0:00:03 > 0:00:07Created by fire and titanic upheavals of the earth,
0:00:07 > 0:00:11islands make up one sixth of the landmass of our planet.
0:00:13 > 0:00:16They are lenses through which to study the complex workings
0:00:16 > 0:00:18of evolution.
0:00:18 > 0:00:22Tropical islands have been important in the understanding
0:00:22 > 0:00:26of evolution ever since Charles Darwin visited the Galapagos
0:00:26 > 0:00:28early in the 19th century.
0:00:28 > 0:00:31We're going to visit three very different tropical islands
0:00:31 > 0:00:35to see what THEY can tell us about evolution, even today.
0:00:37 > 0:00:39Islands are natural laboratories.
0:00:41 > 0:00:45Full of novel experiments in natural selection
0:00:45 > 0:00:47and evolutionary wonders.
0:00:49 > 0:00:54But there's much more to evolution than the survival of the fittest.
0:00:54 > 0:00:56The phrase wasn't even in Darwin's first edition
0:00:56 > 0:00:58of The Origin Of Species.
0:01:01 > 0:01:07'I'm exploring other major influences - geology, geography...'
0:01:07 > 0:01:08Hello!
0:01:08 > 0:01:10'..isolation and time.'
0:01:10 > 0:01:14- You found this? - Yes.- Giants' bones.
0:01:14 > 0:01:18I'll be charting the life cycle of islands -
0:01:18 > 0:01:23from birth and colonisation to the burst of evolutionary creativity
0:01:23 > 0:01:26that often accompanies maturity...
0:01:26 > 0:01:28They take the leaves so delicately.
0:01:30 > 0:01:33..and what eventually happens when an island grows old
0:01:33 > 0:01:35and nears its end.
0:01:35 > 0:01:41You can almost feel this unforgiving rock return ultimately to sea level.
0:01:42 > 0:01:45Places of extinction as well as creation.
0:01:45 > 0:01:49Our story will reveal evolution in action...
0:01:49 > 0:01:54We just discovered new species of the mouse lemurs.
0:01:54 > 0:01:57- So mouse lemurs are still actively evolving?- Yeah.
0:01:57 > 0:02:04..and how life generates abundance, even from a blank slate.
0:02:06 > 0:02:09Islands are the ideal place to understand
0:02:09 > 0:02:12the rules that govern evolution.
0:02:27 > 0:02:30So far in this series, I've been to Hawaii,
0:02:30 > 0:02:33and seen how a freshly born volcanic island is formed
0:02:33 > 0:02:38and colonised by life, and how species adapt to new environments.
0:02:45 > 0:02:48Then, in Madagascar's rainforest,
0:02:48 > 0:02:52I investigated how a large island matures,
0:02:52 > 0:02:54and the extraordinary diversity of habitats,
0:02:54 > 0:02:58plants and animals that long periods of time engender.
0:03:00 > 0:03:04In this third and final episode, I travel to Madeira -
0:03:04 > 0:03:08an island far into the geological ageing process,
0:03:08 > 0:03:13and one that is a refuge for species that are elsewhere extinct.
0:03:18 > 0:03:22It's easy to be seduced by Madeira as a holiday paradise.
0:03:22 > 0:03:24The land of flowers.
0:03:24 > 0:03:27In fact, it's something of an ark,
0:03:27 > 0:03:30but it's an ark where time has not stood still.
0:03:30 > 0:03:34Where evolution is still in action.
0:03:34 > 0:03:37It's a wonderful place to understand the processes underlying
0:03:37 > 0:03:39the origin of species.
0:03:44 > 0:03:47500 miles from the southern tip of Europe
0:03:47 > 0:03:50and 360 from the west coast of Africa,
0:03:50 > 0:03:55Madeira is the largest of a group of ancient volcanic islands.
0:03:59 > 0:04:01And at its heart is the laurisilva.
0:04:08 > 0:04:10Millions of years ago,
0:04:10 > 0:04:13this forest struck root in Madeira's rich volcanic soil.
0:04:19 > 0:04:23And while the biting cold of the last ice age wiped it out
0:04:23 > 0:04:25almost everywhere in Europe,
0:04:25 > 0:04:30fragments of special forest survived on this subtropical island.
0:04:33 > 0:04:36Today this remote and ancient forest can be reached
0:04:36 > 0:04:41following the traditional man-made water channels known as levadas.
0:04:44 > 0:04:49Built over centuries, there are more than 1,000 miles of them,
0:04:49 > 0:04:54lined by invasive agapanthus brought here by the Portuguese settlers.
0:04:54 > 0:04:58The levadas irrigate crops far below.
0:04:59 > 0:05:01But they also provide gateways.
0:05:03 > 0:05:06On the south side of the mountain, the laurisilva is mixed with
0:05:06 > 0:05:11troublesome foreign weeds, but on the other side of the mountain
0:05:11 > 0:05:13there is a secret Eden,
0:05:13 > 0:05:16and I can reach it through an underground tunnel.
0:05:28 > 0:05:30Ooooh...
0:05:37 > 0:05:41It's a bit narrow here. Bloody hell.
0:05:41 > 0:05:45'The levada tunnels are a treacherous walk for the unwary,
0:05:45 > 0:05:48'but others have made a home here.'
0:05:49 > 0:05:53I've just found, in the most unlikely place, in the dark,
0:05:53 > 0:05:55a spider.
0:05:56 > 0:06:01Maybe it's one of those special dark-adapted cave spiders.
0:06:06 > 0:06:09After several hundred feet, I spot distant daylight.
0:06:18 > 0:06:21Oh, wow.
0:06:23 > 0:06:27It's like suddenly going back three million years.
0:06:31 > 0:06:35A designated UNESCO World Heritage site,
0:06:35 > 0:06:39the laurisilva is a living relic of Europe
0:06:39 > 0:06:42as it was millions of years ago.
0:06:45 > 0:06:49Guided by palaeobotanist Carlos A Gois Marques,
0:06:49 > 0:06:52who probably knows more about the island's ancient plants
0:06:52 > 0:06:54than anyone else,
0:06:54 > 0:06:59I first examine the tree from which the forest derives its name.
0:06:59 > 0:07:03Laurisilva means forest of laurels.
0:07:06 > 0:07:14Well, now, that is a fine-looking...old tree.
0:07:14 > 0:07:19- And which one is it?- Well, it's called the stink laurel because
0:07:19 > 0:07:24of its wood, it's very smelly. It smells. It stinks, really.
0:07:24 > 0:07:26And do we know why that might be?
0:07:26 > 0:07:30Most probably it could be like a defence for the tree.
0:07:30 > 0:07:34I gather this has a history, though, this particular tree.
0:07:34 > 0:07:38Yes, this tree once lived in Europe and became extinct
0:07:38 > 0:07:43because of climate change, but they are still living here in Madeira.
0:07:43 > 0:07:44So it really is true
0:07:44 > 0:07:49- that we have walked into a sort of time warp here.- Exactly.
0:07:55 > 0:07:58These tall and ancient laurel species are not alone.
0:08:01 > 0:08:06Other strange and special endemic plants evolved alongside them.
0:08:06 > 0:08:08Even turning into giants.
0:08:09 > 0:08:14This is the common or garden spurge, you probably know,
0:08:14 > 0:08:18but look what it does in the laurisilva.
0:08:19 > 0:08:21It's evolved into a tree.
0:08:30 > 0:08:34Turning into a tree, evolving what is called woodiness,
0:08:34 > 0:08:37is an evolutionary strategy
0:08:37 > 0:08:40also adopted by this relative of the dandelion.
0:08:43 > 0:08:45From seeds carried by bird or by wind,
0:08:45 > 0:08:47such plants had to compete for light
0:08:47 > 0:08:50with the evergreen laurisilva forest,
0:08:50 > 0:08:55and one strategy available to them was to become giants themselves.
0:08:58 > 0:09:00Oh, yes!
0:09:02 > 0:09:04This is a foxglove.
0:09:04 > 0:09:07It's a foxglove that's turned into a tree.
0:09:07 > 0:09:10The flowers are yellow, not pink, like our native foxgloves,
0:09:10 > 0:09:13but it's a real tree hanging out of a cliff.
0:09:15 > 0:09:19Ha! Well, let's see if we can get one. Yes, we can.
0:09:19 > 0:09:21Look at that.
0:09:21 > 0:09:23It's a pretty...
0:09:25 > 0:09:27I suppose a raceme is the technical term for it.
0:09:27 > 0:09:32A bundle of flowers all put together in a terminal bunch,
0:09:32 > 0:09:34and very attractive too.
0:09:37 > 0:09:41In the laurisilva forest, size matters.
0:09:42 > 0:09:45In the absence of grazing animals, defences such as prickles
0:09:45 > 0:09:48and spines became redundant.
0:09:48 > 0:09:50A case of "use it or lose it".
0:09:54 > 0:09:56It's a special bramble.
0:09:56 > 0:10:00Yes. It's a bramble that only grows in laurisilva.
0:10:00 > 0:10:02And has it got some particular features?
0:10:02 > 0:10:05Oh, yes. As you can see it, it has big leaves.
0:10:06 > 0:10:08Very large leaves. Yes.
0:10:08 > 0:10:12And also we have fewer prickles on it.
0:10:16 > 0:10:20Not many spines, and is that because of not much browsing pressure?
0:10:20 > 0:10:25Yeah, most probably this plant evolved in the...in a place
0:10:25 > 0:10:28where there are no mammals to eat the leaves away.
0:10:28 > 0:10:31So it doesn't need much defence.
0:10:31 > 0:10:34And also, it has big blackberries.
0:10:34 > 0:10:36Big blackberries. That sounds good.
0:10:36 > 0:10:41Yes. Unfortunately you are not on the season of the blackberries.
0:10:44 > 0:10:48Back in his lab in the University of Funchal, Carlos shows me how long
0:10:48 > 0:10:52it has taken some of the newer forest plants to evolve into giants.
0:10:55 > 0:10:59So, as you can see, you have here an example of a fossil bramble.
0:10:59 > 0:11:02- A fossil bramble? Can I look down the...?- Yeah, of course.
0:11:02 > 0:11:05Oh, yeah. Three leaflets.
0:11:05 > 0:11:08These are the tips of the bramble itself.
0:11:08 > 0:11:11It was found in the north part of the island
0:11:11 > 0:11:15and it's 1.5 million years old.
0:11:15 > 0:11:19So we're looking back all that time at what you might say is
0:11:19 > 0:11:22an ancestor of what we have on the island today.
0:11:22 > 0:11:26- Exactly.- So over the last million-and-a-half years,
0:11:26 > 0:11:29- this has become bigger. - Exactly.
0:11:29 > 0:11:32And is now a part of the laurisilva flora that is
0:11:32 > 0:11:35- so special to the island.- Exactly.
0:11:35 > 0:11:391.5 million years was time enough to this bramble
0:11:39 > 0:11:41to evolve into something new.
0:11:43 > 0:11:46And deposits like this are extremely rare
0:11:46 > 0:11:48because we are in a volcanic island.
0:11:48 > 0:11:51- So you must have been really pleased when you found it.- Oh, yeah, very.
0:11:51 > 0:11:54Very pleased. It's so rare to find something like this.
0:11:58 > 0:12:02In one-and-a-half million years, the leaves of this fossil have
0:12:02 > 0:12:06grown to be five times larger than when it first arrived.
0:12:09 > 0:12:11A similar growth spurt has accompanied
0:12:11 > 0:12:14the evolution of another Madeiran giant.
0:12:15 > 0:12:20Spiders can be carried far and wide by the wind, and wolf spiders,
0:12:20 > 0:12:22like this nocturnal hunter,
0:12:22 > 0:12:25have possibly been here for millions of years.
0:12:27 > 0:12:31But on the nearby Desertas archipelago -
0:12:31 > 0:12:33a group of small islands off the coast of Madeira -
0:12:33 > 0:12:37they have evolved into an arachnophobe's nightmare.
0:12:43 > 0:12:47The island's only residents are two park rangers.
0:12:47 > 0:12:51One of them, Isamberto Silva, has been ferried back to Madeira
0:12:51 > 0:12:56by the Portuguese navy, with special permission to show me one.
0:12:58 > 0:13:03Since she can give a very nasty bite, I'm taking no chances.
0:13:03 > 0:13:07I'm about to meet Europe's largest spider,
0:13:07 > 0:13:13Hogna ingens, which lives on a small island just off Madeira.
0:13:13 > 0:13:19And I am looking forward to the prospect in a grisly kind of way.
0:13:23 > 0:13:26Hogna ingens is a wolf spider.
0:13:28 > 0:13:33Cousin of the familiar arachnids found in nearly all houses.
0:13:34 > 0:13:40The world's fastest spiders can move at 50cm a second.
0:13:40 > 0:13:44And as you can see, Hogna ingens isn't far behind.
0:14:04 > 0:14:09Every island in this group of islands has an endemic species,
0:14:09 > 0:14:12and they're all a little scary and rather large.
0:14:15 > 0:14:19A wonderful example of island gigantism.
0:14:20 > 0:14:23Will he come on my glove, do you think?
0:14:25 > 0:14:28'According to Mediterranean tradition, it was the bite
0:14:28 > 0:14:31'of the wolf spider that gave rise
0:14:31 > 0:14:34'to the frenzied dance of the tarantella.
0:14:34 > 0:14:38'So when European explorers found even larger spiders
0:14:38 > 0:14:44'in the New World, they called them tarantellas, or tarantulas.'
0:14:46 > 0:14:48Well, I hope she's comfortable.
0:14:48 > 0:14:51I'm a little uncomfortable. HE CHUCKLES
0:14:53 > 0:14:59Well, I think, charming though it is, I don't want to move too fast,
0:14:59 > 0:15:04so maybe I can hand it back to Daddy.
0:15:08 > 0:15:12And have you been bitten by this spider?
0:15:12 > 0:15:15Yes. They have a poison.
0:15:15 > 0:15:17They have a...
0:15:17 > 0:15:19coagulation...
0:15:19 > 0:15:24- Oh, I know, it breaks down the tissue and produces a big scar.- Yes.
0:15:27 > 0:15:30'Having collected spiders like this since he was a boy,
0:15:30 > 0:15:33'Isamberto has built up immunity to their venom.
0:15:35 > 0:15:38'But it's lethal to the small lizards it preys on.
0:15:41 > 0:15:44'Moving from a diet dominated by insects to one including lizards
0:15:44 > 0:15:50'no doubt helped nudge Hogna ingens to become larger.'
0:15:54 > 0:15:57Giants are a common feature of island life,
0:15:57 > 0:16:02but evolution does place limits on a spider's size.
0:16:02 > 0:16:06Even with unlimited resources and no threat of predators,
0:16:06 > 0:16:10there is still a ceiling on how big you can get.
0:16:13 > 0:16:16Spiders - like insects or crustaceans - are arthropods.
0:16:16 > 0:16:19That is, they have jointed legs.
0:16:19 > 0:16:22They carry their skeleton on the outside,
0:16:22 > 0:16:26so their legs, for example, are like tubes with the muscles inside.
0:16:26 > 0:16:31This imposes a real limit on how large they can grow.
0:16:33 > 0:16:35Surprisingly, it's not just gravity
0:16:35 > 0:16:38which imposes limits on the size of arthropods.
0:16:38 > 0:16:42Oxygen also has a crucial role to play.
0:16:42 > 0:16:46Because they have their skeleton on the outside,
0:16:46 > 0:16:51arthropods have to absorb oxygen, as it were, through the skin.
0:16:51 > 0:16:57This too imposes severe limits on the size to which they can grow.
0:16:57 > 0:17:02In some arthropods, there are little tubes inside the animal
0:17:02 > 0:17:04that increase the surface area,
0:17:04 > 0:17:07but even they can only operate up to a certain size.
0:17:07 > 0:17:10As an arthropod gets bigger, the volume increases
0:17:10 > 0:17:13disproportionately to the surface area.
0:17:13 > 0:17:15In other words, once you get large,
0:17:15 > 0:17:19it's harder and harder to get enough oxygen into the system.
0:17:22 > 0:17:26Today, the biggest living arthropods are found in the oceans.
0:17:29 > 0:17:33Water contains roughly 12% more oxygen than air,
0:17:33 > 0:17:38and its buoyancy neutralises the limits gravity imposes on land,
0:17:38 > 0:17:43which means that these spider crabs can grow legs six feet long
0:17:43 > 0:17:45and weigh upwards of 40 pounds.
0:17:47 > 0:17:50Nevertheless, in the past, terrestrial arthropods have
0:17:50 > 0:17:54certainly grown much bigger than they do today.
0:17:54 > 0:17:56300 million years ago,
0:17:56 > 0:17:59the atmosphere was exceptionally rich in oxygen
0:17:59 > 0:18:02and that allowed for giants to appear.
0:18:02 > 0:18:06Dragonflies larger than any that have lived on earth.
0:18:06 > 0:18:08Millipedes two metres long.
0:18:08 > 0:18:13It must have been a rather wonderful, if bizarre, world.
0:18:21 > 0:18:27Today the giants of the Madeiran archipelago live in a kind of ark.
0:18:27 > 0:18:29Laurisilva forest was once found
0:18:29 > 0:18:32all over the Mediterranean and North Africa.
0:18:37 > 0:18:40What remains is just a fragment.
0:18:40 > 0:18:45A time capsule isolated from the outside world whose inhabitants,
0:18:45 > 0:18:49both large and small, have been spared from the predators
0:18:49 > 0:18:53and competitors that might otherwise have led to their extinction.
0:18:55 > 0:19:00If a special habitat persists, then so will the species adapted to it.
0:19:01 > 0:19:04And nowhere proves this better
0:19:04 > 0:19:07than the wonderful laurisilva forest in Madeira.
0:19:13 > 0:19:17But the laurisilva isn't the only persistent habitat on Madeira.
0:19:20 > 0:19:23Directly beneath it lies another ancient ark
0:19:23 > 0:19:25of a very different kind.
0:19:27 > 0:19:31This subterranean world was created by the island's last gasp
0:19:31 > 0:19:36of volcanic activity nearly one million years ago.
0:19:40 > 0:19:43I'm in a cave deep beneath the mountains of Madeira.
0:19:43 > 0:19:47It's a special kind of cave. It's a lava tube.
0:19:47 > 0:19:52And once it was flowing with red-hot liquid volcanic rock.
0:19:59 > 0:20:05Hot basalt magma is extremely liquid and fluid. It flows very fast.
0:20:06 > 0:20:10As it cools, though, it produces a crust on top
0:20:10 > 0:20:12which actually seals the lava in,
0:20:12 > 0:20:19so you could say that the basalt makes its own burial chamber.
0:20:19 > 0:20:23And then eventually it drains out in the further edge of the eruption,
0:20:23 > 0:20:26leaving behind the tube, but here you can see on the base
0:20:26 > 0:20:31of the tube the last moments of the magma as it froze.
0:20:36 > 0:20:40Like an island within an island, these lava tubes have been
0:20:40 > 0:20:44isolated from the outside world for almost a million years.
0:20:44 > 0:20:48And only a few creatures have evolved to survive in them.
0:20:49 > 0:20:51But sightings are so rare,
0:20:51 > 0:20:55I'll need to track one down in the island's capital, Funchal.
0:20:59 > 0:21:02I'm told that in the nice, old natural history museum
0:21:02 > 0:21:06here in Funchal, it is one of these denizens of the deep lava tubes
0:21:06 > 0:21:09which I'm going to try and discover.
0:21:25 > 0:21:29The museum is almost as difficult to navigate as the island's
0:21:29 > 0:21:31labyrinthine lava tubes.
0:21:38 > 0:21:42The object of my quest - a beetle as rare as the most precious gem.
0:21:55 > 0:22:01So, which is the famous cave species in here? That one?
0:22:01 > 0:22:04It's absolutely minute.
0:22:04 > 0:22:08And it rejoices in the name of Thalassophilus pieperi,
0:22:08 > 0:22:11which just goes to prove that the Latin name is in inverse proportion
0:22:11 > 0:22:15to the size of the animal, but then, you know,
0:22:15 > 0:22:19I'm not surprised it's small because after all, in a cave,
0:22:19 > 0:22:21there's very little to eat and
0:22:21 > 0:22:25it doesn't come along very often, so you might say of course it's small.
0:22:30 > 0:22:35To survive stark subterranean environments, many insects shrink,
0:22:35 > 0:22:39becoming dwarfs, which is exactly what this beetle has done.
0:22:43 > 0:22:47But Madeira is home to other invertebrates whose size has
0:22:47 > 0:22:49also been determined by their habitat.
0:22:55 > 0:23:00This tiny snail is one of 180 different snail species.
0:23:01 > 0:23:05It's become a dwarf because it's adapted to living
0:23:05 > 0:23:08on the island's high peaks, where food is scarce.
0:23:10 > 0:23:14In contrast, these much larger snails live close to sea level,
0:23:14 > 0:23:17where there is food in abundance.
0:23:20 > 0:23:24Its large size and hard shell also has a secondary benefit.
0:23:25 > 0:23:29It acts as a deterrent against all but the largest birds.
0:23:31 > 0:23:34Yet it is largely thanks to birds
0:23:34 > 0:23:37that snails colonised Madeira in the first place.
0:23:37 > 0:23:42Recent research suggests that up to 15% of snails can survive
0:23:42 > 0:23:48passing through a bird's digestive system to emerge alive in droppings.
0:23:51 > 0:23:56But oddly, Madeira has almost no native birds.
0:24:13 > 0:24:18While Charles Darwin's finches in the Galapagos
0:24:18 > 0:24:21evolved into many species,
0:24:21 > 0:24:25here in Madeira there's another bird that bears the name of finch.
0:24:26 > 0:24:28The Madeira chaffinch.
0:24:30 > 0:24:34But it's tremendously similar to the European chaffinch
0:24:34 > 0:24:37and is only recognised as a different subspecies.
0:24:39 > 0:24:42In other words, it's almost the same thing.
0:24:47 > 0:24:51'Hawaii's iconic honeycreeper birds are also finches.
0:24:54 > 0:24:56'Yet on Hawaii,
0:24:56 > 0:25:00'an island group younger than Madeira, honeycreeper are not only
0:25:00 > 0:25:07'native but they have diversified into more than 50 endemic species.'
0:25:11 > 0:25:15And each one of them has a specialist ecological niche to fill.
0:25:18 > 0:25:22So why haven't the numerous birds of Madeira evolved
0:25:22 > 0:25:24into endemic species?
0:25:27 > 0:25:30The answer lies here in the natural history museum at Funchal.
0:25:39 > 0:25:42People come to Madeira to watch birds,
0:25:42 > 0:25:45and there are plenty of birds to be seen.
0:25:45 > 0:25:48But walking around this collection, I noticed
0:25:48 > 0:25:51that most of them are actually the same as those in Europe.
0:25:51 > 0:25:53But why is that?
0:25:53 > 0:25:57Birds of passage moving from Africa to northern Europe
0:25:57 > 0:25:59pass through Madeira
0:25:59 > 0:26:04and then most of the common European birds are also found on Madeira.
0:26:04 > 0:26:07Probably because they island-hopped at an earlier stage.
0:26:09 > 0:26:11There is a big difference, in fact,
0:26:11 > 0:26:16how evolution has behaved on Madeira, compared with Hawaii.
0:26:16 > 0:26:19Most of the ecological niches are actually occupied,
0:26:19 > 0:26:21filled by European birds.
0:26:21 > 0:26:23There's not so much opportunity
0:26:23 > 0:26:26for evolution to generate its own novelties.
0:26:27 > 0:26:32Unlike Hawaii, which is located 3,000 miles from the nearest
0:26:32 > 0:26:39continent, Madeira is only 360 miles from Africa and 500 from Europe.
0:26:41 > 0:26:45This proximity means its ecological niches are filled by regular
0:26:45 > 0:26:48immigrations from the nearby continents.
0:26:53 > 0:26:57One other species has moved into Madeira's ecological niches,
0:26:57 > 0:27:01which has arrested the natural processes of evolution.
0:27:01 > 0:27:04Homo sapiens.
0:27:04 > 0:27:09Human development on the island has been a major
0:27:09 > 0:27:13factor in its evolution for well over half a millennium.
0:27:23 > 0:27:26In 1419, Captain Zarco,
0:27:26 > 0:27:28in the service of Henry II of Portugal -
0:27:28 > 0:27:31sometimes called Henry the Navigator -
0:27:31 > 0:27:34set foot on Madeira for the first time.
0:27:34 > 0:27:38Within a few years, huge swathes of its natural forest had been burned.
0:27:38 > 0:27:42One fire is supposed to have burned for seven years.
0:27:42 > 0:27:46Soon, sugar cane was being cultivated in vast areas.
0:27:46 > 0:27:48It made the fortunes of many.
0:27:50 > 0:27:53So with the dawn of the age of discovery for Portugal,
0:27:53 > 0:27:56it was the end of the age of innocence for Madeira.
0:27:59 > 0:28:03The loss of innocence that accompanies humankind's arrival and
0:28:03 > 0:28:08settlement of any island was however not without its benefits to science.
0:28:11 > 0:28:13It's a little-known fact
0:28:13 > 0:28:15that Charles Darwin's The Origin Of Species
0:28:15 > 0:28:18refers to Madeira more often than the Galapagos.
0:28:20 > 0:28:23And that was because his close friend, the pioneering naturalist
0:28:23 > 0:28:29Thomas Vernon Wollaston, spent many years studying endemic insects here.
0:28:31 > 0:28:34In the year 1847 he named
0:28:34 > 0:28:38and described many of the species that are peculiar to the island.
0:28:38 > 0:28:41He was a friend of Darwin's, perhaps not so well-known,
0:28:41 > 0:28:44made a huge contribution in providing the scientific name
0:28:44 > 0:28:48still in use today for the insect fauna of this island,
0:28:48 > 0:28:53and of course Wollaston realised that some of the species on Madeira
0:28:53 > 0:28:56were different from those of anywhere else.
0:28:56 > 0:28:59In other words, he recognised endemics.
0:29:02 > 0:29:05Now, some of those endemics still survive.
0:29:05 > 0:29:09This rather attractive speckled brown butterfly,
0:29:09 > 0:29:12which you can still see flying in some of the highlands here.
0:29:18 > 0:29:21But other species were not so fortunate.
0:29:21 > 0:29:26And just to show how the island has been influenced by human arrival,
0:29:26 > 0:29:32this large white butterfly is named after Wollaston himself.
0:29:32 > 0:29:37And rather poignantly, it is extinct.
0:29:39 > 0:29:44Pieris brassicae wollastoni wasn't the only insect Wollaston was
0:29:44 > 0:29:47interested in studying.
0:29:47 > 0:29:51His great passion was for naming endemic beetles.
0:29:51 > 0:29:56He was particularly intrigued by the prevalence of flightlessness.
0:29:56 > 0:30:00One of the things that happens with endemic speciation is that
0:30:00 > 0:30:03particular characteristics are lost,
0:30:03 > 0:30:05and one of the beetles in front of me,
0:30:05 > 0:30:09which rejoices in the name of Meloe austrinus,
0:30:09 > 0:30:15belongs to a family, most of which have good capacity for flight.
0:30:15 > 0:30:18This particular beetle has become flightless.
0:30:18 > 0:30:20It's an example of what you might term
0:30:20 > 0:30:22the "use it or lose it" principle.
0:30:22 > 0:30:24Why has it become flightless?
0:30:24 > 0:30:27Well, it lives in the high part of the island,
0:30:27 > 0:30:29where the wind hardly ever stops,
0:30:29 > 0:30:33and actually it helps the beetle to stay more on the ground.
0:30:33 > 0:30:35If it took to the air, it would
0:30:35 > 0:30:38probably be blown away to some place it didn't like,
0:30:38 > 0:30:42so this particular endemic species evolved
0:30:42 > 0:30:46to cope with a very particular adaptive problem.
0:30:48 > 0:30:52Wollaston noted that of the 550 beetle species
0:30:52 > 0:30:55he was aware of in Madeira, 200 were flightless.
0:30:57 > 0:31:00This and other evidence of island variation
0:31:00 > 0:31:02proved invaluable to Darwin.
0:31:02 > 0:31:07Even though Wollaston himself, as a conservative Christian,
0:31:07 > 0:31:10could never bring himself to accept evolution.
0:31:14 > 0:31:18Sadly, like Pieris brassicae wollastoni,
0:31:18 > 0:31:21many of his beloved beetles became extinct
0:31:21 > 0:31:24because of the spread of agriculture over Madeira.
0:31:29 > 0:31:32The extent to which humans have transformed the island
0:31:32 > 0:31:34is apparent everywhere.
0:31:34 > 0:31:38Because 90% of the island is steep cliffs,
0:31:38 > 0:31:42the airport is an engineering wonder, extends into the sea.
0:31:44 > 0:31:48Even much of Funchal, the island's capital,
0:31:48 > 0:31:51clings to the precarious slopes of a deep ravine.
0:31:54 > 0:31:58The lower slopes are covered with rich volcanic soil.
0:31:58 > 0:32:02Any crop can grow here. There are bananas, there are grapes,
0:32:02 > 0:32:04a profusion of vegetables,
0:32:04 > 0:32:07and there's practically no room for wildlife of any kind.
0:32:13 > 0:32:17But there is one creature that is more than happy to cohabit
0:32:17 > 0:32:18with the human population.
0:32:20 > 0:32:22The Madeiran wall lizard.
0:32:24 > 0:32:26Since the arrival of these lizards,
0:32:26 > 0:32:30like humans, they have spread to every corner of the island...
0:32:30 > 0:32:33and can be found in all shapes and sizes.
0:32:35 > 0:32:39'As Dr Jose Jesus from the University of Funchal shows me.'
0:32:40 > 0:32:45They have an extremely high colour diversity.
0:32:45 > 0:32:50For example, the colour of the belly is very...
0:32:52 > 0:32:56They're lively as well.
0:32:56 > 0:32:57Oh, yeah.
0:32:57 > 0:33:01For example, you've got here one that is greenish.
0:33:01 > 0:33:04That brilliant greenish colour.
0:33:04 > 0:33:07Yes, and then you have got this one that is darker.
0:33:07 > 0:33:11But dorsal colour pattern...
0:33:11 > 0:33:15- The back.- ..is important. We call this reticulatus.
0:33:15 > 0:33:17- Reticulatus.- Yes.
0:33:17 > 0:33:21Whereas this guy...
0:33:21 > 0:33:23Now, in some cases,
0:33:23 > 0:33:26- those kind of differences would be a species difference.- Yes.
0:33:26 > 0:33:28In many other lizards.
0:33:28 > 0:33:30Yes, but here it's only one species.
0:33:31 > 0:33:34'All these lizards are the SAME species.'
0:33:36 > 0:33:39Madeiran wall lizards found in cultivated areas are usually
0:33:39 > 0:33:45green and brown, indicating their livery is adapted for camouflage.
0:33:46 > 0:33:48But it's not always the case.
0:33:48 > 0:33:53Darker lizards have been found by the coast, possibly to
0:33:53 > 0:33:58protect their skin against the more violent UV radiation from the sun.
0:34:00 > 0:34:02Though they are one species,
0:34:02 > 0:34:06they have several different approaches to reproduction.
0:34:07 > 0:34:11I understand that lizards are quite often territorial animals.
0:34:11 > 0:34:15Does this play out here on Madeira as well?
0:34:15 > 0:34:20Here sometimes when territorial species arrive to the islands,
0:34:20 > 0:34:23they have different answers.
0:34:23 > 0:34:26Some become non-territorial species.
0:34:26 > 0:34:29Ah, this is the sneak strategy, isn't it?
0:34:29 > 0:34:32So it's rather like a man who sneaks in through the back door
0:34:32 > 0:34:34while the husband is away.
0:34:34 > 0:34:41Yes, and it's curious that they have higher reproductive success.
0:34:43 > 0:34:45The Madeiran wall lizard arrived
0:34:45 > 0:34:47nearly three million years ago from Africa.
0:34:49 > 0:34:52Probably on a natural raft of vegetation.
0:34:53 > 0:34:57Since then, the island has become a sort of lizard Shangri-La.
0:34:59 > 0:35:01Although there's only one species,
0:35:01 > 0:35:06they are different in some ways from lizards that don't live on islands.
0:35:06 > 0:35:11Yes, some of these animals, they can reach 16 years.
0:35:11 > 0:35:1316 years.
0:35:13 > 0:35:15Yes, that is more or less
0:35:15 > 0:35:21four times more than most of mainland species of this size.
0:35:21 > 0:35:25So they're the same size but they are four times older, if you like.
0:35:25 > 0:35:29- Yes.- So that's equivalent to us landing on a desert island
0:35:29 > 0:35:32and finding human beings aged maybe 300 years.
0:35:32 > 0:35:36- Yes. Can you imagine? - I can imagine it!
0:35:39 > 0:35:41Unlike mainland species,
0:35:41 > 0:35:44island lizards can't count on rich resources
0:35:44 > 0:35:46to sustain a high birth-rate.
0:35:49 > 0:35:54The Madeiran wall lizard has elected instead to produce fewer young
0:35:54 > 0:35:57and consequently needs to live longer to keep up the population.
0:36:00 > 0:36:03Island life has served to extend their lifespan.
0:36:05 > 0:36:08But islands have a lifespan of their own.
0:36:21 > 0:36:24'To try and grasp the vast geological time periods
0:36:24 > 0:36:28'entailed in the volcanic island's life cycle, I head out to sea.'
0:36:33 > 0:36:37Madeira and the other much-smaller islands surrounding it
0:36:37 > 0:36:41first began to rise from the sea floor 18 million years ago.
0:36:43 > 0:36:47It took a further ten million years for eruptions to raise
0:36:47 > 0:36:51the volcanic pile 4,000 metres to sea level,
0:36:51 > 0:36:55and another seven for Madeira to reach high into the skies.
0:36:57 > 0:37:00It's an extraordinary thought that these magnificent cliffs
0:37:00 > 0:37:05more than 1,800 feet tall, built up layer by layer by volcanic eruption,
0:37:05 > 0:37:09are just the tip of an enormous iceberg.
0:37:09 > 0:37:15The cliffs carry on down, as it were, beneath where I'm standing.
0:37:18 > 0:37:22Today, only 4% of Madeira is above the water line.
0:37:25 > 0:37:27The remaining 96% forms
0:37:27 > 0:37:31one of the largest sea mountains in the North Atlantic.
0:37:41 > 0:37:46This giant geological formation has created a rich deepwater habitat
0:37:46 > 0:37:50that attracts aquatic mammals from all over the world.
0:37:54 > 0:37:58The dolphins and their close cousins, the whales, are living here
0:37:58 > 0:38:02and enjoying life so much because of the geology of Madeira.
0:38:02 > 0:38:05The rock that plunges so deeply down to the abyssal floor
0:38:05 > 0:38:11brings up cold nutrient-rich currents from the depths
0:38:11 > 0:38:12that nourish shoals of fish,
0:38:12 > 0:38:15which, of course, provide their favourite food.
0:38:43 > 0:38:47Back on land, I discover how weathering helps erosion.
0:38:55 > 0:38:59Madeira was built up from a whole series of explosive eruptions,
0:38:59 > 0:39:05and the basalt rock seems so hard and so unforgiving, but even hard,
0:39:05 > 0:39:09unforgiving rock weathers away over geological time,
0:39:09 > 0:39:14and basalt weathers in a most particular style,
0:39:14 > 0:39:16known as onion-skin weathering.
0:39:16 > 0:39:19Here's a largely unweathered centre
0:39:19 > 0:39:23to a concentrically more-weathered area,
0:39:23 > 0:39:28and you can almost feel this unforgiving rock turning into soil.
0:39:28 > 0:39:31Indeed these plants are living on it.
0:39:34 > 0:39:38So you can begin to understand how even a high structure
0:39:38 > 0:39:44like an island like Madeira can return ultimately to sea level.
0:39:49 > 0:39:53Madeira is geological proof that what goes up...
0:39:53 > 0:39:55must go down...
0:40:00 > 0:40:02Wow.
0:40:02 > 0:40:04It feels completely out of control
0:40:04 > 0:40:07but actually I'm sure they know exactly what they are doing.
0:40:09 > 0:40:11That's one way to go round a corner.
0:40:13 > 0:40:15That just shows how steep the...
0:40:17 > 0:40:21..sides of a volcanic pile are, when lava flows
0:40:21 > 0:40:24a pile on top of one another, as we've been
0:40:24 > 0:40:27sliding down on this extraordinary journey.
0:40:28 > 0:40:32'As Madeira's volcanism has come to an end,
0:40:32 > 0:40:36'so the island has begun slowly sinking under the combined force
0:40:36 > 0:40:40'of its own massive weight and the erosive effects of wind and rain.'
0:40:47 > 0:40:51So I suppose for every...foot or so
0:40:51 > 0:40:54we go down here, we're talking about another thousand years of erosion.
0:40:59 > 0:41:02And... Oh, I nearly met the wall then.
0:41:02 > 0:41:03Ah...
0:41:07 > 0:41:10And here we are. Phew.
0:41:15 > 0:41:18But that's far from the end of Madeira's story.
0:41:18 > 0:41:23After all, 96% of the island is beneath the sea.
0:41:27 > 0:41:32I can see some of the unusual species found in these waters
0:41:32 > 0:41:34in the fish market in Funchal.
0:41:40 > 0:41:44These espada... obviously deepwater fish
0:41:44 > 0:41:46because they've got great eyes
0:41:46 > 0:41:50to make use of whatever light there is at that depth,
0:41:50 > 0:41:54and the needle-like teeth don't leave much doubt
0:41:54 > 0:41:56that this is a serious predator.
0:41:56 > 0:41:59So it's quite an ugly critter,
0:41:59 > 0:42:03but actually tastes really rather wonderful.
0:42:05 > 0:42:07Which gives me an idea.
0:42:09 > 0:42:13- Hello. Good afternoon. - Good afternoon.- Please.- Thank you.
0:42:13 > 0:42:16Ah. Thank you very much.
0:42:23 > 0:42:25Thank you.
0:42:27 > 0:42:30Roast sweet pepper too. Quite nice.
0:42:33 > 0:42:36Well, this is the famous espada,
0:42:36 > 0:42:40a black scabbard fish which I've seen in the market,
0:42:40 > 0:42:42and I can't help wondering
0:42:42 > 0:42:45whether its taste lives up to its reputation.
0:42:50 > 0:42:52As indeed it does.
0:42:55 > 0:42:57No, it's really delicious.
0:42:57 > 0:42:59It's not quite as firm as cod,
0:42:59 > 0:43:04but just as kind of succulent on the tongue.
0:43:04 > 0:43:06It's a really delicious fish.
0:43:09 > 0:43:15And the Madeirans don't want to eat anything else. It's hugely popular.
0:43:17 > 0:43:21And it's served here with a banana,
0:43:21 > 0:43:24which, of course, is one of the great crops of Madeira.
0:43:24 > 0:43:28So we've got a large part of Madeiran history on my plate here.
0:43:29 > 0:43:31Actually, the banana's pretty good too.
0:43:35 > 0:43:37Rather less edible examples
0:43:37 > 0:43:40of Madeira's deepwater evolutionary oddities
0:43:40 > 0:43:43are kept in the Marine Biological Station of Funchal.
0:43:46 > 0:43:49The station was originally established more than 70 years ago
0:43:49 > 0:43:55to study deep-sea fish, particularly sharks and rays,
0:43:55 > 0:44:00and as a window onto the marine habitat surrounding Madeira.
0:44:03 > 0:44:07Among the most-prized specimens in their collection is this monster.
0:44:09 > 0:44:11It's an anglerfish.
0:44:11 > 0:44:13The largest specimen ever found,
0:44:13 > 0:44:16and, in a way, the strangest imaginable example
0:44:16 > 0:44:21of how in evolution, if you don't use it, you lose it.
0:44:21 > 0:44:24In this case, the male of the species.
0:44:24 > 0:44:27It has dwindled to virtually nothing.
0:44:27 > 0:44:30You can recognise this as an anglerfish
0:44:30 > 0:44:34by the strange little fishing rod contraption at the top,
0:44:34 > 0:44:36which has a lure to attract its prey.
0:44:46 > 0:44:50It's an extraordinary and rather bizarre looking fish,
0:44:50 > 0:44:54and it's the one in which the male of the species has become
0:44:54 > 0:44:57more reduced than in almost any other organism.
0:44:57 > 0:45:02In fact...this tiny little appendage hanging off the corner here
0:45:02 > 0:45:04is the male.
0:45:04 > 0:45:09It's been reduced to little more than a tiny stump.
0:45:11 > 0:45:15And its function, really, is just to produce sperm.
0:45:15 > 0:45:20So in some ways, this fish is the ultimate feminist icon.
0:45:32 > 0:45:36Today, one of the most important aspects of the centre's work
0:45:36 > 0:45:39is monitoring the effects of human pressure
0:45:39 > 0:45:41on the ecosystem around Madeira.
0:45:47 > 0:45:51Here, often swimming beneath the oblivious tourists above,
0:45:51 > 0:45:55the divers scout for local species like these large starfish.
0:46:02 > 0:46:04Spiny and a little intimidating,
0:46:04 > 0:46:07there are 700 known species of sea urchins.
0:46:10 > 0:46:12Sea urchins and starfish can be good indicators
0:46:12 > 0:46:14of the health of the sea.
0:46:15 > 0:46:19Changes in their abundance can be correlated with pollution levels.
0:46:20 > 0:46:24Although these cloudy waters near the shore would normally
0:46:24 > 0:46:27carry some sediment, washed here by soil erosion,
0:46:27 > 0:46:31in recent years the concentrations have increased.
0:46:33 > 0:46:36And numbers of endemic invertebrates are declining
0:46:36 > 0:46:39due to the changing nature of the coastal waters.
0:46:42 > 0:46:47Two of the divers, Pedro Neves and Claudio Correa Ribiero,
0:46:47 > 0:46:50both marine biologists, have brought back samples.
0:46:58 > 0:47:00So what have we found today?
0:47:00 > 0:47:03Here we have two sea urchins and two starfishes.
0:47:03 > 0:47:09And we normally use these animals for exhibitions.
0:47:09 > 0:47:14Especially with the kids, so that they can feel how it feels to touch.
0:47:16 > 0:47:20So how often do you go out on these dives?
0:47:20 > 0:47:23Lately we have been diving three, four week...
0:47:23 > 0:47:26four times in a week, to survey new spots
0:47:26 > 0:47:28along south coast of Madeira also,
0:47:28 > 0:47:32trying to see if there's a new habitat
0:47:32 > 0:47:35with a different type of species.
0:47:35 > 0:47:38And what particular changes have you noticed
0:47:38 > 0:47:41since you've been doing these kind of studies?
0:47:41 > 0:47:48Right now, we have big thick layer of sediment just on top of all
0:47:48 > 0:47:53the rocks, and that prevents marine organisms from growing as abundantly
0:47:53 > 0:47:58as they used to, so that's one cause for concern right now.
0:48:02 > 0:48:06But one group of specialist filter feeders seems to find
0:48:06 > 0:48:10the marine conditions of Madeira exactly to their taste.
0:48:14 > 0:48:15Joao Canning Clode
0:48:15 > 0:48:19is leading a team investigating animals called bryozoans.
0:48:24 > 0:48:30These minute creatures, some only a millimetre across, band together
0:48:30 > 0:48:34forming large colonies which can abound on parts of the ocean floor.
0:48:39 > 0:48:43Not surprisingly, they are easy to catch.
0:48:43 > 0:48:46We attach this settling plate to a brick and basically, we suspend
0:48:46 > 0:48:51this in a marina or a harbour, and after a certain period of time -
0:48:51 > 0:48:53usually it's three months -
0:48:53 > 0:48:56we already have a pretty mature community of bryozoans.
0:48:59 > 0:49:02Madeira has a wealth of endemic bryozoans,
0:49:02 > 0:49:07but thanks to shipping containers, a huge influx of new invaders
0:49:07 > 0:49:10are arriving from as far afield as Brazil.
0:49:12 > 0:49:16And how do these introduced species arrive here in Madeira?
0:49:16 > 0:49:18A cargo ship comes to Madeira.
0:49:18 > 0:49:21It needs to discharge the water from another part of the world,
0:49:21 > 0:49:24and discharges into Madeira waters.
0:49:24 > 0:49:27And are they ever a problem, these new invasive species?
0:49:27 > 0:49:31They can constitute harm for others, for other native communities,
0:49:31 > 0:49:35but also they could impact what we humans are doing.
0:49:35 > 0:49:38For example, they are... there is a bryozoans species
0:49:38 > 0:49:42which is known as the spaghetti bryozoan.
0:49:42 > 0:49:45It looks like spaghetti, and they can get attached
0:49:45 > 0:49:49to propellers of boats, and this can constitute a problem.
0:49:51 > 0:49:56So how many species are there here, if you count them up?
0:49:56 > 0:49:59We are not 100% sure, but we believe hundreds.
0:49:59 > 0:50:04Just in one family of bryozoans we get 140 species.
0:50:04 > 0:50:08- Good Lord!- We are getting new records for Madeira every two months
0:50:08 > 0:50:10and I'm not exaggerating.
0:50:10 > 0:50:14Just in this plate I can count seven different species.
0:50:20 > 0:50:24Madeira's waters are no longer a persistent
0:50:24 > 0:50:26and slow-changing habitat,
0:50:26 > 0:50:30but one that is undergoing rapid environmental change.
0:50:32 > 0:50:37This deepwater long-snouted lancetfish has a voracious appetite
0:50:37 > 0:50:41and will eat almost anything.
0:50:41 > 0:50:44'Because of this, the centre's director, Manuel Biscoito,
0:50:44 > 0:50:48'conducts regular dissections of its stomach contents.
0:50:48 > 0:50:52'What he finds inside is probably the best available
0:50:52 > 0:50:56'record of how the undersea environment is changing,
0:50:56 > 0:50:59'and whether deep-sea invasive species
0:50:59 > 0:51:02'are entering Madeiran waters.'
0:51:02 > 0:51:05It's a sort of a needlefish.
0:51:05 > 0:51:11Another species, that lives in this mid-water...
0:51:11 > 0:51:15- With a very obvious needle on the front.- Absolutely.
0:51:15 > 0:51:19That's the delicate shell of an argonaut. That's one I do know.
0:51:19 > 0:51:21The female.
0:51:21 > 0:51:26Ooh, is that...? That looks suspiciously like something human.
0:51:26 > 0:51:28That is something human indeed.
0:51:28 > 0:51:32Well, absolutely as you said, and it's an identifiable species too.
0:51:32 > 0:51:37- It's plastic.- It's got a barcode.
0:51:37 > 0:51:42Well. It's a wrapping of some sort of product.
0:51:42 > 0:51:43So the fish would have seen that
0:51:43 > 0:51:46- floating down through the water... - And mistaken it...
0:51:46 > 0:51:51a jellyfish, for example, or other organisms of the plant. It must...
0:51:51 > 0:51:52And we've got another piece.
0:51:52 > 0:51:55Do you think it's the same wrapper or a different one?
0:51:55 > 0:51:57It's probably the same.
0:51:57 > 0:51:59I can't recognise the writing on there.
0:51:59 > 0:52:01No, it seems Greek or Arab.
0:52:01 > 0:52:04So we need a linguistic expert now!
0:52:08 > 0:52:12The invasive species in this case is man-made.
0:52:14 > 0:52:19What makes this find so disturbing is that the lancet hunts
0:52:19 > 0:52:22at depths of over 200 metres,
0:52:22 > 0:52:26and incidences of eating plastic have only appeared
0:52:26 > 0:52:29in the last decade or so.
0:52:30 > 0:52:34Well, that's an amazing inventory from one dissection
0:52:34 > 0:52:39but it's only part of a really long-term series of data.
0:52:39 > 0:52:42It is indeed. It started in 1945.
0:52:42 > 0:52:44Have you got your books for that?
0:52:44 > 0:52:49Yes, we actually have the original registers from there. Which we have.
0:52:49 > 0:52:51Here are the original records,
0:52:51 > 0:52:54and it says here "report on the contents...
0:52:54 > 0:52:57"stomach content of the lancetfish."
0:52:57 > 0:53:02- On March 1945, one of these had six argonauts.- Like those.
0:53:02 > 0:53:06Large argonauts, and some other cephalopods, what is here.
0:53:06 > 0:53:10And it goes on and on and on, along the...
0:53:10 > 0:53:13since 1945, up to now.
0:53:13 > 0:53:17My handwriting, because in the meantime I arrive here...
0:53:17 > 0:53:20I just pick up 2010.
0:53:20 > 0:53:25April... August 17, and I say here, "Plastic debris...
0:53:25 > 0:53:28- "and a piece of newspaper." - HE CHUCKLES
0:53:28 > 0:53:32Madeira is in just the right place, is it not,
0:53:32 > 0:53:37to monitor global changes, perhaps due to climate change?
0:53:37 > 0:53:42Absolutely. We are really in a privileged site to witness that
0:53:42 > 0:53:48and monitor that change and we have been writing new records of fish.
0:53:48 > 0:53:52Tropical species that are appearing here that we've not seen before
0:53:52 > 0:53:56and we know, we are noticing that some fish that are more typical
0:53:56 > 0:54:02from the colder, from the temperate areas, are just slowly vanishing.
0:54:02 > 0:54:05All this proves to me,
0:54:05 > 0:54:08the importance of a long-term vision for science.
0:54:08 > 0:54:10Long-term research is very valuable.
0:54:10 > 0:54:15It's very much known now as old-fashioned science.
0:54:15 > 0:54:18Very hard to get finance for this,
0:54:18 > 0:54:23but it is absolutely crucial to do this, to continue these efforts.
0:54:23 > 0:54:26If we really want to understand what is happening
0:54:26 > 0:54:28to our oceans and our planet.
0:54:38 > 0:54:42Madeira's location on the borders between the temperate
0:54:42 > 0:54:47and tropical zones of the Atlantic Ocean give it a uniquely global
0:54:47 > 0:54:53overview on how climate change is impacting on marine evolution.
0:54:54 > 0:54:57We can only hope that just as the Madeirans have learned
0:54:57 > 0:55:01lessons from their past, so can the rest of us.
0:55:02 > 0:55:06Because the deep blue waters that surround this tiny island
0:55:06 > 0:55:11once ran red with the blood of whales and dolphins.
0:55:11 > 0:55:15Within living memory, Madeira has turned from being
0:55:15 > 0:55:19one of the most prolific whaling islands in the world
0:55:19 > 0:55:23to one of the most popular for dolphin and whale watching.
0:55:27 > 0:55:31It's a story we have also seen on the two other islands of our series.
0:55:34 > 0:55:36That's a lovely view. A lovely view.
0:55:36 > 0:55:40On Madagascar, we joined a small group of dedicated
0:55:40 > 0:55:44conservationists struggling to preserve what remains
0:55:44 > 0:55:49of the rainforest so many of the unique animals and plants depend on.
0:55:53 > 0:55:57While on Hawaii, we witnessed the strenuous efforts being made
0:55:57 > 0:56:01to save rare species after the devastating
0:56:01 > 0:56:05effects of invasive diseases and new predators.
0:56:07 > 0:56:11Here too we saw how modern science is trying to use pioneering
0:56:11 > 0:56:16techniques to bring back species almost from beyond the grave.
0:56:17 > 0:56:20Extinction on islands is ever present.
0:56:21 > 0:56:23Here in the laboratory on Hawaii,
0:56:23 > 0:56:26dedicated to saving their rare plants from extinction,
0:56:26 > 0:56:30might be a good place to ponder what we should think
0:56:30 > 0:56:34about the extinction of species on the planet as a whole.
0:56:35 > 0:56:38Extinction is part of the history of life.
0:56:38 > 0:56:40Always has been, always will be.
0:56:40 > 0:56:44In fact, you could say you can't have evolution without extinction.
0:56:45 > 0:56:48As we have seen throughout this series, islands beautifully
0:56:48 > 0:56:52illustrate how many species can evolve from a single founder.
0:56:57 > 0:57:01Yet many of those ancestors have themselves long since gone extinct.
0:57:05 > 0:57:07What is unprecedented, though,
0:57:07 > 0:57:11is the rate at which these species are now going extinct.
0:57:11 > 0:57:13This probably hasn't happened...
0:57:13 > 0:57:16well, since the extinction of the dinosaurs.
0:57:17 > 0:57:19But islands are particularly vulnerable.
0:57:21 > 0:57:27The introduction by humankind of lethal invasive species has swiftly
0:57:27 > 0:57:31and profoundly transformed Hawaii's long-isolated fauna and flora.
0:57:32 > 0:57:35While Madagascar's rainforest is threatened
0:57:35 > 0:57:37by eucalyptus plantations
0:57:37 > 0:57:41which encourage the slash and burn of native forest.
0:57:42 > 0:57:45But these islands are the very place, as we've seen,
0:57:45 > 0:57:49where we can understand how evolution works most clearly.
0:57:51 > 0:57:55So to save a few plants on Hawaii, for example,
0:57:55 > 0:57:59is not just to save a few pretty organisms,
0:57:59 > 0:58:01but it's to save important evidence
0:58:01 > 0:58:04for the very workings of evolution itself.
0:58:08 > 0:58:13If islands are places where paradise has so often been lost,
0:58:13 > 0:58:16they may also remain our best hope
0:58:16 > 0:58:21for learning how paradise might be regained.
0:58:21 > 0:58:25It's pretty adorable.