1 00:00:07,200 --> 00:00:11,400 Insects are the most diverse group of organisms on Earth. 2 00:00:13,440 --> 00:00:18,000 The true number of species is unknown, but some estimates 3 00:00:18,000 --> 00:00:21,200 suggest that only a fraction have been identified. 4 00:00:26,520 --> 00:00:31,000 They have successfully adapted to every ecosystem on our planet. 5 00:00:40,240 --> 00:00:43,520 But insects still harbour many mysteries. 6 00:00:44,840 --> 00:00:47,240 Where do they come from? 7 00:00:47,240 --> 00:00:49,680 When did they first appear on Earth? 8 00:00:50,680 --> 00:00:55,480 How and why have they diversified and multiplied so successfully? 9 00:00:58,240 --> 00:01:03,200 At a time when certain insect species are in danger of extinction 10 00:01:03,200 --> 00:01:07,160 and there is greater interest in their role within ecosystems, 11 00:01:07,160 --> 00:01:11,000 this is the fascinating story of their origins. 12 00:01:26,240 --> 00:01:29,520 This insect adventure begins in French Guiana 13 00:01:29,520 --> 00:01:32,520 in the heart of the Amazonian rainforest. 14 00:01:43,240 --> 00:01:47,520 It's a fabulous destination for scientists like Romain Garrouste, 15 00:01:47,520 --> 00:01:52,040 a paleo-entomologist at France's National Museum of Natural History. 16 00:02:05,240 --> 00:02:08,840 The climate in French Guiana provides ideal conditions 17 00:02:08,840 --> 00:02:11,400 for the development of life. 18 00:02:16,240 --> 00:02:19,160 Romain is measuring the abundance of life 19 00:02:19,160 --> 00:02:22,000 in this entomologists' paradise. 20 00:02:25,640 --> 00:02:28,080 TRANSLATION: 21 00:03:15,520 --> 00:03:20,240 Scientists so far have identified over two million insect species 22 00:03:20,240 --> 00:03:23,520 but believe that there are many, many more. 23 00:03:23,520 --> 00:03:28,520 Some estimate that between 3 and 10 million species remain unknown. 24 00:04:04,600 --> 00:04:06,120 HE COUGHS 25 00:05:24,640 --> 00:05:27,520 The scientific community still has a long way to go 26 00:05:27,520 --> 00:05:30,400 to fully understand all this biodiversity. 27 00:05:33,240 --> 00:05:37,240 Accompanying Romain is a specialist in interactions between insects 28 00:05:37,240 --> 00:05:39,520 and tropical ecosystems. 29 00:05:39,520 --> 00:05:43,000 Philippe Grandcolas is an entomologist and research director 30 00:05:43,000 --> 00:05:45,240 at France's CNRS. 31 00:05:50,000 --> 00:05:53,160 The two scientists are heading to a site deep in the heart 32 00:05:53,160 --> 00:05:57,760 of the rainforest to examine this extraordinary ecosystem. 33 00:06:46,000 --> 00:06:49,000 To date, insect life has been relatively undisturbed 34 00:06:49,000 --> 00:06:50,600 in French Guiana. 35 00:06:51,600 --> 00:06:54,400 Insects are omnipresent in the forest. 36 00:06:57,520 --> 00:07:01,320 Despite their tiny size, the biomass of insects 37 00:07:01,320 --> 00:07:04,600 is greater than that of any other species on Earth. 38 00:08:21,520 --> 00:08:25,360 To document certain species and even discover new ones, 39 00:08:25,360 --> 00:08:29,160 Romain wants to explore one of the least studied areas 40 00:08:29,160 --> 00:08:32,520 of this environment - the treetop canopy. 41 00:10:22,000 --> 00:10:25,320 While numerous insect species are yet to be discovered, 42 00:10:25,320 --> 00:10:29,520 the significant mystery for scientists is their origin. 43 00:10:30,520 --> 00:10:33,760 How and when did they appear on our planet? 44 00:10:33,760 --> 00:10:36,840 This is a crucial question when 40% of species 45 00:10:36,840 --> 00:10:38,840 are in danger of extinction. 46 00:10:40,800 --> 00:10:43,600 There are now indications that all insects 47 00:10:43,600 --> 00:10:46,240 are descended from a single lineage, 48 00:10:46,240 --> 00:10:49,760 but this hypothesis has yet to be fully proven. 49 00:10:51,240 --> 00:10:56,000 To do this, scientists use the retro-evolution model, 50 00:10:56,000 --> 00:10:58,320 tracing the insect evolutionary tree 51 00:10:58,320 --> 00:11:03,520 back to the hypothetical first insect, which they've named LUCIA. 52 00:11:06,000 --> 00:11:10,520 The acronym for Last Universal Common Insect Ancestor. 53 00:11:21,760 --> 00:11:25,760 Information obtained from insect fossils found all over the world 54 00:11:25,760 --> 00:11:28,240 provide essential evolutionary clues. 55 00:11:29,760 --> 00:11:34,520 Some extraordinary specimens have been found at one site in Germany. 56 00:11:37,240 --> 00:11:40,280 - We are actually here at the Messel pit. 57 00:11:40,280 --> 00:11:43,520 It's an old volcanic crater that was filled up with water, 58 00:11:43,520 --> 00:11:46,360 and so we had an ancient lake 50 million years ago. 59 00:11:52,520 --> 00:11:55,760 - Torsten Wappler is the curator in charge of this former 60 00:11:55,760 --> 00:11:57,400 oil shale mine. 61 00:12:01,000 --> 00:12:04,240 - This lake was quite steep and at the bottom of the lake 62 00:12:04,240 --> 00:12:06,520 we had anoxic conditions, so no oxygen, 63 00:12:06,520 --> 00:12:10,520 so we have no organisms that destroy our fossils 64 00:12:10,520 --> 00:12:13,240 at the bottom, like what happens normally. 65 00:12:14,520 --> 00:12:17,800 This is the reason why we have this special kind of preservation. 66 00:12:19,000 --> 00:12:22,320 So the information that you can get here from the fossil record 67 00:12:22,320 --> 00:12:24,320 could be really quite detailed. 68 00:12:27,520 --> 00:12:32,520 Now we can start to excavate here just smoothly, 69 00:12:32,520 --> 00:12:36,240 then we can lift up these bigger plates 70 00:12:36,240 --> 00:12:41,760 to see if we have some fossils on the surface. 71 00:12:46,240 --> 00:12:48,880 You can estimate 0.1mm per year 72 00:12:48,880 --> 00:12:51,880 how much time you have here in this piece. 73 00:12:53,520 --> 00:12:56,000 You can read in this stone like a book. 74 00:12:56,000 --> 00:12:58,600 So this is the first page, then the next chapter, 75 00:12:58,600 --> 00:13:01,160 and then the next chapter, and then the next chapter, 76 00:13:01,160 --> 00:13:03,760 so you can reconstruct Earth's history, 77 00:13:03,760 --> 00:13:06,200 erm, for the last 50 million years. 78 00:13:18,000 --> 00:13:22,520 Ah, OK, there's a light-brown structure... 79 00:13:23,520 --> 00:13:27,000 ..and close to this light-brown structure here, 80 00:13:27,000 --> 00:13:30,240 there's a net-like structure. This is an insect remain. 81 00:13:32,000 --> 00:13:34,240 It's not really easy to recognise. 82 00:13:41,240 --> 00:13:45,520 And this is what the oil shale makes so fantastic and so interesting 83 00:13:45,520 --> 00:13:49,520 for doing some research, because the preservation of all these materials, 84 00:13:49,520 --> 00:13:54,520 particularly plants and insects, is so, so, erm, fine 85 00:13:54,520 --> 00:13:58,240 and so precise that you have even colour preservation of insects. 86 00:14:00,760 --> 00:14:04,000 When we found blue metallic, shining insects, 87 00:14:04,000 --> 00:14:07,000 that is more or less the original colour of the insects 88 00:14:07,000 --> 00:14:08,760 50 million years ago. 89 00:14:12,760 --> 00:14:15,400 - Each fossil provides crucial information 90 00:14:15,400 --> 00:14:18,760 for understanding certain chapters of insect evolution. 91 00:14:27,560 --> 00:14:31,760 For example, these beetle fossils found in Messel. 92 00:14:35,520 --> 00:14:39,040 Beetles are the insect family with the most species. 93 00:14:40,040 --> 00:14:45,000 500,000, or one-quarter of all known insect species. 94 00:14:46,000 --> 00:14:49,000 The morphological characteristics that define insects 95 00:14:49,000 --> 00:14:51,320 are already present in these fossils. 96 00:14:53,520 --> 00:14:56,000 A body divided into segments. 97 00:14:56,000 --> 00:14:59,520 The head, the thorax, the abdomen, 98 00:14:59,520 --> 00:15:03,400 as well as two pairs of wings and three pairs of legs. 99 00:15:04,400 --> 00:15:05,960 Spiders, for example, 100 00:15:05,960 --> 00:15:08,000 which have four pairs of legs, 101 00:15:08,000 --> 00:15:09,760 aren't insects. 102 00:15:10,760 --> 00:15:15,000 These characteristics haven't changed since the beginning of time. 103 00:15:17,000 --> 00:15:19,280 This anatomical consistency 104 00:15:19,280 --> 00:15:21,600 over tens of millions of years 105 00:15:21,600 --> 00:15:24,760 is the first piece of evidence that allows researchers 106 00:15:24,760 --> 00:15:26,520 to claim that insects, 107 00:15:26,520 --> 00:15:30,160 despite their diverse and sometimes incredible forms, 108 00:15:30,160 --> 00:15:32,760 could have the same common ancestor. 109 00:15:34,160 --> 00:15:35,760 LUCIA. 110 00:15:41,000 --> 00:15:43,520 Research in the field of phylogenetics - 111 00:15:43,520 --> 00:15:46,720 the study of the genetic evolution of species - 112 00:15:46,720 --> 00:15:49,680 is now making it possible to obtain new evidence 113 00:15:49,680 --> 00:15:52,520 and even an idea of when LUCIA appeared. 114 00:15:57,000 --> 00:16:00,520 This is what Bernhard Misof is working on in Bonn, 115 00:16:00,520 --> 00:16:03,520 in his laboratory next to the Koenig Museum. 116 00:16:06,520 --> 00:16:10,000 Thanks to DNA, Bernhard Misof is exploring 117 00:16:10,000 --> 00:16:13,520 the hitherto hidden genealogy of living organisms, 118 00:16:13,520 --> 00:16:16,240 particularly insects. 119 00:16:16,240 --> 00:16:19,560 These species have been his lifelong passion. 120 00:16:29,520 --> 00:16:33,240 - Here we are in the entomological collections of the Museum Koenig. 121 00:16:33,240 --> 00:16:35,840 This is a quite extensive collection - 122 00:16:35,840 --> 00:16:38,240 around 2 to 3 million specimens - 123 00:16:38,240 --> 00:16:41,000 so it makes it a really, really precious thing, 124 00:16:41,000 --> 00:16:43,520 because with these collections we can study 125 00:16:43,520 --> 00:16:46,200 the evolution of diversity and we can also study 126 00:16:46,200 --> 00:16:50,440 how diversity changed due to the impact of humans. 127 00:16:54,840 --> 00:16:57,760 We've studied the morphology, the different shapes, 128 00:16:57,760 --> 00:17:00,400 the different structures, in order to reconstruct 129 00:17:00,400 --> 00:17:02,160 who is related to whom. 130 00:17:05,760 --> 00:17:08,560 But this not an easy task because most likely 131 00:17:08,560 --> 00:17:11,520 insects originated millions of years ago. 132 00:17:17,160 --> 00:17:21,400 They also use these collections to extract molecular information, 133 00:17:21,400 --> 00:17:25,280 for example, entire genomes, to reconstruct relationships 134 00:17:25,280 --> 00:17:29,160 among different species based on the genomic information. 135 00:17:40,240 --> 00:17:44,240 - In the past, visual analysis was the main method used 136 00:17:44,240 --> 00:17:47,760 to establish relationships between different insect species. 137 00:17:51,000 --> 00:17:54,960 Today, genome studies are revealing similarities 138 00:17:54,960 --> 00:17:58,240 and genetic relationships that were once hidden to us. 139 00:18:00,520 --> 00:18:03,160 A sample of the specimen is ground up 140 00:18:03,160 --> 00:18:06,760 and then sequenced to chart each gene. 141 00:18:12,760 --> 00:18:16,240 - If you really want to understand the evolution of insects, 142 00:18:16,240 --> 00:18:18,600 we need to understand the relationship 143 00:18:18,600 --> 00:18:22,000 between the evolution of the genomes and the phenotypes, 144 00:18:22,000 --> 00:18:26,520 so this means which genes are responsible for which character, 145 00:18:26,520 --> 00:18:30,520 and with the genome sequencing, we are starting to get 146 00:18:30,520 --> 00:18:33,840 the necessary information to address these questions. 147 00:18:37,240 --> 00:18:40,600 Now we have huge amounts of information available 148 00:18:40,600 --> 00:18:43,000 from which we can extract information 149 00:18:43,000 --> 00:18:45,000 on relationships of species. 150 00:18:45,000 --> 00:18:48,520 The major challenge is really analysing the data. 151 00:18:54,720 --> 00:18:58,760 - In his laboratory, Bernhard Misof has set up one of the largest 152 00:18:58,760 --> 00:19:03,000 supercomputers in Europe, specifically dedicated to this task. 153 00:19:21,760 --> 00:19:24,760 - You need a lot of computing power because... 154 00:19:24,760 --> 00:19:29,520 ..consider you want to reconstruct the phylogenetic relationships of, 155 00:19:29,520 --> 00:19:32,400 let's say, 1,000 species. 156 00:19:32,400 --> 00:19:36,920 The number of different trees you have to check is uncountable. 157 00:19:36,920 --> 00:19:38,960 It's absolutely uncountable. 158 00:19:42,520 --> 00:19:46,520 These machines have to check billions and billions of different 159 00:19:46,520 --> 00:19:51,000 tree versions until they find a most likely, best solution. 160 00:20:05,240 --> 00:20:09,320 The basic idea for biologists is, if we sequence the genome, 161 00:20:09,320 --> 00:20:13,400 we might be able to say how that animal looks like. 162 00:20:14,400 --> 00:20:16,520 We are not in that stage yet 163 00:20:16,520 --> 00:20:19,880 and we don't know whether this will ever be feasible. 164 00:20:19,880 --> 00:20:23,920 But, in theory, if we sequence insect genomes, 165 00:20:23,920 --> 00:20:27,000 we should be able to trace the transition 166 00:20:27,000 --> 00:20:30,000 and we should be able to say how the ancestral insects 167 00:20:30,000 --> 00:20:31,840 might have looked like. 168 00:20:40,520 --> 00:20:43,000 - So far, these new tools have confirmed 169 00:20:43,000 --> 00:20:46,520 that there has been no break in the evolution of insects. 170 00:20:48,000 --> 00:20:51,320 Unlike other living things such as flowers, 171 00:20:51,320 --> 00:20:54,240 insects only appeared once on Earth. 172 00:20:55,240 --> 00:20:59,160 It's the same original lineage that diverged over time 173 00:20:59,160 --> 00:21:01,240 into numerous species. 174 00:21:05,920 --> 00:21:10,520 Proof that LUCIA, the first universal common insect, 175 00:21:10,520 --> 00:21:14,160 did indeed exist in a distant past. 176 00:21:17,240 --> 00:21:20,240 To try to determine when LUCIA first appeared, 177 00:21:20,240 --> 00:21:24,440 scientists have devised a predictive method - the molecular clock. 178 00:21:25,680 --> 00:21:29,000 Using the available data, the clock estimates the time needed 179 00:21:29,000 --> 00:21:31,240 for two species to diverge. 180 00:21:31,240 --> 00:21:34,520 Then, by counting the number of branches 181 00:21:34,520 --> 00:21:36,760 in the species' family tree, 182 00:21:36,760 --> 00:21:41,160 it calculates how far back in time the tree can be traced. 183 00:21:43,520 --> 00:21:47,240 - There's lots of uncertainty in these calculations. 184 00:21:47,240 --> 00:21:49,880 Every single fossil helps. 185 00:21:49,880 --> 00:21:53,360 As soon as we can place the fossil on the insect backbone tree, 186 00:21:53,360 --> 00:21:57,760 it helps us to recalibrate all of our molecular calculations 187 00:21:57,760 --> 00:22:00,000 of the origin of different groups. 188 00:22:07,000 --> 00:22:10,760 The molecular analysis somehow suggests that the insects 189 00:22:10,760 --> 00:22:16,640 appeared about between 470 and 500 million years ago, roughly. 190 00:22:21,240 --> 00:22:24,240 - Even in the age of genetics and biocomputing, 191 00:22:24,240 --> 00:22:28,520 fossils remain as important as ever, and the search for LUCIA 192 00:22:28,520 --> 00:22:32,160 has opened up a new golden age for paleo-entomology. 193 00:22:33,160 --> 00:22:35,760 Despite very few fossils bearing witness 194 00:22:35,760 --> 00:22:39,760 to the early days of insects, the fossil record contains 195 00:22:39,760 --> 00:22:43,240 vital clues for determining LUCIA's characteristics. 196 00:22:57,520 --> 00:23:00,920 In the Cretaceous period, evolution accelerated rapidly, 197 00:23:00,920 --> 00:23:05,000 with new species suddenly appearing in very large numbers. 198 00:23:05,000 --> 00:23:09,400 This is what scientists call an evolutionary surge. 199 00:23:12,520 --> 00:23:14,480 During this geological period, 200 00:23:14,480 --> 00:23:16,760 which spans almost 100 million years 201 00:23:16,760 --> 00:23:20,400 between 60 and 145 million years ago, 202 00:23:20,400 --> 00:23:24,240 all the lineages of modern insects appeared, 203 00:23:24,240 --> 00:23:28,240 including some totally unexpected ones, 204 00:23:28,240 --> 00:23:32,000 such as this discovery made by Diying Huang, 205 00:23:32,000 --> 00:23:35,760 professor at the Nanjing Institute of Geology and Palaeontology 206 00:23:35,760 --> 00:23:37,520 in China. 207 00:23:38,760 --> 00:23:41,240 TRANSLATION: 208 00:24:07,240 --> 00:24:10,760 Not only are these fleas the earliest known, 209 00:24:10,760 --> 00:24:14,880 they're also ten times the size of our modern flea, 210 00:24:14,880 --> 00:24:18,720 with the females measuring over two centimetres. 211 00:24:18,720 --> 00:24:21,520 They come from a site in Liaoning province 212 00:24:21,520 --> 00:24:25,240 where, 145 million years ago, 213 00:24:25,240 --> 00:24:28,760 a volcanic eruption preserved the landscape. 214 00:24:57,240 --> 00:24:59,600 What still remains a mystery 215 00:24:59,600 --> 00:25:03,720 is why fleas were here 145 million years ago. 216 00:25:04,720 --> 00:25:08,240 What kind of environment and ecosystems supported them? 217 00:25:49,960 --> 00:25:52,760 The flea fossil studied by Diying Huang 218 00:25:52,760 --> 00:25:56,240 had already adapted to living in feathers. 219 00:25:57,760 --> 00:26:00,000 We can distinguish the rostrum, 220 00:26:00,000 --> 00:26:03,520 used to bite and suck the blood of their hosts, 221 00:26:03,520 --> 00:26:08,760 and two mandibles with serrated edges to cling onto skin. 222 00:26:11,000 --> 00:26:15,520 However, these ancient fleas hadn't fully evolved into modern fleas. 223 00:26:15,520 --> 00:26:18,760 Their legs don't have the ability to jump. 224 00:26:19,760 --> 00:26:22,160 This adaptation came later 225 00:26:22,160 --> 00:26:25,520 to escape delousing and to colonise new hosts. 226 00:27:30,520 --> 00:27:34,760 In the late Cretaceous, a major catastrophe caused the extinction 227 00:27:34,760 --> 00:27:37,320 of almost 70% of life on Earth, 228 00:27:37,320 --> 00:27:40,000 most notably the dinosaurs. 229 00:27:41,240 --> 00:27:45,760 But fleas survived and continued to evolve. 230 00:27:45,760 --> 00:27:49,000 Further proof of the incredible adaptive capacity 231 00:27:49,000 --> 00:27:51,760 and resilience of insects. 232 00:28:04,240 --> 00:28:08,000 Scientists are also examining another type of fossil - 233 00:28:08,000 --> 00:28:09,800 amber. 234 00:28:09,800 --> 00:28:12,000 Fossilised resin. 235 00:28:12,000 --> 00:28:16,240 Some of these pieces are over 100 million years old 236 00:28:16,240 --> 00:28:19,840 and contain insects that are particularly well preserved. 237 00:28:26,760 --> 00:28:29,000 Grenoble in France is home to 238 00:28:29,000 --> 00:28:32,240 one of Europe's most high-tech laboratories. 239 00:28:32,240 --> 00:28:35,760 Using new imaging technologies, researchers can observe 240 00:28:35,760 --> 00:28:38,760 the characteristics and properties of objects 241 00:28:38,760 --> 00:28:42,240 right down to the atomic and molecular level. 242 00:28:43,680 --> 00:28:48,760 Kathleen Dollman is a specialist in 3D synchrotron tomography. 243 00:28:49,760 --> 00:28:53,240 In fact, she's about to scan one of these pieces of amber 244 00:28:53,240 --> 00:28:58,520 in an attempt to better understand how certain insect organs evolved 245 00:28:58,520 --> 00:29:01,760 and help determine LUCIA's anatomy. 246 00:29:06,520 --> 00:29:10,520 - This synchrotron is a 844-metre ring. 247 00:29:10,520 --> 00:29:13,400 Basically, we accelerate electrons 248 00:29:13,400 --> 00:29:16,000 and control their flow with magnets, 249 00:29:16,000 --> 00:29:19,000 and by doing this, we produce very, very powerful X-rays 250 00:29:19,000 --> 00:29:22,160 that we use for a number of experimental techniques. 251 00:29:26,360 --> 00:29:30,000 - The insect trapped in the amber is often intact. 252 00:29:31,520 --> 00:29:36,160 X-rays 100,000 times more powerful than a medical scanner 253 00:29:36,160 --> 00:29:40,000 are able to reconstruct its volume by way of measurements 254 00:29:40,000 --> 00:29:42,160 taken through the piece of amber. 255 00:29:43,160 --> 00:29:46,760 - With something like amber insects, they're extremely small, 256 00:29:46,760 --> 00:29:50,000 so when we mount them, we have to make sure that they're perfectly 257 00:29:50,000 --> 00:29:52,760 aligned with where the beam, which is the X-ray energy 258 00:29:52,760 --> 00:29:55,520 from the synchrotron, enters the experimental hatch, 259 00:29:55,520 --> 00:29:57,520 which is the room that we're in. 260 00:30:01,760 --> 00:30:06,320 We have a beam that is 2.5mm wide for something like this 261 00:30:06,320 --> 00:30:10,240 and we have to align it perfectly down 220 metres of pipeline. 262 00:30:10,240 --> 00:30:12,640 - BEEPING 263 00:30:20,480 --> 00:30:22,520 BEEPING STOPS 264 00:30:25,840 --> 00:30:27,760 ALARM BLARES 265 00:30:30,000 --> 00:30:34,560 - I think you have 0.0001 seconds to survive 266 00:30:34,560 --> 00:30:37,840 if you're in one of the hatches when the X-rays are on. 267 00:30:48,520 --> 00:30:53,240 - Tomography is a revolutionary technology for paleo-entomology 268 00:30:53,240 --> 00:30:57,760 as it enables a virtual dissection of fossilised insects. 269 00:31:08,240 --> 00:31:10,000 LONG BEEP 270 00:31:13,280 --> 00:31:16,760 - So, erm... So this, for example, that I'm showing you here, 271 00:31:16,760 --> 00:31:19,920 is a beautiful slice through the amber specimen. 272 00:31:19,920 --> 00:31:22,760 So this is, erm, the insect. 273 00:31:22,760 --> 00:31:25,000 It's very beautiful. 274 00:31:25,000 --> 00:31:28,240 So, to put it in perspective, the size of the specimen, 275 00:31:28,240 --> 00:31:32,520 the specimen... One micron is equal to 1,000th of a millimetre, 276 00:31:32,520 --> 00:31:36,000 so the specimen is extremely small but we can still see a lot 277 00:31:36,000 --> 00:31:41,520 of details, like the individual ridges, these projections out. 278 00:31:44,760 --> 00:31:48,840 - This specimen is particularly interesting as it represents 279 00:31:48,840 --> 00:31:50,840 a lineage of primitive insects 280 00:31:50,840 --> 00:31:54,240 that has mandibles starting to protrude from the head. 281 00:31:55,240 --> 00:31:59,760 In some of their descendants, this will evolve to form the rostrum, 282 00:31:59,760 --> 00:32:03,520 enabling them to bite plants and prey. 283 00:32:08,240 --> 00:32:12,920 By tracing the evolution of an organ as complicated as this mandible, 284 00:32:12,920 --> 00:32:16,000 scientists can deduce the evolutionary mechanisms 285 00:32:16,000 --> 00:32:18,520 for the insect's entire anatomy, 286 00:32:18,520 --> 00:32:23,160 enabling a first composite sketch of LUCIA... 287 00:32:23,160 --> 00:32:26,000 ..the original insect. 288 00:32:32,000 --> 00:32:35,520 In his quest to find LUCIA, Romain has come across 289 00:32:35,520 --> 00:32:38,240 traces of giant insects in the south of France. 290 00:32:44,920 --> 00:32:47,000 Why were they so huge? 291 00:32:47,000 --> 00:32:49,840 And what can they teach us about LUCIA? 292 00:32:59,520 --> 00:33:02,400 These fossils date back to the Permian period - 293 00:33:02,400 --> 00:33:05,520 about 260 million years ago. 294 00:33:06,520 --> 00:33:11,000 They are much older and larger than the fleas found in China. 295 00:33:11,000 --> 00:33:16,520 They are fossils of dragonflies of an unbelievable size... 296 00:33:17,520 --> 00:33:19,320 ..called Meganeura. 297 00:33:50,240 --> 00:33:53,000 Aside from their exceptional size, 298 00:33:53,000 --> 00:33:56,920 Meganeura looked quite similar to today's dragonflies. 299 00:33:57,920 --> 00:34:02,000 A spherical head, large mandibles with teeth, 300 00:34:02,000 --> 00:34:04,400 legs covered in hard hairs, 301 00:34:04,400 --> 00:34:06,240 a large thorax 302 00:34:06,240 --> 00:34:08,520 and a long, thin body. 303 00:34:08,520 --> 00:34:13,240 They were, without question, formidable predators. 304 00:34:32,760 --> 00:34:35,520 To explain why Meganeura was so big, 305 00:34:35,520 --> 00:34:38,160 several theories have been developed, 306 00:34:38,160 --> 00:34:41,520 but the most interesting one is linked to the levels of oxygen 307 00:34:41,520 --> 00:34:43,240 in the atmosphere. 308 00:34:46,520 --> 00:34:51,400 In this period, the air was made up of around 35% oxygen. 309 00:34:51,400 --> 00:34:55,000 Today it's 21%. 310 00:34:55,000 --> 00:34:58,760 This figure is key because insects have a very specific way 311 00:34:58,760 --> 00:35:00,400 of breathing. 312 00:35:30,520 --> 00:35:33,600 Running through insect bodies is a network of channels 313 00:35:33,600 --> 00:35:36,840 whose branches bring air directly into the cells. 314 00:35:39,760 --> 00:35:42,240 Each cell breathes on its own, 315 00:35:42,240 --> 00:35:45,520 giving insects an evolutionary advantage. 316 00:35:53,240 --> 00:35:58,160 Without a doubt, the LUCIA already had this system, 317 00:35:58,160 --> 00:36:00,760 or at least a rudimentary version of it. 318 00:36:05,520 --> 00:36:08,760 The combination of the composition of the atmosphere 319 00:36:08,760 --> 00:36:11,840 and this unique breathing system 320 00:36:11,840 --> 00:36:15,520 allowed large insects to fly. 321 00:36:19,520 --> 00:36:22,000 The cells in the muscles needed for flying 322 00:36:22,000 --> 00:36:24,840 benefited from the oxygen-rich air supply. 323 00:36:39,240 --> 00:36:43,000 Then, 250 million years ago, 324 00:36:43,000 --> 00:36:46,760 70% of vertebrates suddenly disappeared, 325 00:36:46,760 --> 00:36:49,240 and we still don't know why. 326 00:36:49,240 --> 00:36:52,760 This event marked the end of giant insects. 327 00:36:54,000 --> 00:36:59,000 Today, the largest dragonflies have a wingspan of just 16cm. 328 00:37:00,000 --> 00:37:03,760 The biggest known insects are the atlas moth 329 00:37:03,760 --> 00:37:09,320 and the 30cm-long giant stick insect found in the Borneo forest. 330 00:37:13,000 --> 00:37:17,160 After this extinction event, the insects that survived 331 00:37:17,160 --> 00:37:20,680 employed a common strategy for escaping their predators. 332 00:37:20,680 --> 00:37:22,240 INSECT BUZZES 333 00:37:22,240 --> 00:37:25,520 Being small and using mimicry... 334 00:37:27,240 --> 00:37:30,760 ..this strategy allowing them to hide in their environment. 335 00:38:27,000 --> 00:38:29,760 Throughout their history, insects have adapted 336 00:38:29,760 --> 00:38:35,240 in many spectacular ways, with two particular evolutionary successes. 337 00:38:38,240 --> 00:38:39,760 Flying... 338 00:38:40,760 --> 00:38:42,760 ..and metamorphosis. 339 00:38:47,520 --> 00:38:49,760 But when did these changes appear? 340 00:38:51,160 --> 00:38:53,040 And why? 341 00:39:01,520 --> 00:39:07,480 To reach full maturity, many insects must go into chrysalises or cocoons, 342 00:39:07,480 --> 00:39:09,240 or moult. 343 00:39:11,000 --> 00:39:15,400 This spectacular process, which appeared in the Triassic period, 344 00:39:15,400 --> 00:39:19,160 allows adults to take on very varied shapes and sizes 345 00:39:19,160 --> 00:39:22,000 without the need for very complex larvae. 346 00:39:25,240 --> 00:39:29,160 The larvae and the adults do not compete for food. 347 00:39:30,160 --> 00:39:34,760 Insects can also speed up or slow down these metamorphoses 348 00:39:34,760 --> 00:39:38,240 to wait for favourable conditions before becoming adults 349 00:39:38,240 --> 00:39:40,160 and reproducing. 350 00:39:44,240 --> 00:39:49,000 Thanks to this system, the variety of insects has increased. 351 00:39:55,760 --> 00:39:59,520 But flying further boosted this family of species. 352 00:40:02,000 --> 00:40:04,520 To explain the introduction of flight, 353 00:40:04,520 --> 00:40:09,240 Romain is hoping to find clues in the middle of the Arctic Ocean. 354 00:40:13,600 --> 00:40:18,000 These developments would have taken place 100 million years earlier, 355 00:40:18,000 --> 00:40:21,840 between the Triassic and the Carboniferous periods. 356 00:40:21,840 --> 00:40:25,520 Two crucial periods for the future of insects. 357 00:40:28,120 --> 00:40:31,760 Jean Sebastien Steyer, a palaeontologist at France's CNRS, 358 00:40:31,760 --> 00:40:34,000 is one of the specialists of this period. 359 00:40:34,000 --> 00:40:35,960 TRANSLATION: 360 00:41:04,440 --> 00:41:06,520 BIRDS SQUAWK 361 00:41:09,760 --> 00:41:13,520 Until now, scientists have been faced with a significant problem. 362 00:41:15,160 --> 00:41:18,520 Insect fossils have never been found in geological layers 363 00:41:18,520 --> 00:41:23,000 dating back 325 to 385 million years. 364 00:42:10,240 --> 00:42:13,240 The Devonian period is characterised by the appearance 365 00:42:13,240 --> 00:42:15,760 of the first large trees, 366 00:42:15,760 --> 00:42:20,520 and in particular trees with bark and tree ferns. 367 00:42:21,520 --> 00:42:25,760 Low sea levels gave rise to vast marshes and forests. 368 00:43:04,520 --> 00:43:08,400 It's in this environment that one of the most significant developments 369 00:43:08,400 --> 00:43:10,920 in insect evolution took place. 370 00:44:07,520 --> 00:44:10,760 Romain and Jean Sebastien hope to find a fossil 371 00:44:10,760 --> 00:44:13,160 of one of the first flying insects 372 00:44:13,160 --> 00:44:16,240 in the oldest rock layers on Svalbard. 373 00:44:41,520 --> 00:44:44,760 But they will only be able to confirm the fossil's origin 374 00:44:44,760 --> 00:44:47,760 and contents once they are back in the laboratory. 375 00:45:11,000 --> 00:45:14,400 Even without fossils from the Devonian period, 376 00:45:14,400 --> 00:45:17,760 which would help explain how insects came to fly, 377 00:45:17,760 --> 00:45:21,720 scientists have been able to hypothesise where wings came from. 378 00:45:50,000 --> 00:45:54,520 The commonly held theory is that the insect's abdomen segments evolved. 379 00:45:57,000 --> 00:46:00,000 Paddle-shaped protrusions are thought to have helped 380 00:46:00,000 --> 00:46:03,760 the first six-legged specimens to move through the trees. 381 00:46:03,760 --> 00:46:07,240 These paddles then developed into wings. 382 00:46:09,520 --> 00:46:11,840 Rigid at first for gliding, 383 00:46:11,840 --> 00:46:14,760 the theory maintains that the developing wings 384 00:46:14,760 --> 00:46:20,000 became articulated to enable flapping during flight. 385 00:46:22,520 --> 00:46:25,320 For 150 million years, 386 00:46:25,320 --> 00:46:29,520 insects were the only living beings capable of flight. 387 00:46:29,520 --> 00:46:35,000 A major evolutionary advantage that still persists today. 388 00:46:35,000 --> 00:46:37,000 INSECT BUZZES 389 00:46:45,040 --> 00:46:48,400 The anatomy of some species was further simplified 390 00:46:48,400 --> 00:46:52,000 by reducing the number of wings to a single pair. 391 00:46:54,120 --> 00:46:56,240 INSECT BUZZES 392 00:46:56,240 --> 00:46:58,880 Making insects swift and manoeuvrable 393 00:46:58,880 --> 00:47:02,920 with fine and powerful control of their wing movements 394 00:47:02,920 --> 00:47:05,560 allows the angle of attack, 395 00:47:05,560 --> 00:47:09,040 rigidity and flapping frequency to be adjusted. 396 00:47:10,040 --> 00:47:13,400 These flight capacities are so amazing 397 00:47:13,400 --> 00:47:17,240 that they're now the subject of extensive scientific study. 398 00:47:19,240 --> 00:47:22,760 In France, Camille Arachelof, a researcher 399 00:47:22,760 --> 00:47:26,240 at the Physics and Mechanics Laboratory of Sorbonne University, 400 00:47:26,240 --> 00:47:29,240 is studying the flight of dragonflies - 401 00:47:29,240 --> 00:47:32,520 one of the most complex and fascinating species. 402 00:47:33,960 --> 00:47:36,440 TRANSLATION: 403 00:48:24,000 --> 00:48:26,840 After identifying each species, 404 00:48:26,840 --> 00:48:31,360 Camille observes dragonfly flight in slow motion. 405 00:49:56,520 --> 00:49:59,920 In flying insects, the muscles are either attached directly 406 00:49:59,920 --> 00:50:06,680 to the wings or the whole thorax contorts, causing the wings to move. 407 00:50:06,680 --> 00:50:12,520 These systems enable precise control of flapping and angle of movement. 408 00:50:52,000 --> 00:50:55,640 Some dragonflies lie in wait for prey, 409 00:50:55,640 --> 00:50:58,520 others swoop like hawks... 410 00:51:00,240 --> 00:51:03,200 ..reaching speeds of 22mph 411 00:51:03,200 --> 00:51:07,160 and ascending at up to 3mph. 412 00:51:14,240 --> 00:51:18,400 Camille is trying to understand how some insects, like dragonflies, 413 00:51:18,400 --> 00:51:22,240 can generate lifting forces three times their weight. 414 00:51:51,000 --> 00:51:55,240 Camille's first observations led her to think that the wing contortions 415 00:51:55,240 --> 00:51:58,400 contribute greatly to the force being generated. 416 00:51:59,640 --> 00:52:04,000 An energy-saving solution that could also be applied to industry. 417 00:52:07,200 --> 00:52:10,400 Scientists are now attempting to reproduce and analyse 418 00:52:10,400 --> 00:52:14,560 these exceptional evolutionary developments in the laboratory. 419 00:52:16,520 --> 00:52:20,120 Engineers everywhere are looking to these biological models 420 00:52:20,120 --> 00:52:23,520 for solutions to modern technological challenges. 421 00:52:26,240 --> 00:52:31,240 This is called bioinspiration or biomimetics. 422 00:52:33,000 --> 00:52:37,000 But while solutions can be found by studying modern insects, 423 00:52:37,000 --> 00:52:41,240 even more can be obtained by studying ancient ones. 424 00:52:41,240 --> 00:52:45,520 This concept is called paleo-inspiration, 425 00:52:45,520 --> 00:52:51,000 giving the search for LUCIA, the foundation stone of this edifice, 426 00:52:51,000 --> 00:52:53,320 even greater significance. 427 00:52:53,320 --> 00:52:57,240 But one essential question still needs to be answered - 428 00:52:57,240 --> 00:52:59,760 how did insects appear on Earth? 429 00:53:00,760 --> 00:53:03,840 The answer is no doubt hidden somewhere in Miguasha, 430 00:53:03,840 --> 00:53:06,520 a National Park in north-eastern Canada. 431 00:53:07,520 --> 00:53:10,840 Olivier Matton is a palaeontologist and head of conservation 432 00:53:10,840 --> 00:53:12,520 at this site. 433 00:53:12,520 --> 00:53:16,520 He's been excavating here for the past 15 years. 434 00:53:22,240 --> 00:53:26,240 Miguasha is a treasure trove for palaeontologists. 435 00:53:26,240 --> 00:53:29,520 The fossils found here over the last 100 years 436 00:53:29,520 --> 00:53:32,080 tell an extraordinary story. 437 00:53:33,080 --> 00:53:36,000 It's about the origins of the first land animals, 438 00:53:36,000 --> 00:53:38,240 when strange species began 439 00:53:38,240 --> 00:53:41,160 their transition from water to land 440 00:53:41,160 --> 00:53:46,160 in the Devonian period, 380 million years ago. 441 00:55:17,760 --> 00:55:22,040 Bernhard Misof's molecular clock has made it possible to estimate 442 00:55:22,040 --> 00:55:26,520 that insects appeared about 470 million years ago 443 00:55:26,520 --> 00:55:29,520 in the early Devonian or late Silurian period. 444 00:55:31,000 --> 00:55:34,320 Paleo-entomologists believe that the appearance of insects 445 00:55:34,320 --> 00:55:39,440 is thus undoubtedly linked to when life became terrestrial. 446 00:55:39,440 --> 00:55:43,520 In environments like Miguasha, rich in super predators 447 00:55:43,520 --> 00:55:45,600 like the first fish with legs, 448 00:55:45,600 --> 00:55:49,920 it's believed that certain crustaceans came out of the water 449 00:55:49,920 --> 00:55:53,520 and gradually adapted to terrestrial environments. 450 00:55:55,240 --> 00:56:00,520 So crustaceans may have been the ancestors of insects. 451 00:56:01,520 --> 00:56:05,520 In fact, morphological similarities between the two species 452 00:56:05,520 --> 00:56:07,520 validate this theory. 453 00:56:09,520 --> 00:56:13,520 Some insect fossils show traces of organs resembling gills 454 00:56:13,520 --> 00:56:15,160 on their legs. 455 00:56:16,160 --> 00:56:19,600 The development of the nervous system in insects and crustaceans 456 00:56:19,600 --> 00:56:21,520 is strikingly similar. 457 00:56:23,000 --> 00:56:26,400 Even today, some crustaceans and insects 458 00:56:26,400 --> 00:56:30,240 still live between terrestrial and marine environments. 459 00:56:36,040 --> 00:56:40,400 It's thought that to adapt to a terrestrial environment, 460 00:56:40,400 --> 00:56:44,520 insects differentiated themselves from crustaceans. 461 00:56:44,520 --> 00:56:48,240 Their head became separate from their thorax, 462 00:56:48,240 --> 00:56:51,760 the number of their body segments and legs decreased. 463 00:56:53,760 --> 00:56:57,760 But no fossil has been found that confirms this theory. 464 00:56:59,240 --> 00:57:03,760 Maybe one day Olivier will find one that finally proves 465 00:57:03,760 --> 00:57:08,560 the origin of insects and reveals more of LUCIA's secrets. 466 00:57:24,520 --> 00:57:27,760 Insects are indispensable to our world. 467 00:57:27,760 --> 00:57:30,240 They play a vital role in it, 468 00:57:30,240 --> 00:57:33,520 which is why it is so important to protect them. 469 00:57:37,240 --> 00:57:40,160 But just as LUCIA and its descendants have withstood 470 00:57:40,160 --> 00:57:43,520 cataclysms for hundreds of millions of years, 471 00:57:43,520 --> 00:57:46,520 insects will continue their journey 472 00:57:46,520 --> 00:57:49,520 with or without us. 473 00:57:52,520 --> 00:57:54,520 Evolution hasn't ended... 474 00:57:55,520 --> 00:57:58,240 ..and who can predict what insects will look like 475 00:57:58,240 --> 00:58:02,240 in 10, 50, 100 million years?