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00:00:02,802 --> 00:00:04,169
They're dazzling.
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00:00:04,171 --> 00:00:05,371
Priceless.
3
00:00:06,539 --> 00:00:08,874
At times, even glowing.
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00:00:10,710 --> 00:00:16,081
How can one not fall
in love with rocks and minerals?
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00:00:16,083 --> 00:00:18,550
I mean, the colors,
the shapes...
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And they're the building
blocks of modern civilization.
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We wouldn't have televisions,
we wouldn't have automobiles,
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00:00:26,160 --> 00:00:27,493
we wouldn't have buildings
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00:00:27,495 --> 00:00:30,062
without the mineral riches
that we have.
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00:00:30,064 --> 00:00:31,764
But could rocks and minerals
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00:00:31,766 --> 00:00:34,867
also solve the greatest mystery
of all time...
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00:00:34,869 --> 00:00:36,802
the origin of life?
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00:00:38,972 --> 00:00:41,306
The rocks we
pick up tell a story:
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00:00:41,308 --> 00:00:44,176
that life couldn't have occurred
without rocks.
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Could cold, lifeless stone
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00:00:46,447 --> 00:00:49,381
hold the key to every
living thing on Earth?
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00:00:52,118 --> 00:00:56,321
From Australia to Morocco,
18
00:00:56,323 --> 00:01:01,393
NOVA goes around the world
and back in time
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00:01:01,395 --> 00:01:06,031
to investigate the origin
and evolution of life.
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00:01:06,033 --> 00:01:08,801
You look at a rock and you
think, "Ah well, nothing,"
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00:01:08,803 --> 00:01:12,137
but this holds
the signature of life.
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00:01:12,139 --> 00:01:13,839
From its first spark...
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00:01:13,841 --> 00:01:17,910
People were saying they
made Frankenstein in a test tube.
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00:01:17,912 --> 00:01:21,380
to the survival of the fittest.
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00:01:21,382 --> 00:01:22,915
These were immense creatures...
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00:01:22,917 --> 00:01:27,319
sharks that may have been
50 or 60 feet.
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Was it the secret
link between rocks and life
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00:01:32,860 --> 00:01:34,827
that made the difference?
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00:01:37,430 --> 00:01:40,999
"Life's Rocky Start,"
right now on NOVA.
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The ancient market of Marrakech,
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a chaotic, colorful
gathering place
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00:02:09,130 --> 00:02:12,498
teeming with life
for thousands of years.
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The perfect place to ask,
how did this exotic, beautiful,
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00:02:18,072 --> 00:02:22,341
and sometimes bizarre thing
called life begin?
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00:02:29,816 --> 00:02:35,721
How did Earth go
from a lifeless, molten rock
36
00:02:35,723 --> 00:02:39,324
to a living planet
37
00:02:39,326 --> 00:02:42,628
full of diverse
and spectacular creatures?
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00:02:48,067 --> 00:02:51,003
It's a question that has
long perplexed scientists.
39
00:02:55,375 --> 00:02:59,745
Now Robert Hazen, a geologist,
is trying to show
40
00:02:59,747 --> 00:03:01,780
we are missing
an essential ingredient
41
00:03:01,782 --> 00:03:03,949
in the recipe for life...
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00:03:03,951 --> 00:03:06,351
Look at that vein of calcite.
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00:03:06,353 --> 00:03:07,719
Rocks.
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00:03:07,721 --> 00:03:12,491
Nothing seems more
lifeless than a rock.
45
00:03:12,493 --> 00:03:16,728
It's inanimate, it's the
antithesis of a living thing.
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00:03:16,730 --> 00:03:19,498
But we are beginning
to realize that rocks played
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00:03:19,500 --> 00:03:23,001
an absolutely fundamental role
in the origin of life.
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00:03:23,003 --> 00:03:25,437
Aw, yeah.
49
00:03:25,439 --> 00:03:29,508
Hazen is out to
expose a secret relationship
50
00:03:29,510 --> 00:03:32,077
between rocks and life
that helped drive
51
00:03:32,079 --> 00:03:34,379
both the origin of life
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00:03:34,381 --> 00:03:39,618
and its evolution
into complex creatures.
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00:03:39,620 --> 00:03:41,787
This is a very new
set of understandings
54
00:03:41,789 --> 00:03:44,957
and the more we look,
the more we see
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00:03:44,959 --> 00:03:47,392
that life depends on rocks,
rocks depend on life
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and this has been going on
for four billion years.
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00:03:50,431 --> 00:03:54,066
As a geologist, it's no
surprise that Hazen is searching
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00:03:54,068 --> 00:03:56,168
for answers written in stone.
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00:03:57,670 --> 00:03:58,737
But is he right?
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00:04:00,306 --> 00:04:03,642
Are rocks the missing
spark of life?
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00:04:11,718 --> 00:04:16,555
The history of Earth
is unimaginably long.
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00:04:16,557 --> 00:04:19,591
If it were sped up to the
equivalent of a single day,
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00:04:19,593 --> 00:04:23,362
all of humankind
from the earliest skeletons...
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00:04:24,498 --> 00:04:26,832
to the invention of the iPhone
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00:04:26,834 --> 00:04:31,637
would have occurred
in only the last four seconds.
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00:04:31,639 --> 00:04:33,605
Dinosaurs were still
roaming Earth
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00:04:33,607 --> 00:04:37,676
about 20 minutes before that.
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00:04:37,678 --> 00:04:39,411
But the creation of our planet
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00:04:39,413 --> 00:04:43,081
occurred more than
23 hours earlier...
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00:04:43,083 --> 00:04:48,987
two cycles on this clock...
or 4.5 billion years ago.
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00:04:52,458 --> 00:04:58,263
Comprehending Earth's vast
history is a formidable task.
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00:04:58,265 --> 00:05:01,433
There's four and a
half billion years of change.
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00:05:01,435 --> 00:05:03,568
But you can divide it
into half a dozen ways
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00:05:03,570 --> 00:05:05,937
of describing Earth
through time.
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00:05:08,074 --> 00:05:10,976
Bob Hazen has come up
with another way to visualize.
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00:05:10,978 --> 00:05:13,578
Earth's long history
that reveals
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00:05:13,580 --> 00:05:17,716
this special relationship
between rocks and life.
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00:05:22,088 --> 00:05:25,424
He has divided it
into six stages,
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00:05:25,426 --> 00:05:29,761
each represented
by a different color.
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00:05:29,763 --> 00:05:32,831
To understand how we ended up
with green Earth...
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00:05:32,833 --> 00:05:34,566
the planet we now know...
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00:05:34,568 --> 00:05:36,935
requires us to turn
the clock back,
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00:05:36,937 --> 00:05:41,306
to before there was any life
at all.
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00:05:41,308 --> 00:05:46,411
Stage one was the creation
of black Earth.
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00:05:55,788 --> 00:05:56,955
Back in Morocco,
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00:05:56,957 --> 00:06:00,392
Hazen and Adam Aronson,
a meteorite expert,
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00:06:00,394 --> 00:06:04,529
seek out a small rock from
the beginning of our cosmos.
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00:06:07,100 --> 00:06:09,101
Wow, look at this pile here.
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00:06:09,103 --> 00:06:13,205
These are meteorites,
rocks that have fallen from space.
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00:06:13,207 --> 00:06:14,339
This is Tamdackht.
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00:06:14,341 --> 00:06:16,341
This is the one that
fell 20 kilometers
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00:06:16,343 --> 00:06:17,709
up the road from here.
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00:06:17,711 --> 00:06:19,444
People saw it fall.
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00:06:21,447 --> 00:06:25,150
A recent meteorite fall
in Siberia was captured in videos
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00:06:25,152 --> 00:06:28,553
that have shown up on YouTube.
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00:06:28,555 --> 00:06:32,257
Other space rocks have ended up
for sale here in Morocco.
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00:06:32,259 --> 00:06:34,926
So you'd buy this
without doing tests?
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00:06:34,928 --> 00:06:36,361
I would drop the cash right now
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00:06:36,363 --> 00:06:37,729
if he would give me
a good price.
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00:06:39,867 --> 00:06:43,969
Meteorites here can sell
for tens of thousands of dollars.
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00:06:43,971 --> 00:06:47,906
That may seem a steep price
for a lump of rock,
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but these are some
of the very oldest objects
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in our solar system.
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This is the oldest object
you could ever hold in your hand.
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It's 4.6 billion years old
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and it was formed
before earth formed.
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This is the very first
solid material,
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the very first rock
in our solar system
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and these came together
to build all the planets.
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Our Earth was created
out of the rocks and dust
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present at the start
of our solar system.
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Over time, small fragments
of orbiting rock collided,
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coming together into the planets
circling the sun.
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At first, Earth was molten
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00:07:47,835 --> 00:07:52,003
with temperatures
in the thousands of degrees.
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But in the cold vacuum of space
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00:07:54,541 --> 00:07:59,311
this hot rock
began to cool and change.
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Nothing, not a speck of dust,
is believed to have survived
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from the period of black Earth.
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It was a hellishly
unpleasant time.
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Volcanoes spewed hot lava
from deep inside the planet.
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When it cooled,
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00:08:36,750 --> 00:08:41,520
it covered Earth with its first
rock, called basalt.
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00:08:45,258 --> 00:08:47,192
And it was black.
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00:08:54,200 --> 00:08:56,768
It seems
like a desolate landscape.
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But some ingredients
that life will need
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are already here in these rocks.
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Look inside and you begin
to understand how intriguing
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even an ordinary rock is.
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Every rock, you slice
it open, you look inside,
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there's something special.
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Rocks are made up mostly
of minerals, which are crystals
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00:09:22,829 --> 00:09:24,996
like quartz or diamonds.
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Looking through a microscope
at super-thin slices of a rock
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00:09:29,403 --> 00:09:32,671
lets you see
its mineral composition.
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This is the rock peridotite,
made up of small crystals
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00:09:37,344 --> 00:09:39,611
including olivine and pyroxene.
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Even a simple black basalt rock
spewed from a volcano
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00:09:45,852 --> 00:09:49,688
becomes a patchwork
of colorful minerals.
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00:09:49,690 --> 00:09:52,090
It's sort of like a fruitcake.
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00:09:52,092 --> 00:09:54,292
You know, you slice it open,
there's nuts,
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00:09:54,294 --> 00:09:56,962
and there is dried fruit,
and maybe some lemon peel.
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It's made of lots
of little things.
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00:09:58,932 --> 00:10:01,099
And it's not until you slice
into that fruitcake
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00:10:01,101 --> 00:10:04,736
that you see all the stuff
inside that makes it special.
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00:10:13,379 --> 00:10:16,715
What makes them special
is not only their beauty.
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00:10:16,717 --> 00:10:20,485
Minerals have remarkable
chemical and physical properties
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00:10:20,487 --> 00:10:23,254
and are a source
of many of the elements...
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00:10:23,256 --> 00:10:25,390
nature's building blocks.
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00:10:27,793 --> 00:10:30,695
That is why they're essential
in our modern world
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00:10:30,697 --> 00:10:34,232
to make everything
from skyscrapers taller
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00:10:34,234 --> 00:10:37,135
to mobile phones smaller.
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00:10:40,006 --> 00:10:43,742
Extract the element molybdenum
from the mineral molybdenite
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00:10:43,744 --> 00:10:47,379
to make steel harder,
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00:10:47,381 --> 00:10:49,648
or add a pinch of cobalt
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00:10:49,650 --> 00:10:52,784
and your iPhone battery
will last longer.
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00:10:55,821 --> 00:10:59,891
Minerals are the fundamental
building block of societies.
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00:10:59,893 --> 00:11:02,327
We wouldn't have televisions,
we wouldn't have automobiles,
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00:11:02,329 --> 00:11:03,728
we wouldn't have buildings
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00:11:03,730 --> 00:11:05,830
without the mineral riches
that we have.
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So were the remarkable
chemical properties of minerals
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also key in creating life?
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If so, Earth would need more
than it started with.
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It's estimated that the
meteorites that formed Earth
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had only about 250 minerals,
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00:11:31,525 --> 00:11:35,794
sort of a chemical starter kit
containing many of the elements.
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Then in the intense heat
and pressures
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in the creation of our planet,
new minerals began to form.
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This changed the appearance
of our Earth from black to gray.
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Yosemite National Park is a
relatively new piece of Earth.
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00:12:11,030 --> 00:12:14,899
But the kind of rock that makes
up these dramatic cliffs
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00:12:14,901 --> 00:12:18,002
goes back much further.
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These huge walls are granite,
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00:12:26,179 --> 00:12:28,847
containing minerals
like quartz and feldspar.
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00:12:33,686 --> 00:12:37,689
Granite became the foundation
of our continents,
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00:12:37,691 --> 00:12:40,325
leading Earth
into the gray period.
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At this point,
Earth is still a long way
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00:12:48,602 --> 00:12:51,536
from the glorious diversity
of plants and animals
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00:12:51,538 --> 00:12:54,272
that makes Yosemite
so picturesque.
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00:12:56,675 --> 00:12:58,676
But the stage is set
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00:12:58,678 --> 00:13:01,613
for the next character
in our planet's story:
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00:13:01,615 --> 00:13:05,717
water,
which will turn Earth blue.
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Water plays a central role
in every model
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00:13:09,222 --> 00:13:10,455
for the origin of life.
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00:13:10,457 --> 00:13:15,093
That's because water
is such a great solvent.
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00:13:15,095 --> 00:13:17,595
All these different kinds
of molecules
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can be floating around the water
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00:13:19,166 --> 00:13:23,802
and then they have the potential
to interact together.
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00:13:23,804 --> 00:13:25,203
The starting point is the water.
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00:13:27,072 --> 00:13:31,209
So when did Earth cool
enough to have liquid water,
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00:13:31,211 --> 00:13:34,445
this element key to life?
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00:13:34,447 --> 00:13:38,149
One of the biggest
unknowns in this whole idea
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00:13:38,151 --> 00:13:41,419
of going from black to gray
to a blue water-covered Earth
194
00:13:41,421 --> 00:13:42,720
is how quickly it happened.
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00:13:42,722 --> 00:13:45,723
The timing was a big mystery.
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00:13:56,335 --> 00:13:58,503
The Pilbara in Western Australia
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00:13:58,505 --> 00:14:01,606
is one of the oldest places
on Earth,
198
00:14:01,608 --> 00:14:04,576
and so one of the best places
to solve the mystery
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00:14:04,578 --> 00:14:07,045
of the planet's first oceans.
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00:14:09,548 --> 00:14:13,184
Hazen joins an all-star team
of geologists
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00:14:13,186 --> 00:14:15,220
including Martin Van Kranendonk,
202
00:14:15,222 --> 00:14:17,555
from the University
of New South Wales
203
00:14:17,557 --> 00:14:20,425
and John Valley
of the University of Wisconsin.
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00:14:25,431 --> 00:14:28,199
Valley is collecting rocks
that could hold clues
205
00:14:28,201 --> 00:14:30,902
to when water first appeared.
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00:14:32,872 --> 00:14:34,339
We can get zircons
and other minerals
207
00:14:34,341 --> 00:14:36,908
that date all the way back
to 4.4 billion years old.
208
00:14:36,910 --> 00:14:38,190
Hopefully.
209
00:14:39,478 --> 00:14:42,247
Some rocks here
contain sand-sized grains
210
00:14:42,249 --> 00:14:45,750
that weathered from
even older rocks.
211
00:14:45,752 --> 00:14:49,554
One in a million... literally...
is a crystal called zircon,
212
00:14:49,556 --> 00:14:52,490
one of the longest-lasting
materials in nature.
213
00:14:56,662 --> 00:14:59,597
Zircon is a popular gemstone,
214
00:14:59,599 --> 00:15:03,034
but the microscopic zircon
found here
215
00:15:03,036 --> 00:15:04,402
is even more precious.
216
00:15:04,404 --> 00:15:07,171
Zircon crystals
are especially amazing.
217
00:15:07,173 --> 00:15:09,374
Gemstone zircons of course
are valued,
218
00:15:09,376 --> 00:15:11,109
but these tiny ones
that geologists value
219
00:15:11,111 --> 00:15:12,443
are microscopic.
220
00:15:12,445 --> 00:15:15,313
They make a lousy ring, but
they tell an incredible story.
221
00:15:16,615 --> 00:15:19,450
To tell that story,
222
00:15:19,452 --> 00:15:21,953
John Valley must first find
the tiny crystals...
223
00:15:21,955 --> 00:15:25,423
the ultimate
needle in a haystack.
224
00:15:25,425 --> 00:15:28,192
If you want to find
a needle in a haystack,
225
00:15:28,194 --> 00:15:30,528
the first thing you do
is you burn down the haystack.
226
00:15:30,530 --> 00:15:35,133
Then you'd sift through the ash
to look for the needle.
227
00:15:35,135 --> 00:15:39,470
Rocks are pulverized
into sand-sized grains
228
00:15:39,472 --> 00:15:41,406
and sorted by weight
in a machine
229
00:15:41,408 --> 00:15:43,374
developed to pan for gold.
230
00:15:45,244 --> 00:15:49,914
The gold that Valley is looking
for are heavy zircon crystals,
231
00:15:49,916 --> 00:15:53,351
which get channeled
into different tracks.
232
00:15:56,455 --> 00:16:01,192
Then, grain by grain,
with a very steady hand,
233
00:16:01,194 --> 00:16:05,563
thousands of small crystals
are sorted and analyzed.
234
00:16:07,566 --> 00:16:09,867
The chemical structure
of a zircon crystal
235
00:16:09,869 --> 00:16:12,570
holds evidence of both
the environment
236
00:16:12,572 --> 00:16:15,907
and the age when it formed.
237
00:16:21,180 --> 00:16:24,882
Some of these tiny crystals
go very far back,
238
00:16:24,884 --> 00:16:28,453
just over 100 million years
after Earth formed.
239
00:16:30,723 --> 00:16:34,726
They are the oldest pieces
of Earth ever discovered,
240
00:16:34,728 --> 00:16:39,564
so they could shed light on what
our young planet looked like.
241
00:16:46,605 --> 00:16:49,507
It's totally amazing to me.
242
00:16:49,509 --> 00:16:52,110
To hold this grain of sand
in the palm of your hand
243
00:16:52,112 --> 00:16:55,380
is literally to see
back through time.
244
00:16:55,382 --> 00:16:57,515
It is a time machine.
245
00:17:02,187 --> 00:17:05,123
Valley expected
these crystal time machines
246
00:17:05,125 --> 00:17:08,626
would confirm the long-held view
that the young Earth
247
00:17:08,628 --> 00:17:10,695
was covered in molten lava,
248
00:17:10,697 --> 00:17:14,198
still cooling after
its violent formation.
249
00:17:17,870 --> 00:17:21,806
I think the zircon on the left
looks very promising.
250
00:17:21,808 --> 00:17:25,143
So what he
discovered was shocking
251
00:17:25,145 --> 00:17:30,081
because this type of zircon,
created 4.3 billion years ago,
252
00:17:30,083 --> 00:17:34,185
could only have formed
in the presence of liquid water.
253
00:17:36,321 --> 00:17:38,456
But how could there be water
254
00:17:38,458 --> 00:17:41,392
if Earth was still hot
and hell-like?
255
00:17:44,530 --> 00:17:47,765
The implications were
that the early Earth had water.
256
00:17:47,767 --> 00:17:50,701
It was cooler and it was wet.
257
00:17:53,172 --> 00:17:55,039
It's starting to look very much
more familiar.
258
00:17:55,041 --> 00:17:59,277
And if water is a
key starting point for life,
259
00:17:59,279 --> 00:18:02,213
could there be life
that early, too?
260
00:18:07,052 --> 00:18:09,687
The science of the zircon
is telling us that the Earth
261
00:18:09,689 --> 00:18:15,760
for a very, very long time
was a habitable environment.
262
00:18:15,762 --> 00:18:17,795
Not necessarily
that there was life then.
263
00:18:17,797 --> 00:18:19,397
We don't know that yet.
264
00:18:19,399 --> 00:18:21,999
But there's no reason why
there couldn't have been life
265
00:18:22,001 --> 00:18:24,302
as early as 4.3 billion
years ago.
266
00:18:24,304 --> 00:18:29,273
So if life were possible
that early, it begs the question,
267
00:18:29,275 --> 00:18:31,542
how did life begin?
268
00:18:36,115 --> 00:18:38,983
In 1871, Charles Darwin
269
00:18:38,985 --> 00:18:40,952
speculated in a letter
to a friend
270
00:18:40,954 --> 00:18:44,822
th warm little pond
might be life's birthplace.
271
00:18:52,931 --> 00:18:56,801
A warm soup of chemicals
bathed by energy from the sun
272
00:18:56,803 --> 00:18:59,837
would have been, well,
comfortable for molecules
273
00:18:59,839 --> 00:19:03,174
to come together in new ways
and create life.
274
00:19:06,678 --> 00:19:09,780
Darwin was way, way
ahead of his time.
275
00:19:09,782 --> 00:19:14,318
A nice little warm soup
is going to get you a long way.
276
00:19:17,189 --> 00:19:20,358
Jeff Bada of the Scripps
Institution of Oceanography
277
00:19:20,360 --> 00:19:23,060
in San Diego,
has spent his career
278
00:19:23,062 --> 00:19:27,131
working to understand the early
Earth's soup of chemicals.
279
00:19:29,635 --> 00:19:31,836
He began under the direction
of perhaps
280
00:19:31,838 --> 00:19:36,140
the most famous scientist
in origin of life research...
281
00:19:36,142 --> 00:19:39,277
Stanley Miller.
282
00:19:39,279 --> 00:19:42,346
There are in the history
of science turning points
283
00:19:42,348 --> 00:19:45,449
where we suddenly see
the history of Earth
284
00:19:45,451 --> 00:19:47,585
and life differently.
285
00:19:47,587 --> 00:19:49,620
In the early 1950s,
Stanley Miller,
286
00:19:49,622 --> 00:19:52,223
the eager graduate student,
and Harold Urey,
287
00:19:52,225 --> 00:19:55,393
the Nobel Prize winning mentor
at the University of Chicago,
288
00:19:55,395 --> 00:19:57,895
conducted this
astonishing experiment
289
00:19:57,897 --> 00:20:01,866
where they made
an early Earth environment.
290
00:20:01,868 --> 00:20:06,671
It looks like this sort of
a Frankenstein-type apparatus.
291
00:20:06,673 --> 00:20:09,040
But actually, it's a very
carefully thought out design.
292
00:20:10,876 --> 00:20:14,345
Bada sets up a modern-day
test of the 1950s experiment
293
00:20:14,347 --> 00:20:18,349
on Miller's original
lab equipment.
294
00:20:19,484 --> 00:20:22,386
One flask contains water.
295
00:20:22,388 --> 00:20:25,189
That's to simulate the ocean.
296
00:20:25,191 --> 00:20:28,125
The other flask
has just got the gases in it.
297
00:20:28,127 --> 00:20:29,927
So this is the atmosphere.
298
00:20:34,633 --> 00:20:37,301
Just as it does in nature,
299
00:20:37,303 --> 00:20:41,539
water from the ocean evaporates
and rises into the atmosphere,
300
00:20:41,541 --> 00:20:44,475
where it condenses
and returns to the ocean.
301
00:20:47,679 --> 00:20:50,314
Miller simulated what he
believed to be the atmosphere
302
00:20:50,316 --> 00:20:55,753
of early Earth with different
gases like ammonia and methane.
303
00:20:58,890 --> 00:21:01,826
Then,
he added a spark of genius.
304
00:21:07,433 --> 00:21:12,336
Miller and Urey decided to
use a spark to simulate lightning
305
00:21:12,338 --> 00:21:14,305
because that's such
a ubiquitous process
306
00:21:14,307 --> 00:21:16,207
in the atmosphere of the earth.
307
00:21:17,909 --> 00:21:19,443
That was the real inspiration,
308
00:21:19,445 --> 00:21:20,478
these little electric sparks
309
00:21:20,480 --> 00:21:22,440
they acted like simulated
lightning.
310
00:21:23,515 --> 00:21:25,783
The energy from
the spark of lightning
311
00:21:25,785 --> 00:21:28,386
breaks down
the gas and water molecules
312
00:21:28,388 --> 00:21:31,322
so they can undergo
further chemical reactions.
313
00:21:37,429 --> 00:21:41,666
To their astonishment, when
they turned this apparatus on
314
00:21:41,668 --> 00:21:43,801
after only a couple of days
you started seeing
315
00:21:43,803 --> 00:21:46,103
this pink color developing.
316
00:21:48,373 --> 00:21:52,143
And then a few more days,
black, oily goo
317
00:21:52,145 --> 00:21:54,779
is forming around
the electrodes.
318
00:21:58,050 --> 00:22:03,120
The electrodes get
covered with new substances,
319
00:22:03,122 --> 00:22:07,425
organic compounds
usually associated with life.
320
00:22:10,662 --> 00:22:12,496
And it wasn't just
any organic compound,
321
00:22:12,498 --> 00:22:15,666
it was amino acids
that make proteins.
322
00:22:15,668 --> 00:22:18,602
The ingredients for life.
323
00:22:21,640 --> 00:22:24,575
Amino acids are the
building blocks of life.
324
00:22:27,579 --> 00:22:29,880
They form proteins,
325
00:22:29,882 --> 00:22:33,084
which are the key component
of muscles and other tissues.
326
00:22:35,487 --> 00:22:36,687
People thought, "Aha!"
327
00:22:36,689 --> 00:22:39,457
This is a key step
in the origin of life."
328
00:22:39,459 --> 00:22:42,893
And you really believe that
you can bring life to the dead?
329
00:22:42,895 --> 00:22:45,963
That body is not dead.
330
00:22:45,965 --> 00:22:48,432
It has never lived.
331
00:22:48,434 --> 00:22:50,368
I created it.
332
00:22:52,304 --> 00:22:56,707
The experiment raised the
fear that a Frankenstein creation,
333
00:22:56,709 --> 00:22:59,844
like in this classic film,
was just around the corner.
334
00:22:59,846 --> 00:23:01,545
It's moving.
335
00:23:01,547 --> 00:23:06,317
People were saying they
made Frankenstein in a test tube.
336
00:23:06,319 --> 00:23:08,085
It's alive!
337
00:23:08,087 --> 00:23:11,489
Now I know what it feels
like to be God!
338
00:23:14,126 --> 00:23:18,329
Had Miller and Urey
cooked up life in a test tube?
339
00:23:18,331 --> 00:23:20,831
Many of the news
headlines were saying,
340
00:23:20,833 --> 00:23:22,633
"Life created
in the laboratory!"
341
00:23:22,635 --> 00:23:25,002
"Life created in a test tube!"
342
00:23:25,004 --> 00:23:26,404
Well, of course that was wrong.
343
00:23:26,406 --> 00:23:30,174
The real news
was he'd made these compounds
344
00:23:30,176 --> 00:23:32,109
that are part of life.
345
00:23:35,347 --> 00:23:38,949
By creating amino
acids, the Miller-Urey experiment
346
00:23:38,951 --> 00:23:42,186
seemed to confirm
that Darwin was right...
347
00:23:42,188 --> 00:23:46,090
life must have begun
in a shallow pond.
348
00:23:54,199 --> 00:23:58,035
But then, 24 years later,
a shocking discovery
349
00:23:58,037 --> 00:23:59,970
radically challenged that idea.
350
00:24:01,173 --> 00:24:04,141
On the dark ocean floor,
351
00:24:04,143 --> 00:24:06,811
more than a mile
below the surface,
352
00:24:06,813 --> 00:24:11,715
explorers found hot,
mineral-rich hydrothermal vents,
353
00:24:11,717 --> 00:24:13,651
like underwater volcanoes.
354
00:24:15,353 --> 00:24:18,722
Temperatures reached
more than 600 degrees,
355
00:24:18,724 --> 00:24:23,794
and yet here life was thriving,
not off the sun's energy,
356
00:24:23,796 --> 00:24:28,265
but through chemical energy
from the vents.
357
00:24:28,267 --> 00:24:32,136
No one realized that life
could thrive without sunlight.
358
00:24:32,138 --> 00:24:35,306
Here you have
this extreme temperature
359
00:24:35,308 --> 00:24:36,507
and this extreme pressure,
360
00:24:36,509 --> 00:24:38,442
and so you have to shift
your perceptions
361
00:24:38,444 --> 00:24:40,945
and realize that just because
it's extreme to us
362
00:24:40,947 --> 00:24:43,380
doesn't mean it's extreme
to those microbes.
363
00:24:45,016 --> 00:24:48,052
Instead of
the warm shallow pond,
364
00:24:48,054 --> 00:24:53,324
could this dark and unlikely
environment be where life began?
365
00:24:53,326 --> 00:24:57,528
To answer that,
Hazen decided to try creating
366
00:24:57,530 --> 00:25:02,566
life's building blocks in the
conditions of a deep sea vent.
367
00:25:02,568 --> 00:25:03,801
My first thought was gee,
368
00:25:03,803 --> 00:25:05,769
why don't we do
a Miller-Urey experiment,
369
00:25:05,771 --> 00:25:07,931
but do it at high temperature,
high pressures?
370
00:25:09,374 --> 00:25:11,075
Hazen's laboratory
371
00:25:11,077 --> 00:25:12,676
is at the Carnegie Institution
for Science,
372
00:25:12,678 --> 00:25:15,513
which is famous for experiments
that simulate
373
00:25:15,515 --> 00:25:17,882
the intense pressures
deep inside Earth
374
00:25:17,884 --> 00:25:22,520
with powerful tools
called pressure bombs.
375
00:25:22,522 --> 00:25:23,854
They're called bombs
for a reason...
376
00:25:23,856 --> 00:25:25,422
because things can explode.
377
00:25:36,568 --> 00:25:39,303
Hazen and his colleagues
adapted these pressure bombs
378
00:25:39,305 --> 00:25:43,407
to model the environment
of the deep sea vents
379
00:25:43,409 --> 00:25:44,975
in a small gold tube.
380
00:25:47,379 --> 00:25:50,381
What they discovered
came as a surprise.
381
00:25:51,883 --> 00:25:53,317
Nothing happened.
382
00:25:54,753 --> 00:25:57,655
You can take basic gases...
383
00:25:57,657 --> 00:26:03,961
nitrogen, CO2,
maybe some sulfur compounds.
384
00:26:03,963 --> 00:26:05,829
You can mix those,
you can put them in a gold tube,
385
00:26:05,831 --> 00:26:06,864
you can heat them up.
386
00:26:06,866 --> 00:26:08,986
You don't get much
that's very interesting.
387
00:26:11,503 --> 00:26:15,906
Simply squeezing and heating
the ingredients had little effect.
388
00:26:17,175 --> 00:26:19,810
Hazen was missing the spark,
389
00:26:19,812 --> 00:26:21,979
like in the Miller-Urey
experiment,
390
00:26:21,981 --> 00:26:25,449
the thing that kickstarts
the chemistry.
391
00:26:30,188 --> 00:26:33,148
So we said, "What's
going on, what's different?"
392
00:26:34,359 --> 00:26:35,693
Well, look at the natural
environment,
393
00:26:35,695 --> 00:26:37,194
there's all these rocks
and minerals.
394
00:26:37,196 --> 00:26:39,316
Let's try putting
some rocks and minerals in.
395
00:26:40,065 --> 00:26:42,900
They recreate
the early Earth cocktail,
396
00:26:42,902 --> 00:26:48,205
but this time grind in powder
from rocks and minerals.
397
00:26:49,975 --> 00:26:53,944
But will Hazen's beloved rocks
do the trick?
398
00:26:56,582 --> 00:26:58,082
They run the experiment again.
399
00:27:01,019 --> 00:27:06,323
And this time the atoms reform
into new organic molecules...
400
00:27:06,325 --> 00:27:08,659
including amino acids.
401
00:27:10,195 --> 00:27:12,463
As soon as you put
powdered rocks and minerals
402
00:27:12,465 --> 00:27:14,431
into the gold capsules,
403
00:27:14,433 --> 00:27:17,301
then all sorts of really amazing
things started happening.
404
00:27:17,303 --> 00:27:19,103
You made organic molecules,
405
00:27:19,105 --> 00:27:23,240
they became more stable,
they lasted longer,
406
00:27:23,242 --> 00:27:25,109
and it really pointed us
in the direction of saying,
407
00:27:25,111 --> 00:27:27,231
"Aha, this has got to be
part of the story."
408
00:27:28,380 --> 00:27:30,214
While scientists still argue
409
00:27:30,216 --> 00:27:34,551
if life began in shallow ponds
or deep sea vents,
410
00:27:34,553 --> 00:27:36,353
both sides wonder,
411
00:27:36,355 --> 00:27:40,524
what part of the story did rocks
and minerals play?
412
00:27:49,134 --> 00:27:53,303
One possible answer
may be found in London,
413
00:27:53,305 --> 00:27:57,608
in the powerful properties
of mud.
414
00:27:57,610 --> 00:27:59,943
Most people will be familiar
with the material.
415
00:27:59,945 --> 00:28:02,413
It's very gungy.
416
00:28:02,415 --> 00:28:04,415
That's perhaps a British word
417
00:28:04,417 --> 00:28:06,984
that refers to something
which is soft
418
00:28:06,986 --> 00:28:09,053
and unpleasant, generally.
419
00:28:09,055 --> 00:28:11,922
Peter Coveney of
University College London
420
00:28:11,924 --> 00:28:16,293
is busy playing in mud...
at a very sophisticated level.
421
00:28:18,163 --> 00:28:21,565
He has created
powerful computer simulations
422
00:28:21,567 --> 00:28:24,368
that can track
the precise movement
423
00:28:24,370 --> 00:28:27,805
of up to ten million atoms.
424
00:28:29,407 --> 00:28:31,742
Mud can contain clay,
425
00:28:31,744 --> 00:28:36,346
which is made up of some
of Earth's most common minerals.
426
00:28:36,348 --> 00:28:39,149
What makes it so gungy
427
00:28:39,151 --> 00:28:42,352
and perhaps essential
in the origin of life
428
00:28:42,354 --> 00:28:46,657
can be seen deep
in its atomic makeup.
429
00:28:46,659 --> 00:28:50,594
You can see here the
basic structure of any clay.
430
00:28:50,596 --> 00:28:52,963
It's comprised of a large number
of stacked sheets
431
00:28:52,965 --> 00:28:54,331
like a deck of cards.
432
00:28:56,201 --> 00:28:59,470
Sheets of clay
have spaces between them
433
00:28:59,472 --> 00:29:03,841
that fill up with water
and other molecules.
434
00:29:08,513 --> 00:29:12,049
These extensive surface areas
can help create
435
00:29:12,051 --> 00:29:17,888
more complex molecules,
potentially even RNA,
436
00:29:17,890 --> 00:29:20,824
an essential part
of life's genetic code.
437
00:29:24,062 --> 00:29:26,730
One of the most
challenging questions
438
00:29:26,732 --> 00:29:28,832
in the origin of life
439
00:29:28,834 --> 00:29:31,535
is how we get
from the simple building blocks
440
00:29:31,537 --> 00:29:34,138
to the complicated structures
441
00:29:34,140 --> 00:29:38,008
we know are fundamental
to living systems.
442
00:29:38,010 --> 00:29:41,645
Clays provide a clear mechanism
for achieving that.
443
00:29:41,647 --> 00:29:46,283
These simulations
show that the secret to clay
444
00:29:46,285 --> 00:29:50,420
lies in its surfaces.
445
00:29:50,422 --> 00:29:52,256
The surfaces of these minerals
are incredible.
446
00:29:52,258 --> 00:29:54,218
They do all sorts
of chemical tricks.
447
00:29:56,294 --> 00:29:59,096
Hazen says minerals, like clays,
448
00:29:59,098 --> 00:30:02,366
illustrate a fascinating aspect
of chemistry,
449
00:30:02,368 --> 00:30:05,736
because the surface
where reactions take place
450
00:30:05,738 --> 00:30:10,941
can be as important
as the ingredients themselves.
451
00:30:10,943 --> 00:30:14,845
The most exquisite chemistry
occurs at surfaces.
452
00:30:14,847 --> 00:30:19,349
Your body, your cells
are almost entirely surfaces
453
00:30:19,351 --> 00:30:20,918
on which chemistry takes place.
454
00:30:22,921 --> 00:30:25,155
So when we think
about the origin of life,
455
00:30:25,157 --> 00:30:29,827
the minerals sort of replace
surfaces you have in your body
456
00:30:29,829 --> 00:30:31,762
that do that chemical work.
457
00:30:36,034 --> 00:30:39,937
We are finally beginning
to understand the secret role
458
00:30:39,939 --> 00:30:42,873
minerals could have played
in life's origin.
459
00:30:47,378 --> 00:30:52,716
They provided some
of the ingredients and surfaces
460
00:30:52,718 --> 00:30:55,319
where important chemical
reactions take place.
461
00:31:07,365 --> 00:31:11,034
So when in Hazen's color phases
did all this happen?
462
00:31:17,041 --> 00:31:18,609
One of the best places
463
00:31:18,611 --> 00:31:21,778
to figure that out
is back in Australia,
464
00:31:21,780 --> 00:31:24,281
where Hazen and team
are now searching for signs
465
00:31:24,283 --> 00:31:25,983
of Earth's earliest life.
466
00:31:25,985 --> 00:31:28,585
I can't believe these rocks
467
00:31:28,587 --> 00:31:30,320
are three and a half billion
years old.
468
00:31:30,322 --> 00:31:32,789
They look like they formed
last week.
469
00:31:32,791 --> 00:31:36,393
Martin Van
Kranendonk leads the team
470
00:31:36,395 --> 00:31:39,529
to a very unusual
rock formation.
471
00:31:39,531 --> 00:31:43,066
You get your eye casting up,
you see them,
472
00:31:43,068 --> 00:31:44,902
all wrinkly, laminated, black.
473
00:31:44,904 --> 00:31:46,169
Yeah!
474
00:31:46,171 --> 00:31:47,838
And then if
you look a bit further back,
475
00:31:47,840 --> 00:31:49,740
you see a very large
domical structure.
476
00:31:49,742 --> 00:31:50,874
There's no obvious way
477
00:31:50,876 --> 00:31:53,243
that a chemical or physical
process would form that.
478
00:31:53,245 --> 00:31:55,805
Exactly.
479
00:31:56,547 --> 00:31:58,282
These strange shapes
480
00:31:58,284 --> 00:32:02,619
are fossilized remnants of life
called stromatolites,
481
00:32:02,621 --> 00:32:05,889
beautifully preserved
in these ancient rocks.
482
00:32:05,891 --> 00:32:08,992
This is an amazing spot.
483
00:32:08,994 --> 00:32:10,861
We're actually looking down
on the surface
484
00:32:10,863 --> 00:32:12,362
of the ancient Earth here.
485
00:32:12,364 --> 00:32:14,898
This was the seafloor
486
00:32:14,900 --> 00:32:17,200
3.4 billion years ago,
and I can see it in action.
487
00:32:17,202 --> 00:32:19,636
It's like a snap frozen
instant of time.
488
00:32:19,638 --> 00:32:25,242
But billions of
years have taken their toll.
489
00:32:28,880 --> 00:32:31,315
To really understand
stromatolites,
490
00:32:31,317 --> 00:32:35,886
we have to go
nearly 800 miles away.
491
00:32:35,888 --> 00:32:40,524
David Flannery, a geologist,
has come to Shark Bay
492
00:32:40,526 --> 00:32:45,929
in search of their
very distant descendants.
493
00:32:45,931 --> 00:32:53,370
Just below the surface, he finds
a series of round, black mounds:
494
00:32:53,372 --> 00:32:55,739
living stromatolites.
495
00:32:58,476 --> 00:33:01,478
Modern environments like these,
496
00:33:01,480 --> 00:33:03,847
they're very rare,
but they are really the key
497
00:33:03,849 --> 00:33:06,416
to interpreting what we see
in the very early fossil record.
498
00:33:08,786 --> 00:33:11,688
Without environments like these,
we wouldn't know
499
00:33:11,690 --> 00:33:13,590
how stromatolites were built.
500
00:33:13,592 --> 00:33:16,560
Stromatolites
are something like coral,
501
00:33:16,562 --> 00:33:21,531
a hard mineral structure that
has been built layer by layer.
502
00:33:21,533 --> 00:33:24,368
A closer look
reveals the builders.
503
00:33:26,604 --> 00:33:30,207
Microbes... single-celled life.
504
00:33:30,209 --> 00:33:32,109
The living
part of a stromatolite
505
00:33:32,111 --> 00:33:34,177
is only the surface
where the living microbial mat
506
00:33:34,179 --> 00:33:36,213
is building up the structure
layer by layer
507
00:33:36,215 --> 00:33:37,748
at less than a millimeter
per year.
508
00:33:37,750 --> 00:33:42,219
The top layer of
these stromatolites is alive,
509
00:33:42,221 --> 00:33:46,023
with microbes that perform
a remarkable trick.
510
00:33:46,025 --> 00:33:49,226
They capture minerals and sand
in the water
511
00:33:49,228 --> 00:33:52,763
and biologically cement them
layer by layer
512
00:33:52,765 --> 00:33:55,532
into the solid mounds.
513
00:33:59,003 --> 00:34:02,506
The results can be seen
in Shark Bay today
514
00:34:02,508 --> 00:34:06,843
and in the ancient fossils.
515
00:34:06,845 --> 00:34:09,346
Yeah, let me introduce you
to this outcrop.
516
00:34:09,348 --> 00:34:11,782
It's just spectacular
to be able to see this.
517
00:34:11,784 --> 00:34:15,585
And this outcrop is unique.
518
00:34:15,587 --> 00:34:18,722
Van Kranendonk has dated
this stromatolite
519
00:34:18,724 --> 00:34:22,926
to 3.5 billion years ago.
520
00:34:22,928 --> 00:34:27,564
This is the very oldest fossil
of life on Earth.
521
00:34:30,802 --> 00:34:33,036
We all want to
know where we come from,
522
00:34:33,038 --> 00:34:36,673
where life originated,
how long ago, in what form,
523
00:34:36,675 --> 00:34:39,242
and this is the oldest
direct evidence we have
524
00:34:39,244 --> 00:34:40,510
for life on Earth.
525
00:34:50,321 --> 00:34:52,055
But while stromatolites
526
00:34:52,057 --> 00:34:54,658
are the earliest fossil of life
we've found,
527
00:34:54,660 --> 00:34:59,663
that does not make them
the very first living thing.
528
00:34:59,665 --> 00:35:01,898
In fact, Van Kranendonk thinks
529
00:35:01,900 --> 00:35:04,835
that by the time
stromatolites appeared,
530
00:35:04,837 --> 00:35:08,071
life's party was already
in full swing.
531
00:35:08,073 --> 00:35:10,140
There are whole communities
and colonies
532
00:35:10,142 --> 00:35:13,143
that are building fantastically
complex structures,
533
00:35:13,145 --> 00:35:15,278
so we've actually come in
pretty late to the game.
534
00:35:15,280 --> 00:35:18,448
There is a lot that's gone on
before us to get to this stage,
535
00:35:18,450 --> 00:35:21,251
and it's this complexity
that tells us that life
536
00:35:21,253 --> 00:35:23,553
probably originated on Earth
very early.
537
00:35:29,994 --> 00:35:32,429
So if these very early fossils
538
00:35:32,431 --> 00:35:35,765
are too complex
to be the oldest form of life,
539
00:35:35,767 --> 00:35:38,702
is it possible
to find something earlier?
540
00:35:41,205 --> 00:35:45,108
That is what Ruth Blake,
a geologist at Yale University,
541
00:35:45,110 --> 00:35:47,177
is trying to figure out
542
00:35:47,179 --> 00:35:49,312
by turning
to the geological equivalent
543
00:35:49,314 --> 00:35:51,414
of a crime scene investigation.
544
00:35:52,850 --> 00:35:55,252
The crime has been committed.
545
00:35:55,254 --> 00:35:56,653
The criminal is gone,
546
00:35:56,655 --> 00:35:59,422
but they've left behind
some indicator
547
00:35:59,424 --> 00:36:01,158
because they've changed
their environment.
548
00:36:01,160 --> 00:36:05,295
Blake is analyzing some
of the oldest rocks on Earth,
549
00:36:05,297 --> 00:36:08,632
like this ground-up one
from Greenland
550
00:36:08,634 --> 00:36:10,634
that formed
at the bottom of an ocean.
551
00:36:12,336 --> 00:36:15,505
She is looking
for a chemical signature of life
552
00:36:15,507 --> 00:36:19,376
left by microbes,
including bacteria.
553
00:36:19,378 --> 00:36:23,213
What we start with is our ocean
trapped in a rock,
554
00:36:23,215 --> 00:36:26,449
and our bio-signature
is somewhere in here.
555
00:36:26,451 --> 00:36:27,784
We have to get it out.
556
00:36:27,786 --> 00:36:30,987
In the lab, Blake and her team
557
00:36:30,989 --> 00:36:33,890
dissolve these rocks
and extract molecules
558
00:36:33,892 --> 00:36:39,496
that are the chemical signature
left behind by ancient microbes.
559
00:36:42,300 --> 00:36:44,734
All life, like these microbes,
560
00:36:44,736 --> 00:36:47,637
consumes nutrients
to produce energy.
561
00:36:51,409 --> 00:36:55,111
The leftovers carry
the chemical footprint of life.
562
00:37:00,017 --> 00:37:04,254
Even today, we humans leave
behind chemical footprints.
563
00:37:08,125 --> 00:37:11,895
When we breathe, for
example, we're taking in oxygen
564
00:37:11,897 --> 00:37:15,999
and we're exhaling CO2
and water vapor.
565
00:37:16,001 --> 00:37:19,002
That water vapor interacts
with your environment.
566
00:37:22,039 --> 00:37:27,110
Amazingly, rocks
from 3.5 billion years ago,
567
00:37:27,112 --> 00:37:30,180
at the time of the stromatolites
in Australia,
568
00:37:30,182 --> 00:37:35,518
also carry a strong
chemical footprint of life.
569
00:37:35,520 --> 00:37:38,521
But when Blake analyzes
the Greenland rocks
570
00:37:38,523 --> 00:37:41,057
from 300 million years earlier,
571
00:37:41,059 --> 00:37:44,227
she makes a tantalizing
discovery.
572
00:37:44,229 --> 00:37:46,630
As far back as
3.5 billion years,
573
00:37:46,632 --> 00:37:48,632
we see a strong biological
signature.
574
00:37:48,634 --> 00:37:50,600
And the older rocks
are approaching that,
575
00:37:50,602 --> 00:37:52,836
but not quite there,
576
00:37:52,838 --> 00:37:55,338
but we do believe that
we see something there.
577
00:37:57,341 --> 00:38:01,444
Blake believes she has
detected the faint signal of life
578
00:38:01,446 --> 00:38:07,117
at 3.8 billion years ago,
only 700 million years
579
00:38:07,119 --> 00:38:11,554
after Earth was created,
early in the blue phase.
580
00:38:16,093 --> 00:38:18,695
There is still much
that we don't know
581
00:38:18,697 --> 00:38:23,233
about our early planet, but some
things are becoming clearer.
582
00:38:25,436 --> 00:38:28,204
If you could transport yourself
back in time
583
00:38:28,206 --> 00:38:31,641
about four billion years,
parts of our Earth
584
00:38:31,643 --> 00:38:33,276
might not look too different
585
00:38:33,278 --> 00:38:35,745
than this Southern
California beach,
586
00:38:35,747 --> 00:38:40,784
minus the surfers and poodle.
587
00:38:40,786 --> 00:38:45,255
You could stand on cliffs,
probably of granite,
588
00:38:45,257 --> 00:38:49,626
overlooking oceans
that were increasingly rich
589
00:38:49,628 --> 00:38:52,462
with minerals
and early microbial life.
590
00:38:52,464 --> 00:38:56,700
But you would quickly die
in a great deal of pain,
591
00:38:56,702 --> 00:38:59,536
suffocating
in the heavy atmosphere
592
00:38:59,538 --> 00:39:02,572
rich in nitrogen
and carbon dioxide,
593
00:39:02,574 --> 00:39:08,545
but lacking in life-giving
free oxygen.
594
00:39:12,416 --> 00:39:16,519
Then something truly astonishing
happened.
595
00:39:16,521 --> 00:39:18,521
Those harmless-looking microbes
596
00:39:18,523 --> 00:39:21,524
floating in the water
or on stromatolites
597
00:39:21,526 --> 00:39:26,463
started to change everything,
turning Earth red.
598
00:39:37,074 --> 00:39:40,744
Wow.
599
00:39:40,746 --> 00:39:44,314
Oh, my God, this is amazing!
600
00:39:44,316 --> 00:39:46,316
There aren't many places
on earth
601
00:39:46,318 --> 00:39:48,985
you can see something like this.
602
00:39:48,987 --> 00:39:52,422
A remnant of red
Earth can be seen in Australia
603
00:39:52,424 --> 00:39:57,160
at the Hamersley Basin
in Karijini National Park.
604
00:39:57,162 --> 00:40:00,230
In these rocks, Hazen finds
605
00:40:00,232 --> 00:40:03,166
a startling consequence
of early life
606
00:40:03,168 --> 00:40:07,737
as it began to thrive
and evolve.
607
00:40:07,739 --> 00:40:09,806
What we're seeing here
is one of the greatest tricks
608
00:40:09,808 --> 00:40:11,207
that life ever figured out.
609
00:40:11,209 --> 00:40:12,876
And that was
how to take sunlight
610
00:40:12,878 --> 00:40:15,779
and convert it to energy.
611
00:40:15,781 --> 00:40:19,883
Microbes, like those in
the stromatolites at Shark Bay,
612
00:40:19,885 --> 00:40:22,886
eventually began to live
off the sun's energy
613
00:40:22,888 --> 00:40:24,988
through photosynthesis.
614
00:40:24,990 --> 00:40:27,557
That led to a dramatic rise
615
00:40:27,559 --> 00:40:30,693
in a gas that Earth
was not accustomed to:
616
00:40:30,695 --> 00:40:33,930
oxygen.
617
00:40:33,932 --> 00:40:37,634
While to us, oxygen
is a life-giving benign gas,
618
00:40:37,636 --> 00:40:40,170
to a world not accustomed to it,
619
00:40:40,172 --> 00:40:43,740
oxygen created a dangerously
corrosive cocktail.
620
00:40:45,776 --> 00:40:51,247
The early oceans were filled
with dissolved iron.
621
00:40:51,249 --> 00:40:54,284
The new oxygen reacted
with that iron,
622
00:40:54,286 --> 00:40:56,886
and it began to rust
623
00:40:56,888 --> 00:41:00,023
and sank to the bottom
of the sea.
624
00:41:00,025 --> 00:41:02,559
These little microbes,
they're microscopic things,
625
00:41:02,561 --> 00:41:04,561
and you wouldn't think
they could do all that much.
626
00:41:04,563 --> 00:41:06,563
But when they produce
that oxygen
627
00:41:06,565 --> 00:41:09,466
and the oxygen reacts
with the iron in the oceans,
628
00:41:09,468 --> 00:41:11,835
you get the world's
largest deposits of iron...
629
00:41:11,837 --> 00:41:16,339
thousands of feet covering
hundreds of square miles.
630
00:41:16,341 --> 00:41:19,776
These formations
cover a vast area
631
00:41:19,778 --> 00:41:23,246
with trillions of tons
of iron ore.
632
00:41:24,482 --> 00:41:26,883
That is an unimaginable
consequence
633
00:41:26,885 --> 00:41:30,854
of trillions upon trillions
of microbes breathing.
634
00:41:33,457 --> 00:41:36,759
It's a fundamental change
in the chemistry of Earth.
635
00:41:36,761 --> 00:41:39,229
It's a consequence
of the rise of oxygen.
636
00:41:41,465 --> 00:41:44,667
The rise in
oxygen that rusted iron
637
00:41:44,669 --> 00:41:48,171
and sent Earth
into the red phase
638
00:41:48,173 --> 00:41:52,308
also created many new minerals.
639
00:41:52,310 --> 00:41:54,978
As a mineralogist,
when I look at Earth history,
640
00:41:54,980 --> 00:41:56,579
I see big transitions.
641
00:41:56,581 --> 00:41:58,281
I see the moon forming impact,
642
00:41:58,283 --> 00:42:01,317
I see the formation of oceans
and so forth.
643
00:42:01,319 --> 00:42:04,053
But nothing, nothing matches
644
00:42:04,055 --> 00:42:07,457
what life and oxygen did
to create new minerals.
645
00:42:09,560 --> 00:42:12,595
Some estimate that the
meteorites that formed Earth
646
00:42:12,597 --> 00:42:16,065
began with only
about 250 minerals.
647
00:42:22,773 --> 00:42:26,242
Today, there are more
than 5,000.
648
00:42:30,347 --> 00:42:33,349
Hazen believes that two-thirds
of all the minerals
649
00:42:33,351 --> 00:42:35,251
that now make up our planet
650
00:42:35,253 --> 00:42:38,288
were created by the introduction
of oxygen.
651
00:42:38,290 --> 00:42:44,360
And most of that was, in turn,
created by life.
652
00:42:44,362 --> 00:42:47,096
Amethyst.
653
00:42:47,098 --> 00:42:48,865
It's mindboggling.
654
00:42:48,867 --> 00:42:53,903
Rocks create life,
life creates rocks.
655
00:42:53,905 --> 00:42:57,006
They're intertwined in ways that
are just now coming into focus.
656
00:42:58,676 --> 00:43:02,345
But the road ahead
for life and for rocks
657
00:43:02,347 --> 00:43:04,647
would not be easy.
658
00:43:08,018 --> 00:43:10,853
As we head into the next phase
of Earth,
659
00:43:10,855 --> 00:43:13,256
new continents formed
and broke apart,
660
00:43:13,258 --> 00:43:17,360
which may have created dramatic
extremes in the climate.
661
00:43:17,362 --> 00:43:23,533
Earth plunged into an icy
freeze, turning it white.
662
00:43:27,871 --> 00:43:33,276
In these frozen conditions,
life was nearly wiped out.
663
00:43:35,379 --> 00:43:37,880
Fortunately, active volcanoes
664
00:43:37,882 --> 00:43:41,150
still poked through
the icy veneer,
665
00:43:41,152 --> 00:43:44,087
billowing out carbon dioxide,
or CO2.
666
00:43:48,659 --> 00:43:51,694
Like a thermal blanket
around our Earth,
667
00:43:51,696 --> 00:43:55,999
this kept heat in
and rescued life.
668
00:43:58,102 --> 00:44:00,703
Life all but shut down.
669
00:44:02,940 --> 00:44:04,607
And then the CO2 rises and rises
670
00:44:04,609 --> 00:44:06,676
and the greenhouse effect
gets hotter and hotter,
671
00:44:06,678 --> 00:44:08,945
and suddenly the planet melts.
672
00:44:10,648 --> 00:44:13,383
Cycles of these
snowball hothouse conditions
673
00:44:13,385 --> 00:44:16,686
had profound consequences
for life.
674
00:44:18,222 --> 00:44:19,756
One result was more oxygen,
675
00:44:19,758 --> 00:44:24,661
which eventually allowed
for bigger animals.
676
00:44:28,465 --> 00:44:32,468
The dramatic changes
during white Earth
677
00:44:32,470 --> 00:44:34,937
would bring us
to the present phase
678
00:44:34,939 --> 00:44:39,876
starting about
540 million years ago...
679
00:44:39,878 --> 00:44:42,445
a living planet
680
00:44:42,447 --> 00:44:47,016
filled with diverse plants
and spectacular creatures.
681
00:44:52,389 --> 00:44:55,491
But those life-forms
are pitted against each other
682
00:44:55,493 --> 00:44:58,594
in a survival of the fittest,
683
00:44:58,596 --> 00:45:00,263
and rocks can make
the difference
684
00:45:00,265 --> 00:45:03,533
between life and death.
685
00:45:06,470 --> 00:45:11,340
That struggle can be seen
back in Morocco,
686
00:45:11,342 --> 00:45:14,744
at the edge
of the Anti-Atlas Mountains.
687
00:45:16,613 --> 00:45:19,215
Here, Bob Hazen and Adam Aronson
688
00:45:19,217 --> 00:45:22,819
are looking for evidence
of an evolutionary trick
689
00:45:22,821 --> 00:45:26,422
that shows once again
how life and rocks
690
00:45:26,424 --> 00:45:29,959
took a big leap forward
together.
691
00:45:34,998 --> 00:45:37,567
520 million years ago,
692
00:45:37,569 --> 00:45:43,840
this valley was a shallow ocean
filled with new forms of life.
693
00:45:48,612 --> 00:45:52,849
This is when the diversity
of life on Earth exploded,
694
00:45:52,851 --> 00:45:58,087
all thriving in a living sea.
695
00:45:58,089 --> 00:46:01,791
So if you were a scuba diver
and you dove down to this reef,
696
00:46:01,793 --> 00:46:03,893
you'd see all kinds of life
swimming around,
697
00:46:03,895 --> 00:46:06,195
really amazing,
probably very colorful, too.
698
00:46:10,367 --> 00:46:14,904
There is one creature
that dominates this ancient reef
699
00:46:14,906 --> 00:46:18,141
that Hazen wants to find.
700
00:46:18,143 --> 00:46:19,041
Nothing there.
701
00:46:19,043 --> 00:46:20,376
Nothing there.
702
00:46:22,012 --> 00:46:24,580
And nothing there.
703
00:46:24,582 --> 00:46:28,718
Fossil hunting is a
game of luck and persistence,
704
00:46:28,720 --> 00:46:33,322
but it doesn't take long for
Hazen to strike geologic gold.
705
00:46:33,324 --> 00:46:35,324
Whoa!
706
00:46:35,326 --> 00:46:38,528
Jeez, look at that.
707
00:46:38,530 --> 00:46:40,396
That is amazing.
708
00:46:40,398 --> 00:46:42,198
The trilobite.
709
00:46:42,200 --> 00:46:44,400
Hey, look, there's
another head there,
710
00:46:44,402 --> 00:46:46,536
and the head there, two more.
711
00:46:46,538 --> 00:46:48,271
Boy, this is rich rock.
712
00:46:48,273 --> 00:46:50,473
The trilobites here are amazing
713
00:46:50,475 --> 00:46:53,476
because these are the oldest
animals that you can find
714
00:46:53,478 --> 00:46:56,379
that are preserved as
what you think of as a fossil
715
00:46:56,381 --> 00:46:57,980
that you can hold in your hand.
716
00:47:00,250 --> 00:47:03,352
Some trilobites
were like horseshoe crabs
717
00:47:03,354 --> 00:47:06,856
scurrying about the ocean floor.
718
00:47:06,858 --> 00:47:09,792
The reason they are found
as fossils today
719
00:47:09,794 --> 00:47:11,694
is because they developed
720
00:47:11,696 --> 00:47:14,964
an astonishing
evolutionary trick...
721
00:47:14,966 --> 00:47:16,899
shells.
722
00:47:21,471 --> 00:47:24,807
Trilobite shells were made
of calcium carbonate,
723
00:47:24,809 --> 00:47:27,376
the same mineral
found in limestone,
724
00:47:27,378 --> 00:47:31,380
the rock that built
the pyramids.
725
00:47:31,382 --> 00:47:35,284
In effect, life itself
began to make rocks
726
00:47:35,286 --> 00:47:37,286
for its own advantage.
727
00:47:37,288 --> 00:47:41,824
And the idea went viral.
728
00:47:43,660 --> 00:47:46,729
If you had a shell, you're
going to survive a lot longer
729
00:47:46,731 --> 00:47:49,091
than that soft-bodied animal
that doesn't have a shell.
730
00:47:51,902 --> 00:47:54,303
The trilobite had an advantage.
731
00:47:54,305 --> 00:47:57,173
It's survival of the fittest.
732
00:47:57,175 --> 00:47:59,008
The trilobite's mineral shell
733
00:47:59,010 --> 00:48:02,545
heralded a new phase
in the evolution of animals,
734
00:48:02,547 --> 00:48:06,082
catapulting our planet
into the present stage,
735
00:48:06,084 --> 00:48:10,253
green earth, one that is rich
in diverse life.
736
00:48:16,026 --> 00:48:21,631
From humans back to trilobites,
we owe our evolution
737
00:48:21,633 --> 00:48:25,468
and survival
to the world of minerals...
738
00:48:25,470 --> 00:48:30,006
with shells, then eventually
with bones and teeth
739
00:48:30,008 --> 00:48:35,711
that paved the way for life
to grow taller and stronger.
740
00:48:35,713 --> 00:48:39,482
All are evidence of life
co-opting minerals
741
00:48:39,484 --> 00:48:44,287
for its own evolutionary
advantage.
742
00:48:44,289 --> 00:48:47,590
We've thought for centuries,
743
00:48:47,592 --> 00:48:49,725
"Animals, minerals, they're
separate kingdoms, right?"
744
00:48:49,727 --> 00:48:51,661
But it turns out they overlap,
745
00:48:51,663 --> 00:48:53,696
they're intertwined,
they co-evolved.
746
00:48:53,698 --> 00:48:55,731
That life makes minerals,
747
00:48:55,733 --> 00:48:58,134
and minerals have led
to new life-forms.
748
00:48:59,770 --> 00:49:01,671
You can't separate the two.
749
00:49:04,875 --> 00:49:07,543
Life and rocks
are totally intertwined
750
00:49:07,545 --> 00:49:09,625
through billions of years
of Earth history.
751
00:49:18,922 --> 00:49:21,490
One of Hazen's favorite places
752
00:49:21,492 --> 00:49:24,093
to see this intertwined history
of life and minerals
753
00:49:24,095 --> 00:49:29,732
is at the Calvert Cliffs
along the Chesapeake Bay.
754
00:49:29,734 --> 00:49:31,167
He and his wife Margee
755
00:49:31,169 --> 00:49:33,302
pick up shells and shark teeth
from a time
756
00:49:33,304 --> 00:49:38,007
18 million years ago when
massive sea creatures swam here.
757
00:49:38,009 --> 00:49:39,642
That's nice, isn't that pretty?
758
00:49:39,644 --> 00:49:40,943
You find teeth
759
00:49:40,945 --> 00:49:46,282
along the beach that are five,
six, sometimes seven inches long
760
00:49:46,284 --> 00:49:50,286
with serrated edges...
razor-sharp teeth.
761
00:49:53,490 --> 00:49:56,692
These were immense creatures,
762
00:49:56,694 --> 00:50:00,696
sharks that may have been
50 or 60 feet long.
763
00:50:03,834 --> 00:50:06,335
These giants of the sea
764
00:50:06,337 --> 00:50:09,405
would have dwarfed today's
great whites.
765
00:50:09,407 --> 00:50:13,943
And it was the bones and teeth
created with minerals
766
00:50:13,945 --> 00:50:19,382
that enabled them to grow
so large and powerful.
767
00:50:19,384 --> 00:50:22,084
They were feeding on whales.
768
00:50:22,086 --> 00:50:25,221
Dolphins would have been
a snack.
769
00:50:25,223 --> 00:50:30,159
They are just one small
part of a story of co-evolution
770
00:50:30,161 --> 00:50:33,329
stretching back
to Earth's beginning.
771
00:50:37,601 --> 00:50:41,003
The life, the rocks, it's
all part of the same story.
772
00:50:44,007 --> 00:50:47,343
Step by step,
throughout Earth's evolution,
773
00:50:47,345 --> 00:50:51,947
minerals and life
have sparked chemical reactions
774
00:50:51,949 --> 00:50:55,751
that sculpted the planet
into what we see today
775
00:50:55,753 --> 00:50:59,255
and helped create
the life we know.
776
00:50:59,257 --> 00:51:03,726
At this place, you get a
sense of the immensity of time
777
00:51:03,728 --> 00:51:06,896
and the constancy of change.
778
00:51:06,898 --> 00:51:11,901
Life is creating
and sculpting our surroundings
779
00:51:11,903 --> 00:51:14,537
in ways that are
quite wonderful.
780
00:51:14,539 --> 00:51:19,809
And just to recognize the power
of life to transform a planet.
781
00:51:24,549 --> 00:51:27,183
Of course, humans transform
the planet too.
782
00:51:27,185 --> 00:51:30,119
We build cities, we build roads,
783
00:51:30,121 --> 00:51:31,821
we change the composition
of the atmosphere
784
00:51:31,823 --> 00:51:33,903
and change the composition
of the oceans.
785
00:51:35,959 --> 00:51:39,328
There are going to be
global changes.
786
00:51:39,330 --> 00:51:44,166
These changes whose
consequences are now beginning to unfold
787
00:51:44,168 --> 00:51:48,471
are the latest chapter
in Earth's epic story...
788
00:51:48,473 --> 00:51:50,773
a story that began
789
00:51:50,775 --> 00:51:54,176
four and a half billion
years ago with a rock.
790
00:52:05,889 --> 00:52:08,824
The exploration continues
online,
791
00:52:23,707 --> 00:52:26,175
This NOVA program
is available on DVD.
792
00:52:26,177 --> 00:52:31,113
To order, visit shopPBS.org,
or call 1-800-PLAY-PBS.
793
00:52:31,115 --> 00:52:33,482
NOVA is also available
for download on iTunes.