WEBVTT 00:00:00.000 --> 00:00:03.000 Welcome back to another deep dive and a very 00:00:03.000 --> 00:00:05.500 warm welcome to you, the learner. We are so glad 00:00:05.500 --> 00:00:07.019 you're joining us today. Yeah, thanks for tuning 00:00:07.019 --> 00:00:08.980 in. I'm really excited about this one. Because 00:00:08.980 --> 00:00:12.179 today our mission is to take a single seemingly 00:00:12.179 --> 00:00:15.980 basic Wikipedia article about a flower, specifically 00:00:15.980 --> 00:00:19.539 the Iris virginica, and prove to you how a single 00:00:19.539 --> 00:00:22.199 source can connect the mud of a North American 00:00:22.199 --> 00:00:26.379 swamp to, well, the literal foundations of modern 00:00:26.379 --> 00:00:28.359 mathematics. It sounds like a stretch, I know. 00:00:28.699 --> 00:00:33.420 But the trajectory from a wet ditch to complex 00:00:33.420 --> 00:00:35.679 statistical models is just, it's incredible. 00:00:35.780 --> 00:00:37.560 Okay, let's unpack this. Because the premise 00:00:37.560 --> 00:00:40.380 here is that you might walk past this plant in 00:00:40.380 --> 00:00:42.240 a wet ditch somewhere without a second glance, 00:00:42.399 --> 00:00:44.380 right? Oh, absolutely. But if you do that, you'd 00:00:44.380 --> 00:00:46.820 be ignoring a medicinal marvel and a true scientific 00:00:46.820 --> 00:00:50.030 legend. Yeah, it's known by a few names. the 00:00:50.030 --> 00:00:52.789 Virginia blue flag, Virginia iris, great blue 00:00:52.789 --> 00:00:55.289 flag or southern blue flag. Right. Which usually 00:00:55.289 --> 00:00:57.210 means people have a long history with it. But 00:00:57.210 --> 00:00:59.149 before we can really understand its legacy, we 00:00:59.149 --> 00:01:00.850 have to look at the plant itself. Right. Like 00:01:00.850 --> 00:01:03.350 how it survives and what it actually looks like 00:01:03.350 --> 00:01:05.209 out in the wild. Yeah. The physical structure 00:01:05.209 --> 00:01:08.909 is key. It's a perennial and it grows about two 00:01:08.909 --> 00:01:11.370 to three feet tall. So that's roughly zero point 00:01:11.370 --> 00:01:14.390 six to zero point nine meters. OK. Pretty tall 00:01:14.390 --> 00:01:17.290 for a swamp flower. Yeah. And it has these distinct 00:01:17.290 --> 00:01:21.049 bluish green glabrous basil leaves. They're sword 00:01:21.049 --> 00:01:23.230 shaped, and they can get up to three feet long 00:01:23.230 --> 00:01:25.650 and about an inch across at the base. Wait, what 00:01:25.650 --> 00:01:28.890 does glabrous mean? Oh, uh, glabrous just means 00:01:28.890 --> 00:01:31.769 smooth. No hairs or bristles. Just a completely 00:01:31.769 --> 00:01:34.689 smooth surface. Got it. You know, when I was 00:01:34.689 --> 00:01:36.689 reading the source, I kept picturing the anatomy 00:01:36.689 --> 00:01:40.030 of this flower as like a miniature royal pavilion 00:01:40.030 --> 00:01:42.010 standing right in the middle of a swamp. Ooh, 00:01:42.010 --> 00:01:43.969 I like that analogy. Yeah, because you have these 00:01:43.969 --> 00:01:46.870 smooth sword -shaped leaves, right? And they 00:01:46.870 --> 00:01:49.250 act like the guards around the base. Right, standing 00:01:49.250 --> 00:01:52.030 at attention. Exactly. And then rising up from 00:01:52.030 --> 00:01:56.200 those guards are these unbranched... or sparingly 00:01:56.200 --> 00:01:59.400 branched stalks, and they feature one or two 00:01:59.400 --> 00:02:01.920 flowers emerging from the axil on these one to 00:02:01.920 --> 00:02:03.959 five inch pedestals. Which is basically the little 00:02:03.959 --> 00:02:05.859 stem attaching the flower to the main stalk. 00:02:06.280 --> 00:02:09.419 Right, right. And then from May to July, the 00:02:09.419 --> 00:02:12.020 pavilion, you know, it opens, you get these blue 00:02:12.020 --> 00:02:14.139 to blue violet flowers that are about one to 00:02:14.139 --> 00:02:17.000 five inches across. It's a really striking visual, 00:02:17.780 --> 00:02:20.870 especially the petals and sepals. Yes. The anatomy 00:02:20.870 --> 00:02:23.569 is so specific, you have three upright pedals 00:02:23.569 --> 00:02:26.909 which botanists literally call standards, so... 00:02:26.830 --> 00:02:29.229 Continuing my pavilion analogy, those are the 00:02:29.229 --> 00:02:31.770 kingdom's flags flying high. It fits perfectly. 00:02:31.969 --> 00:02:34.270 And then below those you have three drooping 00:02:34.270 --> 00:02:36.590 sepals, which are called falls. And they have 00:02:36.590 --> 00:02:40.129 these distinct white marks and a bit of yellow 00:02:40.129 --> 00:02:42.430 near the throat. They look exactly like grand 00:02:42.430 --> 00:02:45.229 rolled out carpets. What's fascinating here is 00:02:45.229 --> 00:02:48.250 how that highly specific architecture allows 00:02:48.250 --> 00:02:50.669 the plant to adapt geographically. I mean, it 00:02:50.669 --> 00:02:53.189 is incredibly resilient. Yeah, the range is massive. 00:02:53.270 --> 00:02:55.310 It really is. It's found in wet areas across 00:02:55.310 --> 00:02:57.409 the U .S. stretching from Nebraska all the way 00:02:57.409 --> 00:03:00.289 over to New York and from Florida and Texas right 00:03:00.289 --> 00:03:02.949 up to the Canadian border it even grows in Ontario 00:03:02.949 --> 00:03:05.710 and Quebec That's such a crazy temperature difference 00:03:05.710 --> 00:03:08.469 from a swamp in Florida to a freezing marsh in 00:03:08.469 --> 00:03:12.750 Quebec exactly But the unifying factor isn't 00:03:12.750 --> 00:03:16.349 temperature. It's water It thrives in marshes, 00:03:16.550 --> 00:03:19.870 wet meadows, swamps, sloughs, sinkhole ponds, 00:03:20.090 --> 00:03:22.110 and ditches. Sinkhole ponds. Just the phrase 00:03:22.110 --> 00:03:24.469 sinkhole pond sounds like a harsh place to live. 00:03:24.550 --> 00:03:28.229 Oh, it is. But despite that, its conservation 00:03:28.229 --> 00:03:32.289 status is listed as least concerned or secure. 00:03:32.629 --> 00:03:35.069 It is completely dialed into its environment. 00:03:35.210 --> 00:03:37.270 Which naturally leads us to the people who lived 00:03:37.270 --> 00:03:39.729 in those environments. Because the Iris virginica 00:03:39.729 --> 00:03:41.909 grows in these intense waterlogged areas across 00:03:41.909 --> 00:03:44.830 the continent, it inevitably crossed paths with 00:03:44.830 --> 00:03:46.870 the indigenous peoples living there. Right. People 00:03:46.870 --> 00:03:48.770 who were paying very close attention to their 00:03:48.770 --> 00:03:50.810 ecosystem. Exactly. They discovered its hidden 00:03:50.810 --> 00:03:52.789 internal properties. It wasn't just a pretty 00:03:52.789 --> 00:03:55.250 pavilion. It was a swamp pharmacy. Yeah. The 00:03:55.250 --> 00:03:57.189 source outlined some very specific traditional 00:03:57.189 --> 00:03:59.530 medicine applications, mainly using the root. 00:03:59.750 --> 00:04:01.409 And they weren't just using it for one thing. 00:04:01.610 --> 00:04:03.889 The Cherokee traditional medicine used the root 00:04:03.889 --> 00:04:06.530 in several ways. For instance, they pounded it 00:04:06.530 --> 00:04:08.990 into a paste to use as a skin cell. Which makes 00:04:08.990 --> 00:04:11.330 sense for topical issues. Right. But then they 00:04:11.330 --> 00:04:14.590 also made an infusion from it to treat liver 00:04:14.590 --> 00:04:19.329 ailments and a decoction to treat what the source 00:04:19.329 --> 00:04:22.930 calls yellowish urine. And, you know, we should 00:04:22.930 --> 00:04:24.850 clarify the difference there. An infusion is 00:04:24.850 --> 00:04:27.730 like steeping tea, drawing out the delicate compounds. 00:04:27.990 --> 00:04:31.670 But a decoction. is boiling the tough root material 00:04:31.670 --> 00:04:34.329 to extract completely different active chemicals. 00:04:34.550 --> 00:04:36.670 It shows such a deep understanding of the plant. 00:04:37.230 --> 00:04:39.110 But here's where it gets really interesting. 00:04:39.189 --> 00:04:40.629 And I actually want to push back on this a little 00:04:40.629 --> 00:04:43.689 bit. Oh, OK. Let's hear it. So the source mentions 00:04:43.689 --> 00:04:46.110 seminal traditional medicine. And it says it 00:04:46.110 --> 00:04:48.810 may be used to treat. Shock -following alligator 00:04:48.810 --> 00:04:51.810 bite. Yes. I mean, come on. It's hard to imagine 00:04:51.810 --> 00:04:54.269 that a delicate -looking blue flower has the 00:04:54.269 --> 00:04:56.589 chemical punch to deal with something as traumatic 00:04:56.589 --> 00:05:00.329 as an alligator attack. Are we are we underestimating 00:05:00.329 --> 00:05:02.350 smart plants here, or is this more of a folk 00:05:02.350 --> 00:05:05.470 remedy? I get why you'd think that, but we are 00:05:05.470 --> 00:05:07.750 absolutely underestimating swamp plants. Really? 00:05:07.970 --> 00:05:10.769 Yeah. Think about the environment. A sinkhole 00:05:10.769 --> 00:05:13.269 pond is basically a soup of aggressive microbes 00:05:13.269 --> 00:05:17.850 and bacteria. For a fleshy root to survive, submerged 00:05:17.850 --> 00:05:20.790 in that mud without rotting, it has to produce 00:05:20.790 --> 00:05:24.209 incredibly potent chemical defenses. Oh, so it's 00:05:24.209 --> 00:05:26.129 like a chemical weapons factory just to stay 00:05:26.129 --> 00:05:29.269 alive. Precisely. Indigenous medical practitioners 00:05:29.269 --> 00:05:32.009 had an incredibly nuanced understanding of botany. 00:05:32.370 --> 00:05:34.629 They knew that a root capable of fighting off 00:05:34.629 --> 00:05:37.250 swamp rot contained highly active compounds. 00:05:37.410 --> 00:05:39.509 OK, that makes sense. Right. And when someone 00:05:39.509 --> 00:05:41.990 is bitten by an alligator, it's not just a wound. 00:05:42.410 --> 00:05:45.100 The body goes into systemic shock. blood pressure 00:05:45.100 --> 00:05:47.920 drops, the nervous system panics. Physiological 00:05:47.920 --> 00:05:50.939 trauma. Exactly. They were turning this common 00:05:50.939 --> 00:05:53.720 swamp root into targeted decoctions and salves 00:05:53.720 --> 00:05:56.220 to handle both the external trauma and the massive 00:05:56.220 --> 00:05:58.800 internal shock to the nervous system. Wow. So 00:05:58.800 --> 00:06:01.199 they were isolating active compounds to stabilize 00:06:01.199 --> 00:06:04.100 a patient. That is real pharmacology. It really 00:06:04.100 --> 00:06:07.100 is. And that careful observation of the plant's 00:06:07.100 --> 00:06:09.600 traits didn't stop with traditional medicine. 00:06:09.959 --> 00:06:11.800 Right. Because we have to transition into the 00:06:11.800 --> 00:06:15.129 20th century now. Observing the exact physical 00:06:15.129 --> 00:06:17.610 traits of the Iris virginica led to a breakthrough 00:06:17.610 --> 00:06:19.910 in a completely different field. And this is 00:06:19.910 --> 00:06:22.329 the jump that always blows my mind. We go from 00:06:22.329 --> 00:06:25.269 indigenous medicine to mathematics and data analysis. 00:06:25.550 --> 00:06:27.550 It's wild. So the source notes that the plant 00:06:27.550 --> 00:06:30.449 was identified as a separate species by a botanist 00:06:30.449 --> 00:06:33.230 named Edgar Anderson. Yes, Anderson is a key 00:06:33.230 --> 00:06:35.550 player here. And he didn't just casually identify 00:06:35.550 --> 00:06:39.220 it. He meticulously measured it. The Iris virginica 00:06:39.220 --> 00:06:42.120 is one of three Iris species in what became known 00:06:42.120 --> 00:06:45.620 as Anderson's famous Iris flower data set. He 00:06:45.620 --> 00:06:48.660 collected 50 samples of each species, measuring 00:06:48.660 --> 00:06:51.420 the exact length and width of those sepals and 00:06:51.420 --> 00:06:53.319 petals we talked about earlier. It falls in the 00:06:53.319 --> 00:06:55.939 standards. Exactly. He created this incredibly 00:06:55.939 --> 00:06:58.600 precise numerical record of the flower's architecture. 00:06:58.879 --> 00:07:00.660 Okay, but then the source introduces someone 00:07:00.660 --> 00:07:03.889 who isn't a botanist at all, Ronald Fisher. Right. 00:07:04.129 --> 00:07:07.269 In 1936, Fisher published a landmark paper called, 00:07:07.649 --> 00:07:10.050 The Use of Multiple Measurements in Taxonomic 00:07:10.050 --> 00:07:13.350 Problems. And he used Anderson's data set as 00:07:13.350 --> 00:07:15.910 an example of something called linear discriminant 00:07:15.910 --> 00:07:19.170 analysis. Yes, which sounds intimidating, but 00:07:19.170 --> 00:07:21.810 it's a foundational statistical concept. So what 00:07:21.810 --> 00:07:24.029 does this all mean for the listener? I mean, 00:07:24.170 --> 00:07:27.569 why is a statistician in 1936 measuring the falls 00:07:27.569 --> 00:07:29.829 and standards of a swamp flower to do math? What's 00:07:29.829 --> 00:07:32.290 the point? If we connect this to the bigger picture, 00:07:32.589 --> 00:07:35.290 Fisher was trying to solve a massive problem 00:07:35.290 --> 00:07:38.550 in science. How do you mathematically categorize 00:07:38.550 --> 00:07:41.889 things when the data overlaps? Like if two plant 00:07:41.889 --> 00:07:44.889 species look really similar. Exactly. A large 00:07:44.889 --> 00:07:47.329 iris virginico might look like a small version 00:07:47.329 --> 00:07:49.949 of another species. If you only look at one measurement, 00:07:50.110 --> 00:07:52.550 like petal length, you can't draw a clear line 00:07:52.550 --> 00:07:55.069 between them. Because there's a gray area. Right. 00:07:55.629 --> 00:07:58.029 Fisher needed a reliable, standardized set of 00:07:58.029 --> 00:08:00.269 multiple physical measurements to prove a new 00:08:00.269 --> 00:08:02.730 mathematical model. He wanted to use multiple 00:08:02.730 --> 00:08:05.269 data points at the same time to mathematically 00:08:05.269 --> 00:08:08.089 draw a definitive boundary between species. Oh, 00:08:08.089 --> 00:08:11.189 I see. So Anderson's precise botanical measurements 00:08:11.189 --> 00:08:13.709 of the Iris virginica provided the perfect raw 00:08:13.709 --> 00:08:16.470 data for this. It was the exact data he needed. 00:08:17.149 --> 00:08:19.850 Fisher took those four measurements, sepal length, 00:08:20.189 --> 00:08:22.370 sepal width, petal length, and petal width, and 00:08:22.370 --> 00:08:24.829 showed how to use them simultaneously to perform 00:08:24.829 --> 00:08:27.790 linear discriminant analysis. That is just... 00:08:28.319 --> 00:08:30.439 It's staggering when you really step back and 00:08:30.439 --> 00:08:32.399 look at it. It really is. I mean, to wrap up 00:08:32.399 --> 00:08:35.240 this journey for you, the listener, we started 00:08:35.240 --> 00:08:37.399 out looking at a wet ditch, right? Yeah. With 00:08:37.399 --> 00:08:40.360 this bluish -green plant and its smooth sword 00:08:40.360 --> 00:08:43.279 -like leaves. The miniature royal pavilion. Yes. 00:08:43.600 --> 00:08:46.820 And then we traced it to a Cherokee skin salve 00:08:46.820 --> 00:08:50.700 and a seminal alligator bite remedy. Just incredible 00:08:50.700 --> 00:08:53.779 botanical mastery. And from there... to Edgar 00:08:53.779 --> 00:08:56.240 Anderson taking out a ruler to record its botanical 00:08:56.240 --> 00:08:58.259 measurements. Which handed Ronald Fisher the 00:08:58.259 --> 00:09:01.419 exact numbers he needed for his 1936 statistical 00:09:01.419 --> 00:09:03.600 milestone. It's just, it proves that knowledge 00:09:03.600 --> 00:09:06.659 is utterly interconnected. A swamp weed is tied 00:09:06.659 --> 00:09:09.259 to the math that helps categorize our world today. 00:09:09.580 --> 00:09:11.320 Absolutely. And you know, I want to leave the 00:09:11.320 --> 00:09:12.960 listener with a final thought to mull over. Oh, 00:09:13.000 --> 00:09:15.549 please do. Ronald Fisher. Use the measurements 00:09:15.549 --> 00:09:18.889 of this specific flower to solve taxonomic problems. 00:09:19.570 --> 00:09:22.370 Literally figuring out how to categorize the 00:09:22.370 --> 00:09:25.330 chaotic natural world using multiple data points. 00:09:25.490 --> 00:09:28.450 Right. So I would ask you, the listener, to just 00:09:28.450 --> 00:09:30.570 look at the plants outside your window today. 00:09:30.690 --> 00:09:34.169 Look at the weeds in a wet ditch or the flowers 00:09:34.169 --> 00:09:37.350 in a marsh. Yeah. What other hidden mathematical 00:09:37.350 --> 00:09:39.990 codes or undiscovered scientific breakthroughs 00:09:39.990 --> 00:09:42.600 are just sitting there in the soil? waiting for 00:09:42.600 --> 00:09:44.200 someone to take out a ruler and start measuring. 00:09:44.419 --> 00:09:46.980 That is such a great thought to end on, because 00:09:46.980 --> 00:09:48.940 it's all out there just waiting for us to notice 00:09:48.940 --> 00:09:50.620 it. Well, thank you so much for joining us on 00:09:50.620 --> 00:09:52.320 this deep dive. Thanks for having me. We'll see 00:09:52.320 --> 00:09:52.720 you next time.