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NARRATOR:
They're dazzling.
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00:00:04,171 --> 00:00:05,371
Priceless.
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00:00:06,539 --> 00:00:08,874
At times, even glowing.
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00:00:10,710 --> 00:00:16,081
ROBERT HAZEN: 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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NARRATOR: And they're the building
blocks of modern civilization.
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HAZEN: We wouldn't have televisions,
we wouldn't have automobiles,
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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
NARRATOR:
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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HAZEN: 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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NARRATOR:
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,
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NOVA goes around the world
and back in time
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to investigate the origin
and evolution of life.
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You look at a rock and you
think, "Ah well, nothing,"
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but this holds
the signature of life.
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NARRATOR:
From its first spark...
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JEFF BADA: People were saying they
made Frankenstein in a test tube.
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NARRATOR: to the
survival of the fittest.
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These were immense creatures...
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sharks that may have been
50 or 60 feet.
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NARRATOR: Was it the secret
link between rocks and life
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that made the difference?
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"Life's Rocky Start,"
right now on NOVA.
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Major fuNARRATOR: NOVA is
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?
35
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How did Earth go
from a lifeless, molten rock
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to a living planet
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full of diverse
and spectacular creatures?
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It's a question that has
long perplexed scientists.
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00:02:55,375 --> 00:02:59,745
Now Robert Hazen, a geologist,
is trying to show
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00:02:59,747 --> 00:03:01,780
we are missing
an essential ingredient
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00:03:01,782 --> 00:03:03,949
in the recipe for life...
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HAZEN:
Look at that vein of calcite.
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NARRATOR:
Rocks.
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HAZEN: Nothing seems more
lifeless than a rock.
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It's inanimate, it's the
antithesis of a living thing.
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But we are beginning
to realize that rocks played
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an absolutely fundamental role
in the origin of life.
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Aw, yeah.
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NARRATOR: Hazen is out to
expose a secret relationship
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between rocks and life
that helped drive
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both the origin of life
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and its evolution
into complex creatures.
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HAZEN: This is a very new
set of understandings
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and the more we look,
the more we see
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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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NARRATOR: As a geologist, it's no
surprise that Hazen is searching
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for answers written in stone.
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But is he right?
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Are rocks the missing
spark of life?
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The history of Earth
is unimaginably long.
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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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00:04:23,364 --> 00:04:24,496
(phone ringing)
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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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Dinosaurs were still
roaming Earth
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about 20 minutes before that.
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But the creation of our planet
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occurred more than
23 hours earlier...
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two cycles on this clock...
or 4.5 billion years ago.
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Comprehending Earth's vast
history is a formidable task.
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HAZEN: There's four and a
half billion years of change.
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But you can divide it
into half a dozen ways
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of describing Earth
through time.
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NARRATOR: Bob Hazen has come up
with another way to visualize.
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Earth's long history
that reveals
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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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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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to before there was any life
at all.
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Stage one was the creation
of black Earth.
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(indistinct chatter)
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Back in Morocco,
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Hazen and Adam Aronson,
a meteorite expert,
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seek out a small rock from
the beginning of our cosmos.
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Wow, look at this pile here.
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NARRATOR: These are meteorites,
rocks that have fallen from space.
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This is Tamdackht.
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This is the one that
fell 20 kilometers
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up the road from here.
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People saw it fall.
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NARRATOR: A recent meteorite fall
in Siberia was captured in videos
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that have shown up on YouTube.
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Other space rocks have ended up
for sale here in Morocco.
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So you'd buy this
without doing tests?
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I would drop the cash right now
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if he would give me
a good price.
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(speaking Arabic)
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NARRATOR: Meteorites here can sell
for tens of thousands of dollars.
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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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HAZEN: 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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NARRATOR: 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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with temperatures
in the thousands of degrees.
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But in the cold vacuum of space
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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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it covered Earth with its first
rock, called basalt.
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And it was black.
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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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HAZEN: Every rock, you slice
it open, you look inside,
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there's something special.
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NARRATOR: Rocks are made up mostly
of minerals, which are crystals
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like quartz or diamonds.
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00:09:24,998 --> 00:09:29,401
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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becomes a patchwork
of colorful minerals.
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It's sort of like a fruitcake.
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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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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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NARRATOR: What makes them special
is not only their beauty.
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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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That is why they're essential
in our modern world
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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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Extract the element molybdenum
from the mineral molybdenite
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to make steel harder,
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or add a pinch of cobalt
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and your iPhone battery
will last longer.
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HAZEN: Minerals are the fundamental
building block of societies.
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We wouldn't have televisions,
we wouldn't have automobiles,
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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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NARRATOR: 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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But the kind of rock that makes
up these dramatic cliffs
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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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Granite became the foundation
of our continents,
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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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that makes Yosemite
so picturesque.
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But the stage is set
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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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That's because water
is such a great solvent.
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All these different kinds
of molecules
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can be floating around the water
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and then they have the potential
to interact together.
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The starting point is the water.
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NARRATOR: 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
HAZEN: 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
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00:13:41,421 --> 00:13:42,720
is how quickly it happened.
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The timing was a big mystery.
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NARRATOR:
The Pilbara in Western Australia
200
00:13:58,505 --> 00:14:01,606
is one of the oldest places
on Earth,
201
00:14:01,608 --> 00:14:04,576
and so one of the best places
to solve the mystery
202
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
204
00:14:13,186 --> 00:14:15,220
including Martin Van Kranendonk,
205
00:14:15,222 --> 00:14:17,555
from the University
of New South Wales
206
00:14:17,557 --> 00:14:20,425
and John Valley
of the University of Wisconsin.
207
00:14:25,431 --> 00:14:28,199
Valley is collecting rocks
that could hold clues
208
00:14:28,201 --> 00:14:30,902
to when water first appeared.
209
00:14:32,872 --> 00:14:34,339
We can get zircons
and other minerals
210
00:14:34,341 --> 00:14:36,908
that date all the way back
to 4.4 billion years old.
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00:14:36,910 --> 00:14:38,190
Hopefully.
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00:14:39,478 --> 00:14:42,247
NARRATOR: Some rocks here
contain sand-sized grains
213
00:14:42,249 --> 00:14:45,750
that weathered from
even older rocks.
214
00:14:45,752 --> 00:14:49,554
One in a million... literally...
is a crystal called zircon,
215
00:14:49,556 --> 00:14:52,490
one of the longest-lasting
materials in nature.
216
00:14:56,662 --> 00:14:59,597
Zircon is a popular gemstone,
217
00:14:59,599 --> 00:15:03,034
but the microscopic zircon
found here
218
00:15:03,036 --> 00:15:04,402
is even more precious.
219
00:15:04,404 --> 00:15:07,171
HAZEN: Zircon crystals
are especially amazing.
220
00:15:07,173 --> 00:15:09,374
Gemstone zircons of course
are valued,
221
00:15:09,376 --> 00:15:11,109
but these tiny ones
that geologists value
222
00:15:11,111 --> 00:15:12,443
are microscopic.
223
00:15:12,445 --> 00:15:15,313
They make a lousy ring, but
they tell an incredible story.
224
00:15:16,615 --> 00:15:19,450
NARRATOR:
To tell that story,
225
00:15:19,452 --> 00:15:21,953
John Valley must first find
the tiny crystals...
226
00:15:21,955 --> 00:15:25,423
the ultimate
needle in a haystack.
227
00:15:25,425 --> 00:15:28,192
VALLEY: If you want to find
a needle in a haystack,
228
00:15:28,194 --> 00:15:30,528
the first thing you do
is you burn down the haystack.
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00:15:30,530 --> 00:15:35,133
Then you'd sift through the ash
to look for the needle.
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00:15:35,135 --> 00:15:39,470
NARRATOR: Rocks are pulverized
into sand-sized grains
231
00:15:39,472 --> 00:15:41,406
and sorted by weight
in a machine
232
00:15:41,408 --> 00:15:43,374
developed to pan for gold.
233
00:15:45,244 --> 00:15:49,914
The gold that Valley is looking
for are heavy zircon crystals,
234
00:15:49,916 --> 00:15:53,351
which get channeled
into different tracks.
235
00:15:56,455 --> 00:16:01,192
Then, grain by grain,
with a very steady hand,
236
00:16:01,194 --> 00:16:05,563
thousands of small crystals
are sorted and analyzed.
237
00:16:07,566 --> 00:16:09,867
The chemical structure
of a zircon crystal
238
00:16:09,869 --> 00:16:12,570
holds evidence of both
the environment
239
00:16:12,572 --> 00:16:15,907
and the age when it formed.
240
00:16:21,180 --> 00:16:24,882
Some of these tiny crystals
go very far back,
241
00:16:24,884 --> 00:16:28,453
just over 100 million years
after Earth formed.
242
00:16:30,723 --> 00:16:34,726
They are the oldest pieces
of Earth ever discovered,
243
00:16:34,728 --> 00:16:39,564
so they could shed light on what
our young planet looked like.
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00:16:46,605 --> 00:16:49,507
VALLEY (laughing):
It's totally amazing to me.
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00:16:49,509 --> 00:16:52,110
To hold this grain of sand
in the palm of your hand
246
00:16:52,112 --> 00:16:55,380
is literally to see
back through time.
247
00:16:55,382 --> 00:16:57,515
It is a time machine.
248
00:17:02,187 --> 00:17:05,123
NARRATOR: Valley expected
these crystal time machines
249
00:17:05,125 --> 00:17:08,626
would confirm the long-held view
that the young Earth
250
00:17:08,628 --> 00:17:10,695
was covered in molten lava,
251
00:17:10,697 --> 00:17:14,198
still cooling after
its violent formation.
252
00:17:17,870 --> 00:17:21,806
I think the zircon on the left
looks very promising.
253
00:17:21,808 --> 00:17:25,143
NARRATOR: So what he
discovered was shocking
254
00:17:25,145 --> 00:17:30,081
because this type of zircon,
created 4.3 billion years ago,
255
00:17:30,083 --> 00:17:34,185
could only have formed
in the presence of liquid water.
256
00:17:36,321 --> 00:17:38,456
But how could there be water
257
00:17:38,458 --> 00:17:41,392
if Earth was still hot
and hell-like?
258
00:17:44,530 --> 00:17:47,765
VALLEY: The implications were
that the early Earth had water.
259
00:17:47,767 --> 00:17:50,701
It was cooler and it was wet.
260
00:17:53,172 --> 00:17:55,039
It's starting to look very much
more familiar.
261
00:17:55,041 --> 00:17:59,277
NARRATOR: And if water is a
key starting point for life,
262
00:17:59,279 --> 00:18:02,213
could there be life
that early, too?
263
00:18:07,052 --> 00:18:09,687
VALLEY: The science of the zircon
is telling us that the Earth
264
00:18:09,689 --> 00:18:15,760
for a very, very long time
was a habitable environment.
265
00:18:15,762 --> 00:18:17,795
Not necessarily
that there was life then.
266
00:18:17,797 --> 00:18:19,397
We don't know that yet.
267
00:18:19,399 --> 00:18:21,999
But there's no reason why
there couldn't have been life
268
00:18:22,001 --> 00:18:24,302
as early as 4.3 billion
years ago.
269
00:18:24,304 --> 00:18:29,273
NARRATOR: So if life were possible
that early, it begs the question,
270
00:18:29,275 --> 00:18:31,542
how did life begin?
271
00:18:36,115 --> 00:18:38,983
In 1871, Charles Darwin
272
00:18:38,985 --> 00:18:40,952
speculated in a letter
to a friend
273
00:18:40,954 --> 00:18:44,822
th warm little pond
might be life's birthplace.
274
00:18:52,931 --> 00:18:56,801
A warm soup of chemicals
bathed by energy from the sun
275
00:18:56,803 --> 00:18:59,837
would have been, well,
comfortable for molecules
276
00:18:59,839 --> 00:19:03,174
to come together in new ways
and create life.
277
00:19:06,678 --> 00:19:09,780
Darwin was way, way
ahead of his time.
278
00:19:09,782 --> 00:19:14,318
A nice little warm soup
is going to get you a long way.
279
00:19:17,189 --> 00:19:20,358
NARRATOR: Jeff Bada of the Scripps
Institution of Oceanography
280
00:19:20,360 --> 00:19:23,060
in San Diego,
has spent his career
281
00:19:23,062 --> 00:19:27,131
working to understand the early
Earth's soup of chemicals.
282
00:19:29,635 --> 00:19:31,836
He began under the direction
of perhaps
283
00:19:31,838 --> 00:19:36,140
the most famous scientist
in origin of life research...
284
00:19:36,142 --> 00:19:39,277
Stanley Miller.
285
00:19:39,279 --> 00:19:42,346
HAZEN: There are in the history
of science turning points
286
00:19:42,348 --> 00:19:45,449
where we suddenly see
the history of Earth
287
00:19:45,451 --> 00:19:47,585
and life differently.
288
00:19:47,587 --> 00:19:49,620
In the early 1950s,
Stanley Miller,
289
00:19:49,622 --> 00:19:52,223
the eager graduate student,
and Harold Urey,
290
00:19:52,225 --> 00:19:55,393
the Nobel Prize winning mentor
at the University of Chicago,
291
00:19:55,395 --> 00:19:57,895
conducted this
astonishing experiment
292
00:19:57,897 --> 00:20:01,866
where they made
an early Earth environment.
293
00:20:01,868 --> 00:20:06,671
BADA: It looks like this sort of
a Frankenstein-type apparatus.
294
00:20:06,673 --> 00:20:09,040
But actually, it's a very
carefully thought out design.
295
00:20:10,876 --> 00:20:14,345
NARRATOR: Bada sets up a modern-day
test of the 1950s experiment
296
00:20:14,347 --> 00:20:18,349
on Miller's original
lab equipment.
297
00:20:19,484 --> 00:20:22,386
BADA:
One flask contains water.
298
00:20:22,388 --> 00:20:25,189
That's to simulate the ocean.
299
00:20:25,191 --> 00:20:28,125
The other flask
has just got the gases in it.
300
00:20:28,127 --> 00:20:29,927
So this is the atmosphere.
301
00:20:29,929 --> 00:20:32,096
(gas hissing)
302
00:20:34,633 --> 00:20:37,301
NARRATOR:
Just as it does in nature,
303
00:20:37,303 --> 00:20:41,539
water from the ocean evaporates
and rises into the atmosphere,
304
00:20:41,541 --> 00:20:44,475
where it condenses
and returns to the ocean.
305
00:20:47,679 --> 00:20:50,314
Miller simulated what he
believed to be the atmosphere
306
00:20:50,316 --> 00:20:55,753
of early Earth with different
gases like ammonia and methane.
307
00:20:58,890 --> 00:21:01,826
Then,
he added a spark of genius.
308
00:21:04,162 --> 00:21:07,431
(electricity humming)
309
00:21:07,433 --> 00:21:12,336
BADA: Miller and Urey decided to
use a spark to simulate lightning
310
00:21:12,338 --> 00:21:14,305
because that's such
a ubiquitous process
311
00:21:14,307 --> 00:21:16,207
in the atmosphere of the earth.
312
00:21:17,909 --> 00:21:19,443
HAZEN:
That was the real inspiration,
313
00:21:19,445 --> 00:21:20,478
these little electric sparks
314
00:21:20,480 --> 00:21:22,440
they acted like simulated
lightning.
315
00:21:23,515 --> 00:21:25,783
NARRATOR: The energy from
the spark of lightning
316
00:21:25,785 --> 00:21:28,386
breaks down
the gas and water molecules
317
00:21:28,388 --> 00:21:31,322
so they can undergo
further chemical reactions.
318
00:21:37,429 --> 00:21:41,666
HAZEN: To their astonishment, when
they turned this apparatus on
319
00:21:41,668 --> 00:21:43,801
after only a couple of days
you started seeing
320
00:21:43,803 --> 00:21:46,103
this pink color developing.
321
00:21:48,373 --> 00:21:52,143
And then a few more days,
black, oily goo
322
00:21:52,145 --> 00:21:54,779
is forming around
the electrodes.
323
00:21:58,050 --> 00:22:03,120
NARRATOR: The electrodes get
covered with new substances,
324
00:22:03,122 --> 00:22:07,425
organic compounds
usually associated with life.
325
00:22:10,662 --> 00:22:12,496
And it wasn't just
any organic compound,
326
00:22:12,498 --> 00:22:15,666
it was amino acids
that make proteins.
327
00:22:15,668 --> 00:22:18,602
The ingredients for life.
328
00:22:21,640 --> 00:22:24,575
NARRATOR: Amino acids are the
building blocks of life.
329
00:22:27,579 --> 00:22:29,880
They form proteins,
330
00:22:29,882 --> 00:22:33,084
which are the key component
of muscles and other tissues.
331
00:22:35,487 --> 00:22:36,687
People thought, "Aha!"
332
00:22:36,689 --> 00:22:39,457
This is a key step
in the origin of life."
333
00:22:39,459 --> 00:22:42,893
And you really believe that
you can bring life to the dead?
334
00:22:42,895 --> 00:22:45,963
That body is not dead.
335
00:22:45,965 --> 00:22:48,432
It has never lived.
336
00:22:48,434 --> 00:22:50,368
I created it.
337
00:22:52,304 --> 00:22:56,707
NARRATOR: The experiment raised the
fear that a Frankenstein creation,
338
00:22:56,709 --> 00:22:59,844
like in this classic film,
was just around the corner.
339
00:22:59,846 --> 00:23:01,545
It's moving.
340
00:23:01,547 --> 00:23:06,317
BADA: People were saying they
made Frankenstein in a test tube.
341
00:23:06,319 --> 00:23:08,085
It's alive!
342
00:23:08,087 --> 00:23:11,489
Now I know what it feels
like to be God!
343
00:23:14,126 --> 00:23:18,329
NARRATOR: Had Miller and Urey
cooked up life in a test tube?
344
00:23:18,331 --> 00:23:20,831
BADA: Many of the news
headlines were saying,
345
00:23:20,833 --> 00:23:22,633
"Life created
in the laboratory!"
346
00:23:22,635 --> 00:23:25,002
"Life created in a test tube!"
347
00:23:25,004 --> 00:23:26,404
Well, of course that was wrong.
348
00:23:26,406 --> 00:23:30,174
The real news
was he'd made these compounds
349
00:23:30,176 --> 00:23:32,109
that are part of life.
350
00:23:35,347 --> 00:23:38,949
NARRATOR: By creating amino
acids, the Miller-Urey experiment
351
00:23:38,951 --> 00:23:42,186
seemed to confirm
that Darwin was right...
352
00:23:42,188 --> 00:23:46,090
life must have begun
in a shallow pond.
353
00:23:54,199 --> 00:23:58,035
But then, 24 years later,
a shocking discovery
354
00:23:58,037 --> 00:23:59,970
radically challenged that idea.
355
00:24:01,173 --> 00:24:04,141
On the dark ocean floor,
356
00:24:04,143 --> 00:24:06,811
more than a mile
below the surface,
357
00:24:06,813 --> 00:24:11,715
explorers found hot,
mineral-rich hydrothermal vents,
358
00:24:11,717 --> 00:24:13,651
like underwater volcanoes.
359
00:24:15,353 --> 00:24:18,722
Temperatures reached
more than 600 degrees,
360
00:24:18,724 --> 00:24:23,794
and yet here life was thriving,
not off the sun's energy,
361
00:24:23,796 --> 00:24:28,265
but through chemical energy
from the vents.
362
00:24:28,267 --> 00:24:32,136
No one realized that life
could thrive without sunlight.
363
00:24:32,138 --> 00:24:35,306
Here you have
this extreme temperature
364
00:24:35,308 --> 00:24:36,507
and this extreme pressure,
365
00:24:36,509 --> 00:24:38,442
and so you have to shift
your perceptions
366
00:24:38,444 --> 00:24:40,945
and realize that just because
it's extreme to us
367
00:24:40,947 --> 00:24:43,380
doesn't mean it's extreme
to those microbes.
368
00:24:45,016 --> 00:24:48,052
NARRATOR: Instead of
the warm shallow pond,
369
00:24:48,054 --> 00:24:53,324
could this dark and unlikely
environment be where life began?
370
00:24:53,326 --> 00:24:57,528
To answer that,
Hazen decided to try creating
371
00:24:57,530 --> 00:25:02,566
life's building blocks in the
conditions of a deep sea vent.
372
00:25:02,568 --> 00:25:03,801
HAZEN:
My first thought was gee,
373
00:25:03,803 --> 00:25:05,769
why don't we do
a Miller-Urey experiment,
374
00:25:05,771 --> 00:25:07,931
but do it at high temperature,
high pressures?
375
00:25:09,374 --> 00:25:11,075
NARRATOR:
Hazen's laboratory
376
00:25:11,077 --> 00:25:12,676
is at the Carnegie Institution
for Science,
377
00:25:12,678 --> 00:25:15,513
which is famous for experiments
that simulate
378
00:25:15,515 --> 00:25:17,882
the intense pressures
deep inside Earth
379
00:25:17,884 --> 00:25:22,520
with powerful tools
called pressure bombs.
380
00:25:22,522 --> 00:25:23,854
They're called bombs
for a reason...
381
00:25:23,856 --> 00:25:25,422
because things can explode.
382
00:25:29,861 --> 00:25:32,796
(loud explosion)
383
00:25:36,568 --> 00:25:39,303
NARRATOR: Hazen and his colleagues
adapted these pressure bombs
384
00:25:39,305 --> 00:25:43,407
to model the environment
of the deep sea vents
385
00:25:43,409 --> 00:25:44,975
in a small gold tube.
386
00:25:47,379 --> 00:25:50,381
What they discovered
came as a surprise.
387
00:25:51,883 --> 00:25:53,317
Nothing happened.
388
00:25:54,753 --> 00:25:57,655
HAZEN:
You can take basic gases...
389
00:25:57,657 --> 00:26:03,961
nitrogen, CO2,
maybe some sulfur compounds.
390
00:26:03,963 --> 00:26:05,829
You can mix those,
you can put them in a gold tube,
391
00:26:05,831 --> 00:26:06,864
you can heat them up.
392
00:26:06,866 --> 00:26:08,986
You don't get much
that's very interesting.
393
00:26:11,503 --> 00:26:15,906
NARRATOR: Simply squeezing and heating
the ingredients had little effect.
394
00:26:17,175 --> 00:26:19,810
Hazen was missing the spark,
395
00:26:19,812 --> 00:26:21,979
like in the Miller-Urey
experiment,
396
00:26:21,981 --> 00:26:25,449
the thing that kickstarts
the chemistry.
397
00:26:30,188 --> 00:26:33,148
HAZEN: So we said, "What's
going on, what's different?"
398
00:26:34,359 --> 00:26:35,693
Well, look at the natural
environment,
399
00:26:35,695 --> 00:26:37,194
there's all these rocks
and minerals.
400
00:26:37,196 --> 00:26:39,316
Let's try putting
some rocks and minerals in.
401
00:26:40,065 --> 00:26:42,900
NARRATOR: They recreate
the early Earth cocktail,
402
00:26:42,902 --> 00:26:48,205
but this time grind in powder
from rocks and minerals.
403
00:26:49,975 --> 00:26:53,944
But will Hazen's beloved rocks
do the trick?
404
00:26:53,946 --> 00:26:56,580
(air hissing)
405
00:26:56,582 --> 00:26:58,082
They run the experiment again.
406
00:27:01,019 --> 00:27:06,323
And this time the atoms reform
into new organic molecules...
407
00:27:06,325 --> 00:27:08,659
including amino acids.
408
00:27:10,195 --> 00:27:12,463
HAZEN: As soon as you put
powdered rocks and minerals
409
00:27:12,465 --> 00:27:14,431
into the gold capsules,
410
00:27:14,433 --> 00:27:17,301
then all sorts of really amazing
things started happening.
411
00:27:17,303 --> 00:27:19,103
You made organic molecules,
412
00:27:19,105 --> 00:27:23,240
they became more stable,
they lasted longer,
413
00:27:23,242 --> 00:27:25,109
and it really pointed us
in the direction of saying,
414
00:27:25,111 --> 00:27:27,231
"Aha, this has got to be
part of the story."
415
00:27:28,380 --> 00:27:30,214
NARRATOR:
While scientists still argue
416
00:27:30,216 --> 00:27:34,551
if life began in shallow ponds
or deep sea vents,
417
00:27:34,553 --> 00:27:36,353
both sides wonder,
418
00:27:36,355 --> 00:27:40,524
what part of the story did rocks
and minerals play?
419
00:27:49,134 --> 00:27:53,303
One possible answer
may be found in London,
420
00:27:53,305 --> 00:27:57,608
in the powerful properties
of mud.
421
00:27:57,610 --> 00:27:59,943
Most people will be familiar
with the material.
422
00:27:59,945 --> 00:28:02,413
It's very gungy.
423
00:28:02,415 --> 00:28:04,415
That's perhaps a British word
424
00:28:04,417 --> 00:28:06,984
that refers to something
which is soft
425
00:28:06,986 --> 00:28:09,053
and unpleasant, generally.
426
00:28:09,055 --> 00:28:11,922
NARRATOR: Peter Coveney of
University College London
427
00:28:11,924 --> 00:28:16,293
is busy playing in mud...
at a very sophisticated level.
428
00:28:18,163 --> 00:28:21,565
He has created
powerful computer simulations
429
00:28:21,567 --> 00:28:24,368
that can track
the precise movement
430
00:28:24,370 --> 00:28:27,805
of up to ten million atoms.
431
00:28:29,407 --> 00:28:31,742
Mud can contain clay,
432
00:28:31,744 --> 00:28:36,346
which is made up of some
of Earth's most common minerals.
433
00:28:36,348 --> 00:28:39,149
What makes it so gungy
434
00:28:39,151 --> 00:28:42,352
and perhaps essential
in the origin of life
435
00:28:42,354 --> 00:28:46,657
can be seen deep
in its atomic makeup.
436
00:28:46,659 --> 00:28:50,594
COVENEY: You can see here the
basic structure of any clay.
437
00:28:50,596 --> 00:28:52,963
It's comprised of a large number
of stacked sheets
438
00:28:52,965 --> 00:28:54,331
like a deck of cards.
439
00:28:56,201 --> 00:28:59,470
NARRATOR: Sheets of clay
have spaces between them
440
00:28:59,472 --> 00:29:03,841
that fill up with water
and other molecules.
441
00:29:08,513 --> 00:29:12,049
These extensive surface areas
can help create
442
00:29:12,051 --> 00:29:17,888
more complex molecules,
potentially even RNA,
443
00:29:17,890 --> 00:29:20,824
an essential part
of life's genetic code.
444
00:29:24,062 --> 00:29:26,730
COVENEY: One of the most
challenging questions
445
00:29:26,732 --> 00:29:28,832
in the origin of life
446
00:29:28,834 --> 00:29:31,535
is how we get
from the simple building blocks
447
00:29:31,537 --> 00:29:34,138
to the complicated structures
448
00:29:34,140 --> 00:29:38,008
we know are fundamental
to living systems.
449
00:29:38,010 --> 00:29:41,645
Clays provide a clear mechanism
for achieving that.
450
00:29:41,647 --> 00:29:46,283
NARRATOR: These simulations
show that the secret to clay
451
00:29:46,285 --> 00:29:50,420
lies in its surfaces.
452
00:29:50,422 --> 00:29:52,256
The surfaces of these minerals
are incredible.
453
00:29:52,258 --> 00:29:54,218
They do all sorts
of chemical tricks.
454
00:29:56,294 --> 00:29:59,096
NARRATOR:
Hazen says minerals, like clays,
455
00:29:59,098 --> 00:30:02,366
illustrate a fascinating aspect
of chemistry,
456
00:30:02,368 --> 00:30:05,736
because the surface
where reactions take place
457
00:30:05,738 --> 00:30:10,941
can be as important
as the ingredients themselves.
458
00:30:10,943 --> 00:30:14,845
The most exquisite chemistry
occurs at surfaces.
459
00:30:14,847 --> 00:30:19,349
Your body, your cells
are almost entirely surfaces
460
00:30:19,351 --> 00:30:20,918
on which chemistry takes place.
461
00:30:22,921 --> 00:30:25,155
So when we think
about the origin of life,
462
00:30:25,157 --> 00:30:29,827
the minerals sort of replace
surfaces you have in your body
463
00:30:29,829 --> 00:30:31,762
that do that chemical work.
464
00:30:36,034 --> 00:30:39,937
NARRATOR: We are finally beginning
to understand the secret role
465
00:30:39,939 --> 00:30:42,873
minerals could have played
in life's origin.
466
00:30:47,378 --> 00:30:52,716
They provided some
of the ingredients and surfaces
467
00:30:52,718 --> 00:30:55,319
where important chemical
reactions take place.
468
00:31:07,365 --> 00:31:11,034
So when in Hazen's color phases
did all this happen?
469
00:31:17,041 --> 00:31:18,609
One of the best places
470
00:31:18,611 --> 00:31:21,778
to figure that out
is back in Australia,
471
00:31:21,780 --> 00:31:24,281
where Hazen and team
are now searching for signs
472
00:31:24,283 --> 00:31:25,983
of Earth's earliest life.
473
00:31:25,985 --> 00:31:28,585
HAZEN:
I can't believe these rocks
474
00:31:28,587 --> 00:31:30,320
are three and a half billion
years old.
475
00:31:30,322 --> 00:31:32,789
They look like they formed
last week.
476
00:31:32,791 --> 00:31:36,393
NARRATOR: Martin Van
Kranendonk leads the team
477
00:31:36,395 --> 00:31:39,529
to a very unusual
rock formation.
478
00:31:39,531 --> 00:31:43,066
You get your eye casting up,
you see them,
479
00:31:43,068 --> 00:31:44,902
all wrinkly, laminated, black.
480
00:31:44,904 --> 00:31:46,169
Yeah!
481
00:31:46,171 --> 00:31:47,838
VAN KRANENDONK: And then if
you look a bit further back,
482
00:31:47,840 --> 00:31:49,740
you see a very large
domical structure.
483
00:31:49,742 --> 00:31:50,874
HAZEN:
There's no obvious way
484
00:31:50,876 --> 00:31:53,243
that a chemical or physical
process would form that.
485
00:31:53,245 --> 00:31:55,805
VAN KRANENDONK:
Exactly.
486
00:31:56,547 --> 00:31:58,282
NARRATOR:
These strange shapes
487
00:31:58,284 --> 00:32:02,619
are fossilized remnants of life
called stromatolites,
488
00:32:02,621 --> 00:32:05,889
beautifully preserved
in these ancient rocks.
489
00:32:05,891 --> 00:32:08,992
VAN KRANENDONK:
This is an amazing spot.
490
00:32:08,994 --> 00:32:10,861
We're actually looking down
on the surface
491
00:32:10,863 --> 00:32:12,362
of the ancient Earth here.
492
00:32:12,364 --> 00:32:14,898
This was the seafloor
493
00:32:14,900 --> 00:32:17,200
3.4 billion years ago,
and I can see it in action.
494
00:32:17,202 --> 00:32:19,636
It's like a snap frozen
instant of time.
495
00:32:19,638 --> 00:32:25,242
NARRATOR: But billions of
years have taken their toll.
496
00:32:28,880 --> 00:32:31,315
To really understand
stromatolites,
497
00:32:31,317 --> 00:32:35,886
we have to go
nearly 800 miles away.
498
00:32:35,888 --> 00:32:40,524
David Flannery, a geologist,
has come to Shark Bay
499
00:32:40,526 --> 00:32:45,929
in search of their
very distant descendants.
500
00:32:45,931 --> 00:32:53,370
Just below the surface, he finds
a series of round, black mounds:
501
00:32:53,372 --> 00:32:55,739
living stromatolites.
502
00:32:58,476 --> 00:33:01,478
FLANNERY:
Modern environments like these,
503
00:33:01,480 --> 00:33:03,847
they're very rare,
but they are really the key
504
00:33:03,849 --> 00:33:06,416
to interpreting what we see
in the very early fossil record.
505
00:33:08,786 --> 00:33:11,688
Without environments like these,
we wouldn't know
506
00:33:11,690 --> 00:33:13,590
how stromatolites were built.
507
00:33:13,592 --> 00:33:16,560
NARRATOR: Stromatolites
are something like coral,
508
00:33:16,562 --> 00:33:21,531
a hard mineral structure that
has been built layer by layer.
509
00:33:21,533 --> 00:33:24,368
A closer look
reveals the builders.
510
00:33:26,604 --> 00:33:30,207
Microbes... single-celled life.
511
00:33:30,209 --> 00:33:32,109
FLANNERY: The living
part of a stromatolite
512
00:33:32,111 --> 00:33:34,177
is only the surface
where the living microbial mat
513
00:33:34,179 --> 00:33:36,213
is building up the structure
layer by layer
514
00:33:36,215 --> 00:33:37,748
at less than a millimeter
per year.
515
00:33:37,750 --> 00:33:42,219
NARRATOR: The top layer of
these stromatolites is alive,
516
00:33:42,221 --> 00:33:46,023
with microbes that perform
a remarkable trick.
517
00:33:46,025 --> 00:33:49,226
They capture minerals and sand
in the water
518
00:33:49,228 --> 00:33:52,763
and biologically cement them
layer by layer
519
00:33:52,765 --> 00:33:55,532
into the solid mounds.
520
00:33:59,003 --> 00:34:02,506
The results can be seen
in Shark Bay today
521
00:34:02,508 --> 00:34:06,843
and in the ancient fossils.
522
00:34:06,845 --> 00:34:09,346
Yeah, let me introduce you
to this outcrop.
523
00:34:09,348 --> 00:34:11,782
It's just spectacular
to be able to see this.
524
00:34:11,784 --> 00:34:15,585
NARRATOR:
And this outcrop is unique.
525
00:34:15,587 --> 00:34:18,722
Van Kranendonk has dated
this stromatolite
526
00:34:18,724 --> 00:34:22,926
to 3.5 billion years ago.
527
00:34:22,928 --> 00:34:27,564
This is the very oldest fossil
of life on Earth.
528
00:34:30,802 --> 00:34:33,036
HAZEN: We all want to
know where we come from,
529
00:34:33,038 --> 00:34:36,673
where life originated,
how long ago, in what form,
530
00:34:36,675 --> 00:34:39,242
and this is the oldest
direct evidence we have
531
00:34:39,244 --> 00:34:40,510
for life on Earth.
532
00:34:50,321 --> 00:34:52,055
NARRATOR:
But while stromatolites
533
00:34:52,057 --> 00:34:54,658
are the earliest fossil of life
we've found,
534
00:34:54,660 --> 00:34:59,663
that does not make them
the very first living thing.
535
00:34:59,665 --> 00:35:01,898
In fact, Van Kranendonk thinks
536
00:35:01,900 --> 00:35:04,835
that by the time
stromatolites appeared,
537
00:35:04,837 --> 00:35:08,071
life's party was already
in full swing.
538
00:35:08,073 --> 00:35:10,140
There are whole communities
and colonies
539
00:35:10,142 --> 00:35:13,143
that are building fantastically
complex structures,
540
00:35:13,145 --> 00:35:15,278
so we've actually come in
pretty late to the game.
541
00:35:15,280 --> 00:35:18,448
There is a lot that's gone on
before us to get to this stage,
542
00:35:18,450 --> 00:35:21,251
and it's this complexity
that tells us that life
543
00:35:21,253 --> 00:35:23,553
probably originated on Earth
very early.
544
00:35:29,994 --> 00:35:32,429
NARRATOR:
So if these very early fossils
545
00:35:32,431 --> 00:35:35,765
are too complex
to be the oldest form of life,
546
00:35:35,767 --> 00:35:38,702
is it possible
to find something earlier?
547
00:35:41,205 --> 00:35:45,108
That is what Ruth Blake,
a geologist at Yale University,
548
00:35:45,110 --> 00:35:47,177
is trying to figure out
549
00:35:47,179 --> 00:35:49,312
by turning
to the geological equivalent
550
00:35:49,314 --> 00:35:51,414
of a crime scene investigation.
551
00:35:52,850 --> 00:35:55,252
BLAKE:
The crime has been committed.
552
00:35:55,254 --> 00:35:56,653
The criminal is gone,
553
00:35:56,655 --> 00:35:59,422
but they've left behind
some indicator
554
00:35:59,424 --> 00:36:01,158
because they've changed
their environment.
555
00:36:01,160 --> 00:36:05,295
NARRATOR: Blake is analyzing some
of the oldest rocks on Earth,
556
00:36:05,297 --> 00:36:08,632
like this ground-up one
from Greenland
557
00:36:08,634 --> 00:36:10,634
that formed
at the bottom of an ocean.
558
00:36:12,336 --> 00:36:15,505
She is looking
for a chemical signature of life
559
00:36:15,507 --> 00:36:19,376
left by microbes,
including bacteria.
560
00:36:19,378 --> 00:36:23,213
What we start with is our ocean
trapped in a rock,
561
00:36:23,215 --> 00:36:26,449
and our bio-signature
is somewhere in here.
562
00:36:26,451 --> 00:36:27,784
We have to get it out.
563
00:36:27,786 --> 00:36:30,987
NARRATOR:
In the lab, Blake and her team
564
00:36:30,989 --> 00:36:33,890
dissolve these rocks
and extract molecules
565
00:36:33,892 --> 00:36:39,496
that are the chemical signature
left behind by ancient microbes.
566
00:36:42,300 --> 00:36:44,734
All life, like these microbes,
567
00:36:44,736 --> 00:36:47,637
consumes nutrients
to produce energy.
568
00:36:51,409 --> 00:36:55,111
The leftovers carry
the chemical footprint of life.
569
00:37:00,017 --> 00:37:04,254
Even today, we humans leave
behind chemical footprints.
570
00:37:08,125 --> 00:37:11,895
BLAKE: When we breathe, for
example, we're taking in oxygen
571
00:37:11,897 --> 00:37:15,999
and we're exhaling CO2
and water vapor.
572
00:37:16,001 --> 00:37:19,002
That water vapor interacts
with your environment.
573
00:37:22,039 --> 00:37:27,110
NARRATOR: Amazingly, rocks
from 3.5 billion years ago,
574
00:37:27,112 --> 00:37:30,180
at the time of the stromatolites
in Australia,
575
00:37:30,182 --> 00:37:35,518
also carry a strong
chemical footprint of life.
576
00:37:35,520 --> 00:37:38,521
But when Blake analyzes
the Greenland rocks
577
00:37:38,523 --> 00:37:41,057
from 300 million years earlier,
578
00:37:41,059 --> 00:37:44,227
she makes a tantalizing
discovery.
579
00:37:44,229 --> 00:37:46,630
BLAKE: As far back as
3.5 billion years,
580
00:37:46,632 --> 00:37:48,632
we see a strong biological
signature.
581
00:37:48,634 --> 00:37:50,600
And the older rocks
are approaching that,
582
00:37:50,602 --> 00:37:52,836
but not quite there,
583
00:37:52,838 --> 00:37:55,338
but we do believe that
we see something there.
584
00:37:57,341 --> 00:38:01,444
NARRATOR: Blake believes she has
detected the faint signal of life
585
00:38:01,446 --> 00:38:07,117
at 3.8 billion years ago,
only 700 million years
586
00:38:07,119 --> 00:38:11,554
after Earth was created,
early in the blue phase.
587
00:38:16,093 --> 00:38:18,695
There is still much
that we don't know
588
00:38:18,697 --> 00:38:23,233
about our early planet, but some
things are becoming clearer.
589
00:38:25,436 --> 00:38:28,204
If you could transport yourself
back in time
590
00:38:28,206 --> 00:38:31,641
about four billion years,
parts of our Earth
591
00:38:31,643 --> 00:38:33,276
might not look too different
592
00:38:33,278 --> 00:38:35,745
than this Southern
California beach,
593
00:38:35,747 --> 00:38:40,784
minus the surfers and poodle.
594
00:38:40,786 --> 00:38:45,255
You could stand on cliffs,
probably of granite,
595
00:38:45,257 --> 00:38:49,626
overlooking oceans
that were increasingly rich
596
00:38:49,628 --> 00:38:52,462
with minerals
and early microbial life.
597
00:38:52,464 --> 00:38:56,700
But you would quickly die
in a great deal of pain,
598
00:38:56,702 --> 00:38:59,536
suffocating
in the heavy atmosphere
599
00:38:59,538 --> 00:39:02,572
rich in nitrogen
and carbon dioxide,
600
00:39:02,574 --> 00:39:08,545
but lacking in life-giving
free oxygen.
601
00:39:12,416 --> 00:39:16,519
Then something truly astonishing
happened.
602
00:39:16,521 --> 00:39:18,521
Those harmless-looking microbes
603
00:39:18,523 --> 00:39:21,524
floating in the water
or on stromatolites
604
00:39:21,526 --> 00:39:26,463
started to change everything,
turning Earth red.
605
00:39:37,074 --> 00:39:40,744
HAZEN:
Wow.
606
00:39:40,746 --> 00:39:44,314
Oh, my God, this is amazing!
607
00:39:44,316 --> 00:39:46,316
There aren't many places
on earth
608
00:39:46,318 --> 00:39:48,985
you can see something like this.
609
00:39:48,987 --> 00:39:52,422
NARRATOR: A remnant of red
Earth can be seen in Australia
610
00:39:52,424 --> 00:39:57,160
at the Hamersley Basin
in Karijini National Park.
611
00:39:57,162 --> 00:40:00,230
In these rocks, Hazen finds
612
00:40:00,232 --> 00:40:03,166
a startling consequence
of early life
613
00:40:03,168 --> 00:40:07,737
as it began to thrive
and evolve.
614
00:40:07,739 --> 00:40:09,806
What we're seeing here
is one of the greatest tricks
615
00:40:09,808 --> 00:40:11,207
that life ever figured out.
616
00:40:11,209 --> 00:40:12,876
And that was
how to take sunlight
617
00:40:12,878 --> 00:40:15,779
and convert it to energy.
618
00:40:15,781 --> 00:40:19,883
NARRATOR: Microbes, like those in
the stromatolites at Shark Bay,
619
00:40:19,885 --> 00:40:22,886
eventually began to live
off the sun's energy
620
00:40:22,888 --> 00:40:24,988
through photosynthesis.
621
00:40:24,990 --> 00:40:27,557
That led to a dramatic rise
622
00:40:27,559 --> 00:40:30,693
in a gas that Earth
was not accustomed to:
623
00:40:30,695 --> 00:40:33,930
oxygen.
624
00:40:33,932 --> 00:40:37,634
While to us, oxygen
is a life-giving benign gas,
625
00:40:37,636 --> 00:40:40,170
to a world not accustomed to it,
626
00:40:40,172 --> 00:40:43,740
oxygen created a dangerously
corrosive cocktail.
627
00:40:45,776 --> 00:40:51,247
The early oceans were filled
with dissolved iron.
628
00:40:51,249 --> 00:40:54,284
The new oxygen reacted
with that iron,
629
00:40:54,286 --> 00:40:56,886
and it began to rust
630
00:40:56,888 --> 00:41:00,023
and sank to the bottom
of the sea.
631
00:41:00,025 --> 00:41:02,559
HAZEN: These little microbes,
they're microscopic things,
632
00:41:02,561 --> 00:41:04,561
and you wouldn't think
they could do all that much.
633
00:41:04,563 --> 00:41:06,563
But when they produce
that oxygen
634
00:41:06,565 --> 00:41:09,466
and the oxygen reacts
with the iron in the oceans,
635
00:41:09,468 --> 00:41:11,835
you get the world's
largest deposits of iron...
636
00:41:11,837 --> 00:41:16,339
thousands of feet covering
hundreds of square miles.
637
00:41:16,341 --> 00:41:19,776
NARRATOR: These formations
cover a vast area
638
00:41:19,778 --> 00:41:23,246
with trillions of tons
of iron ore.
639
00:41:24,482 --> 00:41:26,883
That is an unimaginable
consequence
640
00:41:26,885 --> 00:41:30,854
of trillions upon trillions
of microbes breathing.
641
00:41:33,457 --> 00:41:36,759
HAZEN: It's a fundamental change
in the chemistry of Earth.
642
00:41:36,761 --> 00:41:39,229
It's a consequence
of the rise of oxygen.
643
00:41:41,465 --> 00:41:44,667
NARRATOR: The rise in
oxygen that rusted iron
644
00:41:44,669 --> 00:41:48,171
and sent Earth
into the red phase
645
00:41:48,173 --> 00:41:52,308
also created many new minerals.
646
00:41:52,310 --> 00:41:54,978
HAZEN: As a mineralogist,
when I look at Earth history,
647
00:41:54,980 --> 00:41:56,579
I see big transitions.
648
00:41:56,581 --> 00:41:58,281
I see the moon forming impact,
649
00:41:58,283 --> 00:42:01,317
I see the formation of oceans
and so forth.
650
00:42:01,319 --> 00:42:04,053
But nothing, nothing matches
651
00:42:04,055 --> 00:42:07,457
what life and oxygen did
to create new minerals.
652
00:42:09,560 --> 00:42:12,595
NARRATOR: Some estimate that the
meteorites that formed Earth
653
00:42:12,597 --> 00:42:16,065
began with only
about 250 minerals.
654
00:42:22,773 --> 00:42:26,242
Today, there are more
than 5,000.
655
00:42:30,347 --> 00:42:33,349
Hazen believes that two-thirds
of all the minerals
656
00:42:33,351 --> 00:42:35,251
that now make up our planet
657
00:42:35,253 --> 00:42:38,288
were created by the introduction
of oxygen.
658
00:42:38,290 --> 00:42:44,360
And most of that was, in turn,
created by life.
659
00:42:44,362 --> 00:42:47,096
BOY:
Amethyst.
660
00:42:47,098 --> 00:42:48,865
HAZEN:
It's mindboggling.
661
00:42:48,867 --> 00:42:53,903
Rocks create life,
life creates rocks.
662
00:42:53,905 --> 00:42:57,006
They're intertwined in ways that
are just now coming into focus.
663
00:42:58,676 --> 00:43:02,345
NARRATOR: But the road ahead
for life and for rocks
664
00:43:02,347 --> 00:43:04,647
would not be easy.
665
00:43:08,018 --> 00:43:10,853
As we head into the next phase
of Earth,
666
00:43:10,855 --> 00:43:13,256
new continents formed
and broke apart,
667
00:43:13,258 --> 00:43:17,360
which may have created dramatic
extremes in the climate.
668
00:43:17,362 --> 00:43:23,533
Earth plunged into an icy
freeze, turning it white.
669
00:43:27,871 --> 00:43:33,276
In these frozen conditions,
life was nearly wiped out.
670
00:43:35,379 --> 00:43:37,880
Fortunately, active volcanoes
671
00:43:37,882 --> 00:43:41,150
still poked through
the icy veneer,
672
00:43:41,152 --> 00:43:44,087
billowing out carbon dioxide,
or CO2.
673
00:43:48,659 --> 00:43:51,694
Like a thermal blanket
around our Earth,
674
00:43:51,696 --> 00:43:55,999
this kept heat in
and rescued life.
675
00:43:58,102 --> 00:44:00,703
HAZEN:
Life all but shut down.
676
00:44:02,940 --> 00:44:04,607
And then the CO2 rises and rises
677
00:44:04,609 --> 00:44:06,676
and the greenhouse effect
gets hotter and hotter,
678
00:44:06,678 --> 00:44:08,945
and suddenly the planet melts.
679
00:44:10,648 --> 00:44:13,383
NARRATOR: Cycles of these
snowball hothouse conditions
680
00:44:13,385 --> 00:44:16,686
had profound consequences
for life.
681
00:44:18,222 --> 00:44:19,756
One result was more oxygen,
682
00:44:19,758 --> 00:44:24,661
which eventually allowed
for bigger animals.
683
00:44:28,465 --> 00:44:32,468
The dramatic changes
during white Earth
684
00:44:32,470 --> 00:44:34,937
would bring us
to the present phase
685
00:44:34,939 --> 00:44:39,876
starting about
540 million years ago...
686
00:44:39,878 --> 00:44:42,445
a living planet
687
00:44:42,447 --> 00:44:47,016
filled with diverse plants
and spectacular creatures.
688
00:44:52,389 --> 00:44:55,491
But those life-forms
are pitted against each other
689
00:44:55,493 --> 00:44:58,594
in a survival of the fittest,
690
00:44:58,596 --> 00:45:00,263
and rocks can make
the difference
691
00:45:00,265 --> 00:45:03,533
between life and death.
692
00:45:06,470 --> 00:45:11,340
That struggle can be seen
back in Morocco,
693
00:45:11,342 --> 00:45:14,744
at the edge
of the Anti-Atlas Mountains.
694
00:45:16,613 --> 00:45:19,215
Here, Bob Hazen and Adam Aronson
695
00:45:19,217 --> 00:45:22,819
are looking for evidence
of an evolutionary trick
696
00:45:22,821 --> 00:45:26,422
that shows once again
how life and rocks
697
00:45:26,424 --> 00:45:29,959
took a big leap forward
together.
698
00:45:34,998 --> 00:45:37,567
520 million years ago,
699
00:45:37,569 --> 00:45:43,840
this valley was a shallow ocean
filled with new forms of life.
700
00:45:48,612 --> 00:45:52,849
This is when the diversity
of life on Earth exploded,
701
00:45:52,851 --> 00:45:58,087
all thriving in a living sea.
702
00:45:58,089 --> 00:46:01,791
HAZEN: So if you were a scuba diver
and you dove down to this reef,
703
00:46:01,793 --> 00:46:03,893
you'd see all kinds of life
swimming around,
704
00:46:03,895 --> 00:46:06,195
really amazing,
probably very colorful, too.
705
00:46:10,367 --> 00:46:14,904
NARRATOR: There is one creature
that dominates this ancient reef
706
00:46:14,906 --> 00:46:18,141
that Hazen wants to find.
707
00:46:18,143 --> 00:46:19,041
HAZEN:
Nothing there.
708
00:46:19,043 --> 00:46:20,376
Nothing there.
709
00:46:22,012 --> 00:46:24,580
And nothing there.
710
00:46:24,582 --> 00:46:28,718
NARRATOR: Fossil hunting is a
game of luck and persistence,
711
00:46:28,720 --> 00:46:33,322
but it doesn't take long for
Hazen to strike geologic gold.
712
00:46:33,324 --> 00:46:35,324
Whoa!
713
00:46:35,326 --> 00:46:38,528
Jeez, look at that.
714
00:46:38,530 --> 00:46:40,396
That is amazing.
715
00:46:40,398 --> 00:46:42,198
NARRATOR:
The trilobite.
716
00:46:42,200 --> 00:46:44,400
HAZEN: Hey, look, there's
another head there,
717
00:46:44,402 --> 00:46:46,536
and the head there, two more.
718
00:46:46,538 --> 00:46:48,271
Boy, this is rich rock.
719
00:46:48,273 --> 00:46:50,473
The trilobites here are amazing
720
00:46:50,475 --> 00:46:53,476
because these are the oldest
animals that you can find
721
00:46:53,478 --> 00:46:56,379
that are preserved as
what you think of as a fossil
722
00:46:56,381 --> 00:46:57,980
that you can hold in your hand.
723
00:47:00,250 --> 00:47:03,352
NARRATOR: Some trilobites
were like horseshoe crabs
724
00:47:03,354 --> 00:47:06,856
scurrying about the ocean floor.
725
00:47:06,858 --> 00:47:09,792
The reason they are found
as fossils today
726
00:47:09,794 --> 00:47:11,694
is because they developed
727
00:47:11,696 --> 00:47:14,964
an astonishing
evolutionary trick...
728
00:47:14,966 --> 00:47:16,899
shells.
729
00:47:21,471 --> 00:47:24,807
Trilobite shells were made
of calcium carbonate,
730
00:47:24,809 --> 00:47:27,376
the same mineral
found in limestone,
731
00:47:27,378 --> 00:47:31,380
the rock that built
the pyramids.
732
00:47:31,382 --> 00:47:35,284
In effect, life itself
began to make rocks
733
00:47:35,286 --> 00:47:37,286
for its own advantage.
734
00:47:37,288 --> 00:47:41,824
And the idea went viral.
735
00:47:43,660 --> 00:47:46,729
HAZEN: If you had a shell, you're
going to survive a lot longer
736
00:47:46,731 --> 00:47:49,091
than that soft-bodied animal
that doesn't have a shell.
737
00:47:51,902 --> 00:47:54,303
The trilobite had an advantage.
738
00:47:54,305 --> 00:47:57,173
It's survival of the fittest.
739
00:47:57,175 --> 00:47:59,008
NARRATOR:
The trilobite's mineral shell
740
00:47:59,010 --> 00:48:02,545
heralded a new phase
in the evolution of animals,
741
00:48:02,547 --> 00:48:06,082
catapulting our planet
into the present stage,
742
00:48:06,084 --> 00:48:10,253
green earth, one that is rich
in diverse life.
743
00:48:16,026 --> 00:48:21,631
From humans back to trilobites,
we owe our evolution
744
00:48:21,633 --> 00:48:25,468
and survival
to the world of minerals...
745
00:48:25,470 --> 00:48:30,006
with shells, then eventually
with bones and teeth
746
00:48:30,008 --> 00:48:35,711
that paved the way for life
to grow taller and stronger.
747
00:48:35,713 --> 00:48:39,482
All are evidence of life
co-opting minerals
748
00:48:39,484 --> 00:48:44,287
for its own evolutionary
advantage.
749
00:48:44,289 --> 00:48:47,590
HAZEN:
We've thought for centuries,
750
00:48:47,592 --> 00:48:49,725
"Animals, minerals, they're
separate kingdoms, right?"
751
00:48:49,727 --> 00:48:51,661
But it turns out they overlap,
752
00:48:51,663 --> 00:48:53,696
they're intertwined,
they co-evolved.
753
00:48:53,698 --> 00:48:55,731
That life makes minerals,
754
00:48:55,733 --> 00:48:58,134
and minerals have led
to new life-forms.
755
00:48:59,770 --> 00:49:01,671
You can't separate the two.
756
00:49:04,875 --> 00:49:07,543
Life and rocks
are totally intertwined
757
00:49:07,545 --> 00:49:09,625
through billions of years
of Earth history.
758
00:49:18,922 --> 00:49:21,490
NARRATOR:
One of Hazen's favorite places
759
00:49:21,492 --> 00:49:24,093
to see this intertwined history
of life and minerals
760
00:49:24,095 --> 00:49:29,732
is at the Calvert Cliffs
along the Chesapeake Bay.
761
00:49:29,734 --> 00:49:31,167
He and his wife Margee
762
00:49:31,169 --> 00:49:33,302
pick up shells and shark teeth
from a time
763
00:49:33,304 --> 00:49:38,007
18 million years ago when
massive sea creatures swam here.
764
00:49:38,009 --> 00:49:39,642
That's nice, isn't that pretty?
765
00:49:39,644 --> 00:49:40,943
HAZEN:
You find teeth
766
00:49:40,945 --> 00:49:46,282
along the beach that are five,
six, sometimes seven inches long
767
00:49:46,284 --> 00:49:50,286
with serrated edges...
razor-sharp teeth.
768
00:49:53,490 --> 00:49:56,692
These were immense creatures,
769
00:49:56,694 --> 00:50:00,696
sharks that may have been
50 or 60 feet long.
770
00:50:03,834 --> 00:50:06,335
NARRATOR:
These giants of the sea
771
00:50:06,337 --> 00:50:09,405
would have dwarfed today's
great whites.
772
00:50:09,407 --> 00:50:13,943
And it was the bones and teeth
created with minerals
773
00:50:13,945 --> 00:50:19,382
that enabled them to grow
so large and powerful.
774
00:50:19,384 --> 00:50:22,084
HAZEN:
They were feeding on whales.
775
00:50:22,086 --> 00:50:25,221
Dolphins would have been
a snack.
776
00:50:25,223 --> 00:50:30,159
NARRATOR: They are just one small
part of a story of co-evolution
777
00:50:30,161 --> 00:50:33,329
stretching back
to Earth's beginning.
778
00:50:37,601 --> 00:50:41,003
HAZEN: The life, the rocks, it's
all part of the same story.
779
00:50:44,007 --> 00:50:47,343
NARRATOR: Step by step,
throughout Earth's evolution,
780
00:50:47,345 --> 00:50:51,947
minerals and life
have sparked chemical reactions
781
00:50:51,949 --> 00:50:55,751
that sculpted the planet
into what we see today
782
00:50:55,753 --> 00:50:59,255
and helped create
the life we know.
783
00:50:59,257 --> 00:51:03,726
HAZEN: At this place, you get a
sense of the immensity of time
784
00:51:03,728 --> 00:51:06,896
and the constancy of change.
785
00:51:06,898 --> 00:51:11,901
Life is creating
and sculpting our surroundings
786
00:51:11,903 --> 00:51:14,537
in ways that are
quite wonderful.
787
00:51:14,539 --> 00:51:19,809
And just to recognize the power
of life to transform a planet.
788
00:51:23,113 --> 00:51:24,547
(engine revving)
789
00:51:24,549 --> 00:51:27,183
Of course, humans transform
the planet too.
790
00:51:27,185 --> 00:51:30,119
We build cities, we build roads,
791
00:51:30,121 --> 00:51:31,821
we change the composition
of the atmosphere
792
00:51:31,823 --> 00:51:33,903
and change the composition
of the oceans.
793
00:51:35,959 --> 00:51:39,328
There are going to be
global changes.
794
00:51:39,330 --> 00:51:44,166
NARRATOR: These changes whose
consequences are now beginning to unfold
795
00:51:44,168 --> 00:51:48,471
are the latest chapter
in Earth's epic story...
796
00:51:48,473 --> 00:51:50,773
a story that began
797
00:51:50,775 --> 00:51:54,176
four and a half billion
years ago with a rock.
798
00:52:05,889 --> 00:52:08,824
The exploration continues
online,
799
00:52:23,707 --> 00:52:26,175
This NOVA program
is available on DVD.
800
00:52:26,177 --> 00:52:31,113
To order, visit shopPBS.org,
or call 1-800-PLAY-PBS.
801
00:52:31,115 --> 00:52:33,482
NOVA is also available
for download on iTunes.