1
00:00:15,880 --> 00:00:18,920
This creature is a wonder of life.


2
00:00:22,120 --> 00:00:24,480
A voracious predator,


3
00:00:24,480 --> 00:00:27,640
this male has lived underwater
for nearly five months,


4
00:00:27,640 --> 00:00:32,560
feeding, growing,
preparing for this moment.


5
00:00:37,360 --> 00:00:38,920
He's about to undertake


6
00:00:38,920 --> 00:00:41,560
one of the most remarkable
transformations


7
00:00:41,560 --> 00:00:43,240
in the natural world.


8
00:00:45,960 --> 00:00:50,000
From aquatic predator...
to master of the air.


9
00:01:15,000 --> 00:01:17,080
The brief adult life of a dragonfly


10
00:01:17,080 --> 00:01:19,920
is amongst the most
energetic in nature.


11
00:01:28,000 --> 00:01:32,440
Dragonflies are
the most remarkable animals.


12
00:01:32,440 --> 00:01:36,800
You can see their
incredible agility in flight


13
00:01:36,800 --> 00:01:41,040
just watching them skim across
the surface of this pond.


14
00:01:41,040 --> 00:01:43,840
They can pull two and a half G
in a turn,


15
00:01:43,840 --> 00:01:45,880
and they can fly at 15 mph,


16
00:01:45,880 --> 00:01:48,920
which is fast
for something that big.


17
00:01:51,040 --> 00:01:54,840
They've been around on Earth since
before the time of the dinosaurs,


18
00:01:54,840 --> 00:01:59,200
and in that time they've been
fine-tuned by natural selection


19
00:01:59,200 --> 00:02:04,040
to do what they do - which is
to catch their prey on the wing.


20
00:02:18,560 --> 00:02:23,200
So, dragonflies are beautiful
pieces of engineering.


21
00:02:23,200 --> 00:02:26,880
They're intricate, complex machines.


22
00:02:26,880 --> 00:02:29,440
But is that all they are?


23
00:02:31,880 --> 00:02:36,720
Because once their brief lives are
over, their vitality will be gone.


24
00:02:41,360 --> 00:02:44,480
And this raises deep questions.


25
00:02:48,960 --> 00:02:51,560
What is it that makes
something alive?


26
00:02:55,560 --> 00:02:59,040
And how did life begin
in the first place?


27
00:03:01,240 --> 00:03:05,640
So, what is the difference
between the living and the dead?


28
00:03:05,640 --> 00:03:07,680
What is life?


29
00:03:41,560 --> 00:03:45,400
I've come to one of the most
isolated regions of the Philippines


30
00:03:45,400 --> 00:03:48,000
to visit the remote
hilltop town of Sagada.


31
00:03:50,640 --> 00:03:54,000
It's a two-day drive
from the capital, Manila,


32
00:03:54,000 --> 00:03:56,240
over some of the country's
roughest roads


33
00:03:56,240 --> 00:04:00,320
that wind their way 1,500
metres up into the hills.


34
00:04:17,480 --> 00:04:18,760
This is a place


35
00:04:18,760 --> 00:04:22,960
where the traditional belief is
that mountain spirits give us life


36
00:04:22,960 --> 00:04:26,520
and that our souls return
to the mountain when we die...


37
00:04:30,400 --> 00:04:34,200
..and where the people who live here
still imagine that


38
00:04:34,200 --> 00:04:37,280
the spirits of the dead
walk among the living.


39
00:04:50,960 --> 00:04:54,400
Tonight is November 1st,
and here in Sagada -


40
00:04:54,400 --> 00:04:58,080
in fact across the Philippines -
that means it's the Day of the Dead.


41
00:04:58,080 --> 00:05:02,040
That's the day when people come to
this graveyard on a hillside


42
00:05:02,040 --> 00:05:06,200
and, well, celebrate
the lives of their relatives.


43
00:05:16,560 --> 00:05:20,560
The people light fires to honour
and warm the departed,


44
00:05:20,560 --> 00:05:23,480
inviting their souls
to commune with them.


45
00:05:42,200 --> 00:05:45,720
Now, not matter how
unscientific it sounds,


46
00:05:45,720 --> 00:05:51,200
this idea that there's some kind of
soul or spirit or animating force


47
00:05:51,200 --> 00:05:56,240
that makes us what we are and that
persists after our death is common.


48
00:05:56,240 --> 00:05:58,640
Virtually every culture,
every religion,


49
00:05:58,640 --> 00:06:00,760
has that deeply-held belief.


50
00:06:02,360 --> 00:06:06,280
And there's a reason for that -
because it feels right.


51
00:06:06,280 --> 00:06:10,040
I mean, just think about it. It's
hard to accept that when you die


52
00:06:10,040 --> 00:06:14,920
you will just stop existing
and that you are, your life,


53
00:06:14,920 --> 00:06:18,000
the essence of you,
is just really something


54
00:06:18,000 --> 00:06:22,840
that emerges from an inanimate
bag of stuff.


55
00:06:55,000 --> 00:06:57,280
Don't get too close.


56
00:07:01,880 --> 00:07:03,640
You can see that these people feel


57
00:07:03,640 --> 00:07:06,520
not only do they come to celebrate
the lives of their relatives,


58
00:07:06,520 --> 00:07:09,200
but they're coming in some sense
to communicate with them.


59
00:07:09,200 --> 00:07:12,560
Their relatives, even though
their physical bodies have died,


60
00:07:12,560 --> 00:07:15,360
are still in some sense here.


61
00:07:17,080 --> 00:07:20,200
When you think about it,
that's not so easy to dismiss.


62
00:07:20,200 --> 00:07:25,960
If we are to state that science
can explain everything about us,


63
00:07:25,960 --> 00:07:29,800
then it's incumbent on science
to answer the question,


64
00:07:29,800 --> 00:07:33,080
what is it that animates
living things?


65
00:07:33,080 --> 00:07:37,160
What is the difference
between a piece of rock


66
00:07:37,160 --> 00:07:40,480
that's carved into a gravestone
and me?


67
00:07:49,880 --> 00:07:53,720
For millennia, some form of
spirituality has been evoked


68
00:07:53,720 --> 00:07:58,240
to explain what it means
to be alive, and how life began.


69
00:08:03,960 --> 00:08:05,960
It's only recently


70
00:08:05,960 --> 00:08:10,200
that science has begun to answer
these deepest of questions.


71
00:08:32,120 --> 00:08:33,640
In February 1943,


72
00:08:33,640 --> 00:08:37,720
the physicist Erwin Schrodinger
gave a series of lectures in Dublin.


73
00:08:37,720 --> 00:08:40,880
Now, Schrodinger is almost
certainly most famous


74
00:08:40,880 --> 00:08:43,520
for being one of the founders
of quantum theory.


75
00:08:43,520 --> 00:08:46,680
But in these lectures, which
he wrote up in this little book,


76
00:08:46,680 --> 00:08:50,640
he asked a very different
question - What Is Life?


77
00:08:50,640 --> 00:08:56,680
And right up front, on page one,
he says precisely what it isn't.


78
00:08:56,680 --> 00:08:59,360
It isn't something mystical,
says Schrodinger.


79
00:08:59,360 --> 00:09:03,240
There isn't some magical spark
that animates life.


80
00:09:03,240 --> 00:09:05,280
Life is a process.


81
00:09:05,280 --> 00:09:07,800
It's the interaction between
matter and energy


82
00:09:07,800 --> 00:09:11,040
described by the laws
of physics and chemistry.


83
00:09:11,040 --> 00:09:12,480
The same laws that describe


84
00:09:12,480 --> 00:09:15,960
the falling of the rain
or the shining of the stars.


85
00:09:23,680 --> 00:09:25,680
So, the question is,


86
00:09:25,680 --> 00:09:30,720
how is that this magnificent
complexity that we call life


87
00:09:30,720 --> 00:09:34,720
could have assembled itself
on the surface of a planet


88
00:09:34,720 --> 00:09:36,880
which itself formed


89
00:09:36,880 --> 00:09:41,400
from nothing more than a
collapsing cloud of gas and dust?


90
00:09:46,560 --> 00:09:50,520
To Schrodinger, the answer had to
lie in the way living things process


91
00:09:50,520 --> 00:09:56,480
one of the universe's most elusive
properties - energy.


92
00:10:17,760 --> 00:10:21,280
Energy is a concept
that's central to physics,


93
00:10:21,280 --> 00:10:23,640
but because it's a word
we use every day


94
00:10:23,640 --> 00:10:25,680
its meaning has got a bit woolly.


95
00:10:25,680 --> 00:10:27,880
I mean, it's easy to say
what it is in a sense.


96
00:10:27,880 --> 00:10:31,720
Obviously this river has got energy
because over decades and centuries


97
00:10:31,720 --> 00:10:34,920
it's cut this valley
through solid rock.


98
00:10:36,400 --> 00:10:39,880
But while this description
sounds simple,


99
00:10:39,880 --> 00:10:43,480
in reality things are
a little more complicated.


100
00:10:43,480 --> 00:10:45,320
For me, the best definition is that


101
00:10:45,320 --> 00:10:48,040
it's the length of the space time
four vector and time direction,


102
00:10:48,040 --> 00:10:50,360
but that's not very enlightening,
I'll grant you that.


103
00:10:55,440 --> 00:10:57,120
Over the years,


104
00:10:57,120 --> 00:11:01,360
the nature of energy has proved
notoriously difficult to pin down.


105
00:11:01,360 --> 00:11:05,000
Not least because it has
the seemingly magical property


106
00:11:05,000 --> 00:11:07,240
that it never runs out.


107
00:11:07,240 --> 00:11:10,520
It only ever changes
from one form to another.


108
00:11:15,360 --> 00:11:17,640
Take the water in that waterfall.


109
00:11:17,640 --> 00:11:19,440
At the top of the waterfall,


110
00:11:19,440 --> 00:11:22,600
it's got something called
gravitational potential energy,


111
00:11:22,600 --> 00:11:24,320
which is the energy it possesses


112
00:11:24,320 --> 00:11:26,920
due to its height
above the Earth's surface.


113
00:11:26,920 --> 00:11:31,680
See, if I scoop some water
out of the river into this beaker,


114
00:11:31,680 --> 00:11:35,880
then I'd have to do work to carry
it up to the top of the waterfall.


115
00:11:35,880 --> 00:11:38,560
I'd have to expend energy
to get it up there.


116
00:11:38,560 --> 00:11:42,520
So it would have that
energy as gravitational potential.


117
00:11:42,520 --> 00:11:44,360
I can even do the sums for you.


118
00:11:44,360 --> 00:11:46,800
Half a litre of water
has a mass of half a kilogram,


119
00:11:46,800 --> 00:11:49,480
multiply by the height,
that's about five metres,


120
00:11:49,480 --> 00:11:53,560
the acceleration due to gravity's
about ten metres per second squared.


121
00:11:53,560 --> 00:11:57,960
So that's half times five times ten
is 25 joules.


122
00:11:57,960 --> 00:12:00,160
So I'd have to put in 25 joules


123
00:12:00,160 --> 00:12:04,040
to carry this water
to the top of the waterfall.


124
00:12:04,040 --> 00:12:07,480
Then if I emptied it over
the top of the waterfall,


125
00:12:07,480 --> 00:12:10,080
then all that gravitational
potential energy


126
00:12:10,080 --> 00:12:13,000
would be transformed
into other types of energy.


127
00:12:15,120 --> 00:12:18,280
Its sound, which is
pressure waves in the air.


128
00:12:18,280 --> 00:12:22,640
There's the energy of the waves
in the river. And there's heat.


129
00:12:22,640 --> 00:12:24,280
So it'll be a bit hotter down there


130
00:12:24,280 --> 00:12:26,480
because the water's
cascading into the pool


131
00:12:26,480 --> 00:12:28,440
at the foot of the waterfall.


132
00:12:28,440 --> 00:12:31,400
Buy the key thing is
energy is conserved,


133
00:12:31,400 --> 00:12:33,160
it's not created or destroyed.


134
00:12:36,240 --> 00:12:37,880
So, because energy is conserved,


135
00:12:37,880 --> 00:12:40,400
if I were to add up
all the energy in the water waves,


136
00:12:40,400 --> 00:12:43,400
all the energy in the sound waves,


137
00:12:43,400 --> 00:12:46,000
all the heat energy
at the bottom of the pool,


138
00:12:46,000 --> 00:12:49,720
then I would find
that it would be precisely equal


139
00:12:49,720 --> 00:12:53,640
to the gravitational potential
energy at the top of the falls.


140
00:12:58,040 --> 00:13:02,880
What's true for the waterfall is
true for everything in the universe.


141
00:13:04,360 --> 00:13:06,840
It's a fundamental law of nature,


142
00:13:06,840 --> 00:13:10,920
known as the first law
of thermodynamics.


143
00:13:10,920 --> 00:13:14,440
And the fact that energy
is neither created nor destroyed


144
00:13:14,440 --> 00:13:17,280
has a profound implication.


145
00:13:18,680 --> 00:13:21,840
It means energy is eternal.


146
00:13:26,120 --> 00:13:28,920
The energy that's here now
has always been here,


147
00:13:28,920 --> 00:13:31,960
and the story of the
evolution of the universe


148
00:13:31,960 --> 00:13:35,280
is just the story of the
transformation of that energy


149
00:13:35,280 --> 00:13:37,000
from one form to another,


150
00:13:37,000 --> 00:13:39,040
from the origin
of the first galaxies


151
00:13:39,040 --> 00:13:41,320
to the ignition of the first stars


152
00:13:41,320 --> 00:13:43,840
and the formation
of the first planets.


153
00:13:50,760 --> 00:13:54,080
Every single joule of energy
in the universe today


154
00:13:54,080 --> 00:13:59,400
was present at the Big Bang,
13.7 billion years ago.


155
00:14:02,120 --> 00:14:06,520
Potential energy held in
primordial clouds of gas and dust


156
00:14:06,520 --> 00:14:09,400
was transformed into kinetic energy


157
00:14:09,400 --> 00:14:13,160
as they collapsed to form stars
and planetary systems,


158
00:14:13,160 --> 00:14:15,240
just like our own solar system.


159
00:14:23,920 --> 00:14:25,280
In the Sun,


160
00:14:25,280 --> 00:14:29,640
heat from the collapse initiated
fusion reactions at its core.


161
00:14:34,680 --> 00:14:37,080
Hydrogen became helium.


162
00:14:37,080 --> 00:14:41,560
Nuclear-binding energy was released,
heating the surface of the Sun,


163
00:14:41,560 --> 00:14:46,800
producing the light that
began to bathe the young Earth.


164
00:14:53,520 --> 00:14:57,960
And at some point in that story,
around four billion years ago,


165
00:14:57,960 --> 00:15:03,720
that transformation of energy
led to the origin of life on Earth.


166
00:15:21,880 --> 00:15:27,280
Around 350 kilometres
south of Sagada, this is Lake Taal.


167
00:15:33,680 --> 00:15:36,480
Despite its sleepy,
languid appearance,


168
00:15:36,480 --> 00:15:41,040
this landscape has been
violently transformed by energy.


169
00:16:06,240 --> 00:16:07,680
When I think of a volcano,


170
00:16:07,680 --> 00:16:10,160
I usually think of
a pointy, fiery mountain


171
00:16:10,160 --> 00:16:12,560
with a little crater in the top.


172
00:16:12,560 --> 00:16:14,880
Probably a bit like that one.


173
00:16:14,880 --> 00:16:19,480
But actually this entire lake is the
flooded crater of a giant volcano.


174
00:16:19,480 --> 00:16:23,640
It began erupting
only about 140,000 years ago,


175
00:16:23,640 --> 00:16:30,760
and in that time it's blown 120
billion cubic metres of ash and rock


176
00:16:30,760 --> 00:16:33,280
into the Earth's atmosphere.


177
00:16:33,280 --> 00:16:38,560
This crater is 30 kilometres across
and in places 150 metres deep.


178
00:16:38,560 --> 00:16:41,320
That's a cube of rock


179
00:16:41,320 --> 00:16:46,080
five kilometres by five kilometres
by five kilometres


180
00:16:46,080 --> 00:16:48,480
just blown away.


181
00:16:53,440 --> 00:16:56,480
It's a big volcano.


182
00:17:04,800 --> 00:17:07,960
Taal Lake is testament
to the immense power


183
00:17:07,960 --> 00:17:11,200
locked within the Earth
at the time of its formation.


184
00:17:20,840 --> 00:17:23,480
Since the lake was created,


185
00:17:23,480 --> 00:17:26,920
a series of further eruptions
formed the island in the centre.


186
00:17:28,480 --> 00:17:30,080
And at its heart


187
00:17:30,080 --> 00:17:34,400
is a place where you can glimpse
the turmoil of the inner Earth,


188
00:17:34,400 --> 00:17:38,600
where energy from the core
still bubbles up to the surface...


189
00:17:42,680 --> 00:17:46,640
..producing conditions similar
to those that may have provided


190
00:17:46,640 --> 00:17:49,160
the very first spark of life.


191
00:18:02,840 --> 00:18:06,280
The water in this lake
is different from drinking water


192
00:18:06,280 --> 00:18:08,360
in a very interesting way.


193
00:18:08,360 --> 00:18:13,520
See, if I test this
bottle of water with this,


194
00:18:13,520 --> 00:18:17,120
which is called
universal indicator paper,


195
00:18:17,120 --> 00:18:20,640
then you see immediately
that it goes green.


196
00:18:20,640 --> 00:18:23,800
And that means
that it's completely neutral.


197
00:18:23,800 --> 00:18:25,880
It's called PH7 in the jargon.


198
00:18:25,880 --> 00:18:29,920
But then look what happens
when I test the water from the lake.


199
00:18:32,680 --> 00:18:35,040
Now the indicator paper
stays orange.


200
00:18:35,040 --> 00:18:38,200
In fact, it might have gone
a bit more orange.


201
00:18:38,200 --> 00:18:41,160
So that means that this is acid.
It's about PH3.


202
00:18:45,840 --> 00:18:47,640
At the most basic level,


203
00:18:47,640 --> 00:18:50,560
the energy trapped inside the Earth
is melting rocks.


204
00:18:50,560 --> 00:18:53,920
And when you melt rock like this
you produce gases.


205
00:18:53,920 --> 00:18:55,680
A lot of carbon dioxide,


206
00:18:55,680 --> 00:18:59,480
and in this case of this volcano,
a lot of sulphur dioxide.


207
00:18:59,480 --> 00:19:02,600
Now, sulphur dioxide
dissolves in water


208
00:19:02,600 --> 00:19:05,960
and you get H2SO4,
sulphuric acid.


209
00:19:10,720 --> 00:19:14,240
Now, what I mean
when I say that water is acidic?


210
00:19:17,000 --> 00:19:21,560
Well, water is H2O - hydrogen
and oxygen bonded together.


211
00:19:21,560 --> 00:19:25,560
But actually when it's liquid it's
a bit more complicated than that.


212
00:19:25,560 --> 00:19:28,560
It's actually a sea of ions.


213
00:19:28,560 --> 00:19:31,320
So H-plus ions,
that's just single protons.


214
00:19:31,320 --> 00:19:35,400
And OH-minus ions, that's
oxygen and hydrogen bonded together,


215
00:19:35,400 --> 00:19:37,480
all floating around.


216
00:19:37,480 --> 00:19:40,160
Now, when something's neutral,
when the PH is seven,


217
00:19:40,160 --> 00:19:43,640
that means that the concentrations
of those ions


218
00:19:43,640 --> 00:19:46,280
are perfectly balanced.


219
00:19:46,280 --> 00:19:48,160
When you make water acidic,


220
00:19:48,160 --> 00:19:52,480
then you change the concentration
of those ions and, to be specific,


221
00:19:52,480 --> 00:19:57,400
you increase the concentration
of the H-plus ions of the protons.


222
00:20:01,920 --> 00:20:06,800
So, this process of acidification
has stored the energy of the volcano


223
00:20:06,800 --> 00:20:09,240
as chemical potential energy.


224
00:20:13,040 --> 00:20:18,000
The volcano transforms heat from the
inner Earth into chemical energy


225
00:20:18,000 --> 00:20:22,200
and stores it as a reservoir
of protons in the lake.


226
00:20:25,080 --> 00:20:27,040
And this is the same way
energy is stored


227
00:20:27,040 --> 00:20:31,160
in a simple battery
or fuel cell.


228
00:20:34,040 --> 00:20:37,400
These bottles contain a weak acid


229
00:20:37,400 --> 00:20:41,080
and are connected by
a semi-permeable membrane.


230
00:20:41,080 --> 00:20:44,680
Passing an electric current
through them has a similar effect


231
00:20:44,680 --> 00:20:48,680
to the volcano's energy
bubbling up into the lake.


232
00:20:48,680 --> 00:20:52,800
It causes protons to build up
in one of the bottles.


233
00:20:55,760 --> 00:20:58,200
You can think of it, I suppose,
like a waterfall,


234
00:20:58,200 --> 00:21:02,040
where the protons are up here
waiting to flow down.


235
00:21:02,040 --> 00:21:04,160
All you have to do
to release that energy


236
00:21:04,160 --> 00:21:07,240
and do something useful with it
is complete the circuit.


237
00:21:07,240 --> 00:21:11,120
Which I can do by
just connecting a motor to it.


238
00:21:15,080 --> 00:21:17,600
There you go. Look at that.


239
00:21:17,600 --> 00:21:20,720
That's the protons
cascading down the waterfall


240
00:21:20,720 --> 00:21:23,840
and driving the motor around.


241
00:21:29,320 --> 00:21:31,680
It actually works!


242
00:21:32,960 --> 00:21:35,280
Quite remarkable, actually.


243
00:21:36,640 --> 00:21:39,880
Now, the fuel cell
produces and exploits


244
00:21:39,880 --> 00:21:44,360
its proton gradient artificially.
But there are places on Earth


245
00:21:44,360 --> 00:21:48,360
where that gradient occurs
completely naturally.


246
00:21:48,360 --> 00:21:50,120
Here, for example.


247
00:21:50,120 --> 00:21:52,600
So we've got the
proton reservoir over there,


248
00:21:52,600 --> 00:21:55,280
the acidic volcanic lake.


249
00:21:55,280 --> 00:21:57,960
If you look that way,
there's another lake,


250
00:21:57,960 --> 00:22:01,200
and the reaction of the water
with the rocks on the shore


251
00:22:01,200 --> 00:22:03,320
make that lake slightly alkaline,


252
00:22:03,320 --> 00:22:06,760
which is to say that there's
a deficit of protons down there.


253
00:22:06,760 --> 00:22:09,120
So here's the waterfall,


254
00:22:09,120 --> 00:22:12,240
a reservoir of protons up there,
a deficit down there.


255
00:22:12,240 --> 00:22:14,000
If you could just connect them,


256
00:22:14,000 --> 00:22:17,800
then you'd have a naturally
occurring geological fuel cell.


257
00:22:17,800 --> 00:22:21,680
And it's thought that
the first life on our planet


258
00:22:21,680 --> 00:22:25,120
may have exploited
the energy released


259
00:22:25,120 --> 00:22:28,160
in those natural proton waterfalls.


260
00:22:55,800 --> 00:22:58,960
What do you think?
It's good, isn't it?


261
00:23:06,440 --> 00:23:09,320
These are pictures
from deep below the surface


262
00:23:09,320 --> 00:23:13,520
of the Atlantic Ocean, somewhere
between Bermuda and the Canaries.


263
00:23:13,520 --> 00:23:16,200
And it's a place
known as the Lost City.


264
00:23:16,200 --> 00:23:18,520
You can see why.


265
00:23:18,520 --> 00:23:23,520
Look at these huge towers of rock,
some of them 50-60 metres high,


266
00:23:23,520 --> 00:23:27,120
reaching up from the floor
of the Atlantic and into the ocean.


267
00:23:27,120 --> 00:23:30,560
It's what's known as
a hydrothermal vent system.


268
00:23:30,560 --> 00:23:34,240
So these things are formed by
hot water and minerals and gases


269
00:23:34,240 --> 00:23:37,440
rising up from
deep within the Earth.


270
00:23:37,440 --> 00:23:40,960
But the reason it's thought that
life on Earth may have begun


271
00:23:40,960 --> 00:23:43,200
in such structures is because


272
00:23:43,200 --> 00:23:46,160
these are a very unique
kind of hydrothermal vent


273
00:23:46,160 --> 00:23:48,520
called an alkaline vent.


274
00:23:48,520 --> 00:23:51,920
And, about four billion years ago,
when life on Earth began,


275
00:23:51,920 --> 00:23:55,800
seawater would have been
mildly acidic.


276
00:23:55,800 --> 00:24:00,840
So, here is that proton gradient,
that source of energy for life.


277
00:24:00,840 --> 00:24:04,200
You've got a reservoir of protons
in the acidic seawater


278
00:24:04,200 --> 00:24:08,640
and a deficit of protons
around the vents.


279
00:24:13,520 --> 00:24:16,760
And the vents don't just provide
an energy source.


280
00:24:16,760 --> 00:24:20,320
They're also rich in
the raw materials life needs.


281
00:24:23,040 --> 00:24:26,400
Hydrogen gas, carbon dioxide


282
00:24:26,400 --> 00:24:31,080
and minerals containing iron,
nickel and sulphur.


283
00:24:33,040 --> 00:24:34,800
But there's more than that.


284
00:24:34,800 --> 00:24:39,040
See, these vents are porous - there
are little chambers inside them -


285
00:24:39,040 --> 00:24:42,280
and they can act to concentrate
organic molecules.


286
00:24:47,960 --> 00:24:50,840
You've got everything
inside these vents.


287
00:24:50,840 --> 00:24:54,320
You've got concentrated
building blocks of life


288
00:24:54,320 --> 00:24:56,640
trapped inside the rock.


289
00:24:58,880 --> 00:25:00,960
And you've got that proton gradient,


290
00:25:00,960 --> 00:25:06,040
you've got that waterfall
that provides the energy for life.


291
00:25:06,040 --> 00:25:10,760
So this could be where
your distant ancestors come from.


292
00:25:10,760 --> 00:25:17,360
And places like these could be the
places where life on Earth began.


293
00:25:21,600 --> 00:25:25,040
The first living things
might have started out


294
00:25:25,040 --> 00:25:27,840
as part of the rock
that created them.


295
00:25:33,600 --> 00:25:36,120
Simple organisms
that exploited energy


296
00:25:36,120 --> 00:25:40,200
from the naturally-occurring
proton gradients in the vents.


297
00:25:45,320 --> 00:25:47,440
And we think this because


298
00:25:47,440 --> 00:25:52,440
living things still get their energy
using proton gradients today.


299
00:26:04,960 --> 00:26:07,400
Deep within ourselves,


300
00:26:07,400 --> 00:26:11,240
the chemistry the first life
exploited in the vents


301
00:26:11,240 --> 00:26:15,320
is wrapped up in structures
called mitochondria -


302
00:26:15,320 --> 00:26:19,920
microscopic batteries
that power the processes of life.


303
00:26:25,920 --> 00:26:30,040
This is a picture
of the mitochondria


304
00:26:30,040 --> 00:26:32,960
from the little brown bat.


305
00:26:32,960 --> 00:26:36,000
This is a picture
of the mitochondria from a plant.


306
00:26:36,000 --> 00:26:39,440
It's actually a member
of the mustard family.


307
00:26:39,440 --> 00:26:43,800
This is a picture
of the mitochondria in bread mould.


308
00:26:43,800 --> 00:26:49,680
And this of mitochondria
inside a malaria parasite.


309
00:26:49,680 --> 00:26:56,680
So, the fascinating thing is that
all these animals and plants,


310
00:26:56,680 --> 00:27:00,360
and in fact virtually every
living thing on the planet,


311
00:27:00,360 --> 00:27:05,800
uses proton gradients
to produce energy to live. Why?


312
00:27:05,800 --> 00:27:08,120
Well, the answer is probably


313
00:27:08,120 --> 00:27:12,200
because all these radically
different forms of life


314
00:27:12,200 --> 00:27:14,440
share a common ancestor.


315
00:27:14,440 --> 00:27:17,840
And that common ancestor
was something that lived in


316
00:27:17,840 --> 00:27:22,000
those ancient undersea vents,
four billion years ago,


317
00:27:22,000 --> 00:27:25,720
where naturally-occurring
proton gradients


318
00:27:25,720 --> 00:27:28,760
provided the energy
for the first life.


319
00:27:28,760 --> 00:27:33,560
So, if you're looking for
a universal spark of life,


320
00:27:33,560 --> 00:27:35,880
then this is it.


321
00:27:35,880 --> 00:27:40,280
The spark of life
is proton gradients.


322
00:27:49,600 --> 00:27:54,720
In those four billion years,
that spark has grown into a flame.


323
00:27:56,560 --> 00:28:00,760
And a few simple organisms
clustered around a hydrothermal vent


324
00:28:00,760 --> 00:28:05,120
have evolved to produce
all the magnificent diversity


325
00:28:05,120 --> 00:28:06,880
that covers the Earth today.


326
00:28:32,560 --> 00:28:35,560
Today, life on Earth
is so diverse,


327
00:28:35,560 --> 00:28:39,520
it covers so much of the planet that
you can find places like this lake,


328
00:28:39,520 --> 00:28:43,360
where it's effectively
its own sealed ecosystem.


329
00:28:43,360 --> 00:28:46,160
It's saltwater,
it's connected to the sea,


330
00:28:46,160 --> 00:28:49,920
but it's only connected through
small channels through the rock.


331
00:28:49,920 --> 00:28:54,040
So that means that the marine life
in here is effectively isolated.


332
00:29:06,880 --> 00:29:08,720
This is the Golden Jellyfish,


333
00:29:08,720 --> 00:29:15,640
a unique sub-species only found
in this one lake on this one island,


334
00:29:15,640 --> 00:29:18,560
in the tiny Micronesian
Republic of Palau.


335
00:29:22,080 --> 00:29:24,280
They used to live
like most jellyfish,


336
00:29:24,280 --> 00:29:29,120
cruising the open ocean, catching
tiny creatures, zooplankton,


337
00:29:29,120 --> 00:29:32,080
in their long tentacles.


338
00:29:33,760 --> 00:29:37,240
But today their tentacles
have all but disappeared


339
00:29:37,240 --> 00:29:39,640
because the Golden Jellyfish


340
00:29:39,640 --> 00:29:43,800
have evolved to do something that
very few other animals can do.


341
00:29:58,720 --> 00:30:01,720
It really is incredible.


342
00:30:01,720 --> 00:30:05,120
There are,
I want to say millions of jellyfish,


343
00:30:05,120 --> 00:30:06,600
as far as you can see,


344
00:30:06,600 --> 00:30:10,920
all the way down till the light
vanishes there are jellyfish.


345
00:30:10,920 --> 00:30:14,000
And you can see they've
congregated in the sun.


346
00:30:14,000 --> 00:30:16,600
If you go over there to where
the lake's in shade,


347
00:30:16,600 --> 00:30:17,880
there are just none.


348
00:30:17,880 --> 00:30:20,520
They're in this pool of light,
beneath the sun.


349
00:30:20,520 --> 00:30:22,960
There are millions of them.


350
00:30:22,960 --> 00:30:25,720
Beautifully elegant things
just floating around.


351
00:30:27,440 --> 00:30:30,720
I'm not being unduly hyperbolic,
it's quite remarkable.


352
00:30:33,280 --> 00:30:36,280
MAKES MUFFLED NOISE


353
00:30:54,520 --> 00:30:58,520
This lake is home to
over 20 million jellyfish.


354
00:31:02,560 --> 00:31:05,960
Whose success comes down
to a remarkable adaptation.


355
00:31:08,240 --> 00:31:12,800
Their bodies play host to
thousands of other organisms -


356
00:31:12,800 --> 00:31:17,480
photosynthetic algae that harvest
energy directly from sunlight.


357
00:31:26,360 --> 00:31:29,360
The jellyfish engulf
the algae as juveniles,


358
00:31:29,360 --> 00:31:35,160
and by adulthood algal cells make
up around 10% of their biomass.


359
00:31:37,800 --> 00:31:41,120
Grouped into clusters
of up to 200 individuals,


360
00:31:41,120 --> 00:31:44,520
they live inside the jellyfish's
own cells.


361
00:31:50,760 --> 00:31:53,280
The Golden Jellyfish uses algae


362
00:31:53,280 --> 00:31:56,920
to get most of its energy
from photosynthesis.


363
00:32:10,000 --> 00:32:13,920
They go to the surface and
gently... Wow, there's one there.


364
00:32:13,920 --> 00:32:15,680
They're gently turning.


365
00:32:15,680 --> 00:32:18,360
The reason they do that
is to give all their algae


366
00:32:18,360 --> 00:32:21,120
an equal dose of sunlight.


367
00:32:23,280 --> 00:32:25,920
So they're quite
democratic creatures,


368
00:32:25,920 --> 00:32:29,360
just making sure
they get as much food as they can.


369
00:32:29,360 --> 00:32:34,440
They just come up you, jellying
around, photosynthesising.


370
00:32:41,080 --> 00:32:43,920
They tell me they don't sting.


371
00:32:43,920 --> 00:32:46,400
But I'm sure I've got
a tingling from it.


372
00:32:51,240 --> 00:32:53,200
And it's not just their anatomy


373
00:32:53,200 --> 00:32:55,520
that's adapted to harvest
solar energy.


374
00:32:57,000 --> 00:32:59,520
Every morning as the sun rises,


375
00:32:59,520 --> 00:33:02,720
the jellyfish begin to swim
towards the east.


376
00:33:07,040 --> 00:33:12,120
As the sun tracks across the sky,
they move back again
towards the west,


377
00:33:12,120 --> 00:33:13,840
where they spend their night.


378
00:33:19,320 --> 00:33:24,120
So the jellyfish have
this beautiful, intimate


379
00:33:24,120 --> 00:33:28,200
and complex relationship with
the position of the sun in the sky.


380
00:33:32,880 --> 00:33:35,920
As sunlight is captured
by their algae,


381
00:33:35,920 --> 00:33:38,280
it's converted into chemical energy.


382
00:33:40,600 --> 00:33:44,120
Energy they use to combine
simple molecules,


383
00:33:44,120 --> 00:33:48,880
water and carbon dioxide, to
produce are far more complex one.


384
00:33:50,360 --> 00:33:51,600
Glucose.


385
00:33:52,840 --> 00:33:57,520
Once absorbed by the jellyfish,
glucose and other molecules


386
00:33:57,520 --> 00:34:00,760
not only power their daily voyage
across the lake,


387
00:34:00,760 --> 00:34:04,280
they provide the basic
building blocks the jellyfish


388
00:34:04,280 --> 00:34:08,840
use to grow the elegant and complex
structures of their bodies.


389
00:34:18,400 --> 00:34:22,440
So the jellyfish, through
their symbiotic algae,


390
00:34:22,440 --> 00:34:27,560
absorb the light, the energy from
the sun, and they use it to live,


391
00:34:27,560 --> 00:34:29,640
to power their processes of life.


392
00:34:29,640 --> 00:34:32,000
And that's true,
directly or indirectly,


393
00:34:32,000 --> 00:34:36,720
for every form of life
on the surface of our planet.


394
00:34:36,720 --> 00:34:39,840
But things are a little bit more
interesting than that,


395
00:34:39,840 --> 00:34:43,680
because energy is neither
created nor destroyed.


396
00:34:43,680 --> 00:34:48,280
So life doesn't eat it somehow,
it doesn't use it up,


397
00:34:48,280 --> 00:34:50,800
it doesn't remove
it from the universe.


398
00:34:50,800 --> 00:34:51,960
So what does it do?


399
00:34:56,600 --> 00:34:59,200
To understand how energy
sustains life,


400
00:34:59,200 --> 00:35:04,480
you have to understand exactly what
happens to it as the cosmos evolves.


401
00:35:11,400 --> 00:35:14,080
POWERFUL EXPLOSION BOOMS


402
00:35:14,080 --> 00:35:16,400
In the first instance
after the Big Bang


403
00:35:16,400 --> 00:35:19,840
there was nothing in the universe
but energy.


404
00:35:26,200 --> 00:35:30,880
As it changed from one form
to another, galaxies, stars


405
00:35:30,880 --> 00:35:32,200
and planets were born.


406
00:35:37,400 --> 00:35:42,040
But while the total amount of energy
in the universe stays constant,


407
00:35:42,040 --> 00:35:46,320
with every single transformation
something does change.


408
00:35:48,080 --> 00:35:52,560
The energy itself becomes
less and less useful.


409
00:35:52,560 --> 00:35:54,640
It becomes ever more disordered.


410
00:35:58,480 --> 00:36:02,240
And you can see this process
in action as energy from the sun


411
00:36:02,240 --> 00:36:04,120
hits the surface of the Earth.


412
00:36:08,280 --> 00:36:10,560
So think about think about this
sand on the beach,


413
00:36:10,560 --> 00:36:13,000
it's been under
the glare of the sun all day,


414
00:36:13,000 --> 00:36:16,640
it's been absorbing its light
which has been heating it up,


415
00:36:16,640 --> 00:36:19,600
and now that the sun is dipping
below the horizon,


416
00:36:19,600 --> 00:36:21,880
then the sand
is still hot to the touch


417
00:36:21,880 --> 00:36:26,880
because it's re-radiating all the
energy that it absorbed as heat


418
00:36:26,880 --> 00:36:29,160
back into the universe.


419
00:36:29,160 --> 00:36:33,320
The key word there is "all".
All the energy.


420
00:36:33,320 --> 00:36:36,280
If it didn't do that then
it'd just gradually heat up


421
00:36:36,280 --> 00:36:37,920
day after day after day,


422
00:36:37,920 --> 00:36:40,960
and eventually, I suppose,
the whole beach would melt.


423
00:36:40,960 --> 00:36:42,840
So what's changed?


424
00:36:42,840 --> 00:36:46,960
Well, it's the quality
of the energy, if you like.


425
00:36:46,960 --> 00:36:48,240
Think about it.


426
00:36:48,240 --> 00:36:52,360
If as much energy is coming
back off this sand now
as it absorbed from the sun,


427
00:36:52,360 --> 00:36:54,800
then it should
be giving me a suntan.


428
00:36:54,800 --> 00:36:58,240
I should need sun cream if I sit
looking at this beach all night.


429
00:36:58,240 --> 00:36:59,960
And obviously I don't.


430
00:36:59,960 --> 00:37:04,840
The difference is that this
energy is of a lower quality.


431
00:37:04,840 --> 00:37:06,920
It can do less.


432
00:37:06,920 --> 00:37:10,680
It's heat, which is a very low
quality of energy indeed.


433
00:37:10,680 --> 00:37:13,800
So what the sand's done
is take highly ordered,


434
00:37:13,800 --> 00:37:15,800
high quality energy from the sun


435
00:37:15,800 --> 00:37:21,880
and convert it to an equal amount
of low quality disordered energy.


436
00:37:28,720 --> 00:37:30,640
This descent into disorder


437
00:37:30,640 --> 00:37:33,400
is happening across
the entire universe.


438
00:37:45,400 --> 00:37:51,040
As time passes, every single joule
of energy is converted into heat.


439
00:37:54,320 --> 00:37:59,400
The universe gradually cools
towards absolute zero.


440
00:37:59,400 --> 00:38:04,800
Until with no ordered energy left,
the cosmos grinds to a halt


441
00:38:04,800 --> 00:38:08,840
and every structure in it
decays away.


442
00:38:19,040 --> 00:38:24,720
Yet whilst the universe is dying,
everywhere you look life goes on.


443
00:38:26,840 --> 00:38:30,480
It's a deep paradox that
Schroedinger was well aware of


444
00:38:30,480 --> 00:38:33,120
when he wrote his book in 1943.


445
00:38:36,280 --> 00:38:38,080
"How can it be,"
writes Schroedinger,


446
00:38:38,080 --> 00:38:41,640
"That the living organism
avoids decay?"


447
00:38:41,640 --> 00:38:46,960
In other words, how can it be that
life seems to continue to build


448
00:38:46,960 --> 00:38:48,800
increasingly complex structures


449
00:38:48,800 --> 00:38:54,880
when the rest of the universe is
falling to bits, is decaying away?


450
00:38:54,880 --> 00:39:00,560
Now, that's a paradox, because the
universe is falling to bits,


451
00:39:00,560 --> 00:39:03,600
it is tending towards disorder.


452
00:39:03,600 --> 00:39:06,320
That is enshrined in
a law of physics called


453
00:39:06,320 --> 00:39:09,000
the Second Law Of Thermodynamics.


454
00:39:09,000 --> 00:39:12,920
And I think most physicists
believe that it's the one


455
00:39:12,920 --> 00:39:16,040
law of physics
that will never be broken.


456
00:39:31,280 --> 00:39:36,480
The key to understanding how life
obeys the laws of thermodynamics


457
00:39:36,480 --> 00:39:38,840
is to look at both
the energy it takes in


458
00:39:38,840 --> 00:39:41,520
and the energy it gives out.


459
00:39:46,600 --> 00:39:50,840
This is a thermal camera,
so hot things show up as red,


460
00:39:50,840 --> 00:39:52,400
and cold things show up as blue.


461
00:39:52,400 --> 00:39:54,280
COCKEREL CROWS


462
00:39:54,280 --> 00:39:57,520
So what you're seeing here
is that the chicken is hotter


463
00:39:57,520 --> 00:39:59,040
than its surroundings.


464
00:39:59,040 --> 00:40:02,560
Now, heat is a highly disordered
form of energy,


465
00:40:02,560 --> 00:40:09,080
so the chicken is radiating disorder
out into the wider universe.


466
00:40:12,760 --> 00:40:15,480
By converting chemical
energy into heat,


467
00:40:15,480 --> 00:40:20,960
life transforms energy from an
ordered to a disordered form,


468
00:40:20,960 --> 00:40:25,680
in exactly the same way as every
other process in the universe.


469
00:40:29,200 --> 00:40:31,680
COCKEREL CROWS


470
00:40:33,080 --> 00:40:35,440
In fact, every single human being


471
00:40:35,440 --> 00:40:40,560
can generate 6,000 times more heat
per kilogram than the sun.


472
00:40:44,040 --> 00:40:48,800
And it's by converting so much
energy from one form to another


473
00:40:48,800 --> 00:40:54,600
that life is able to hang on to
a tiny amount of order for itself.


474
00:40:54,600 --> 00:40:59,800
Just enough to resist the inevitable
decay of the universe.


475
00:40:59,800 --> 00:41:02,120
COCKEREL CROWS


476
00:41:02,120 --> 00:41:04,920
So it's no accident
that living things are hot


477
00:41:04,920 --> 00:41:07,920
and export heat
to their surroundings.


478
00:41:07,920 --> 00:41:11,040
Because it's an essential
part of being alive.


479
00:41:11,040 --> 00:41:15,040
Living things borrow
order from the wider universe,


480
00:41:15,040 --> 00:41:18,280
and then they export it
again as disorder.


481
00:41:18,280 --> 00:41:20,600
But it's not precisely in balance.


482
00:41:20,600 --> 00:41:23,200
They have to export more disorder


483
00:41:23,200 --> 00:41:25,880
than the amount of order
they import.


484
00:41:25,880 --> 00:41:28,680
That is the content
of the Second Law Of Thermodynamics.


485
00:41:28,680 --> 00:41:31,680
And living things have
to obey the Second Law


486
00:41:31,680 --> 00:41:36,400
because they're physical structures,
they obey the laws of physics.


487
00:41:41,840 --> 00:41:46,920
Just by being alive, we too are part
of the process of energy


488
00:41:46,920 --> 00:41:50,840
transformation that drives
the evolution of the universe.


489
00:41:54,480 --> 00:41:59,440
We take sunlight that has its
origins at the very start of time,


490
00:41:59,440 --> 00:42:04,320
and transform it into heat
that will last for eternity.


491
00:42:09,160 --> 00:42:11,440
So, far from being a paradox,


492
00:42:11,440 --> 00:42:16,200
living things can be
explained by the laws of physics.


493
00:42:16,200 --> 00:42:20,000
The very same laws that describe
the falling of the rain


494
00:42:20,000 --> 00:42:21,760
and the shining of the stars.


495
00:42:44,800 --> 00:42:48,280
The dragonfly draws its energy
from proton gradients,


496
00:42:48,280 --> 00:42:52,400
the fundamental chemistry
that powers life.


497
00:42:56,520 --> 00:42:59,360
But the real miracles
are the structures


498
00:42:59,360 --> 00:43:01,280
they build with that energy.


499
00:43:06,120 --> 00:43:08,800
Borrowing order to generate cells.


500
00:43:10,560 --> 00:43:13,120
Arranging those cells into tissues.


501
00:43:15,040 --> 00:43:19,920
And those tissues into the intricate
architecture of their bodies.


502
00:43:23,520 --> 00:43:26,360
So we've developed a quite
detailed understanding


503
00:43:26,360 --> 00:43:31,000
of the underlying machinery
that powers these dragonflies,


504
00:43:31,000 --> 00:43:33,200
and indeed all life on Earth.


505
00:43:33,200 --> 00:43:36,440
And whilst we don't have all the
answers, it is certainly safe to say


506
00:43:36,440 --> 00:43:38,720
that there's no mysticism required.


507
00:43:38,720 --> 00:43:41,560
You don't need
some kind of magical flame


508
00:43:41,560 --> 00:43:43,720
to animate these little machines.


509
00:43:43,720 --> 00:43:47,000
They operate according
to the laws of physics,


510
00:43:47,000 --> 00:43:49,960
and I think they're no less
magical for that.


511
00:43:54,560 --> 00:43:59,960
Yet the dragonfly will only maintain
this delicate balancing act
for so long.


512
00:44:01,280 --> 00:44:04,640
Because all living things
share the same fate.


513
00:44:09,800 --> 00:44:11,920
Each individual will die.


514
00:44:14,840 --> 00:44:17,160
But life itself endures.


515
00:44:18,360 --> 00:44:22,360
DRAGONFLIES BUZZ


516
00:44:25,320 --> 00:44:28,440
This is because there's something
that separates life


517
00:44:28,440 --> 00:44:31,040
from every other process
in the universe.


518
00:44:36,520 --> 00:44:40,800
BOAT ENGINE CHUGS


519
00:44:42,600 --> 00:44:46,960
WILD ANIMAL ROARS


520
00:44:46,960 --> 00:44:50,680
MONKEYS CHATTER


521
00:44:52,400 --> 00:44:54,800
This is the
Malaysian state of Sabah,


522
00:44:54,800 --> 00:44:57,440
on the northern tip
of the island of Borneo.


523
00:44:59,400 --> 00:45:03,160
It's one of the most bio-diverse
places on the planet.


524
00:45:03,160 --> 00:45:05,920
INSECT BUZZES


525
00:45:05,920 --> 00:45:08,640
Home to 15,000 plant species...


526
00:45:10,400 --> 00:45:12,640
..3,000 species of tree...


527
00:45:14,440 --> 00:45:16,920
..420 species of bird...


528
00:45:19,400 --> 00:45:22,640
..and 222 species of mammals.


529
00:45:23,920 --> 00:45:27,520
Including those.
ELEPHANTS ROAR LOUDLY


530
00:45:31,080 --> 00:45:34,960
Borneo's rainforests contain
trees that are thought to live


531
00:45:34,960 --> 00:45:36,800
for more than 1,000 years.


532
00:45:41,200 --> 00:45:45,560
But the forest itself has existed
for tens of millions of years.


533
00:45:51,640 --> 00:45:56,960
The reason it persists is because
each generation of animal and plant


534
00:45:56,960 --> 00:46:01,880
passes the information to recreate
itself on to the next generation.


535
00:46:03,360 --> 00:46:04,880
And that's possible


536
00:46:04,880 --> 00:46:09,280
because of a molecule found
in every cell of every living thing.


537
00:46:11,400 --> 00:46:14,560
A molecule called DNA.


538
00:46:25,760 --> 00:46:32,000
Now, all I need to isolate my DNA
is some washing up liquid,


539
00:46:32,000 --> 00:46:38,760
a bit of salt, and the chemist's
best friend, vodka.


540
00:46:38,760 --> 00:46:42,720
Now, to get a sample of DNA
I can just use myself.


541
00:46:42,720 --> 00:46:47,040
If I just swill my tongue
around on the edge of my cheek,


542
00:46:47,040 --> 00:46:50,160
I'll dislodge some cheek cells
into my saliva.


543
00:46:51,840 --> 00:46:53,800
DOG BARKS OUTSIDE


544
00:46:55,160 --> 00:46:57,040
LAUGHS


545
00:46:57,040 --> 00:46:59,160
I missed the test tube.


546
00:46:59,160 --> 00:47:01,960
There we are.
A physicist doing an experiment.


547
00:47:05,320 --> 00:47:06,680
STIFLES LAUGHTER


548
00:47:07,680 --> 00:47:12,000
Then I add a bit
of washing up liquid.


549
00:47:12,000 --> 00:47:17,960
Now, what this will do is it will
break open those cheek cells


550
00:47:17,960 --> 00:47:21,280
and it will also degrade
the membrane that surrounds


551
00:47:21,280 --> 00:47:25,560
the cell nucleus
that contains the DNA.


552
00:47:25,560 --> 00:47:30,560
Salt will encourage
the molecules to clump together.


553
00:47:31,640 --> 00:47:35,640
DNA is insoluble in alcohol.


554
00:47:35,640 --> 00:47:42,080
So you should get a layer of alcohol


555
00:47:42,080 --> 00:47:44,960
with DNA molecules precipitated out.


556
00:47:49,920 --> 00:47:54,280
Yeah. There, can you see?


557
00:47:54,280 --> 00:47:57,680
Those strands of white.


558
00:47:57,680 --> 00:48:03,280
And so in that cloudy,
almost innocuous looking solid


559
00:48:03,280 --> 00:48:08,160
are all the instructions needed
to build a human being.


560
00:48:12,760 --> 00:48:17,080
So that is what makes life unique.


561
00:48:27,680 --> 00:48:31,240
Only living things have
the ability to encode


562
00:48:31,240 --> 00:48:33,680
and transmit information
in this way.


563
00:48:36,920 --> 00:48:40,320
And the consequences of that
profoundly affect


564
00:48:40,320 --> 00:48:43,320
our understanding
of what it is to be alive.


565
00:48:44,960 --> 00:48:48,520
This rainforest is
part of the Sepilok Forest Reserve,


566
00:48:48,520 --> 00:48:53,600
and in here somewhere are some
of our closest genetic relatives.


567
00:49:06,800 --> 00:49:08,480
Shh-shh.


568
00:49:11,400 --> 00:49:13,200
There, there, can you see?


569
00:49:20,360 --> 00:49:25,120
Orang-utans are highly specialised
for a life lived
in the forest canopy.


570
00:49:26,720 --> 00:49:30,280
Their arms are twice as long
as their legs.


571
00:49:30,280 --> 00:49:33,720
And all four limbs
are incredibly flexible.


572
00:49:33,720 --> 00:49:38,240
Each one ending in a hand
whose curved bones


573
00:49:38,240 --> 00:49:41,360
are perfectly adapted
for gripping branches.


574
00:49:44,840 --> 00:49:48,400
These adaptations are encoded
in information


575
00:49:48,400 --> 00:49:50,640
passed down in their DNA.


576
00:49:55,520 --> 00:49:56,640
LAUGHS GENTLY


577
00:49:56,640 --> 00:49:57,680
He's got a hat on.


578
00:50:00,240 --> 00:50:02,160
He has actually just put a hat on.


579
00:50:16,640 --> 00:50:20,400
This is the orang-utan's
genetic code.


580
00:50:20,400 --> 00:50:22,240
It was published in 2011,


581
00:50:22,240 --> 00:50:27,480
and there are over three billion
letters in it.


582
00:50:27,480 --> 00:50:29,240
If flip through it...


583
00:50:32,360 --> 00:50:33,560
..look at that.


584
00:50:35,240 --> 00:50:39,000
Now, it's composed of only
four letters, A, C, T and G,


585
00:50:39,000 --> 00:50:41,080
which are known as bases.


586
00:50:41,080 --> 00:50:44,800
They're chemical compounds.
They're molecules.


587
00:50:44,800 --> 00:50:48,840
And the way it works
is beautifully simple.


588
00:50:48,840 --> 00:50:51,960
They're grouped into threes,
called codons,


589
00:50:51,960 --> 00:50:56,880
and some of them just tell
the code reader, if you like,


590
00:50:56,880 --> 00:50:59,400
how to start, or where
to start and when...


591
00:50:59,400 --> 00:51:01,400
and when it's going to stop.


592
00:51:03,320 --> 00:51:05,720
LAUGHS


593
00:51:07,360 --> 00:51:08,600
He's fast.


594
00:51:11,440 --> 00:51:14,200
So you'd have a start and a stop.


595
00:51:14,200 --> 00:51:19,440
In between, each group of three
codes for a particular amino acid.


596
00:51:21,600 --> 00:51:24,800
Now, amino acids are the
building blocks of proteins,


597
00:51:24,800 --> 00:51:29,240
which are the building blocks
of all living things.


598
00:51:29,240 --> 00:51:32,120
So you would just read along,


599
00:51:32,120 --> 00:51:35,480
you'd find, start, stop, and then


600
00:51:35,480 --> 00:51:38,760
you'd go along in threes,
build amino acid, build amino acid,


601
00:51:38,760 --> 00:51:40,720
build amino acid, build amino acid,


602
00:51:40,720 --> 00:51:42,760
stitch those together
into a protein,


603
00:51:42,760 --> 00:51:44,760
and if you keep doing that,


604
00:51:44,760 --> 00:51:48,360
eventually you'll come out
with one of those.


605
00:51:52,160 --> 00:51:57,000
It's not that simple of course.
But the basics are there.


606
00:51:59,200 --> 00:52:04,440
This code, written in there,
are the instructions to make him.


607
00:52:13,400 --> 00:52:16,160
To faithfully reproduce
those instructions


608
00:52:16,160 --> 00:52:18,120
for generation after generation,


609
00:52:18,120 --> 00:52:21,680
the orang-utans and,
and indeed all life on Earth,


610
00:52:21,680 --> 00:52:24,800
rely on a remarkable property
of DNA.


611
00:52:25,840 --> 00:52:29,840
Its incredible stability
and resistance to change.


612
00:52:34,600 --> 00:52:38,200
Every time a cell divides,
its DNA must be copied.


613
00:52:38,200 --> 00:52:42,000
And the genetic code is highly
resistant to copying errors.


614
00:52:42,000 --> 00:52:45,560
The little enzymes, the chemical
machines that do the copying,


615
00:52:45,560 --> 00:52:49,840
on average make only one
mistake in a billion letters.


616
00:52:49,840 --> 00:52:53,840
I mean, that's like copying out
the Bible about 280 times


617
00:52:53,840 --> 00:52:55,240
and making just one mistake.


618
00:53:00,080 --> 00:53:04,360
That fidelity means adaptations
are faithfully transmitted


619
00:53:04,360 --> 00:53:06,400
from parent to offspring.


620
00:53:08,560 --> 00:53:13,440
And so while we think of evolution
as a process of constant change,


621
00:53:13,440 --> 00:53:17,280
in fact the vast majority
of the code is preserved.


622
00:53:19,680 --> 00:53:22,960
So even though we're separated
from the orang-utans


623
00:53:22,960 --> 00:53:26,160
by nearly 14 million years
of evolution,


624
00:53:26,160 --> 00:53:30,120
what's really striking
is just how similar we are.


625
00:53:31,120 --> 00:53:35,040
And those similarities are far
more than skin deep.


626
00:53:38,000 --> 00:53:42,200
Orang-utans are surely
one of the most human of animals.


627
00:53:42,200 --> 00:53:47,040
And they share many behavioural
traits that you would


628
00:53:47,040 --> 00:53:49,480
define as being uniquely human.


629
00:53:51,240 --> 00:53:54,680
They nurture their young for
eight years before they let them


630
00:53:54,680 --> 00:53:56,560
go on their own into the forest.


631
00:53:56,560 --> 00:54:00,640
In that time the infants learn
which fruits are safe to eat


632
00:54:00,640 --> 00:54:02,160
and which are poisonous.


633
00:54:02,160 --> 00:54:06,200
Which branches will
hold their weight and which won't.


634
00:54:06,200 --> 00:54:09,960
And they can do all that
because they have a memory,


635
00:54:09,960 --> 00:54:12,720
they can remember things
that happened to them in their life,


636
00:54:12,720 --> 00:54:14,040
they can learn from them,


637
00:54:14,040 --> 00:54:17,280
and they can pass them on
from generation to generation.


638
00:54:24,280 --> 00:54:28,920
And that deep connection extends
far beyond our closest relatives.


639
00:54:30,400 --> 00:54:33,160
Because our DNA
contains the fingerprint


640
00:54:33,160 --> 00:54:37,320
of almost four billion years
of evolution.


641
00:54:37,320 --> 00:54:40,240
BIRDS SING


642
00:54:43,240 --> 00:54:46,520
If I draw a tree of life
for the primates,


643
00:54:46,520 --> 00:54:52,360
then we share a common ancestor
with the chimps, Bonobos.


644
00:54:52,360 --> 00:54:55,400
About four to six million years ago.


645
00:54:55,400 --> 00:55:01,840
And if you compare our
genetic sequences you find


646
00:55:01,840 --> 00:55:07,320
that our genes are 99% the same.


647
00:55:07,320 --> 00:55:11,000
You go back to the split
with gorillas,


648
00:55:11,000 --> 00:55:14,640
about six to eight million
years ago and again,


649
00:55:14,640 --> 00:55:21,480
if you compare our genes you
find that they are 98.4% the same.


650
00:55:23,520 --> 00:55:27,560
Back in time again, common ancestor
with our friends over there,


651
00:55:27,560 --> 00:55:34,560
the orang-utans,
then our genes are 97.4% the same.


652
00:55:34,560 --> 00:55:36,800
And you could carry on
all the way back in time.


653
00:55:36,800 --> 00:55:40,680
You could look for our common
ancestor with a chicken,


654
00:55:40,680 --> 00:55:44,880
and you'd find that our codes
are about 60% the same.


655
00:55:44,880 --> 00:55:48,880
And in fact, if you look
for any animal, like him,


656
00:55:48,880 --> 00:55:53,640
a little fly, or a bacteria,
something that seems superficially


657
00:55:53,640 --> 00:55:57,160
completely unrelated to us,
then you'll still find sequences


658
00:55:57,160 --> 00:56:01,480
in the genetic code which are
identical to sequences in my cells.


659
00:56:01,480 --> 00:56:07,040
So this tells us
that all life on Earth is related,


660
00:56:07,040 --> 00:56:10,760
it's all connected
through our genetic code.


661
00:56:20,480 --> 00:56:23,120
DNA is the blueprint for life.


662
00:56:25,000 --> 00:56:30,400
But its extraordinary fidelity
means it also contains a story.


663
00:56:30,400 --> 00:56:32,400
And what a story it is.


664
00:56:35,160 --> 00:56:39,720
The entire history of evolution
from the present day


665
00:56:39,720 --> 00:56:43,560
all the way back to
the very first spark of life.


666
00:56:46,960 --> 00:56:51,960
And it tells us that we're
connected, not only to every plant


667
00:56:51,960 --> 00:56:58,120
and animal alive today, but to every
single thing that has ever lived.


668
00:57:21,840 --> 00:57:23,240
The question, what is life,


669
00:57:23,240 --> 00:57:26,200
is surely one of the grandest
of questions.


670
00:57:26,200 --> 00:57:29,720
And we've learnt that life
isn't really a thing at all.


671
00:57:29,720 --> 00:57:33,400
It's a collection of chemical
processes that can harness


672
00:57:33,400 --> 00:57:36,960
a flow of energy to create
local islands of order,


673
00:57:36,960 --> 00:57:39,280
like me and this forest,


674
00:57:39,280 --> 00:57:42,560
by borrowing order
from the wider universe


675
00:57:42,560 --> 00:57:46,440
and then transmitting it
from generation to generation


676
00:57:46,440 --> 00:57:49,640
through the elegant
chemistry of DNA.


677
00:57:49,640 --> 00:57:51,920
And the origins of that chemistry


678
00:57:51,920 --> 00:57:54,600
can be traced back
four billion years,


679
00:57:54,600 --> 00:57:58,200
most likely to vents
in the primordial ocean.


680
00:57:58,200 --> 00:58:02,560
And, most wonderfully of all,
the echoes of that history,


681
00:58:02,560 --> 00:58:06,160
stretching back for a third
of the age of the universe,


682
00:58:06,160 --> 00:58:11,640
can be seen in every cell
of every living thing on Earth.


683
00:58:11,640 --> 00:58:15,200
And that leads to what I think is
the most exciting idea of all,


684
00:58:15,200 --> 00:58:20,400
because far from being some chance
event ignited by a mystical spark,


685
00:58:20,400 --> 00:58:23,320
the emergence of life
on Earth might have been


686
00:58:23,320 --> 00:58:27,240
an inevitable consequence
of the laws of physics.


687
00:58:27,240 --> 00:58:28,560
And if that's true,


688
00:58:28,560 --> 00:58:32,880
then a living cosmos might be
the only way our cosmos can be.


689
00:58:46,520 --> 00:58:52,960
# Just remember you're a tiny
little person on a planet


690
00:58:52,960 --> 00:58:55,920
# In a universe expanding
and immense


691
00:58:57,120 --> 00:59:01,320
# That life began evolving
and dissolving and resolving


692
00:59:01,320 --> 00:59:05,280
# In the deep primordial
oceans by the hydrothermal vents


693
00:59:05,280 --> 00:59:09,120
# Our Earth which had its birth
almost five billion years ago


694
00:59:09,120 --> 00:59:12,920
# From out a collapsing
cloud of gas


695
00:59:12,920 --> 00:59:15,120
# Grew life which was quite new


696
00:59:15,120 --> 00:59:16,920
# And eventually led to you


697
00:59:16,920 --> 00:59:20,480
# In only 3.5 billion years
or less. #


698
00:59:20,480 --> 00:59:22,840
WHISTLING TO END OF SONG


699
00:59:22,840 --> 00:59:24,800
Subtitles by Red Bee Media Ltd