and depressing. 00:55:27.659 --> 00:55:34.780 Yeah, it's both simultaneously. One of these 00:55:34.780 --> 00:55:37.000 days, actually, as a plug, I don't know if it'll 00:55:37.000 --> 00:55:39.699 be my last episode of the season, but because 00:55:39.699 --> 00:55:41.440 of just the nature of when things need to be 00:55:41.440 --> 00:55:43.320 published, because we're going to I have another 00:55:43.320 --> 00:55:44.900 one that I have to record that I don't know what 00:55:44.900 --> 00:55:47.480 I can get out. It's going to be all about volcanoes 00:55:47.480 --> 00:55:50.579 and climate change and how we know that volcanoes 00:55:50.579 --> 00:55:53.230 do not put out. nearly as much co2 as humans 00:55:53.230 --> 00:55:56.349 i'm going to go through the the nerdy math and 00:55:56.349 --> 00:55:58.170 the melt inclusions and the whole nine yards 00:55:58.170 --> 00:56:01.429 so that that i don't know if it'll help but you 00:56:01.429 --> 00:56:05.210 know what i mean yeah no dispelling any alternative 00:56:05.210 --> 00:56:07.909 then we're doing it to ourselves is definitely 00:56:07.909 --> 00:56:11.530 part of the puzzle okay so we're nearing the 00:56:11.530 --> 00:56:14.130 end and it's time for call outs this is your 00:56:14.130 --> 00:56:18.030 chance to flag cool projects something you're 00:56:18.030 --> 00:56:20.690 working on something completely random it's whatever 00:56:20.690 --> 00:56:23.039 you want Yeah, I mean, really, I just want to 00:56:23.039 --> 00:56:24.860 acknowledge all the people that have contributed 00:56:24.860 --> 00:56:28.340 to this. What we do with sturgeon is a team effort, 00:56:28.380 --> 00:56:31.599 and we have a number of irons in the fire. You 00:56:31.599 --> 00:56:33.719 know, we're looking at spontaneous autopolycoiding 00:56:33.719 --> 00:56:36.780 in wild fish because it seems to be happening 00:56:36.780 --> 00:56:40.280 in the wild as well in really hot weather years. 00:56:40.969 --> 00:56:45.449 We're continuing to look at how things like shad, 00:56:45.730 --> 00:56:47.570 which are the big thing in the Columbia River 00:56:47.570 --> 00:56:50.429 Basin now, huge, huge runs of shad that turn 00:56:50.429 --> 00:56:53.130 out to have a lot of something called thiaminase 00:56:53.130 --> 00:56:57.630 in their tissue. And that thiaminase causes the 00:56:57.630 --> 00:57:00.550 eggs to be thiamin deficient and for these fish 00:57:00.550 --> 00:57:04.900 to die or grow weird. So we have a number of 00:57:04.900 --> 00:57:07.699 projects that we're working on, and all of them 00:57:07.699 --> 00:57:10.619 depend on our collaborations with state agencies 00:57:10.619 --> 00:57:13.880 and universities to work. And in particular, 00:57:13.980 --> 00:57:16.860 I want to acknowledge the leadership of Janella 00:57:16.860 --> 00:57:19.719 Miller, who's now a manager with Pritvik, but 00:57:19.719 --> 00:57:22.219 was formerly with the Yakima Nation Fisheries 00:57:22.219 --> 00:57:24.599 when they developed their conservation aquaculture 00:57:24.599 --> 00:57:28.840 program. And she has been... Just a huge, steadfast 00:57:28.840 --> 00:57:31.159 champion for understanding and rebuilding white 00:57:31.159 --> 00:57:33.460 surgeon populations. I'm really glad to be able 00:57:33.460 --> 00:57:37.440 to work with her. Awesome. You know what that 00:57:37.440 --> 00:57:40.679 means. It's time for the infamous question. The 00:57:40.679 --> 00:57:43.539 one that I warn every single guest is coming. 00:57:43.699 --> 00:57:47.239 I warn it before they even see what kind of topics 00:57:47.239 --> 00:57:49.400 I'm going to ask them or anything else. It is 00:57:49.400 --> 00:57:53.420 the traditional last question. What is your favorite 00:57:53.420 --> 00:57:57.239 science joke? Yeah. I don't know if I would call 00:57:57.239 --> 00:58:02.139 it a joke or a lament, but I have always enjoyed 00:58:02.139 --> 00:58:04.199 the description of the kind of work that I do 00:58:04.199 --> 00:58:06.679 by a guy named John Shepard, who's sort of a 00:58:06.679 --> 00:58:11.059 famous fishery professor. He said that studying 00:58:11.059 --> 00:58:14.340 fish populations is exactly like studying forests, 00:58:14.679 --> 00:58:18.760 except you can't see them and they move, which 00:58:18.760 --> 00:58:21.739 I guess makes white sturgeon like the giant sequoias 00:58:21.739 --> 00:58:24.460 of the freshwater fish world. So I'm glad to 00:58:24.460 --> 00:58:29.219 be working on that. Perfect. Well, thank you 00:58:29.219 --> 00:58:31.780 so much for taking the time to come on and teaching 00:58:31.780 --> 00:58:34.380 me a lot about white surgeon. Yep. I'm always 00:58:34.380 --> 00:58:36.360 happy to talk about surgeon and genetics. My 00:58:36.360 --> 00:58:40.159 favorite things. And that brings the second to 00:58:40.159 --> 00:58:45.659 last episode of season two to an end. Okay. So 00:58:45.659 --> 00:58:49.039 that means that next episode is the last of season 00:58:49.039 --> 00:58:52.159 two and it's going to be a solo episode. All 00:58:52.159 --> 00:58:58.659 about volcanoes and CO2 and climate change. A 00:58:58.659 --> 00:59:01.719 little bit of a historical romp, I guess, through 00:59:01.719 --> 00:59:06.000 how we can prove that volcanoes do not put out 00:59:06.000 --> 00:59:09.079 anywhere near the amount of CO2 that humans do. 00:59:09.360 --> 00:59:14.980 A fitting way to end Season 2. At any rate, just 00:59:14.980 --> 00:59:17.059 remember that over the summer there will be encore 00:59:17.059 --> 00:59:20.300 editions to kind of fill the feed to make sure 00:59:20.300 --> 00:59:23.409 that the... Computer overlords are still happy 00:59:23.409 --> 00:59:25.889 with whimsical wavelengths. And then we'll be 00:59:25.889 --> 00:59:28.150 back in September. There are a few things that 00:59:28.150 --> 00:59:30.090 could get into the mix, and I'll repeat these 00:59:30.090 --> 00:59:32.849 next time, because I'm also expecting a surgery 00:59:32.849 --> 00:59:35.510 somewhere over summer, and I really don't know 00:59:35.510 --> 00:59:38.190 when that'll happen. So hopefully everything 00:59:38.190 --> 00:59:40.889 lines up, and I'll be able to start Season 3 00:59:40.889 --> 00:59:46.489 on time September 14th. All right. I'll see you 00:59:46.489 --> 00:59:53.250 again in two weeks. so chaotic so misbehaved 00:59:53.250 --> 01:00:00.349 echoes of melodies remind us it's always colors 01:00:00.349 --> 01:00:08.090 weave stories painting the sky swaying to rhythms 01:00:08.090 --> 01:00:27.650 as the galaxies fly by deep in our bones through 01:00:27.650 --> 01:00:34.789 this melodic maze our minds explore change