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I've spent most of my life
trying to understand


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the forces that shaped our planet,


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and as a geologist,
it always seemed to me


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that rocks were right
at the heart of things.


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But now, I'm discovering it's not
only volcanoes
and colliding continents


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that have driven
the Earth's greatest changes,


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because at crucial moments
in its history,


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another force has helped create
the planet we live on...


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...plants.


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It's a whole new story
about the Earth,


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revealing how,
from its earliest history,


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plants have shaped our world.


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So far, we've seen how plants
and their ancestors began


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by producing
our life-giving atmosphere.


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I'm breathing oxygen that was made
two-and-a-half billion years ago.


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They'd harnessed light from the sun,


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bringing energy to the world.


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And they'd formed the fertile soil,


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allowing life to colonise the land.


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But the next chapter
will take us even further,


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because a powerful newcomer
to the plant world was on its way.


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It would conquer every corner
of the planet.


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It would shape the very surface
of the Earth


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and it would drive the evolution
of animal life,


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including our own ancestors.


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This is its story.


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These buildings are
nearly 1,000 years old.


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The largest religious site
in the world,


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covering 200 square kilometres.


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This is the temple of Angkor Wat
in Cambodia.


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I am here to witness the importance


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of one of the most powerful symbols
known to humankind.


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A symbol central to an ancient
Buddhist ceremony.


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Flowers.


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(BUDDHIST CHANTING)


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You see lotus flowers and jasmine
just arranged beautifully up there.


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The lotus are the big ones
and the jasmine the trail
of little flowers.


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See how the lotus petals are all
folded in amongst themselves,


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the different layers representing
the various levels of heaven.


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For these monks,
flowers have a crucial role.


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And this is just one ceremony
from one religion.


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Flowers are central to cultures
throughout the world.


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They're deeply woven
into all our lives.


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But it's not only a human obsession.


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Because since they evolved,


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flowers have been the driving force
for the whole of life on Earth.


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They've become enmeshed
in the lives


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of virtually the entire animal
kingdom in all its rich diversity.


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From the smallest insect to
some of the largest mammals,


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they've all been shaped by flowers.


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But how did this happen?


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And why?


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The emergence of flowers


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is one of the biggest turning points
in Earth's history.


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To understand how
they changed our planet,


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we need to go right back
to a prehistoric time...


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...to the moment when
the very first flower appeared.


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Up until around 140 million years
ago, the Earth was very different.


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The animal kingdom was dominated
by dinosaurs.


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And the separate continents
we know today didn't exist.


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Instead, there had been a single
huge continent, Pangaea.


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I'm heading for a place that's about
as close as you can get


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to that ancient supercontinent.


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It's in the remote South Pacific,
1,500km from Australia.


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The island of New Caledonia.


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It looks like Paradise, doesn't it?


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What makes New Caledonia
just so interesting


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is that it's like a Noah's Ark
of ancient plants.


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This little journey is going to take
us back in time 140 million years.


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Because this part of the world
is so isolated,


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it gives a glimpse of the plant
world before flowers existed.


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Back then, the plant kingdom
had two mighty rulers.


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One of them was the tall conifers,


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like this prehistoric species
of pine.


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Look at these trees.
Bizarre, aren't they?


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They're huge.


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Araucaria, Cook pine,


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named after Captain Cook
who explored this corner
of the world.


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Pine trees are a family of conifers
that are amongst the oldest
in the world


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so when the dinosaurs were around,
these were nature's real giants.


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What made flowers so revolutionary


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was the limitations of the ancient
plants that came before them.


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To reproduce, conifers like these
relied on the vagaries of the wind.


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This is pollen, the male sex cells
of conifers.


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Each grain has to be magnified
1,000 times to really see it.


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The two air sacs, one in each side,
catch the breeze.


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With luck, the male pollen
will be blown


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to a female cone on a nearby tree.


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But for that to happen,
each conifer needs vast amounts.


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It's very wasteful.


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Up to 10 billion grains have to be
released by a single tree.


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The other big player back then
was the ferns.


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Their method of reproduction
was also restricting.


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Because ferns evolved in wet,
swampy conditions,


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they needed water to transport
their sex cells.


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And they use a surprising device.


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What they do is they release
a sperm,


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which swims through the water
and mud to a nearby plant


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and fertilises the egg.


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Under a microscope, you can see
that by thrashing around,


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the male sperm cell can propel
itself through water.


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It's able to swim
for over two hours.


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It's amazing to think that a plant


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produces something
like a human sperm.


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But the downside was that ferns
had to live near water.


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It was hugely limiting.


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All this meant something was lacking
in the world of Pangaea...


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..diversity.


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There were few species of ferns
and even fewer types of conifers.


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Just 1% of the range of plants
we have today.


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And the animal kingdom
was also limited.


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Scientists have found evidence
of 700 different dinosaurs.


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It sounds a lot,


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but today there are over 5,500
species of mammals alone.


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There was little variety.


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It was a monotonous green world.


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And that's how life on the planet
would have continued.


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140 million years ago,
somewhere in Pangaea,


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one plant of one species happened to
chance on a new way of reproducing.


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And it would change the Earth
for ever.


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I've pushed further into
New Caledonia's jungle.


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The plant I'm after is really rare,
which is why I've come so far.


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This is the only place that you find
it. It's died out everywhere else.


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Mind you, amongst all of this,
it's like a needle in a haystack.


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Hang on a minute.


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That looks like the leaves.


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That wood.


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Got them.


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I've come all the way round
the world to find that.


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That is the Amborella plant.


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Amborella trichopoda
is the closest living relative


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of the first flower to evolve.


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All flowers today have descended
from its ancestor.


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Botanists believe it began
when a single plant mutated


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to have leaves that became petals
which, instead of being green,


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were probably white
like those of Amborella.


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We now consider them to be
the very first petals
of the very first flower.


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To grasp the significance of this
plant, you have to imagine a scene


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in some primordial forest where
everything's just completely green.


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And then there's this flash
of colour and glint of white.


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Some chance mutation.


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And the thing is that scurrying
amongst it is a little beetle.


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Certainly not a bee because
bees hadn't evolved yet,


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but a beetle spies this dash
of white and scurries across
to have a look.


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And then munches
on these little white buds


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that are just packed full of pollen.


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But not all the pollen is eaten.


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Some sticks to the beetle,
and on it goes to other plants.


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Unknowingly, it's become a courier,
delivering pollen
from plant to plant,


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pollinating them
as it looks for food.


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Plants had evolved
an ingenious way of reproducing


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that no longer relied
on haphazard methods,


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like the wind for conifers
or water for ferns.


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Instead it was reliable.


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Insects carried pollen directly
to other plants.


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It was the birth of flowers.


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It's hard to grasp just how
revolutionary this was.


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I'm used to thinking of momentous
changes in the Earth


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as occurring through huge events -


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vast continents colliding
or mountains uplifting,


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but this was the tiniest of events.


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A subtle alteration
of how a plant looked


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and a chance encounter
with a curious beetle.


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And on the back of that,
the world changed for ever.


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Back then, the supercontinent
of Pangaea was splitting up.


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Smaller continents were forming...


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...creating countless new
landscapes...


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..with new climates
and environments -


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rising mountain ranges...


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..and dry inhospitable deserts.


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For conifers and ferns,
so dependent on wind and water,


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the new landscapes
were impregnable.


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But for flowering plants, it was
the chance they'd been waiting for.


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Because they had a powerful
in-built advantage.


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This is a monkey puzzle tree.


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Like most conifers, monkey puzzles
live for hundreds of years,


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and crucially, they don't reach
sexual maturity till they're 40.


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Now...this is a campion flower,


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which in the shadow of this thing
looks pretty puny,


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but the campion flower
has the last laugh


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because this, like most flowers,
matures much quicker.


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In fact, the campion flower can
reproduce after just four months.


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It means that in the time
that it takes this conifer


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to produce just one generation,


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the flowers can go through
120 generations.


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What's so fascinating is the impact
that this has got on evolution


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because every time
there's a new generation,


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there's a possibility
of a genetic mutation,


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a mutation that might give a
characteristic that helps survival.


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So the faster the life cycles,


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the more species can adapt
to new environments,


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which, of course,
is crucial to our story.


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140 million years ago,
these rapid life cycles


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helped flowers exploit
the most hostile environments.


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Just like Tankwa Karoo
in South Africa.


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Because beneath this desert
is a hidden carpet of flowers.


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Each year, it rains
for just two months.


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The plants only have
this brief window to reproduce.


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So how do they ensure
they are pollinated in time?


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They evolved colour.


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Each type of flower that you see
is using colour


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in a struggle to get noticed
by insects.


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And there isn't much time.


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In a few weeks or days
the rains will be gone,


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and if these flowers aren't
fertilised by then,
the plants will die


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and the opportunity to reproduce
will be lost.


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Hundreds of different flowers,
dozens of different colours,


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whether it be orange gazanias,


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purple dew flowers,


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or the red balloon pea plant.


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And it wasn't random.


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Many used a different specific
colour to attract insects.


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00:17:49,040 --> 00:17:51,080
They became targets,


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using insects to transfer
the right pollen to the right plant,


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00:17:55,840 --> 00:17:57,960
even over great distances.


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00:18:01,080 --> 00:18:05,200
And flowers evolved a clever way
to enhance this colour.


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To the naked eye,
a petal looks smooth.


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But magnify it 1,000 times
and you can see its real structure.


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It's not a flat surface at all.


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Instead, the petal is made up
of countless nodules.


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Each acts like a tiny prism,
which reflects and diffracts light.


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It gives the petal an iridescence,
to attract passing insects.


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And in their use of colour,
flowers went even further.


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It's a heck of a contraption,
isn't it?


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A special camera to give you
a kind of...


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00:19:28,120 --> 00:19:31,680
insect's view of what
a flower looks like.


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That's nice. Look at that.


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00:19:38,280 --> 00:19:40,760
Insects and this camera


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00:19:40,760 --> 00:19:44,760
can see a part of the light spectrum
called ultraviolet


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that's normally invisible
to us humans.


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00:19:59,040 --> 00:20:03,520
The camera reveals how flowers
that appear plain to us


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look completely different to insects


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And the markings
are really important


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because they are like
airport runway lights


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that guide the insect down
onto the petals.


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Like neon signs that say
"free food here".


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00:20:33,120 --> 00:20:38,640
But once the flowers
were pollinated, they still faced
a big challenge


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00:20:38,640 --> 00:20:43,480
because their offspring
then had to make it through
the rest of the year.


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00:20:45,720 --> 00:20:49,400
Here in the Karoo, that could be
ten months of drought.


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To survive, flowers perfected
another trick,


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00:20:54,480 --> 00:20:57,440
which had a powerful impact
on life on Earth.


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00:20:59,560 --> 00:21:00,880
Seeds.


243
00:21:01,920 --> 00:21:04,320
Because seeds have
this remarkable ability


244
00:21:04,320 --> 00:21:06,320
that we don't normally think about.


245
00:21:08,640 --> 00:21:12,520
These are seeds of the Canna
indica flower, and this...


246
00:21:12,520 --> 00:21:15,160
This is an empty shotgun cartridge.


247
00:21:16,320 --> 00:21:19,880
I'm going to pack the seeds in where
the lead pellets would have been.


248
00:21:29,480 --> 00:21:31,200
(GUNSHOTS)


249
00:21:36,960 --> 00:21:39,040
(BANG)


250
00:21:46,000 --> 00:21:48,480
Oh! It's gone right through.


251
00:21:50,600 --> 00:21:52,600
Look at that!


252
00:21:53,600 --> 00:21:55,640
That looks perfectly intact.


253
00:21:57,400 --> 00:22:02,720
The story goes that during
the Indian Mutiny
of the 19th century...


254
00:22:02,720 --> 00:22:07,000
soldiers used these seeds
instead of lead shot.


255
00:22:13,000 --> 00:22:17,240
They're hard enough to be blasted
out of a barrel and through wood.


256
00:22:20,360 --> 00:22:22,720
These seeds are so tough, in fact,


257
00:22:22,720 --> 00:22:28,120
that it's said that despite being
fired from a gun,
they can still germinate.


258
00:22:28,120 --> 00:22:30,720
Sounds unlikely, I know,


259
00:22:30,720 --> 00:22:32,480
though we'll see.


260
00:22:34,040 --> 00:22:39,000
But a tough shell wasn't all,
because seeds from flowering plants


261
00:22:39,000 --> 00:22:41,320
developed a further
evolutionary advantage


262
00:22:41,320 --> 00:22:43,120
that no other plant possessed.


263
00:22:51,280 --> 00:22:54,600
It all starts at the moment
of pollination.


264
00:22:57,320 --> 00:22:59,840
Having been delivered by an insect,


265
00:22:59,840 --> 00:23:03,200
two cells from the pollen burrow
deep into the flower's ovary.


266
00:23:06,040 --> 00:23:11,720
Here, one fertilises an egg
to create an embryonic plant.


267
00:23:15,320 --> 00:23:17,640
But, and here's the clever bit,


268
00:23:17,640 --> 00:23:22,200
the second cell from the pollen
does a completely different job.


269
00:23:22,200 --> 00:23:24,880
Instead of becoming a new plant,


270
00:23:24,880 --> 00:23:28,800
it grows into a food source
for the fertilised egg.


271
00:23:28,800 --> 00:23:31,040
A kind of packed lunch.


272
00:23:31,040 --> 00:23:34,880
It's called double fertilisation


273
00:23:34,880 --> 00:23:37,920
and it's unique
to the seeds of flowers.


274
00:23:45,160 --> 00:23:48,520
It meant seeds could lie dormant
for months or even years


275
00:23:48,520 --> 00:23:50,840
until conditions were right.


276
00:23:54,840 --> 00:23:59,960
As for my Canna indica seeds,
well, this is how they fared.


277
00:23:59,960 --> 00:24:04,240
Despite being blasted
from a shotgun,


278
00:24:04,240 --> 00:24:06,640
four weeks later,
here they are now...


279
00:24:07,680 --> 00:24:12,000
..successfully germinating
into a tiny flowering plant.


280
00:24:13,120 --> 00:24:14,400
Remarkable!


281
00:24:18,680 --> 00:24:20,840
By 100 million years ago,


282
00:24:20,840 --> 00:24:25,160
flowers were redrawing the global
map of where plants could live.


283
00:24:27,880 --> 00:24:32,880
They were turning once infertile
areas into oases of life.


284
00:24:38,080 --> 00:24:41,440
And it wasn't just about plants.


285
00:24:41,440 --> 00:24:47,320
Because these flower oases were now
luring animals, too.


286
00:24:47,320 --> 00:24:52,600
There was one ability above all
that gave flowers the power
to do this.


287
00:24:54,160 --> 00:24:56,000
Plants can do something unique


288
00:24:56,000 --> 00:24:59,960
that marks them out amongst all
other living things on the planet.


289
00:24:59,960 --> 00:25:04,600
Their leaves can capture energy
from our nearest star, the sun,


290
00:25:04,600 --> 00:25:06,840
and turn it into food.


291
00:25:09,720 --> 00:25:15,400
And the total amount of energy
photosynthesis brings to the Earth


292
00:25:15,400 --> 00:25:16,600
is staggering.


293
00:25:32,520 --> 00:25:34,080
I know this is a bit odd,


294
00:25:34,080 --> 00:25:38,200
but just imagine
that this little scooter
and all the fuel that it uses


295
00:25:38,200 --> 00:25:42,280
represents all the energy that
the USA consumes in just one year.


296
00:25:44,440 --> 00:25:47,080
Now imagine that you take
all the plants in the world,


297
00:25:47,080 --> 00:25:49,560
all the trees,
flowers and grasses...


298
00:25:51,360 --> 00:25:53,880
..all the jungles, forests
and savannas


299
00:25:53,880 --> 00:25:55,480
and you add up the total energy


300
00:25:55,480 --> 00:25:57,880
harnessed by plants
from the sun every year.


301
00:26:00,120 --> 00:26:03,120
It's not two scooters' worth or ten.


302
00:26:03,120 --> 00:26:05,560
It's all of this.


303
00:26:05,560 --> 00:26:09,960
40 times the amount of energy
consumed by America every year.


304
00:26:15,320 --> 00:26:20,000
It's 100 trillion watts
of energy every year.


305
00:26:21,400 --> 00:26:27,160
Astonishing as this is,
flowers took all this energy
and went even further.


306
00:26:28,840 --> 00:26:31,760
An adaptation that would have
enormous repercussions


307
00:26:31,760 --> 00:26:33,840
for the animal kingdom.


308
00:26:33,840 --> 00:26:36,560
They developed this
ingenious method


309
00:26:36,560 --> 00:26:39,880
of making the sugars available
to their pollinators,


310
00:26:39,880 --> 00:26:44,520
and if I take this syringe here
and just slide it delicately
in here...


311
00:26:45,760 --> 00:26:48,320
..I can show you
what they came up with.


312
00:26:53,920 --> 00:26:57,720
It's this really sweet-tasting
liquid, nectar, of course.


313
00:26:57,720 --> 00:27:00,760
One of the most energetic sources
of food on the planet


314
00:27:00,760 --> 00:27:04,520
and something animals found
utterly irresistible.


315
00:27:05,800 --> 00:27:08,840
The nectar from this
bird of paradise flower


316
00:27:08,840 --> 00:27:12,680
has three times the sugar
concentration of Coca-Cola.


317
00:27:17,600 --> 00:27:22,440
Flowers were now pumping bite-sized
packets of liquid energy


318
00:27:22,440 --> 00:27:24,080
into the food chain.


319
00:27:25,480 --> 00:27:29,080
And this began driving the evolution
of entirely new insects.


320
00:27:33,160 --> 00:27:35,240
Just take a look at this.


321
00:27:35,240 --> 00:27:37,800
Isn't it beautiful?


322
00:27:37,800 --> 00:27:42,080
For me, this is one of the most
incredible fossils ever found.


323
00:27:42,080 --> 00:27:44,200
It's such intricate detail.


324
00:27:44,200 --> 00:27:46,280
The material is amber.


325
00:27:46,280 --> 00:27:48,400
And inside it is a bee.


326
00:27:53,920 --> 00:27:59,000
It's a very primitive bee
that got stuck in liquid tree resin


327
00:27:59,000 --> 00:28:03,520
which then solidified
and preserved the hapless insect.


328
00:28:07,720 --> 00:28:12,720
Bee fossils like these
began appearing
roughly 100 million years ago.


329
00:28:13,840 --> 00:28:16,960
And what they show
is the incredible impact


330
00:28:16,960 --> 00:28:20,440
flowering plants were now
having on evolution.


331
00:28:21,520 --> 00:28:26,080
What I love about this fossil
is that it's like a snapshot
of an ancient past,


332
00:28:26,080 --> 00:28:27,880
just captured in time.


333
00:28:27,880 --> 00:28:31,240
And it makes you realise that
there was a particular point


334
00:28:31,240 --> 00:28:33,880
when bees first arrived on Earth.


335
00:28:35,200 --> 00:28:37,680
Bees evolved from carnivorous wasps


336
00:28:37,680 --> 00:28:42,760
which had turned their backs on meat
in favour of pollen and nectar.


337
00:28:45,200 --> 00:28:48,960
As they evolved, their whole bodies
became covered in hair,


338
00:28:48,960 --> 00:28:50,440
to collect more pollen.


339
00:28:53,720 --> 00:28:56,840
They developed sophisticated
compound eyes,


340
00:28:56,840 --> 00:29:00,800
with hundreds of tiny lenses
to spot the flowers.


341
00:29:03,240 --> 00:29:07,480
Inside were special cells
to detect UV light.


342
00:29:09,520 --> 00:29:12,440
There are more types of early bees
in South Africa


343
00:29:12,440 --> 00:29:16,240
than anywhere else in the world so
it's thought they originated here.


344
00:29:16,240 --> 00:29:17,920
And if you think about it,


345
00:29:17,920 --> 00:29:21,560
without the power of flowers,
you'd have no bees at all.


346
00:29:23,680 --> 00:29:27,480
But by creating insects
to pollinate them,


347
00:29:27,480 --> 00:29:31,160
the flowers introduced
a new problem for themselves.


348
00:29:32,640 --> 00:29:36,600
There was a risk that after
an insect picked up pollen
from a flower,


349
00:29:36,600 --> 00:29:41,240
it would then travel on to
a different species of flower
and fail to fertilise it


350
00:29:42,320 --> 00:29:44,480
The pollen would be wasted.


351
00:29:46,080 --> 00:29:49,200
The solution of flowers
was inspired.


352
00:29:51,880 --> 00:29:55,240
Down under these cliffs
on the South African coast,


353
00:29:55,240 --> 00:29:57,720
you can see what they came up with.


354
00:30:00,360 --> 00:30:04,040
This lovely pink flower
is Orphium frutescens...


355
00:30:05,080 --> 00:30:08,400
..which flourishes here in these
salty conditions near the sea,


356
00:30:08,400 --> 00:30:10,920
but what's truly amazing
about this plant


357
00:30:10,920 --> 00:30:14,880
is that it's struck
up this exclusive relationship
with a particular bee.


358
00:30:16,480 --> 00:30:19,360
Orphium flowers
don't contain nectar.


359
00:30:19,360 --> 00:30:22,240
The payment they provide is pollen.


360
00:30:22,240 --> 00:30:25,280
But strangely,
they keep it locked up.


361
00:30:25,280 --> 00:30:29,640
Special twisted stamens stop it
being stolen by visiting insects.


362
00:30:29,640 --> 00:30:33,320
All, that is, except one -


363
00:30:33,320 --> 00:30:35,960
the female carpenter bee.


364
00:30:35,960 --> 00:30:38,720
Only she has the key.


365
00:30:40,480 --> 00:30:45,880
Let me show you what the bee has to
do, using these tuning forks here.


366
00:30:45,880 --> 00:30:47,920
When the bee lands on the flower,


367
00:30:47,920 --> 00:30:52,560
it changes the rate at which
it beats its wings to just
the right frequency.


368
00:30:52,560 --> 00:30:53,760
From this note...


369
00:30:53,760 --> 00:30:55,320
(HIGH NOTE)


370
00:30:56,360 --> 00:30:57,440
..to this one.


371
00:30:57,440 --> 00:30:59,360
(LOWER NOTE)


372
00:31:00,320 --> 00:31:02,200
Middle C.


373
00:31:02,200 --> 00:31:06,640
And it's these vibrations that are
the key to unlocking the stamens


374
00:31:06,640 --> 00:31:12,160
which open up at the top here and
just shower the bee with pollen.


375
00:31:12,160 --> 00:31:13,440
(TUNING FORK BUZZES)


376
00:31:13,440 --> 00:31:15,160
Ah! Look at that.


377
00:31:15,160 --> 00:31:18,640
Look at the amount of yellow pollen
on there. Fantastic!


378
00:31:20,880 --> 00:31:22,920
(BEE BUZZES)


379
00:31:22,920 --> 00:31:25,560
Now watch the bee do the same,


380
00:31:25,560 --> 00:31:27,480
hitting the middle C note...


381
00:31:27,480 --> 00:31:28,720
(BUZZING DROPS)


382
00:31:28,720 --> 00:31:31,080
..with the beat of its wings...


383
00:31:32,280 --> 00:31:34,360
..and unlocking the pollen.


384
00:31:35,800 --> 00:31:38,560
No other insect does this.


385
00:31:38,560 --> 00:31:40,560
It's incredible, isn't it?


386
00:31:40,560 --> 00:31:44,360
One single species of flower,
one particular type of bee


387
00:31:44,360 --> 00:31:48,200
have evolved together
to give this intimate partnership.


388
00:31:50,920 --> 00:31:55,000
It ensured that a flower's pollen
was successfully taken


389
00:31:55,000 --> 00:31:57,080
to a plant of the same species.


390
00:32:00,200 --> 00:32:02,520
But these increasingly
tight relationships


391
00:32:02,520 --> 00:32:06,480
between insects and flowers
had another impact on life on Earth.


392
00:32:06,480 --> 00:32:10,880
Because they led to tighter
and more isolated populations,


393
00:32:10,880 --> 00:32:14,520
that started creating gaps
in the overall ecosystem.


394
00:32:14,520 --> 00:32:20,560
This, in turn, encouraged
new species to evolve,
filling in those spaces.


395
00:32:22,520 --> 00:32:27,240
Flowers were now driving a huge
increase in the diversity of life.


396
00:32:28,320 --> 00:32:33,400
And they were fuelling this increase
by pumping nectar
into the food chain.


397
00:32:38,120 --> 00:32:44,040
The insects, bees, butterflies
and moths, such as the hawk moth,


398
00:32:44,040 --> 00:32:47,440
were eating it with long,
probing tongues.


399
00:32:49,760 --> 00:32:54,400
There were new species of birds,
like the Calliope hummingbird,


400
00:32:54,400 --> 00:32:56,960
with beaks perfect
for trumpet-shaped flowers.


401
00:32:59,200 --> 00:33:03,720
And predators, such as
these toucans, that ate
the pollinators.


402
00:33:04,800 --> 00:33:08,440
Between 120 and about
90 million years ago,


403
00:33:08,440 --> 00:33:10,800
all thanks to flowering plants,


404
00:33:10,800 --> 00:33:16,040
evolution had entered
the most explosive phase
in the Earth's history.


405
00:33:27,320 --> 00:33:29,680
By now Pangaea had split up,


406
00:33:29,680 --> 00:33:33,000
creating the continents
so familiar to us today,


407
00:33:33,000 --> 00:33:36,080
and flowers dominated them.


408
00:33:37,040 --> 00:33:41,560
They'd conquered the ancient
conifers and ferns,
and covered half the Earth.


409
00:33:46,520 --> 00:33:49,480
But it wasn't just life
they were changing.


410
00:33:50,720 --> 00:33:54,480
Because they started altering
the very shape of the planet itself.


411
00:34:01,640 --> 00:34:04,720
This is Ha Long Bay in Vietnam.


412
00:34:04,720 --> 00:34:08,520
I'm here because it's evidence
of how flowers unleashed


413
00:34:08,520 --> 00:34:11,320
some of the most powerful
forces on Earth.


414
00:34:12,840 --> 00:34:15,920
This whole landscape
just dwarfs you.


415
00:34:15,920 --> 00:34:20,520
You can see these pinnacles
of limestone just soaring upwards,


416
00:34:20,520 --> 00:34:22,960
limestone that you get
all over Vietnam.


417
00:34:22,960 --> 00:34:28,160
And it gives this
really distinctive, even iconic
landscape called karst.


418
00:34:28,160 --> 00:34:31,800
The thing is, when you look
at things as huge as that


419
00:34:31,800 --> 00:34:35,440
you look for huge geological
processes to create them,


420
00:34:35,440 --> 00:34:37,960
but it's not always the case.


421
00:34:42,200 --> 00:34:44,520
That's because 90 million years ago,


422
00:34:44,520 --> 00:34:47,920
flowers began to build an empire
across the planet...


423
00:34:50,720 --> 00:34:53,280
..in a totally unexpected way.


424
00:34:57,480 --> 00:35:01,840
They did it by creating vast
tropical rainforests.


425
00:35:14,320 --> 00:35:18,840
Almost all the trees are really
giant flowering plants.


426
00:35:18,840 --> 00:35:21,480
You can see one here in flower.


427
00:35:21,480 --> 00:35:25,320
And all the trees
are doing one thing.


428
00:35:31,480 --> 00:35:33,040
Breathe out on a piece of glass


429
00:35:33,040 --> 00:35:36,280
and it's pretty obvious that
there's moisture in your breath.


430
00:35:36,280 --> 00:35:39,600
And in a funny kind of way,
plants are breathing out
moisture too.


431
00:35:39,600 --> 00:35:41,360
It's just much harder to see.


432
00:35:44,080 --> 00:35:49,440
But take a look at this. If I tie
a clear plastic bag
over this big leaf,


433
00:35:49,440 --> 00:35:55,440
then we should be able to actually
see the plant breathing away.


434
00:35:55,440 --> 00:35:59,760
And all we need to do now is...
wait a couple of hours.


435
00:36:07,480 --> 00:36:10,920
Look how much moisture this single
banana leaf produces.


436
00:36:14,880 --> 00:36:17,200
It's losing water, or transpiring,


437
00:36:17,200 --> 00:36:21,080
through tiny pores in the leaf
called stomata.


438
00:36:24,760 --> 00:36:27,760
Close up, you can see the veins
of the leaf,


439
00:36:27,760 --> 00:36:30,320
which transport water
around the plant.


440
00:36:31,640 --> 00:36:35,280
Leaves of flowering plants contain
four times more veins


441
00:36:35,280 --> 00:36:36,520
than other plants.


442
00:36:43,560 --> 00:36:46,720
Because they share the same type
of special vein leaves,


443
00:36:46,720 --> 00:36:50,200
trees like these act as kind of
giant water pumps


444
00:36:50,200 --> 00:36:54,160
drawing moisture up from the soil
and pumping it into the atmosphere.


445
00:36:54,160 --> 00:36:58,480
Some of these trees chuck out
five tonnes of water every day.


446
00:37:07,240 --> 00:37:11,760
All this transpiration meant
that 90 million years ago,


447
00:37:11,760 --> 00:37:15,160
flowering plants were creating
more clouds...


448
00:37:19,200 --> 00:37:21,800
..which led to more rain.


449
00:37:21,800 --> 00:37:23,480
(THUNDER CRACKS)


450
00:37:24,840 --> 00:37:26,720
Water that, when it fell,


451
00:37:26,720 --> 00:37:30,920
was then drawn up from
the forest floor by the same trees,


452
00:37:30,920 --> 00:37:35,720
forming a self-sustaining cycle
of almost perpetual rainfall.


453
00:37:37,920 --> 00:37:41,880
In fact, 80% of the water
in the rainforests


454
00:37:41,880 --> 00:37:44,800
came from the flowering plants
themselves.


455
00:37:47,480 --> 00:37:49,320
In this new age of rain,


456
00:37:49,320 --> 00:37:53,000
water became an ever powerful
sculpting force.


457
00:37:56,680 --> 00:38:01,480
And today, you can see its effects
in an astonishing hidden world.


458
00:38:15,920 --> 00:38:19,200
Deep beneath the rainforest
in central Vietnam


459
00:38:19,200 --> 00:38:21,080
are the caverns of Hang Son Doong.


460
00:38:23,040 --> 00:38:27,000
We are the first British film crew
to explore them.


461
00:38:32,360 --> 00:38:37,120
Hang Son Doong is the largest
cave passage ever discovered


462
00:38:37,120 --> 00:38:39,360
anywhere on Earth.


463
00:39:04,360 --> 00:39:08,560
This single cavern
is nearly two kilometres long.


464
00:39:09,880 --> 00:39:14,720
All carved from solid rock
by nothing more than water.


465
00:39:22,200 --> 00:39:25,640
All of which has trickled down
from a single source -


466
00:39:25,640 --> 00:39:28,040
the vast jungle above.


467
00:39:30,240 --> 00:39:34,800
It is a relentless force that has
carved out a dozen enormous caverns.


468
00:39:37,480 --> 00:39:41,320
An underground monument
to the power of flowering plants.


469
00:39:51,760 --> 00:39:55,880
And deep in this labyrinth is what,
for me, is perhaps the greatest


470
00:39:55,880 --> 00:39:58,280
of all the wonders
of the plant world.


471
00:40:08,960 --> 00:40:14,040
Here, at the heart of the cave,
a whole rainforest.


472
00:40:24,480 --> 00:40:26,520
Where the roof has collapsed,


473
00:40:26,520 --> 00:40:29,240
flowering plants have made
their home...


474
00:40:33,120 --> 00:40:36,040
..200 metres below ground level.


475
00:40:40,720 --> 00:40:42,840
It is like a lost world.


476
00:40:42,840 --> 00:40:48,040
The thing is,
just a few minutes ago,
there was me in a cool, dark cave,


477
00:40:48,040 --> 00:40:52,000
and then ejected into this place
with streaming sunlight.


478
00:40:52,000 --> 00:40:55,240
Hot and sticky rainforest.


479
00:40:57,400 --> 00:41:01,720
And where there's water and light,
flowers have produced life.


480
00:41:13,600 --> 00:41:16,360
Plants such as this
banana flower thrive,


481
00:41:16,360 --> 00:41:19,920
which in turn attracts butterflies
and other animals.


482
00:41:22,200 --> 00:41:25,360
It's a thriving ecosystem here.


483
00:41:25,360 --> 00:41:27,320
And the whole thing is fed, really,


484
00:41:27,320 --> 00:41:31,240
everything, this whole food chain,
is fed by the flowering plants.


485
00:41:36,160 --> 00:41:40,760
Flowering plants have created
a small but perfect version


486
00:41:40,760 --> 00:41:42,800
of the rainforest above.


487
00:41:49,800 --> 00:41:51,920
Look at that mist.


488
00:41:51,920 --> 00:41:54,920
There's a whole weird microclimate
in here.


489
00:41:54,920 --> 00:41:57,960
Clouds of moisture
envelope everything.


490
00:41:57,960 --> 00:42:00,440
And the plants just soak up
that moisture,


491
00:42:00,440 --> 00:42:03,200
just draw it up
and then pass it out.


492
00:42:03,200 --> 00:42:05,480
So that cycle of transpiration


493
00:42:05,480 --> 00:42:08,200
that we see on a big scale
up in the tropical forests


494
00:42:08,200 --> 00:42:10,160
is captured in miniature down here.


495
00:42:15,920 --> 00:42:19,840
Caves formed under all the world's
great rainforests.


496
00:42:20,880 --> 00:42:25,840
And this extra water even began
to transform the global climate.


497
00:42:28,400 --> 00:42:32,600
As water evaporates, it absorbs heat
and cools the planet.


498
00:42:33,880 --> 00:42:39,360
The Amazon rainforest alone
keeps its whole region
five degrees colder.


499
00:42:39,360 --> 00:42:43,200
Across the planet,
water injected into the water cycle


500
00:42:43,200 --> 00:42:46,000
was eroding deep canyons,


501
00:42:46,000 --> 00:42:48,640
carving high mountains,


502
00:42:48,640 --> 00:42:52,640
and sculpting the karst towers
so iconic of Asia.


503
00:42:56,960 --> 00:42:59,080
It's extraordinary, isn't it?


504
00:42:59,080 --> 00:43:01,120
Especially when you think
that all this


505
00:43:01,120 --> 00:43:04,440
comes not from huge forces
deep underground,


506
00:43:04,440 --> 00:43:09,160
but in part from tiny changes
on the leaves of flowering plants.


507
00:43:15,840 --> 00:43:20,120
65 million years ago was
the age of the rainforests.


508
00:43:22,240 --> 00:43:25,880
They'd spread from the equator
to cover most of the Earth.


509
00:43:26,920 --> 00:43:32,040
It meant three quarters
of all plants were now flowers.


510
00:43:32,040 --> 00:43:36,000
A rich, lush home for millions
of new animals.


511
00:43:38,160 --> 00:43:43,160
The dominance of the flowering
plants seemed unassailable.


512
00:43:43,160 --> 00:43:45,480
But it was not to last.


513
00:43:51,280 --> 00:43:58,000
A 10km-wide asteroid coming
from deep space was on
a collision course.


514
00:44:06,160 --> 00:44:10,800
It hit the Earth with a force
of a billion Hiroshima bombs.


515
00:44:10,800 --> 00:44:16,880
70 billion tonnes of pulverised rock
were blasted into a low orbit.


516
00:44:20,600 --> 00:44:25,400
Scientists called it ejector
and travelling at supersonic speeds


517
00:44:25,400 --> 00:44:29,120
its friction with the atmosphere
heated the Earth up


518
00:44:29,120 --> 00:44:31,560
by over 200 degrees Celsius.


519
00:44:33,280 --> 00:44:37,520
It spontaneously triggered fires
across the land.


520
00:44:42,960 --> 00:44:47,480
It was one of the worst mass
extinctions in the history
of the Earth.


521
00:44:50,280 --> 00:44:53,400
And famously killed off
the dinosaurs.


522
00:45:01,880 --> 00:45:05,960
But less well known
is the immediate impact on plants.


523
00:45:08,400 --> 00:45:10,800
Scientists believe that for them,


524
00:45:10,800 --> 00:45:14,240
the effect of the asteroid
was also devastating.


525
00:45:16,920 --> 00:45:19,000
Not only were there fires,


526
00:45:19,000 --> 00:45:23,920
but the ejector created clouds
of nitric and sulphur dioxide...


527
00:45:25,880 --> 00:45:29,200
..which fell as acid rain...


528
00:45:31,480 --> 00:45:34,080
..destroying plants
from the roots up.


529
00:45:50,440 --> 00:45:52,200
I think it's really hard to imagine


530
00:45:52,200 --> 00:45:55,960
what the most recent and powerful
extinction event must've been like,


531
00:45:55,960 --> 00:45:59,360
but perhaps the closest you can get
to it is a newly-erupted volcano,


532
00:45:59,360 --> 00:46:01,360
like here in White Island,
New Zealand.


533
00:46:04,280 --> 00:46:06,520
I think it's just the desolation,
really.


534
00:46:07,680 --> 00:46:12,080
The bleakness, that sense that
life's just been...obliterated.


535
00:46:15,920 --> 00:46:17,520
For plants,


536
00:46:17,520 --> 00:46:21,200
the aftermath of the asteroid impact
must have been similar.


537
00:46:21,200 --> 00:46:22,680
Here on White Island,


538
00:46:22,680 --> 00:46:25,800
vegetation has been incinerated
by successive eruptions.


539
00:46:27,920 --> 00:46:32,840
And the volcanic fumes create
acid rain, just like after
the asteroid.


540
00:46:34,080 --> 00:46:36,280
For flowering plants,
it was a disaster.


541
00:46:36,280 --> 00:46:39,760
That close, almost inseparable
relationship with insects


542
00:46:39,760 --> 00:46:41,400
was now their Achilles heel,


543
00:46:41,400 --> 00:46:45,480
because even if a flowering plant
had survived the initial calamity,


544
00:46:45,480 --> 00:46:48,040
it needed a specific animal
to pollinate it,


545
00:46:48,040 --> 00:46:51,720
and often they'd simply
been wiped out.


546
00:47:01,040 --> 00:47:03,880
But flowers weren't beaten yet.


547
00:47:04,960 --> 00:47:07,200
All those evolutionary devices


548
00:47:07,200 --> 00:47:10,960
that had allowed them to thrive
on a hostile planet
in the first place


549
00:47:10,960 --> 00:47:14,120
now became their ultimate
tools for survival.


550
00:47:16,520 --> 00:47:20,560
Coloured petals to attract
the few surviving pollinators.


551
00:47:21,600 --> 00:47:25,200
Nectar to repay them
in desperate times.


552
00:47:27,560 --> 00:47:32,400
Above all, flowers could rely on
those superb survival capsules


553
00:47:32,400 --> 00:47:36,480
that could have been purpose-built
for just such an apocalypse...


554
00:47:37,520 --> 00:47:38,960
..seeds.


555
00:47:48,560 --> 00:47:51,680
Now, following the asteroid impact,


556
00:47:51,680 --> 00:47:54,840
seeds helped flowers
to re-colonise the Earth.


557
00:47:55,880 --> 00:47:57,200
And as they did so,


558
00:47:57,200 --> 00:48:02,800
once again flowers formed
an inseparable relationship
with animals.


559
00:48:02,800 --> 00:48:09,160
The dinosaurs had gone, but another
type of animal had replaced them...


560
00:48:09,160 --> 00:48:10,720
..mammals.


561
00:48:15,120 --> 00:48:18,960
This time, flowers used mammals
to help them distribute their seeds.


562
00:48:28,800 --> 00:48:32,640
Here in Thailand, this whole
floating market celebrates


563
00:48:32,640 --> 00:48:36,120
the clever evolutionary device
flowers came up with.


564
00:48:37,760 --> 00:48:41,360
More sophisticated flowers
developed a really sneaky way


565
00:48:41,360 --> 00:48:43,040
of spreading their seeds.


566
00:48:43,040 --> 00:48:47,000
A method that didn't just disperse
at metres, but kilometres.


567
00:48:47,000 --> 00:48:50,280
And to do that, they again harnessed
the hunger of animals.


568
00:48:50,280 --> 00:48:52,360
They developed fruit.


569
00:48:58,200 --> 00:48:59,600
What is that?


570
00:48:59,600 --> 00:49:01,880
Durian. This is durian?


571
00:49:01,880 --> 00:49:04,360
I cut. You taste. OK, yeah.


572
00:49:05,720 --> 00:49:09,480
You can't come to Asia
without trying the smelliest,


573
00:49:09,480 --> 00:49:12,200
most notorious fruit on Earth.


574
00:49:12,200 --> 00:49:13,480
Beautiful!


575
00:49:14,640 --> 00:49:17,600
I hope it tastes better
than it smells, though.


576
00:49:18,680 --> 00:49:21,320
Ah! There's the seeds in there.


577
00:49:22,720 --> 00:49:24,640
And then this flesh.


578
00:49:24,640 --> 00:49:26,160
Texture's...


579
00:49:28,920 --> 00:49:31,000
THEY LAUGH


580
00:49:31,000 --> 00:49:33,280
They're all laughing.
They're laughing.


581
00:49:33,280 --> 00:49:36,040
It's like an off avocado, really.


582
00:49:37,520 --> 00:49:40,800
I think that's what they call
an acquired taste.


583
00:49:41,800 --> 00:49:44,640
The botanical definition of a fruit


584
00:49:44,640 --> 00:49:48,080
is that it must actually develop
from the flower itself.


585
00:49:49,280 --> 00:49:54,600
The fleshy coating was once
the ovary, as it grew around
the maturing seeds.


586
00:49:54,600 --> 00:49:57,720
Lovely. Incredibly sweet.


587
00:49:57,720 --> 00:49:59,400
Very subtle.


588
00:50:00,400 --> 00:50:04,320
Isn't that great? The way all
of them hide this inside,
this little seed.


589
00:50:06,480 --> 00:50:09,800
You can see why some warm-blooded
mammal or bird


590
00:50:09,800 --> 00:50:12,960
would want to eat this -
it's just packed with nutrition.


591
00:50:12,960 --> 00:50:14,880
And of course, as you do that...


592
00:50:14,880 --> 00:50:16,160
you...


593
00:50:16,160 --> 00:50:18,120
you swallow the seed.


594
00:50:19,800 --> 00:50:23,560
And then later on you pass that out
somewhere, miles away,


595
00:50:23,560 --> 00:50:26,160
dumped in some little dollop
of manure.


596
00:50:26,160 --> 00:50:29,600
But that's really the point
of all of these different types.


597
00:50:29,600 --> 00:50:33,160
All this diversity is designed
to attract animals to eat it.


598
00:50:45,600 --> 00:50:50,400
Fruit is one of the most remarkable
transformations in nature.


599
00:50:52,600 --> 00:50:56,960
What begins as an advertisement
for an insect, a flower,


600
00:50:56,960 --> 00:51:00,760
becomes a protective covering
for the seeds inside.


601
00:51:02,480 --> 00:51:08,200
And then a final burst...
swells into the juicy flesh
of a fruit.


602
00:51:24,440 --> 00:51:29,400
55 million years ago, one group
of early mammals was evolving


603
00:51:29,400 --> 00:51:32,960
that relied almost entirely
on fruit.


604
00:51:32,960 --> 00:51:37,640
In fact, without it, they'd probably
never have existed.


605
00:51:42,800 --> 00:51:48,200
It was an animal which
would directly link flowers
to our human story.


606
00:51:52,400 --> 00:51:56,600
They live here in Thailand's
Khao Sok National Park.


607
00:51:56,600 --> 00:52:00,240
Somewhere in these trees
there are primates.


608
00:52:00,240 --> 00:52:02,040
GIBBONS CALLING


609
00:52:02,040 --> 00:52:04,200
I'm sure they're up there.


610
00:52:04,200 --> 00:52:07,480
You see the trees just...
The branches moving but...


611
00:52:07,480 --> 00:52:13,000
trying to pinpoint the actual
gibbons is...really tricky.


612
00:52:13,000 --> 00:52:14,440
Oh, there's one.


613
00:52:16,160 --> 00:52:20,600
Do you see it? It's kind of
silhouetted in the branches
just up there.


614
00:52:22,200 --> 00:52:25,040
I'm sure it... Yeah, it's moving.


615
00:52:25,040 --> 00:52:28,120
My first gibbon.


616
00:52:29,160 --> 00:52:32,800
The primates - lemurs, monkeys
and apes -


617
00:52:32,800 --> 00:52:36,840
evolved an inseparable partnership
with the fruit from flowers.


618
00:52:36,840 --> 00:52:40,320
And it determined
their whole anatomy.


619
00:52:40,320 --> 00:52:43,360
Primates have got the perfect tools
for reaching fruit.


620
00:52:43,360 --> 00:52:45,680
They've got these really
strong hands which,


621
00:52:45,680 --> 00:52:49,120
along with their powerful chest
and shoulder muscles,


622
00:52:49,120 --> 00:52:51,800
allow them to get up into the trees.


623
00:52:52,800 --> 00:52:58,400
All these are important traits
that we human primates
have inherited today.


624
00:52:59,600 --> 00:53:01,200
And all came from the need


625
00:53:01,200 --> 00:53:05,640
for the first primates to reach
the fruit of flowering plants.


626
00:53:10,160 --> 00:53:13,640
Norberto Asensio is a primatologist.


627
00:53:13,640 --> 00:53:18,600
He studies the crucial role fruit
plays in the diet of monkeys.


628
00:53:20,360 --> 00:53:25,080
For most primates, fruit is
important. It's part of their diet -
so what?


629
00:53:25,080 --> 00:53:28,080
Is it the core of the diet?
The essential core, do you think?


630
00:53:28,080 --> 00:53:29,360
I would say so.


631
00:53:29,360 --> 00:53:35,080
I would say that most of the primates
will have 70% to 90% of their diet


632
00:53:35,080 --> 00:53:36,800
on fruit. It's quite a lot.


633
00:53:37,880 --> 00:53:43,000
But back then, flowering plants
created a problem for themselves.


634
00:53:43,000 --> 00:53:45,720
Primates were so hungry for fruit...


635
00:53:47,120 --> 00:53:51,000
..they would pick it long before
the seeds inside were mature.


636
00:53:52,080 --> 00:53:54,840
It meant seeds were being wasted.


637
00:53:57,320 --> 00:54:00,760
So flowers came up with a solution.


638
00:54:06,640 --> 00:54:12,160
When fruit was ripe, they made it
sweet, juicy and brightly coloured.


639
00:54:12,160 --> 00:54:14,800
It was a colour-coded time delay.


640
00:54:15,880 --> 00:54:21,400
And it encouraged primates to take
only fruit that was fully mature.


641
00:54:23,960 --> 00:54:26,440
Norberto studies how
this colour coding


642
00:54:26,440 --> 00:54:30,480
drove changes in
our ancient ancestors.


643
00:54:30,480 --> 00:54:35,720
Before now, primates,
like all mammals, were colour-blind.


644
00:54:36,880 --> 00:54:41,560
This made spotting ripe fruit
difficult, as I'm about to find out.


645
00:54:41,560 --> 00:54:43,360
Let's do an experiment.


646
00:54:43,360 --> 00:54:49,880
Here you have glasses that are going
to turn you into a simple mammal.


647
00:54:49,880 --> 00:54:51,320
Let's see.


648
00:54:51,320 --> 00:54:52,720
Oh, gosh!


649
00:54:53,680 --> 00:54:58,320
The glasses simulate
colour blindness by removing
red from the picture.


650
00:54:59,440 --> 00:55:02,960
I can kind of tell the difference
in contrast between some of them.


651
00:55:02,960 --> 00:55:07,320
That's gone a very funny shade
of bluishness.


652
00:55:07,320 --> 00:55:09,480
The interesting ones are these reds.


653
00:55:09,480 --> 00:55:12,600
I know they're red but they
just don't seem red at all.


654
00:55:12,600 --> 00:55:18,600
Overall it's just got a very...
almost bland greyness to it all.


655
00:55:23,400 --> 00:55:25,280
For primates to perceive red,


656
00:55:25,280 --> 00:55:28,880
they had to evolve a more
sophisticated vision system.


657
00:55:32,000 --> 00:55:36,760
In the retina are special photo
receptor cells that detect colour,


658
00:55:36,760 --> 00:55:38,240
called cones.


659
00:55:39,280 --> 00:55:43,160
There are 150,000 per square mm.


660
00:55:44,160 --> 00:55:49,440
Early mammals only had two types
of cone, one for green
and one for blue.


661
00:55:50,560 --> 00:55:52,560
It meant they were colour-blind.


662
00:55:52,560 --> 00:55:55,920
But primates evolved a third type.


663
00:55:55,920 --> 00:55:59,120
It was sensitive to red.


664
00:56:00,360 --> 00:56:03,160
Now they could spot ripe fruit.


665
00:56:04,120 --> 00:56:07,160
Colour vision helped give primates
the advantage,


666
00:56:07,160 --> 00:56:12,440
kick-starting the evolutionary
journey that resulted in us humans.


667
00:56:12,440 --> 00:56:15,280
That's why we have colour vision now


668
00:56:15,280 --> 00:56:18,520
and we have this wonderful
rainbow of colours


669
00:56:18,520 --> 00:56:21,200
that we can see now and enjoy it.


670
00:56:25,400 --> 00:56:30,000
Fruit drove the evolution
of so many of the traits
of our ancient ancestors,


671
00:56:30,000 --> 00:56:34,520
but this simple need, the ability
to see if fruit was ready
to eat or not,


672
00:56:34,520 --> 00:56:38,520
had given primates perhaps
for the first time on our planet


673
00:56:38,520 --> 00:56:43,160
this capacity to see in full
glorious technicolour.


674
00:56:43,160 --> 00:56:46,560
And it's something that I think
we just take for granted.


675
00:56:54,280 --> 00:56:58,040
Since they'd evolved
140 million years ago,


676
00:56:58,040 --> 00:57:01,120
flowers had transformed our planet.


677
00:57:01,120 --> 00:57:04,200
They'd come to dominate
the plant kingdom,


678
00:57:04,200 --> 00:57:06,640
sculpting the Earth itself.


679
00:57:07,800 --> 00:57:12,400
Above all, flowers drove
the evolution of animals,


680
00:57:12,400 --> 00:57:14,400
especially primates,


681
00:57:14,400 --> 00:57:17,560
shaping our human evolution.


682
00:57:29,480 --> 00:57:32,880
It seems to me that we are
rather animal-centric.


683
00:57:32,880 --> 00:57:36,000
That by being members
of the animal kingdom ourselves,


684
00:57:36,000 --> 00:57:38,800
we somehow see them as the thing
that's at the heart


685
00:57:38,800 --> 00:57:41,280
of driving changes to life on Earth,


686
00:57:41,280 --> 00:57:43,440
but I don't think that's true.


687
00:57:43,440 --> 00:57:46,200
Most of the big changes
to life on the planet


688
00:57:46,200 --> 00:57:48,320
have been brought around by flowers.


689
00:57:48,320 --> 00:57:52,120
They are the ones that are more
manipulative, more inventive,


690
00:57:52,120 --> 00:57:55,720
more powerful than any
of the animals that they
are interacting with.


691
00:57:55,720 --> 00:58:00,360
Most animals are only here
because of flowers, including us.


692
00:58:00,360 --> 00:58:05,240
It's an intriguing thought for next
time you're out doing the roses.


693
00:58:06,440 --> 00:58:10,600
Next, we reveal the epic battle
between the forests


694
00:58:10,600 --> 00:58:13,840
and their greatest challenger,
a new type of plant...


695
00:58:13,840 --> 00:58:15,520
the grasses.


696
00:58:15,520 --> 00:58:19,440
It was a conflict that would
set the world on fire.


697
00:58:19,440 --> 00:58:23,960
The victor would force our ancient
ape ancestors out of the forests


698
00:58:23,960 --> 00:58:25,680
and into the savanna.


699
00:58:26,720 --> 00:58:31,120
And go on to trigger the birth
of human civilisation.


700
00:58:37,200 --> 00:58:40,200
Subtitles by Red Bee Media Ltd


701
00:58:40,200 --> 00:58:43,280
Email subtitling@bbc.co.uk