WEBVTT 00:00:01.024 --> 00:00:02.754 Paleontology. 00:00:02.778 --> 00:00:05.619 A science geared towards small children. 00:00:05.643 --> 00:00:08.532 Focused on digging up dinosaurs 00:00:08.556 --> 00:00:10.635 while sporting a "Jurassic Park" costume. 00:00:11.188 --> 00:00:13.236 Skulls are popped out of the ground 00:00:13.260 --> 00:00:15.736 and put on display for public gawking. 00:00:16.204 --> 00:00:20.951 The relevance of this beyond clickbait, coloring books and monster movies 00:00:20.975 --> 00:00:22.125 is unknown. 00:00:22.792 --> 00:00:25.033 No, wait. 00:00:26.801 --> 00:00:29.221 That's not paleontology at all. 00:00:29.815 --> 00:00:33.965 Paleontology is nothing less than the study of past life. 00:00:33.989 --> 00:00:35.545 All past life. 00:00:35.569 --> 00:00:38.264 From ancestors to alien forms. 00:00:38.693 --> 00:00:42.336 It involves fundamental questions like, who are we, 00:00:42.360 --> 00:00:44.042 and how did we get here, 00:00:44.066 --> 00:00:46.736 using the broadest possible definition of "we." 00:00:47.058 --> 00:00:48.796 Life itself. 00:00:49.714 --> 00:00:52.769 Dinosaurs, a category of birds, 00:00:52.793 --> 00:00:54.960 are just a small percentage of that. 00:00:54.984 --> 00:00:56.182 (Laughter) 00:00:56.206 --> 00:00:59.174 Yet, they get the most media attention. 00:00:59.198 --> 00:01:01.568 (Laughter) 00:01:01.592 --> 00:01:03.425 It's a very accurate meme, 00:01:03.449 --> 00:01:05.251 I didn't even make this one. 00:01:05.275 --> 00:01:06.886 This is just the truth. 00:01:06.910 --> 00:01:09.966 Anyway, most of us paleontologists 00:01:09.990 --> 00:01:12.590 consider dinosaurs to be a gateway drug. 00:01:12.919 --> 00:01:15.855 There is so much cooler stuff in the fossil record, 00:01:15.879 --> 00:01:18.227 and we know so much about it. 00:01:18.251 --> 00:01:21.244 Let's go on a brief, dinosaur-free tour 00:01:21.268 --> 00:01:23.482 of the last four billion years. 00:01:23.506 --> 00:01:24.783 (Laughter) 00:01:24.807 --> 00:01:26.720 First up, genetic material. 00:01:26.744 --> 00:01:29.886 Viruses, basically, started producing proteins 00:01:29.910 --> 00:01:32.102 and wrecking their environment. 00:01:32.514 --> 00:01:35.243 The earth was infected with life. 00:01:35.826 --> 00:01:39.723 Some of these new bacteria learned how to eat sunshine, 00:01:39.747 --> 00:01:41.255 producing oxygen, 00:01:41.279 --> 00:01:43.247 pulling carbon from the air, 00:01:43.271 --> 00:01:47.075 and destroying the iron food of other microbes, 00:01:47.099 --> 00:01:48.764 by turning it into rust. 00:01:48.788 --> 00:01:51.557 This went on for billions of years. 00:01:51.581 --> 00:01:54.724 Some bacteria consumed other bacteria, 00:01:54.748 --> 00:01:58.423 gaining their power to turn oxygen into energy, 00:01:58.447 --> 00:02:01.685 becoming the precursors of animals and plants. 00:02:01.709 --> 00:02:04.494 But as a result, there were climate shocks 00:02:04.518 --> 00:02:07.005 from hot to cold and back again, 00:02:07.029 --> 00:02:11.091 which ended up turning the earth into a snowball covered with glaciers. 00:02:11.538 --> 00:02:14.834 The technical term for this time period is snowball earth. 00:02:15.434 --> 00:02:18.283 (Laughter) 00:02:18.307 --> 00:02:20.728 Seven hundred, eight hundred million years ago. 00:02:20.752 --> 00:02:23.337 Anyway, microbes banded together, 00:02:23.361 --> 00:02:25.672 creating multicelular life. 00:02:25.696 --> 00:02:27.617 Six hundred million years ago, 00:02:27.641 --> 00:02:29.410 geometric colonies appeared, 00:02:29.434 --> 00:02:31.720 sucking microbes from he water. 00:02:31.744 --> 00:02:33.339 There were soon replaced 00:02:33.363 --> 00:02:35.736 by the ancestors of modern animals. 00:02:36.077 --> 00:02:38.442 The Cambrian explosion. 00:02:38.466 --> 00:02:41.633 Lobster relatives ate other animals, 00:02:41.657 --> 00:02:44.390 capturing them using their grasping arms. 00:02:44.749 --> 00:02:49.455 Armored wriggling clam worms crawled across the sea floor and into it, 00:02:49.479 --> 00:02:51.518 creating new ecosystems. 00:02:52.097 --> 00:02:54.093 Our tadpole-like ancestors 00:02:54.117 --> 00:02:56.403 [unclear] along ancient coastlines, 00:02:56.427 --> 00:02:59.998 while their eel-like relatives with gnashing throat teeth 00:03:00.022 --> 00:03:04.401 swam above the ice cream cone corals of the first reefs, 00:03:04.425 --> 00:03:06.457 dodging school bus-sized krakens 00:03:06.481 --> 00:03:08.750 and hungry sea scorpions. 00:03:09.139 --> 00:03:11.353 Plant fungus came onto land. 00:03:11.703 --> 00:03:15.189 But then the glaciers returned killing pretty much everything. 00:03:15.641 --> 00:03:18.380 But mass extinctions open opportunities. 00:03:18.404 --> 00:03:20.800 Jawless fishes invaded the ocean, 00:03:20.824 --> 00:03:24.522 sporting points, prongs, and finally, fins. 00:03:24.546 --> 00:03:29.172 Spiders, scorpions, snails and worms came onto land. 00:03:29.649 --> 00:03:31.101 Somewhere around China, 00:03:31.125 --> 00:03:33.117 a fish developed jaws. 00:03:33.141 --> 00:03:35.768 And its descendants drove jawless fishes, 00:03:35.792 --> 00:03:37.895 sea scorpions and branching plankton 00:03:37.919 --> 00:03:39.537 to extinction. 00:03:39.561 --> 00:03:40.752 Some of these fishes, 00:03:40.776 --> 00:03:42.672 which had arm bones in their fins, 00:03:42.696 --> 00:03:44.141 sprouted fingers, 00:03:44.165 --> 00:03:46.434 seven or eight per flipper. 00:03:47.007 --> 00:03:49.252 On land, plants became trees, 00:03:49.276 --> 00:03:50.656 growing massive 00:03:50.680 --> 00:03:54.014 or spreading their spores only once before dying. 00:03:54.617 --> 00:03:56.958 But then the glaciers came back again 00:03:56.982 --> 00:03:59.347 and it was mass extinction number two. 00:03:59.371 --> 00:04:01.283 It was the age of weird fishes 00:04:01.307 --> 00:04:02.998 and plated sea lilies. 00:04:03.022 --> 00:04:04.680 Sharks with wings. 00:04:04.704 --> 00:04:06.609 Sharks with buzz saw jaws. 00:04:06.633 --> 00:04:09.299 Sharks with fins covered in tiny teeth. 00:04:09.323 --> 00:04:11.489 Sharks with crushing tooth plates. 00:04:11.513 --> 00:04:14.871 Bony fishes that looked like [unclear] and angel fish and eels 00:04:14.895 --> 00:04:16.274 for the first time. 00:04:16.649 --> 00:04:18.014 Wetlands developed, 00:04:18.038 --> 00:04:21.887 sporting ten-foot long millipedes and giant dragon flies. 00:04:21.911 --> 00:04:25.474 These spread across the supercontinent of Pangaea and died, 00:04:25.498 --> 00:04:27.006 creating coal, 00:04:27.030 --> 00:04:30.259 leading to 100-million-year ice age. 00:04:30.716 --> 00:04:35.002 Finally, vertebrates made it onto land on a permanent basis, 00:04:35.026 --> 00:04:37.359 leading to alligator-like amphibians, 00:04:37.383 --> 00:04:40.343 and saber-toothed protomammals. 00:04:40.367 --> 00:04:44.047 But then, volcanoes erupted all over Siberia, 00:04:44.071 --> 00:04:45.251 everything almost died, 00:04:45.275 --> 00:04:47.531 and it was mass extinction number three. 00:04:49.111 --> 00:04:50.778 The day life nearly died. 00:04:51.307 --> 00:04:55.970 A single, lonely tusked mammal survived and thrived. 00:04:56.434 --> 00:04:59.591 But it was soon replaced by galloping crocodiles. 00:04:59.615 --> 00:05:02.353 In the ocean, marine reptiles, 00:05:02.377 --> 00:05:06.551 giant [unclear] made of the living relatives of sea urchins. 00:05:06.853 --> 00:05:09.728 And armored squids, ammonoids 00:05:09.752 --> 00:05:11.759 of every kind and form. 00:05:12.347 --> 00:05:14.760 But then, Pangaea started to split apart, 00:05:14.784 --> 00:05:16.481 forming a sea of lava 00:05:16.505 --> 00:05:19.260 that would one day become the Atlantic ocean, 00:05:19.284 --> 00:05:21.696 spewing toxic gas into the atmosphere 00:05:21.720 --> 00:05:23.853 and mass extinction number four. 00:05:24.195 --> 00:05:25.426 (Laughter) 00:05:25.450 --> 00:05:27.798 Yeah, there's actually a lot more than these five, 00:05:27.822 --> 00:05:29.029 these are the big ones. 00:05:29.053 --> 00:05:31.186 (Laughter) 00:05:32.662 --> 00:05:36.790 So, finally, there were whale-sized fishes, 00:05:36.814 --> 00:05:38.877 and modern fishes mobbed corals, 00:05:38.901 --> 00:05:40.266 made gigantic, 00:05:40.290 --> 00:05:43.935 by using their captured algae to eat sunshine. 00:05:44.269 --> 00:05:48.697 Crabs, stingrays and other fishes with crushing teeth appeared, 00:05:48.721 --> 00:05:49.936 smashing shells 00:05:49.960 --> 00:05:53.466 and leading to an arms race between predators and prey. 00:05:53.490 --> 00:05:56.623 There was an explosion of marine biodiversity. 00:05:57.244 --> 00:05:59.434 Mammals climbed trees, flew, 00:05:59.458 --> 00:06:01.045 and did a lot of other things 00:06:01.069 --> 00:06:03.693 that are seemingly sort of modern. 00:06:04.238 --> 00:06:06.199 They were feeding on the first flowers 00:06:06.223 --> 00:06:08.389 pollinated by the first bees. 00:06:08.413 --> 00:06:12.214 There were ecological revolutions on land and at sea, 00:06:12.238 --> 00:06:14.105 leading to the modern world. 00:06:14.434 --> 00:06:17.490 Except that an asteroid hit Mexico, 00:06:17.514 --> 00:06:21.704 and then that triggered volcanoes on the other side of the world in India, 00:06:21.728 --> 00:06:24.100 and everything almost died again. 00:06:24.124 --> 00:06:25.586 (Laughter) 00:06:25.610 --> 00:06:27.935 But -- there's always a but, 00:06:27.959 --> 00:06:29.260 because we're still here. 00:06:30.038 --> 00:06:32.419 Mammals arose from the ashes, 00:06:32.443 --> 00:06:34.380 became small under extreme heat 00:06:34.404 --> 00:06:36.212 and then ever larger. 00:06:36.236 --> 00:06:38.966 There were palm trees and snakes in the Arctic. 00:06:38.990 --> 00:06:42.569 Predatory deer dogs frolicked along ancient rivers, 00:06:42.593 --> 00:06:45.048 while their relatives returned to the ocean 00:06:45.072 --> 00:06:48.246 to become the first otter-like whales. 00:06:48.270 --> 00:06:51.730 Not hyenas and other sort of carnivores 00:06:51.754 --> 00:06:54.839 were chased off by giant long-necked rhinos. 00:06:54.863 --> 00:06:57.672 Everything at this point seems kind of familiar, 00:06:57.696 --> 00:06:58.846 but not really. 00:06:59.268 --> 00:07:02.545 In Antarctica, an ice age started, 00:07:02.569 --> 00:07:04.768 forming the first permanent polar ice cap 00:07:04.792 --> 00:07:06.799 in two hundred million years. 00:07:07.268 --> 00:07:09.553 This dried out the rest of the world. 00:07:09.577 --> 00:07:11.807 But it allowed the rise of grasses, 00:07:11.831 --> 00:07:13.632 of rodents, of cats. 00:07:13.998 --> 00:07:15.506 Somewhere in Africa, 00:07:15.530 --> 00:07:18.091 an ape started walking across the new savannah. 00:07:19.002 --> 00:07:21.661 Oh, and there were giant saber-toothed salmon, 00:07:21.685 --> 00:07:23.153 I just have to mention that. 00:07:23.177 --> 00:07:25.070 (Laughter) 00:07:26.225 --> 00:07:29.307 So we know all of this happened. 00:07:29.331 --> 00:07:30.736 And so much more. 00:07:30.760 --> 00:07:31.911 How? 00:07:31.935 --> 00:07:33.141 Why? 00:07:33.165 --> 00:07:35.816 Paleontology is a thriving science 00:07:35.840 --> 00:07:40.374 at the intersection of multiple other fields and technologies. 00:07:40.398 --> 00:07:43.128 There is no bigger data than the fossil record, 00:07:43.152 --> 00:07:45.112 and we mine every bit of it. 00:07:45.136 --> 00:07:46.429 We use CAT scans, 00:07:46.453 --> 00:07:47.802 we use isotopes, 00:07:47.826 --> 00:07:49.350 we use genomes, 00:07:49.374 --> 00:07:50.696 we use robots, 00:07:50.720 --> 00:07:52.783 we use mathematical simulations, 00:07:52.807 --> 00:07:55.149 and all kinds of analytics. 00:07:55.173 --> 00:07:56.704 We maximize all of it 00:07:56.728 --> 00:07:58.970 so that we can understand the past 00:07:58.994 --> 00:08:00.594 and how evolution works. 00:08:01.049 --> 00:08:04.049 It also lets us make predictions for the future. 00:08:04.073 --> 00:08:06.827 What will happen after the next mass extinction? 00:08:06.851 --> 00:08:08.918 What weird things will show up? 00:08:09.307 --> 00:08:11.374 Will mammals get smaller again? 00:08:11.712 --> 00:08:13.767 Will there even be mammals? 00:08:14.831 --> 00:08:16.355 In sum, 00:08:16.379 --> 00:08:19.831 we have learned a lot about dinosaurs. 00:08:20.236 --> 00:08:21.838 But there's so much left to learn 00:08:21.862 --> 00:08:26.013 from the other 99.9 percent of things that have ever lived. 00:08:26.434 --> 00:08:28.545 And that's paleontology. 00:08:28.990 --> 00:08:30.188 Thank you. 00:08:30.212 --> 00:08:35.219 (Applause and cheers)