0:00:10 > 0:00:15Let's face it, our world is downright weird...
0:00:15 > 0:00:17SCREAMING
0:00:17 > 0:00:21..crawling with creatures you've never heard of...
0:00:21 > 0:00:24I can't believe that's a living thing.
0:00:24 > 0:00:27..full of the unexpected,
0:00:27 > 0:00:31like freak weather exploding out of the blue...
0:00:31 > 0:00:33I thought I was going to die.
0:00:33 > 0:00:36..and rocks that spontaneously combust...
0:00:36 > 0:00:39I thought it was dynamite going off.
0:00:39 > 0:00:41..and the unexplained -
0:00:41 > 0:00:46an unborn twin, discovered inside a brain.
0:00:46 > 0:00:50There was multiple hair follicles, bone and teeth.
0:00:53 > 0:00:58We've scoured the globe to bring you the very weirdest stories.
0:00:58 > 0:00:59Yeah!
0:01:01 > 0:01:03I could feel this intense pain
0:01:03 > 0:01:07as if you were being stabbed by hundreds of syringes.
0:01:12 > 0:01:15In this series, we're going to examine the evidence,
0:01:15 > 0:01:19test the science and unravel the mysteries.
0:01:19 > 0:01:24We're going to discover what in the weird world is going on.
0:01:37 > 0:01:40In this episode, we'll uncover the secrets
0:01:40 > 0:01:43to some of the natural world's weirdest events.
0:01:45 > 0:01:49How can a lake form beneath the ocean?
0:01:49 > 0:01:51- Sick.- Whoa!
0:01:51 > 0:01:53- Whoa!- Oh, wow!
0:01:53 > 0:01:55And can money really grow on trees?
0:01:58 > 0:02:00Just how exactly can a kingfisher
0:02:00 > 0:02:03help you design the perfect train?
0:02:04 > 0:02:08And how are bird brains being used to battle disease?
0:02:17 > 0:02:20On our journey around this weird world, we've come across
0:02:20 > 0:02:22all sorts of different things -
0:02:22 > 0:02:27exploding birds, mutant frogs, even a giant slick
0:02:27 > 0:02:29made of anchovies.
0:02:29 > 0:02:32But today we're going to Siberia for a mystery
0:02:32 > 0:02:34of an altogether different magnitude.
0:02:39 > 0:02:43Yes, our first story comes from Siberia.
0:02:44 > 0:02:46The Yamal Peninsula,
0:02:46 > 0:02:49known locally as "the end of the world."
0:02:51 > 0:02:55In July 2014, a pilot flying over this barren wilderness
0:02:55 > 0:02:56spotted something strange.
0:03:00 > 0:03:04What looked like a crater, or a mysterious hole...
0:03:07 > 0:03:09..and not just any hole.
0:03:11 > 0:03:15It was 60 metres across and 70 metres deep -
0:03:15 > 0:03:21large enough to fit a 25-storey skyscraper inside.
0:03:21 > 0:03:25And then, over the coming weeks,
0:03:25 > 0:03:29more holes began appearing,
0:03:29 > 0:03:31with four confirmed locations
0:03:31 > 0:03:36and three more reported by local herders who almost fell in.
0:03:36 > 0:03:39Stranger still, scientists predict that there could be
0:03:39 > 0:03:4220-30 more yet to be discovered.
0:03:45 > 0:03:49When these first appeared, they created global attention
0:03:49 > 0:03:52to the extent that scientists all over the world
0:03:52 > 0:03:53were asking the question -
0:03:53 > 0:03:56what caused these gigantic craters?
0:04:05 > 0:04:08Now, extraordinary holes appear all over the planet
0:04:08 > 0:04:09for a variety of reasons...
0:04:11 > 0:04:14..like this sinkhole in Louisiana which emerged
0:04:14 > 0:04:19when a cave ceiling collapsed, swallowing an entire lake
0:04:19 > 0:04:21and the surrounding trees.
0:04:21 > 0:04:22Oh, wow!
0:04:22 > 0:04:27In Turkmenistan in 1971, it's thought that natural gases
0:04:27 > 0:04:30were ignited and they're still burning to this day.
0:04:34 > 0:04:39And meteorites like this one which streaked across the sky in Russia
0:04:39 > 0:04:42can create huge flat-bottomed craters on impact.
0:04:46 > 0:04:47But here's the thing -
0:04:47 > 0:04:51our Siberian hole didn't look like any of these.
0:04:51 > 0:04:55And for one geologist, it was this unique appearance
0:04:55 > 0:04:56that had him intrigued.
0:04:58 > 0:05:01I think the thing that makes the Siberian holes unique is
0:05:01 > 0:05:03their morphology.
0:05:03 > 0:05:06They really are these strange sort of deep chasms
0:05:06 > 0:05:08with a crater around the outside.
0:05:08 > 0:05:11You almost walk up and peer into the abyss.
0:05:13 > 0:05:16They're in such a remote area, the information about them is little
0:05:16 > 0:05:20and sparse, and that adds an extra mystique to their formation.
0:05:29 > 0:05:31What could it have been?
0:05:31 > 0:05:32Alien landing?
0:05:32 > 0:05:34Come on, I don't think so.
0:05:34 > 0:05:39But whatever it was, it had those scientists completely baffled.
0:05:39 > 0:05:42That is, until one bright spark came up with the idea
0:05:42 > 0:05:45that they were looking in the wrong place.
0:05:47 > 0:05:51Rather than concentrating on the exterior of the crater,
0:05:51 > 0:05:54the scientists decided to head down into the abyss.
0:06:00 > 0:06:03They took measurements, collected samples,
0:06:03 > 0:06:06looking for clues as to the source of this mysterious monster.
0:06:10 > 0:06:13The first theory that the scientists came up with was that this
0:06:13 > 0:06:14was a pingo.
0:06:14 > 0:06:19Not a penguin, that's a pingu - a pingo - and pingos
0:06:19 > 0:06:23are geological formations produced when a glacier retreats.
0:06:23 > 0:06:27You see, they leave a large ball of ice embedded in the ground
0:06:27 > 0:06:29and then it melts, leaving a crater.
0:06:29 > 0:06:30Simple.
0:06:34 > 0:06:36But this theory had a flaw.
0:06:36 > 0:06:41If a pingo had formed and a giant ball of ice had melted,
0:06:41 > 0:06:43where had all the water gone?
0:06:48 > 0:06:52Pingos are often associated - or melted pingos - with lake deposits,
0:06:52 > 0:06:55and because that's not the case here, it does add a bit of intrigue.
0:06:57 > 0:06:58So, what was going on?
0:07:02 > 0:07:06Was there something else present in the crater that would have
0:07:06 > 0:07:08been powerful enough to cause an explosion?
0:07:10 > 0:07:12Some of these sinkholes, you can actually measure natural gases
0:07:12 > 0:07:15escaping from them. Now, that could be that they're just
0:07:15 > 0:07:18natural areas for gas to escape from the ground,
0:07:18 > 0:07:21or it could actually be the smoking gun that tells you that
0:07:21 > 0:07:24one of the things that formed that feature was gas escape.
0:07:27 > 0:07:31And gas is exactly what they found,
0:07:31 > 0:07:34and not just any gas, they found...
0:07:34 > 0:07:38methane in exceptionally high concentrations.
0:07:38 > 0:07:42But what was it doing there and where had it come from?
0:07:45 > 0:07:48Well, methane is a naturally occurring gas
0:07:48 > 0:07:51produced by the decomposition of organic matter.
0:07:53 > 0:07:57Deep underground, bubbles of methane become trapped.
0:07:59 > 0:08:02A volatile bomb ready to ignite.
0:08:06 > 0:08:10So, methane could be to blame,
0:08:10 > 0:08:13but not in the fiery way you might think.
0:08:13 > 0:08:16What happened in Siberia was all down to an
0:08:16 > 0:08:19immense release of pressure.
0:08:19 > 0:08:23The escape of gas through the ground could cause a hole-like structure
0:08:23 > 0:08:26by building up the gas and not allowing it to escape.
0:08:26 > 0:08:28It builds up enough pressure, and then boom!
0:08:28 > 0:08:31It pops through the surface and causes almost like
0:08:31 > 0:08:34a pock-like blister on the earth's surface.
0:08:34 > 0:08:36It's a bit like how a cork...
0:08:38 > 0:08:40..gets shot out of a champagne bottle,
0:08:40 > 0:08:44but in this case, the pressure release as the methane escaped
0:08:44 > 0:08:48would have had the power to shift thousands of tonnes of solid rock.
0:08:49 > 0:08:52Now, the data still needs to be analysed thoroughly
0:08:52 > 0:08:55before the case is closed on this mystery,
0:08:55 > 0:08:57but the methane theory?
0:08:57 > 0:08:59Well, it's looking pretty good.
0:09:03 > 0:09:07So, a monstrous methane explosion could have been the culprit
0:09:07 > 0:09:10and, thankfully, it occurred in the middle of nowhere.
0:09:10 > 0:09:13Imagine if that had happened in the heart of a city.
0:09:13 > 0:09:15Doesn't bear thinking about.
0:09:15 > 0:09:19But then, phenomena like this can crop up almost anywhere.
0:09:19 > 0:09:24I mean, imagine a lake at the bottom of the ocean.
0:09:24 > 0:09:26Sounds impossible, doesn't it?
0:09:30 > 0:09:32The mysteries of the deep have intrigued
0:09:32 > 0:09:35oceanic explorers for centuries.
0:09:37 > 0:09:41But one man in particular has taken marine exploration to extremes.
0:09:43 > 0:09:46As a deep-sea biologist, I study animals that live
0:09:46 > 0:09:50at the bottom of the ocean at depths usually greater than a mile.
0:09:53 > 0:09:56Chuck has spent thousands of hours in submersibles,
0:09:56 > 0:10:00combing the sea floor, discovering all kinds of amazing new species
0:10:00 > 0:10:02along the way.
0:10:03 > 0:10:08But nothing prepared him for what he and his team saw from a sub
0:10:08 > 0:10:13at the bottom of the Gulf of Mexico in 2006.
0:10:13 > 0:10:16At a depth of over 2,000 metres,
0:10:16 > 0:10:17he came across this.
0:10:19 > 0:10:20- Sick.- Whoa.
0:10:20 > 0:10:23- Wow.- Oh, wow.
0:10:23 > 0:10:24A lake...
0:10:24 > 0:10:26at the bottom of the ocean.
0:10:32 > 0:10:37You're down a half a mile looking at a lake on the seafloor.
0:10:37 > 0:10:40You can see it as a pool on the bottom of the ocean.
0:10:40 > 0:10:43When the submarine lands on it, it floats.
0:10:45 > 0:10:48Little ripples go off from the edge...
0:10:51 > 0:10:53..which is an otherworldly experience.
0:10:59 > 0:11:01OK, let's get this straight.
0:11:01 > 0:11:05What we're dealing with here is a lake, which is a body of water,
0:11:05 > 0:11:09within an ocean, which is a larger body of water.
0:11:09 > 0:11:13So, that's water within water, which surely can't be possible, can it?
0:11:21 > 0:11:25Well, it's all to do with different water densities
0:11:25 > 0:11:27and how they interact with each other.
0:11:31 > 0:11:33Imagine this is an ocean...
0:11:36 > 0:11:40..and then we create a separate solution of brine,
0:11:40 > 0:11:43four times more salty than seawater...
0:11:44 > 0:11:47..and when we bring the two together,
0:11:47 > 0:11:48they don't mix.
0:11:49 > 0:11:52The saltier brine solution is heavier,
0:11:52 > 0:11:58so it sinks, resulting in two very distinct layers.
0:11:59 > 0:12:02The bottom layer represents the underwater lake.
0:12:04 > 0:12:07Imagine this tomato is Chuck's submersible.
0:12:12 > 0:12:15The brine is so dense...
0:12:17 > 0:12:19..that it floats on the surface of the pool.
0:12:22 > 0:12:25The same thing is happening at the bottom of the ocean.
0:12:25 > 0:12:29Hundreds of metres below the surface, this dense briny water
0:12:29 > 0:12:33is sitting below the typical salty seawater.
0:12:33 > 0:12:36The question is - where is all of this salt coming from?
0:12:38 > 0:12:41The continental shelf of the Gulf of Mexico
0:12:41 > 0:12:44is a really unique place, cos underlying the continental shelf
0:12:44 > 0:12:46is a salt evaporate.
0:12:46 > 0:12:49It was laid down in the Jurassic, it's called the Louann Salt
0:12:49 > 0:12:51and it's several kilometres thick.
0:12:52 > 0:12:58So, a thick layer of salt as old as the dinosaurs is moving up
0:12:58 > 0:13:00through cracks in the ocean floor
0:13:00 > 0:13:05to form these underwater lakes...
0:13:05 > 0:13:09and these deep-sea lagoons can be massive -
0:13:09 > 0:13:12up to 100km in length...
0:13:14 > 0:13:17..and subaquatic lakes are just the start.
0:13:21 > 0:13:23Now, there's other places in the Gulf of Mexico where
0:13:23 > 0:13:26the brine is coming out on the side of a slope
0:13:26 > 0:13:29and you'll have a brine river and that is also
0:13:29 > 0:13:33a very otherworldly experience, to be on the seafloor a mile deep
0:13:33 > 0:13:36and look down and see a river going by.
0:13:39 > 0:13:43Ripples on the surface, just like you're looking at a mountain stream
0:13:43 > 0:13:45on the surface of the planet.
0:13:45 > 0:13:47Whoa.
0:13:47 > 0:13:49Rivers underwater are awesome!
0:13:50 > 0:13:54Yes, underwater rivers, I kid you not.
0:13:55 > 0:14:00In fact, one has been recently discovered in the Gulf of Mexico
0:14:00 > 0:14:02and when the seabed was mapped,
0:14:02 > 0:14:05it was found to be 120 metres deep.
0:14:07 > 0:14:09If this river existed on the surface,
0:14:09 > 0:14:12it would be the fourth deepest in the world.
0:14:13 > 0:14:18Deep enough for the Statue of Liberty to stand inside -
0:14:18 > 0:14:19torch and all!
0:14:22 > 0:14:25It's amazing, isn't it? That something as simple as salt
0:14:25 > 0:14:27can produce such a wonder,
0:14:27 > 0:14:30but then ancient mineral deposits show up all over the place.
0:14:30 > 0:14:34They turned up here in the 1860s, causing a gold rush,
0:14:34 > 0:14:38but these days gold turns up in much more unusual places.
0:14:47 > 0:14:51Australia is one of the largest gold-producers in the world.
0:14:54 > 0:14:57Since the gold rush in the 19th century,
0:14:57 > 0:15:02people have been flocking here with dreams of striking it rich.
0:15:02 > 0:15:05But gold is becoming more elusive.
0:15:05 > 0:15:09Discoveries have declined by 45% in the last decade -
0:15:09 > 0:15:12all very disappointing.
0:15:12 > 0:15:16That is until recently, when a specialist team began
0:15:16 > 0:15:21prospecting in an unlikely place - a eucalyptus forest.
0:15:24 > 0:15:27But, surely, money can't grow on trees?
0:15:27 > 0:15:30Here are some of the gum leaves here that we have been sampling.
0:15:32 > 0:15:35What we found by looking at them under the microscope, we've actually
0:15:35 > 0:15:39been able to see very small gold nuggets within the leaf structure.
0:15:43 > 0:15:46But hold on to your horses, before you all up sticks
0:15:46 > 0:15:49and head to Australia, secateurs in hand -
0:15:49 > 0:15:53this isn't exactly a get-rich-quick scheme,
0:15:53 > 0:15:55there's a catch.
0:15:57 > 0:16:01The pieces of gold are microscopic.
0:16:01 > 0:16:06Each nugget is only one fifth of the diameter of a human hair.
0:16:07 > 0:16:13In fact, it would take 500 trees to make just one gold ring,
0:16:13 > 0:16:17and the leaves go through numerous complex processes, taking the
0:16:17 > 0:16:21most advanced systems of microscopy to spot the micro-nuggets.
0:16:23 > 0:16:25So if the amount of gold in the leaves is
0:16:25 > 0:16:30so small, why is everyone getting so excited?
0:16:30 > 0:16:33Well, these tiny fragments of gold are actually
0:16:33 > 0:16:37indicators of something bigger - a lot bigger.
0:16:42 > 0:16:45The eucalyptus, or gum trees, that Colin and his team have been
0:16:45 > 0:16:50sampling have the deepest roots of any tree found in Australia.
0:16:50 > 0:16:54It can be so dry here that these roots need to grow deep
0:16:54 > 0:16:57underground to find hidden water sources,
0:16:57 > 0:17:01reaching anywhere between 20 and 50 metres deep.
0:17:01 > 0:17:06So deep, in fact, that some trees have quite literally...
0:17:08 > 0:17:10..struck gold.
0:17:12 > 0:17:18You see, these root systems act like hydraulic pumps sucking up water,
0:17:18 > 0:17:21and if there are mineral deposits beneath the tree,
0:17:21 > 0:17:25particles dissolved in that water can get sucked up, too.
0:17:27 > 0:17:30Although incredibly valuable to us, precious metals like gold
0:17:30 > 0:17:33are actually toxic to the eucalyptus.
0:17:33 > 0:17:36So the tree reacts,
0:17:36 > 0:17:38transporting the deposits out to the leaves,
0:17:38 > 0:17:40where they are eventually discarded.
0:17:45 > 0:17:49So importantly for Colin and his team,
0:17:49 > 0:17:52gold in the leaves means gold under the ground.
0:17:56 > 0:17:58By sampling the trees
0:17:58 > 0:18:03and by analysing the leaves to very low sensitivity for gold,
0:18:03 > 0:18:06you may be able to determine that the trees in one part of the forest
0:18:06 > 0:18:10have more gold in them than trees in the other part of the forest.
0:18:10 > 0:18:12Therefore, one area has more potential
0:18:12 > 0:18:14for mineralisation than the other.
0:18:17 > 0:18:20So the trees are indicators.
0:18:21 > 0:18:25They can show the prospectors exactly where the gold is.
0:18:28 > 0:18:32Which is crucial, because traditional mining methods result
0:18:32 > 0:18:37in thousands of hectares of forest being felled for gold exploration.
0:18:39 > 0:18:44Thanks to leaf sampling, gold-rich areas can be targeted
0:18:44 > 0:18:45far more effectively.
0:18:49 > 0:18:51And it's not just happening in Australia.
0:18:52 > 0:18:57In Canada, prospectors are locating mineral deposits using pine trees.
0:18:58 > 0:19:02Not the easiest place to sample, so they've had to get innovative -
0:19:02 > 0:19:04extreme sampling.
0:19:07 > 0:19:11Mining companies are no longer looking for a needle in a haystack.
0:19:11 > 0:19:14It's early days, but this technology could
0:19:14 > 0:19:19revolutionise the way we find precious metals for ever.
0:19:23 > 0:19:26So money doesn't grow on trees. Sadly nothing new there.
0:19:26 > 0:19:30But what it has done is perhaps stop the unnecessary destruction
0:19:30 > 0:19:32of our forests.
0:19:32 > 0:19:36It's an ecological result from a weird phenomenon.
0:19:37 > 0:19:42From mysterious holes appearing all over the Siberian wilderness...
0:19:43 > 0:19:47..to lakes and rivers being created underwater...
0:19:50 > 0:19:54..and the secrets of where to strike gold.
0:19:54 > 0:19:58It's a weird world of mysteries, just waiting to be revealed.
0:20:00 > 0:20:04And now, from talking in tongues to firing fish out of a cannon.
0:20:04 > 0:20:09Yes, you heard me correctly - firing fish out of a cannon.
0:20:09 > 0:20:12But first, how would you feel if you woke up in the morning...
0:20:12 > 0:20:15HIS VOICE CHANGES: ..and you didn't recognise
0:20:15 > 0:20:17the sound of your own voice?
0:20:17 > 0:20:19NORMAL: Or the words you were speaking?
0:20:28 > 0:20:30THEY SPEAK MANDARIN
0:20:30 > 0:20:32- BOTH:- Oh, my God!
0:20:32 > 0:20:36Meet Ben McMahon, born as an English-speaking Australian,
0:20:36 > 0:20:39he now speaks fluent Mandarin...
0:20:39 > 0:20:41HE SPEAKS MANDARIN
0:20:41 > 0:20:44..and stars in his very own Chinese talk show.
0:20:50 > 0:20:56His fluency, however, is down to something far more dramatic...
0:20:56 > 0:20:58- BOTH:- Oh, my God!
0:21:00 > 0:21:02..a car crash.
0:21:03 > 0:21:07I can remember the morning, having breakfast with my dad,
0:21:07 > 0:21:10but apart from that it was a blank week.
0:21:10 > 0:21:13From what I understand, I was a passenger in the car
0:21:13 > 0:21:15and a truck crashed into the side of the car.
0:21:17 > 0:21:20Ben was involved in a horrific collision which left him
0:21:20 > 0:21:23,in a coma for a week and when he woke up,
0:21:23 > 0:21:26things were very different.
0:21:30 > 0:21:33He could only speak Mandarin...
0:21:33 > 0:21:35HE SPEAKS MANDARIN
0:21:35 > 0:21:38..a language he studied at school,
0:21:38 > 0:21:41but, by his own admission, he was never fluent.
0:21:42 > 0:21:44So what on earth had happened?
0:21:44 > 0:21:48Well, to understand it, we first need a lesson in how our brains
0:21:48 > 0:21:50learn languages.
0:21:55 > 0:21:58Where language is stored in the brain
0:21:58 > 0:22:00is still somewhat of a mystery,
0:22:00 > 0:22:02but the area commonly associated
0:22:02 > 0:22:04with language is found in the
0:22:04 > 0:22:07frontal lobe of the left hemisphere,
0:22:07 > 0:22:11a region called the Broca's area.
0:22:16 > 0:22:20And although we don't know exactly what happened in Ben's
0:22:20 > 0:22:24brain following the accident, we do know that he was
0:22:24 > 0:22:29sitting on the left side of the car when it was hit, and suffered
0:22:29 > 0:22:32injuries to the left side of his head -
0:22:32 > 0:22:35specifically his frontal lobe.
0:22:35 > 0:22:38Experts believe that Ben's language switch could have been
0:22:38 > 0:22:42due to the damage to the Broca's area of his brain.
0:22:42 > 0:22:46We're still learning lots about why this phenomenon occurs when somebody
0:22:46 > 0:22:51speaks with a different language following a head injury or a stroke.
0:22:53 > 0:22:57In Ben's case it would seem that the area of the brain where
0:22:57 > 0:23:01he stored and used his native tongue, English,
0:23:01 > 0:23:07was more damaged than that where he had learned Mandarin as a child.
0:23:07 > 0:23:10Unintentionally switching languages in this way is
0:23:10 > 0:23:15known as bilingual aphasia, and those with the condition can
0:23:15 > 0:23:19often find themselves suddenly better at their second language.
0:23:20 > 0:23:26Ben was now speaking Mandarin more fluently than he ever had before.
0:23:26 > 0:23:29So had his accident improved his language skills?
0:23:30 > 0:23:31Surely not.
0:23:31 > 0:23:35It would seem that there's some sort of selective effect, such that
0:23:35 > 0:23:38one language is affected and not another.
0:23:38 > 0:23:41Once English was taken away from him he could only use Mandarin.
0:23:41 > 0:23:43Access to that second language is improved
0:23:43 > 0:23:46because that's all that you've got available to you.
0:23:46 > 0:23:48Luckily for Ben,
0:23:48 > 0:23:51once the swelling on his brain had gone down, his English
0:23:51 > 0:23:56began to come back, which should have meant that
0:23:56 > 0:23:59his days of speaking Mandarin were over -
0:23:59 > 0:24:03but, fantastically, Ben kept his new-found fluency.
0:24:05 > 0:24:08It seems that this freak accident permanently unlocked
0:24:08 > 0:24:12the second language and changed Ben's life for ever.
0:24:18 > 0:24:22When you think about it, language is really important to us.
0:24:22 > 0:24:27It's one of the things that truly defines us as human.
0:24:27 > 0:24:29And animals, well, of course, they are very, very
0:24:29 > 0:24:32good at communicating with one another - we know that.
0:24:32 > 0:24:33But what about plants?
0:24:33 > 0:24:36Surely they can't communicate in the same sort of way?
0:24:36 > 0:24:40Surely that's the stuff of fiction, isn't it?
0:24:40 > 0:24:43Let's take a walk in the woods,
0:24:43 > 0:24:46through the shadows and the dappled sunlight.
0:24:47 > 0:24:52Woodlands can be wonderfully mysterious places,
0:24:52 > 0:24:56with the whisper of the wind in the trees.
0:24:56 > 0:25:00But, wait, what if it's not the wind?
0:25:00 > 0:25:03What if the trees were really talking?
0:25:07 > 0:25:10When plants are attacked by insects
0:25:10 > 0:25:14or by microbes that are trying to invade and cause disease,
0:25:14 > 0:25:17straightaway those plants respond -
0:25:17 > 0:25:21they produce chemicals to deter aphids, for example.
0:25:24 > 0:25:27'What we didn't know until recently'
0:25:27 > 0:25:29was that plants can actually communicate
0:25:29 > 0:25:32this information to their neighbours.
0:25:33 > 0:25:37So plants DO talk to each other.
0:25:38 > 0:25:40Scientists have confirmed this
0:25:40 > 0:25:43by introducing aphids on to one plant
0:25:43 > 0:25:46and then seeing how the others respond.
0:25:47 > 0:25:49They found that those nearby
0:25:49 > 0:25:53soon began to prepare for an attack,
0:25:53 > 0:25:56pumping out distasteful defence chemicals
0:25:56 > 0:25:59before the aphids were even close.
0:25:59 > 0:26:02They knew the aphids were coming.
0:26:04 > 0:26:07They'd been warned of an approaching attack...
0:26:09 > 0:26:11..but how are they sharing this information?
0:26:11 > 0:26:17Is it through sound, vibrations, a sort of plant-based semaphore?
0:26:17 > 0:26:18Well, no.
0:26:18 > 0:26:22The plants aren't communicating directly at all.
0:26:22 > 0:26:24There's a middleman...
0:26:30 > 0:26:31..fungi.
0:26:34 > 0:26:37But it's not the mushroom we see growing above the surface.
0:26:38 > 0:26:42It's the tiny thread-like tubes found under the ground,
0:26:42 > 0:26:44known as mycelia.
0:26:45 > 0:26:47When we think of plants,
0:26:47 > 0:26:51we usually think of a plant as being an individual organism on its own,
0:26:51 > 0:26:56but, in fact, plants are intimately connected to fungi via their roots.
0:26:58 > 0:27:02These fungi, they form networks through the forest floor,
0:27:02 > 0:27:06so one plant could be connected to another plant
0:27:06 > 0:27:08by a fungal network.
0:27:10 > 0:27:12These networks move
0:27:12 > 0:27:15water and nutrients around them and, at the same time,
0:27:15 > 0:27:19they can move, communicating signals from one plant to another
0:27:19 > 0:27:23in the same way that we might use the telephone network
0:27:23 > 0:27:25or the internet.
0:27:26 > 0:27:32A vast network of natural cabling, perfect for secret chatter.
0:27:32 > 0:27:34So these subterranean networks
0:27:34 > 0:27:36transmit the messages from one plant to another.
0:27:39 > 0:27:40A bit like e-mail,
0:27:40 > 0:27:42or, in this case, tree-mail.
0:27:45 > 0:27:48And it doesn't just convey warnings.
0:27:48 > 0:27:51It transports vital resources, too.
0:27:53 > 0:27:56These fungi feed the plant with water
0:27:56 > 0:27:57and with mineral nutrients
0:27:57 > 0:28:00and, in return, the plant gives the fungus sugars
0:28:00 > 0:28:03that it's made during photosynthesis.
0:28:05 > 0:28:07It's a cosy arrangement
0:28:07 > 0:28:10and this wood-wide-web
0:28:10 > 0:28:13has another similarity to its technological counterpart.
0:28:16 > 0:28:19Much like your own home broadband,
0:28:19 > 0:28:22you getter a better service if you pay more.
0:28:22 > 0:28:28Yes, plants that give more food to the fungi get a faster connection.
0:28:28 > 0:28:29The fungus holds all the power
0:28:29 > 0:28:33because it can decide where the messages go.
0:28:34 > 0:28:36So unless you're keeping your fungus sweet,
0:28:36 > 0:28:40you may not find out about an aphid or disease attack
0:28:40 > 0:28:42until it's too late.
0:28:44 > 0:28:48A wild web of fungi - what a fantastic thought,
0:28:48 > 0:28:52but what might we learn from this sort of covert communication?
0:28:52 > 0:28:55Not just chitchat, as it turns out.
0:28:55 > 0:28:58In fact, a way to save human lives.
0:29:01 > 0:29:03Autumn in the UK.
0:29:04 > 0:29:06The skies are full of starlings,
0:29:06 > 0:29:11flying in beautiful formations, known as murmurations.
0:29:13 > 0:29:15With as many as 3,000 birds in flight,
0:29:15 > 0:29:20it's a remarkable spectacle of coordination and teamwork.
0:29:22 > 0:29:26And it's this behaviour that's of interest to Sabine Hauert -
0:29:26 > 0:29:28not because she's a twitcher, no -
0:29:28 > 0:29:31Sabine is a mathematical engineer.
0:29:31 > 0:29:34It's fascinating when you look up to the sky and you see
0:29:34 > 0:29:35these huge flocks of birds
0:29:35 > 0:29:38that are doing these beautiful, complex behaviours.
0:29:42 > 0:29:45You can keep adding birds to the flock, they keep flying as a group.
0:29:45 > 0:29:47If a bird falls from the sky,
0:29:47 > 0:29:49the whole flock doesn't fall to the ground,
0:29:49 > 0:29:51and together they're much better at avoiding predators
0:29:51 > 0:29:55for example, so they're better as a group than the individuals.
0:29:55 > 0:29:57And it was this flock movement
0:29:57 > 0:30:00that inspired Sabine to create something,
0:30:00 > 0:30:03well, slightly creepy...
0:30:05 > 0:30:07..her very own robotic swarm.
0:30:09 > 0:30:13We don't actually know what the birds are doing exactly -
0:30:13 > 0:30:16it is quite complicated to understand what each bird is doing.
0:30:16 > 0:30:20But what we can do is we have a set of basic rules we can follow
0:30:20 > 0:30:22that gives us behaviours that look like flocking,
0:30:22 > 0:30:24or like murmurations.
0:30:24 > 0:30:26WHIRRING
0:30:28 > 0:30:31And these basic rules are, you know, if you take a robot
0:30:31 > 0:30:34that's trying to behave like a bird in a flock,
0:30:34 > 0:30:36that robot would just look at its neighbours
0:30:36 > 0:30:38and then it would be attracted to its neighbours
0:30:38 > 0:30:41because it wants to stay in a group.
0:30:41 > 0:30:44That robot is also going to be repulsed from its neighbours -
0:30:44 > 0:30:47it wants to go away because otherwise they would all collide,
0:30:47 > 0:30:50and then it tries to match the speeds
0:30:50 > 0:30:53of the robots that are around it.
0:30:53 > 0:30:55With those three basic rules,
0:30:55 > 0:30:58you get some very interesting flocking-like behaviours.
0:31:05 > 0:31:09Swarming robots are something that scientists around the globe
0:31:09 > 0:31:11have been working to develop for many years.
0:31:12 > 0:31:18Moving intelligently and flying in a variety of formations.
0:31:18 > 0:31:23Their potential uses range from exploring hostile environments
0:31:23 > 0:31:26to delivering your latest online purchase.
0:31:27 > 0:31:32But Sabine wants to take her robots to a whole new level.
0:31:33 > 0:31:37Sabine has got an even more bird-brained idea.
0:31:37 > 0:31:41She wants to go weird, radical - she wants to go small -
0:31:41 > 0:31:44she wants to put the swarm inside you.
0:31:48 > 0:31:52It sounds like the stuff of science fiction,
0:31:52 > 0:31:55but the plans are already underway.
0:31:58 > 0:32:01Thankfully, Sabine is not an evil genius.
0:32:01 > 0:32:04Her mission is a noble one,
0:32:04 > 0:32:10because she plans to use her robot army against cancer.
0:32:13 > 0:32:17So, imagine that the red robots are the cancer cells
0:32:17 > 0:32:20and the green ones are the swarm
0:32:20 > 0:32:23programmed to flock together.
0:32:23 > 0:32:26When they come into contact with the cancer cells,
0:32:26 > 0:32:28they go into attack mode.
0:32:28 > 0:32:31They turn blue and bind together,
0:32:31 > 0:32:34preventing the cancer cells from spreading.
0:32:38 > 0:32:42Now, clearly, this is too big to fit inside the human body,
0:32:42 > 0:32:44but Sabine has plans.
0:32:44 > 0:32:49Once she's perfected the simulation of the cancer-killing swarm
0:32:49 > 0:32:52in the lab, she wants to make these things smaller.
0:32:52 > 0:32:54Much, much smaller.
0:32:58 > 0:33:01Once Sabine's got the perfect formation,
0:33:01 > 0:33:06she can downsize from robots to programmable particles.
0:33:06 > 0:33:12Swarms of up to a trillion drug-delivering nanoparticles,
0:33:12 > 0:33:15each tinier than the width of a human hair.
0:33:16 > 0:33:18Once in your system,
0:33:18 > 0:33:24these attack particles will swarm to seek out and target tumours.
0:33:28 > 0:33:30It's a nice example
0:33:30 > 0:33:33of how sometimes we can take the lead from the natural world,
0:33:33 > 0:33:35and occasionally, of course,
0:33:35 > 0:33:38we get to help animals back - and so we should,
0:33:38 > 0:33:39particularly when it's us
0:33:39 > 0:33:42that's caused them problems in the first place.
0:33:47 > 0:33:48Salmon.
0:33:49 > 0:33:52Every year they migrate thousands of kilometres
0:33:52 > 0:33:56from the ocean back to their freshwater spawning grounds.
0:33:59 > 0:34:02It's one of nature's greatest journeys,
0:34:02 > 0:34:06but increasingly they have a new hurdle to deal with.
0:34:09 > 0:34:12Now, salmon have an astonishing ability
0:34:12 > 0:34:15to leap and clear natural obstacles.
0:34:15 > 0:34:20But even the strongest, most determined salmon has its limits.
0:34:24 > 0:34:31There are already 75,000 dams in the United States alone
0:34:31 > 0:34:34and this number is set to increase.
0:34:34 > 0:34:38It's a bleak future for our salmon friends.
0:34:38 > 0:34:43So in some cases as much as 50 or more percent of the habitat
0:34:43 > 0:34:48that used to be used by the salmon has been completely blocked off.
0:34:52 > 0:34:55The numbers of fish that are now returning
0:34:55 > 0:34:59is a fraction of the historical numbers.
0:34:59 > 0:35:02Until now, the solution was fish ladders.
0:35:03 > 0:35:05OK, they're not actually ladders,
0:35:05 > 0:35:09but incremental steps along the side of a dam
0:35:09 > 0:35:13which take advantage of the fish's natural instinct to leap.
0:35:13 > 0:35:16These are OK for small dams,
0:35:16 > 0:35:20but they are no good for 40-metre-high structures.
0:35:20 > 0:35:26No salmon, however desperate, would climb a ladder that high.
0:35:26 > 0:35:28And on that account, some great minds
0:35:28 > 0:35:31have got together and come up with an invention which is...
0:35:31 > 0:35:34Um, well, I'll let you decide.
0:35:34 > 0:35:37It's called...the salmon cannon.
0:35:37 > 0:35:39It's not a joke.
0:35:39 > 0:35:44The salmon cannon is a brilliantly bizarre problem-solver.
0:35:44 > 0:35:47The company originally started in the fruit business,
0:35:47 > 0:35:49um, moving soft fruit,
0:35:49 > 0:35:53trying to solve the problem of
0:35:53 > 0:35:57taking fruit from a tree
0:35:57 > 0:36:01and putting it in a packing case in the field.
0:36:02 > 0:36:04So they came up with this.
0:36:06 > 0:36:08An octopus in an orchard.
0:36:08 > 0:36:09And you have to stay with me here -
0:36:09 > 0:36:13I promise this isn't descending into the realms of the ridiculous,
0:36:13 > 0:36:17because apples and salmon are both easily damaged
0:36:17 > 0:36:21and need to be transported carefully. No bruising.
0:36:22 > 0:36:25And if apples could be gently sucked through tubes
0:36:25 > 0:36:27to their destination,
0:36:27 > 0:36:28why not a salmon?
0:36:30 > 0:36:32So, the engineers got to work
0:36:32 > 0:36:35adapting their kit from fruit to fish.
0:36:38 > 0:36:41The cannon itself relies on...
0:36:41 > 0:36:44high-volume, but very low-pressure air
0:36:44 > 0:36:48to move the fish gently through this tube.
0:36:48 > 0:36:50The fish enters the cannon,
0:36:50 > 0:36:53a door closes behind it and then a blower
0:36:53 > 0:36:56pushes the fish and a little bit of water
0:36:56 > 0:36:58through this slippery tube.
0:36:58 > 0:37:00Though it's called a cannon,
0:37:00 > 0:37:05the device doesn't actually blast the fish out at force.
0:37:05 > 0:37:07It's more of a fish flume,
0:37:07 > 0:37:09pushing the salmon through the tubing.
0:37:09 > 0:37:13Quite a ride, though, at up to 15mph.
0:37:13 > 0:37:16But don't worry - the salmon pops out unscathed.
0:37:20 > 0:37:22So we've been very careful to make sure
0:37:22 > 0:37:25that the design doesn't harm the fish.
0:37:27 > 0:37:29They still spawn successfully
0:37:29 > 0:37:34and there's no impact on the number of young that fish can produce.
0:37:34 > 0:37:38With a fish fluming through every three seconds,
0:37:38 > 0:37:42this weird technology has already helped over 10,000 salmon
0:37:42 > 0:37:46clear the dams, and it's now being rolled out across rivers
0:37:46 > 0:37:51in America and Europe to help salmon on their way, in style.
0:37:52 > 0:37:56I wonder if they'll be offering them any frequent-flyer incentives.
0:37:59 > 0:38:02The salmon cannon!
0:38:02 > 0:38:04What a brilliant solution to a slippery problem.
0:38:04 > 0:38:08I just love it, absolutely genius!
0:38:09 > 0:38:11It's the least we could do,
0:38:11 > 0:38:14after putting so many "dam" obstacles in their way.
0:38:17 > 0:38:21So, a brain injury can really help you speak another language.
0:38:22 > 0:38:23- BOTH:- Oh, my God!
0:38:23 > 0:38:28While fungi are the woodland communication experts,
0:38:28 > 0:38:33in the future we might be cured by tiny swarms...
0:38:33 > 0:38:37and an apple-picking octopus has given salmon wings.
0:38:46 > 0:38:49So, our next chain of thought hops weirdly
0:38:49 > 0:38:53from some unexpected sniffing to some animal-inspired technology.
0:38:57 > 0:38:59Let me introduce our next story.
0:39:01 > 0:39:06Like many introductions, this one starts with a handshake.
0:39:07 > 0:39:10A greeting used all around the world,
0:39:10 > 0:39:12it's part of our cultural identity
0:39:12 > 0:39:17and can even be your entry into a secret society.
0:39:17 > 0:39:21But a recent scientific study may change our understanding
0:39:21 > 0:39:22of the handshake...
0:39:22 > 0:39:23for ever.
0:39:26 > 0:39:30This is the Weizmann Institute of Science in Israel.
0:39:32 > 0:39:35271 human test subjects are secretly filmed...
0:39:36 > 0:39:39..shaking hands.
0:39:39 > 0:39:43We sat them in a experimental room and we filmed them
0:39:43 > 0:39:44without them knowing.
0:39:46 > 0:39:49An experimenter would enter the room
0:39:49 > 0:39:50and shake their hands
0:39:50 > 0:39:53and we observed their behaviour.
0:39:54 > 0:39:57You see, Idan and his team had spotted something curious
0:39:57 > 0:39:59about handshaking.
0:40:01 > 0:40:04So together, they set up this very experiment to see
0:40:04 > 0:40:07if their suspicions were correct.
0:40:07 > 0:40:10But it wasn't the handshake itself they were interested in,
0:40:10 > 0:40:12it was what happened next.
0:40:13 > 0:40:14Watch closely.
0:40:16 > 0:40:17See that.
0:40:18 > 0:40:19And that?
0:40:20 > 0:40:22She did it too.
0:40:23 > 0:40:25Moving the hand to the face.
0:40:27 > 0:40:29It's a subtle gesture, basically.
0:40:29 > 0:40:32Actually bringing the hand to the nose
0:40:32 > 0:40:34and taking a loud inhale.
0:40:34 > 0:40:36Basically a sniff.
0:40:37 > 0:40:40Idan's suspicions were correct.
0:40:40 > 0:40:43Up to 40% of the test subjects were caught
0:40:43 > 0:40:47apparently sniffing their fingers following a handshake.
0:40:47 > 0:40:51Weird and maybe a bit gross, but why?
0:40:52 > 0:40:56What curious correlation could there be between the two?
0:40:57 > 0:41:01Idan needed to know exactly what his test subjects were so keen to sniff.
0:41:05 > 0:41:09So, he popped on a glove and shook hands again,
0:41:09 > 0:41:11gathering a sample from the subjects' palm.
0:41:13 > 0:41:17We shook hands using the glove
0:41:17 > 0:41:21and we just sampled the surface of the rubber
0:41:21 > 0:41:25of the actual glove to see which chemicals are being deposited.
0:41:30 > 0:41:32The samples on the glove showed the presence
0:41:32 > 0:41:35of a multitude of pheromones -
0:41:35 > 0:41:39chemical signals that reveal many aspects of a person,
0:41:39 > 0:41:44ranging from their emotional state to their genetic make-up.
0:41:44 > 0:41:48Idan's team believe that the purpose of the handshake could be to
0:41:48 > 0:41:52gather these vital clues, helping you determine
0:41:52 > 0:41:55whether the person you are greeting is scared,
0:41:55 > 0:42:01a dominance threat, or even how sexually compatible you might be.
0:42:05 > 0:42:08It's the type of valuable information that animals
0:42:08 > 0:42:11look for when they greet each other.
0:42:11 > 0:42:14Although they use a more direct and, some might say,
0:42:14 > 0:42:16less gentlemanly approach.
0:42:18 > 0:42:21And it's thought that we actually evolved the handshake
0:42:21 > 0:42:25to allow us to get the same information,
0:42:25 > 0:42:27but in a more discreet way.
0:42:32 > 0:42:34Just imagine all of the sniffing that
0:42:34 > 0:42:37goes on around a boardroom table.
0:42:37 > 0:42:38It's fascinating, isn't it?
0:42:38 > 0:42:40And the interesting thing is I'd never thought of it before,
0:42:40 > 0:42:43but from now on, whenever I shake someone's hand,
0:42:43 > 0:42:46I'm going to be consciously aware of whether I then...
0:42:47 > 0:42:49..have a little sniff or not.
0:42:54 > 0:42:58So, handshaking is a clever tool with all sorts of hidden uses,
0:42:58 > 0:43:00signals and meanings.
0:43:02 > 0:43:04But what if I were to tell you that it's
0:43:04 > 0:43:08not just us humans that are making use of it?
0:43:08 > 0:43:11SCREECHING
0:43:13 > 0:43:15I'm very interested in chimpanzees and their behaviour
0:43:15 > 0:43:18because they are our closest living relatives.
0:43:21 > 0:43:24We discovered a certain kind of grooming behaviour
0:43:24 > 0:43:26that's not typical for chimpanzees.
0:43:26 > 0:43:28It's called the grooming handclasp.
0:43:30 > 0:43:33Personally, I think it looks like they're sniffing
0:43:33 > 0:43:35each other's armpits.
0:43:35 > 0:43:38But scientists in Tanzania believe there may be more to
0:43:38 > 0:43:40this handclasp than meets the eye.
0:43:42 > 0:43:44We think that the chimpanzees might engage in
0:43:44 > 0:43:49a grooming handclasp behaviour to establish close social bonds.
0:43:49 > 0:43:52It's a behaviour where they give each other a handclasp,
0:43:52 > 0:43:55a handshake or a high-five, raise their arms up in the air
0:43:55 > 0:43:57and groom each other with the other free arm.
0:43:59 > 0:44:01It's a very intimate posture
0:44:01 > 0:44:04and they seem to do it more after some times of separation.
0:44:06 > 0:44:09Handclasping behaviour in chimpanzees had been
0:44:09 > 0:44:12witnessed in the wild in the 1960s,
0:44:12 > 0:44:16but Edwin's discovery at Chimfunshi Wildlife Sanctuary
0:44:16 > 0:44:19took this behaviour to a whole new level.
0:44:22 > 0:44:25The chimpanzees were split into four separate groups
0:44:25 > 0:44:29and what was so exciting was that each of these groups
0:44:29 > 0:44:31had developed their own style.
0:44:33 > 0:44:37They can either clasp each other's hands with the palm...
0:44:39 > 0:44:41..or with the wrist...
0:44:43 > 0:44:45..or even the forearm or elbow.
0:44:46 > 0:44:49Edwin realised that the handclasping behaviour
0:44:49 > 0:44:53was part of each group's identity.
0:44:53 > 0:44:55It wasn't part of their genetic make-up -
0:44:55 > 0:44:59it was learned and part of their social character.
0:45:01 > 0:45:05So, just like humans, depending on where they were born
0:45:05 > 0:45:07and who they grew up with,
0:45:07 > 0:45:11the chimpanzees develop a very specific style of handshake.
0:45:13 > 0:45:16And these handshakes were being passed down
0:45:16 > 0:45:18from generation to generation.
0:45:20 > 0:45:22The handclasp behaviour in chimpanzees, it links to
0:45:22 > 0:45:25our human greeting behaviour in a sense that it's
0:45:25 > 0:45:28something that we learn socially.
0:45:28 > 0:45:31It's something that you are not born with, you just copy each
0:45:31 > 0:45:35other's behaviour and, therefore, a group tradition emerges.
0:45:36 > 0:45:39So, one member of the troop comes up with something new,
0:45:39 > 0:45:41some of the others take it in,
0:45:41 > 0:45:44they copy it and then, critically,
0:45:44 > 0:45:45they pass it on.
0:45:45 > 0:45:47It's a bit like a new craze at school.
0:45:51 > 0:45:54And I've got to tell you that shaking hands is not the only
0:45:54 > 0:45:57fashion that's taken off in the chimp community.
0:45:59 > 0:46:02No, at the same sanctuary, Edwin also witnessed
0:46:02 > 0:46:04some other strange behaviours.
0:46:06 > 0:46:09It was behaviour that started with one female who just started
0:46:09 > 0:46:11putting grass in her ear...
0:46:13 > 0:46:15..and instead of just tickling her ear,
0:46:15 > 0:46:17she would just leave it there for the whole time
0:46:17 > 0:46:21and started doing other things, like playing or grooming.
0:46:21 > 0:46:24So, she would just walk around with grass in her ear -
0:46:24 > 0:46:27sometimes out of two ears -
0:46:27 > 0:46:30and that is the most peculiar thing I've ever seen in chimpanzees.
0:46:33 > 0:46:37The chimpanzee was called Julie - she was known to be a bit kooky,
0:46:37 > 0:46:39if a chimp can be such a thing,
0:46:39 > 0:46:41so Edwin wasn't too surprised.
0:46:43 > 0:46:48Until, as the weeks went by, he realised something extraordinary -
0:46:48 > 0:46:52the other chimpanzees in the group had started to copy her.
0:46:55 > 0:46:57The grass-in-the-ear phenomenon can tell us
0:46:57 > 0:47:00about chimpanzee societies in the sense that it sheds light
0:47:00 > 0:47:02on the fact that chimpanzees copy each other's behaviour,
0:47:02 > 0:47:05even when there's no function for it.
0:47:05 > 0:47:09So, unlike the grooming handclasp behaviour, which has a purpose,
0:47:09 > 0:47:13the grass in the ear seems to have no benefit at all
0:47:13 > 0:47:15to the chimpanzees.
0:47:15 > 0:47:17So, why on earth are they doing it?
0:47:18 > 0:47:22This might be considered as a case of chimpanzees using
0:47:22 > 0:47:26things in their environment to accessorise themselves.
0:47:26 > 0:47:30So, it's a new chimpanzee fashion craze.
0:47:30 > 0:47:35Where Julie's inspiration came from, we may never know,
0:47:35 > 0:47:38but what we do know is that it's become a tradition
0:47:38 > 0:47:42for the chimps in this group and, some might say,
0:47:42 > 0:47:45Julie was the trendsetter for this new fashion fad.
0:47:53 > 0:47:55Um, bit of grass behind the ear.
0:47:55 > 0:47:59Not exactly the most inspired fashion choice, is it?
0:47:59 > 0:48:02But very often, changes in an animals' appearance have got
0:48:02 > 0:48:03nothing to do with fashion sense.
0:48:03 > 0:48:06They, in fact, can be real life-savers.
0:48:08 > 0:48:12All of these animals have gained a new lease of life
0:48:12 > 0:48:14with the help of some human intervention.
0:48:16 > 0:48:18Derby was born with deformed front legs,
0:48:18 > 0:48:21but, with specially designed replacements,
0:48:21 > 0:48:24he can now walk, run and romp on all fours.
0:48:27 > 0:48:31This dolphin was given a custom-made prosthetic fluke...
0:48:33 > 0:48:36..and stabilisers were the perfect support for this goat
0:48:36 > 0:48:39born with underdeveloped hind limbs.
0:48:40 > 0:48:45Modern technology gave this lot a second chance to love life again.
0:48:47 > 0:48:49And with further advances in science,
0:48:49 > 0:48:53even the most complex of animal injuries can be repaired.
0:48:58 > 0:49:03July 2014, off the Mediterranean coast of Turkey,
0:49:03 > 0:49:06a loggerhead turtle was swimming near the surface
0:49:06 > 0:49:09when it was struck by a boat propeller...
0:49:11 > 0:49:12..ripping off its lower jaw.
0:49:20 > 0:49:23It was rushed to a local turtle rescue centre.
0:49:27 > 0:49:31It had a fractured jaw and 60% of the right side of its beak
0:49:31 > 0:49:33was missing.
0:49:33 > 0:49:36Unable to eat on its own, the turtle had to be handfed.
0:49:38 > 0:49:43So, was this loggerhead then destined for a life in captivity?
0:49:47 > 0:49:51The problem is that a turtle's beak is a vital tool
0:49:51 > 0:49:52for its survival.
0:49:52 > 0:49:55It's used to break open hard-shelled prey.
0:49:55 > 0:49:59Without a beak, there was no chance of an independent life.
0:50:00 > 0:50:04But hope wasn't entirely lost.
0:50:04 > 0:50:07Recent news stories showed animals that were in the process
0:50:07 > 0:50:13of being helped by some rather impressive new technology.
0:50:13 > 0:50:18So, could this be the answer for our lone loggerhead?
0:50:18 > 0:50:23Well, some Turkish tech whizzes decided to take on the challenge
0:50:23 > 0:50:26and make the first ever 3D-printed turtle beak.
0:50:30 > 0:50:35These scientists had only ever worked on human prosthetics,
0:50:35 > 0:50:38so this animal challenge would be tough.
0:50:38 > 0:50:42Taking scans of the turtle's face, they hoped that they could
0:50:42 > 0:50:45recreate a beak that would be the perfect fit.
0:50:45 > 0:50:51After four months in development, the titanium beak was printed
0:50:51 > 0:50:56and the turtle underwent a 2½-hour operation to fit it,
0:50:56 > 0:50:58involving ground-breaking surgery.
0:51:06 > 0:51:09And, finally, it has its new beak.
0:51:14 > 0:51:17It's still undergoing observation to make sure it doesn't
0:51:17 > 0:51:21reject the prosthetic, but the hope is that, soon, it could be
0:51:21 > 0:51:25released back into its ocean home.
0:51:32 > 0:51:36So, state-of-the-art technology helps these animals live long,
0:51:36 > 0:51:39fruitful and happy lives, which is a good thing.
0:51:39 > 0:51:42And it's not all a one-way street, either, because sometimes
0:51:42 > 0:51:49the genius of animal design helps us solve our technological conundrums.
0:51:52 > 0:51:54Case in point -
0:51:54 > 0:51:59how could a spot of bird-watching revolutionise rail travel?
0:52:02 > 0:52:06The Shinkansen, otherwise known as the bullet train.
0:52:08 > 0:52:12This is the jewel in Japan's rail network.
0:52:13 > 0:52:19With an estimated 64 million people a day travelling by train,
0:52:19 > 0:52:25this futuristic, high-speed service revolutionised rail travel
0:52:25 > 0:52:28when it was introduced back in 1964.
0:52:28 > 0:52:30However, in the early days,
0:52:30 > 0:52:35when these trains sped from city to city, strange things started
0:52:35 > 0:52:39happening in the countryside they were travelling through.
0:52:39 > 0:52:41BOOM ECHOES
0:52:41 > 0:52:43BIRDS SQUAWK
0:52:43 > 0:52:47Deafening booms were heard, sending shock waves through
0:52:47 > 0:52:49the surrounding villages.
0:52:49 > 0:52:50BOOM ECHOES
0:52:50 > 0:52:55Reported from far and wide, these explosive sounds coincided
0:52:55 > 0:52:57with the train passing through a tunnel.
0:53:01 > 0:53:04As an acoustic engineer, this is fascinating, cos it's such
0:53:04 > 0:53:06an unusual phenomena.
0:53:09 > 0:53:12Fundamentally, sound is little variations in pressure.
0:53:12 > 0:53:13As I talk to you now, I'm creating little
0:53:13 > 0:53:16fluctuations in pressure that you're listening to.
0:53:16 > 0:53:21And it's the movement of air creating sound which explains
0:53:21 > 0:53:23what was happening in the tunnels.
0:53:23 > 0:53:26As a train goes through the countryside, it's pushing air
0:53:26 > 0:53:29out from the front and down its sides.
0:53:29 > 0:53:33Now, when it reaches a tunnel, that air's got nowhere to go.
0:53:33 > 0:53:36What you get is a pulse of air being generated.
0:53:38 > 0:53:41It's a bit like putting a plunger down the end of a tube.
0:53:42 > 0:53:46The air gets trapped in front of the train and when it reaches
0:53:46 > 0:53:51the exit, this compressed air is expelled,
0:53:51 > 0:53:55creating a loud boom.
0:53:58 > 0:54:02It explains the sound, but why was this phenomenon only
0:54:02 > 0:54:07occurring in Japan, when trains go through tunnels all over the world?
0:54:08 > 0:54:10These tunnel booms are actually quite rare,
0:54:10 > 0:54:13because you need three unusual factors to come together.
0:54:13 > 0:54:15You need a high-speed train, you need very long tunnels,
0:54:15 > 0:54:18but you also need very narrow tunnels.
0:54:18 > 0:54:22And that was what made the Japanese problem unique.
0:54:22 > 0:54:26Not only were its trains fast, but the tunnels were narrow
0:54:26 > 0:54:30and exceptionally long, meaning there wasn't enough
0:54:30 > 0:54:32space for the air to escape.
0:54:37 > 0:54:42So, we understand the problem, but how can we solve it?
0:54:42 > 0:54:45Clearly, replacing the tunnels wasn't an option.
0:54:46 > 0:54:49Experts were reaching a dead end.
0:54:51 > 0:54:57Until, one day, a solution came from a very unusual place.
0:54:58 > 0:55:05Eiji Nakatsu, an engineer from Japan Railways, was out bird watching.
0:55:05 > 0:55:10Through his binoculars, he noticed the exquisite dive of a kingfisher.
0:55:21 > 0:55:23Well, a kingfisher has a pointy bill, so when it
0:55:23 > 0:55:27dives into the water to get fish, it cuts through the water very easily.
0:55:27 > 0:55:31You can imagine what it would be like if it had a flat-fronted beak,
0:55:31 > 0:55:35it would be really painful every time it tried to get into the water.
0:55:35 > 0:55:39So, could the streamlined bill of the kingfisher be the answer?
0:55:45 > 0:55:48Over the years, the animal kingdom has provided
0:55:48 > 0:55:52a wealth of inspiration to many of our design conundrums.
0:55:54 > 0:55:59From shark skin that inspired super-sleek swimwear...
0:56:02 > 0:56:04..to termite mounds that have informed
0:56:04 > 0:56:07air-conditioning systems in buildings
0:56:09 > 0:56:13Yet again, nature had the answer.
0:56:16 > 0:56:21But the blunt-fronted bullet train needed a nose job.
0:56:21 > 0:56:25They transplanted a diving bird's beak onto the front of the train.
0:56:25 > 0:56:28If you make the train pointed, it cuts through
0:56:28 > 0:56:30the air at the start of the tunnel. And what this means is,
0:56:30 > 0:56:35the pressure pulse is not so severe and you don't get such bad booms.
0:56:35 > 0:56:39Eiji Nakatsu and his team put their bird-inspired train
0:56:39 > 0:56:43into production and they were amazed by the results.
0:56:44 > 0:56:49The new shape not only reduced the sonic booms, it reduced tunnel
0:56:49 > 0:56:55pressure changes and lowered power consumption, too - all good stuff.
0:56:55 > 0:57:00But, most importantly, villagers near the train lines could
0:57:00 > 0:57:06finally have a peaceful life, free of mysterious booms.
0:57:09 > 0:57:12The silent splash of the kingfisher had helped solve
0:57:12 > 0:57:15the engineer's design dilemma.
0:57:15 > 0:57:19It's a perfect example of a hi-tech human problem
0:57:19 > 0:57:21being solved by nature.
0:57:24 > 0:57:30So, handshakes might allow us to sniff each other in secret.
0:57:31 > 0:57:36And show that chimpanzees have a sense of identity and style.
0:57:36 > 0:57:403D printing could be bringing new life to animals who
0:57:40 > 0:57:44thought their number was up.
0:57:44 > 0:57:48Whilst a bird's beak provided the accessory required to improve
0:57:48 > 0:57:51the world's fastest train.
0:57:51 > 0:57:58We've lifted the lid on all that's weird about the natural world.
0:57:58 > 0:58:00What can I say?
0:58:00 > 0:58:04We told you it was going to be weird and, boy, has it!
0:58:04 > 0:58:06It's been curious, it's been astonishing,
0:58:06 > 0:58:09it's been sometimes surprising and, at others,
0:58:09 > 0:58:11absolutely terrifying.
0:58:11 > 0:58:13But the one thing that's still for sure
0:58:13 > 0:58:17is that there's a lot more weirdness just waiting out there.
0:58:17 > 0:58:22So, try and find it for yourself, weirdos!