WEBVTT 00:00:32.435 --> 00:00:34.273 Wow! It's so great to be here! 00:00:34.273 --> 00:00:36.722 I'm so happy to see you guys. 00:00:36.722 --> 00:00:40.638 Arguably, one of the most disruptive events in the history of the planet 00:00:40.638 --> 00:00:42.848 has got to be the rise of the animal kingdom. 00:00:42.848 --> 00:00:44.181 Definitely. 00:00:44.181 --> 00:00:47.222 I mean, here is Earth, simmering along, minding its own, single-cell business 00:00:47.222 --> 00:00:50.555 for nearly four billion years, and some group of restless cells 00:00:50.555 --> 00:00:54.191 comes together and decides to become multi-cellular metazoa and well... 00:00:54.191 --> 00:00:57.328 the neighborhood's never been the same since, has it? 00:00:57.328 --> 00:01:00.331 And we have a remarkable diversity of animals 00:01:00.331 --> 00:01:02.635 with whom we share the planet, don't we? 00:01:02.635 --> 00:01:05.972 Millions of species swimming, scurrying, slipping around, 00:01:05.972 --> 00:01:08.773 seemingly endless forms, most beautiful. 00:01:08.773 --> 00:01:10.803 How do you make sense of it all? 00:01:10.803 --> 00:01:15.245 Well, it may just help to know that 99% of all animal life 00:01:15.245 --> 00:01:18.303 fall into just eight major groups. 00:01:18.303 --> 00:01:20.972 Eight body plans. 00:01:20.972 --> 00:01:23.120 Scientists call these "phyla". 00:01:23.120 --> 00:01:27.359 And if you know these eight plans, you've got an incredible grasp 00:01:27.359 --> 00:01:31.376 of the constraints and freedoms of the animal world. 00:01:31.376 --> 00:01:33.832 And there's something special about these eight phyla. 00:01:33.832 --> 00:01:38.209 While species go extinct every day, these phyla have prevailed and persisted 00:01:38.209 --> 00:01:41.505 for over 550 million years. 00:01:41.505 --> 00:01:44.174 Every mass extinction the planet has mustered, 00:01:44.174 --> 00:01:46.156 they've managed to make it through. 00:01:46.156 --> 00:01:48.405 So who are these amazing methuselahs? 00:01:48.405 --> 00:01:51.321 Let's look at plan 1: the sponges. 00:01:51.321 --> 00:01:54.018 These are Earth's first true blue animals. 00:01:54.018 --> 00:01:57.209 They scripted that vital language for single cells to work together 00:01:57.209 --> 00:02:00.929 with other cells for a common cause, in this case, pumping. 00:02:00.929 --> 00:02:03.126 So hail Mother Sponge! 00:02:03.126 --> 00:02:05.457 It sucks, it pumps, it's a mother of us all. 00:02:05.457 --> 00:02:08.875 And you know, some of us have a problem being descendants from apes. Well... 00:02:08.875 --> 00:02:13.293 So, plan number 2: the cnidarians: anemones, jellies and corals. 00:02:13.293 --> 00:02:17.708 These were the first guys to put muscle and nerve together into a body plan, 00:02:17.708 --> 00:02:20.245 and with that, we get animal behavior. 00:02:20.245 --> 00:02:23.626 They're characterized by a round body, radially symmetric, 00:02:23.626 --> 00:02:25.983 and little stinging cells called "cnidae". 00:02:25.983 --> 00:02:27.958 If any of you have been stung by a jellyfish, 00:02:27.958 --> 00:02:29.927 you know what I mean, they pack a punch. 00:02:29.927 --> 00:02:32.856 So these were the first guys to coin animal behavior. 00:02:32.856 --> 00:02:36.931 Okay, our next body plan – look at those little anemones – 00:02:36.931 --> 00:02:39.958 – are the platyhelminthes. Very contemptuous phylum, 00:02:39.958 --> 00:02:42.167 many biologists don't feel it's a true phylum, 00:02:42.167 --> 00:02:44.435 but comprised of many different phyla, 00:02:44.435 --> 00:02:50.177 and so right now the animal tree is being shaken right at its roots. 00:02:50.177 --> 00:02:54.912 But what you need to take home from this representative body plan is that, 00:02:54.912 --> 00:02:58.708 here we see the first representation of a left-right symmetry. 00:02:58.708 --> 00:03:01.876 Bilateral symmetry, which all complex animals have. 00:03:01.876 --> 00:03:05.782 And a concentration of sense organs right at one part of the body. 00:03:05.782 --> 00:03:07.485 The makings of a head, 00:03:07.485 --> 00:03:09.651 and with a head you can have directed animal behavior, 00:03:09.651 --> 00:03:11.519 and hunting. 00:03:11.519 --> 00:03:14.323 This is also where we think animals first started 00:03:14.323 --> 00:03:18.950 to get a threshold level of genetic complexity 00:03:18.950 --> 00:03:21.831 and pole body patterning genes called Hox genes. 00:03:21.831 --> 00:03:24.701 And that, coupled with the right environmental conditions, 00:03:24.701 --> 00:03:27.069 and serendipitous fossilization, 00:03:27.069 --> 00:03:30.866 catalyzed its incredible radiation of animal diversity 00:03:30.866 --> 00:03:33.577 best known from the Cambrian explosion. 00:03:33.577 --> 00:03:37.479 Also in this group is, we think, the appearance of the first penis. 00:03:37.479 --> 00:03:40.363 And as I've raised that subject, 00:03:40.363 --> 00:03:44.283 I have to talk about one modern representative, the turbellarians. 00:03:44.283 --> 00:03:48.658 These guys have not one, but two penises that are hypodermic. 00:03:48.658 --> 00:03:50.492 And they joust with them. 00:03:50.492 --> 00:03:53.332 And the first one to jab its sperm into the other gets to be the boy, 00:03:53.332 --> 00:03:56.066 while the jab-ee gets to be the girl. 00:03:56.066 --> 00:03:59.431 And this remarkable behavior is aptly called penis-fencing. 00:03:59.431 --> 00:04:01.264 Go figure. (Laughter) 00:04:01.264 --> 00:04:03.874 OK, moving on to the fourth: we have the annelids. 00:04:03.874 --> 00:04:09.846 These animals have a body cavity called the coelom. 00:04:09.846 --> 00:04:14.181 And they're known by having these little rings running down their bodies. 00:04:14.181 --> 00:04:16.752 What these guys brought into the animal world 00:04:16.752 --> 00:04:21.656 was the ability to penetrate into the soil, bring oxygen in and release carbon dioxide. 00:04:21.656 --> 00:04:24.013 And releasing carbon dioxide actually helped 00:04:24.013 --> 00:04:26.845 to heat the planet up and make it more livable for other life. 00:04:26.845 --> 00:04:29.513 Now we've got too much CO2, but at the time, 00:04:29.513 --> 00:04:32.304 this was really an important thing that the annelids brought to the planet – 00:04:32.304 --> 00:04:34.598 Bioturbation. Okay. 00:04:34.598 --> 00:04:38.372 Our next plan we've got are the mollusks. Amazing phylum. 00:04:38.372 --> 00:04:41.420 Tiny little shelled animals to giant squid. 00:04:41.420 --> 00:04:44.263 All characterized by a single slimy foot. 00:04:44.263 --> 00:04:47.762 And what the mollusks show us, most of them are shelled. 00:04:47.762 --> 00:04:52.585 And we can see in the mollusk phylum is this arms race escalation, 00:04:52.585 --> 00:04:55.497 with shells becoming more increasingly complex 00:04:55.497 --> 00:05:00.140 in response to more complex predation from other phyla, 00:05:00.140 --> 00:05:03.224 so they kind of exemplify an arms race escalation, 00:05:03.224 --> 00:05:06.214 with some of them actually doing away with the shell completely, 00:05:06.214 --> 00:05:11.223 trading it for smarts and psychedelic skin that we see in the squid and the octopus. 00:05:11.223 --> 00:05:13.992 And these are the guys who can change color 00:05:13.992 --> 00:05:17.001 and texture of their skin in split-seconds, 00:05:17.001 --> 00:05:19.891 the rockstars of the mollusk phylum. Gotta love these guys. (Laughter) 00:05:19.891 --> 00:05:21.975 And they can even be bipedal! 00:05:21.975 --> 00:05:26.029 Okay, our next phylum are the echinoderms, the spiny-skinned guys. 00:05:26.029 --> 00:05:29.965 The sea stars, sea urchins, and sea cucumbers. 00:05:29.965 --> 00:05:33.802 And they're characterized by an internal skeleton of little plates 00:05:33.802 --> 00:05:37.914 that can lock together with very little energy expenditure. 00:05:37.914 --> 00:05:40.916 And underneath are these tube feet that allow them to move 00:05:40.916 --> 00:05:43.278 and shuttle food to their central mouth. 00:05:43.278 --> 00:05:45.166 Now, these are a complex animal, 00:05:45.166 --> 00:05:47.614 but they decided to do away with bilateral symmetry, 00:05:47.614 --> 00:05:49.916 they have a five-part symmetry. 00:05:49.916 --> 00:05:51.832 And they have no brain. 00:05:51.832 --> 00:05:57.584 And they seem like they don't do much, they just sit there on the sea floor. 00:05:57.584 --> 00:06:01.250 But you speed them up in timelapse and you see that they're incredibly industrious. 00:06:01.250 --> 00:06:05.083 And they actually comprise the bulk of the biomass in the deep sea environment. 00:06:05.083 --> 00:06:07.333 Very successful body plan. 00:06:07.333 --> 00:06:10.665 Our next one, the true rulers of the planet, the arthropods. 00:06:10.665 --> 00:06:15.477 Now, if you look at all the animals, the arthropods comprise the bulk. 00:06:15.477 --> 00:06:18.145 Eighty percent are arthropods. 00:06:18.145 --> 00:06:23.951 If you added up the biomass of humans, they are 300 times the biomass of all humans. 00:06:23.951 --> 00:06:26.498 And most of them are insects! 00:06:26.498 --> 00:06:31.083 Did you know that four out of five animals have six legs? 00:06:31.083 --> 00:06:36.530 So, these are the first guys that walked out of the ocean 00:06:36.530 --> 00:06:38.503 and started to explore at land. 00:06:38.503 --> 00:06:40.750 They were the first ones that took to the skies. 00:06:40.750 --> 00:06:45.400 100 millions of years before the birds ever thought of doing such a thing. 00:06:45.400 --> 00:06:47.274 So, what is the secret to their success? 00:06:47.274 --> 00:06:50.217 How are they able to be in every environment imaginable? 00:06:50.217 --> 00:06:53.282 Well, it has something to do with that outside skeleton, 00:06:53.282 --> 00:06:54.916 their exoskeleton. 00:06:54.916 --> 00:06:56.999 And their diversity of appendages down their body, 00:06:56.999 --> 00:06:58.666 like a little Swiss army knife. 00:06:58.666 --> 00:07:01.167 They can have multiple antennae, multiple legs, multiple wings, 00:07:01.167 --> 00:07:05.027 multiple reproductive organs, it's just an amazing attribute 00:07:05.027 --> 00:07:09.636 that allows them to infiltrate every habitable space on the planet. 00:07:09.636 --> 00:07:13.135 And the last phylum, the chordates. 00:07:13.135 --> 00:07:17.104 This is, of course, where we originated over 550 million years ago. 00:07:17.104 --> 00:07:20.308 And it's characterized by having a spinal cord, 00:07:20.308 --> 00:07:23.944 right there you see in pink, that blossoms into a brain in vertebrates, 00:07:23.944 --> 00:07:26.581 and underneath a notochord, 00:07:26.581 --> 00:07:29.665 which turns into a bony spinal column in the vertebrates as well. 00:07:29.665 --> 00:07:32.888 And this is all the guys that make the silver screen all the time. 00:07:32.888 --> 00:07:37.627 The mammals, and the amphibians, and the reptiles, and of course, the fish. 00:07:37.627 --> 00:07:40.501 The bulk of the chordates are the fishes. 00:07:40.501 --> 00:07:43.131 And these are all the guys we know and love. 00:07:43.131 --> 00:07:47.350 And of course, the fish – 00:07:47.350 --> 00:07:50.830 that's one of my favorite fish, the mola mola. 00:07:50.830 --> 00:07:54.108 And it includes our kin, our land-loving hominids. 00:07:54.108 --> 00:07:56.166 These are my little ones. 00:07:56.166 --> 00:07:59.381 So that's the basic eight, 00:07:59.381 --> 00:08:06.054 and, I think, to recap, why don't we do that with a song? 00:08:06.054 --> 00:08:09.725 Alright, you guys ready? Okay. 00:08:09.725 --> 00:08:12.228 And now, a song. 00:08:12.228 --> 00:08:16.031 The sponges started everything, pumping up a storm, 00:08:16.031 --> 00:08:18.534 ...among the ruckus, the rest of us was born. 00:08:18.534 --> 00:08:21.704 Cnidarians muscled up, mixed nerves into the potion, 00:08:21.704 --> 00:08:25.138 and with that quick addition got us brand-new locomotion. 00:08:25.138 --> 00:08:28.545 The flattish worm-like hunters got a head and then some traction, 00:08:28.545 --> 00:08:31.916 and with some senses and a penis –  Oooh! – scored some action. 00:08:31.916 --> 00:08:33.948 The shape of life, yeah. 00:08:33.948 --> 00:08:38.819 And here we have penis fencing in flagrante delicto. 00:08:38.819 --> 00:08:45.269 The shape of life, yeah... 00:08:45.269 --> 00:08:48.602 Now, being male and female, that just works out great, 00:08:48.602 --> 00:08:52.434 anybody in the world can double as your date. 00:08:52.434 --> 00:08:55.603 Then all hell broke loose and the other plans appeared. 00:08:55.603 --> 00:08:58.853 The Cambrian exploded, launched the world into high gear. 00:08:58.853 --> 00:09:02.352 The annelids took to the dirt and bioturbatin'. 00:09:02.352 --> 00:09:05.884 The mollusks took to fighting and arms race escalating. 00:09:05.884 --> 00:09:08.925 Echinos said, "The heck with this, we're better off instead 00:09:08.925 --> 00:09:12.735 taking life into the slow land, lopping off that head." 00:09:12.735 --> 00:09:16.093 Arthros stepped onto the land and ruled, that ain't no mystery, 00:09:16.093 --> 00:09:19.426 till bonehead chordates followed and soon would rewrite history. 00:09:19.426 --> 00:09:22.153 The shape of life, yeah... 00:09:22.153 --> 00:09:24.675 Okay, very good! (Applause) 00:09:30.873 --> 00:09:35.595 So why study these mostly slimy, spineless critters 00:09:35.595 --> 00:09:39.348 with whom we co-pilot spaceship Earth? 00:09:39.348 --> 00:09:41.328 Well, were it not for them, 00:09:41.328 --> 00:09:44.554 none of us would be strutting and fretting our ten minutes upon this stage. 00:09:44.554 --> 00:09:47.690 It's the animal life and all the life that came before us 00:09:47.690 --> 00:09:51.227 and with whom we share this planet that not only set the stage, 00:09:51.227 --> 00:09:55.132 but created the very stage for all life to flourish in the future. 00:09:55.132 --> 00:09:58.348 And I can't put it any more eloquently than E. O. Wilson, who says: 00:09:58.348 --> 00:10:03.674 "Humanity is exalted, not because we are so far above every thing living, 00:10:03.674 --> 00:10:07.941 but because knowing them well elevates the very concept of life." 00:10:07.941 --> 00:10:09.692 Thank you. 00:10:09.692 --> 00:10:13.692 (Applause)