Nova (1974–…): Season 43, Episode 2 - Life's Rocky Start - full transcript

Four and a half billion years ago, the young Earth was a hellish place-a seething chaos of meteorite impacts, volcanoes belching noxious gases, and lightning flashing through a thin, torrid atmosphere. Then, in a process that has ...

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They're dazzling

Priceless

At times, even glowing

How can one not fall in love
with rocks and minerals?

I mean, the colors, the shapes

And they're the building blocks
of modern civilization

We wouldn't have televisions,
we wouldn't have automobiles,

we wouldn't have buildings

without the mineral riches
that we have

But could rocks and minerals

also solve the greatest mystery
of all time...



The origin of life?

The rocks we pick up
tell a story:

that life couldn't have occurred
without rocks

Could cold, lifeless stone

hold the key to every
living thing on Earth?

From Australia to Morocco,

NOVA goes around the world
and back in time

to investigate the origin
and evolution of life

You look at a rock and you
think, "Ah well, nothing,"

but this holds
the signature of life

From its first spark

People were saying they made
Frankenstein in a test tube

to the survival of the fittest

These were immense creatures...



Sharks that may have been
50 or 60 feet

Was it the secret link
between rocks and life

that made the difference?

"Life's Rocky Start,"
right now on NOVA.

The ancient market of Marrakech,

a chaotic, colorful
gathering place

teeming with life
for thousands of years

The perfect place to ask,
how did this exotic, beautiful,

and sometimes bizarre thing
called life begin?

How did Earth go
from a lifeless, molten rock

to a living planet

full of diverse
and spectacular creatures?

It's a question that has
long perplexed scientists

Now Robert Hazen, a geologist,
is trying to show

we are missing
an essential ingredient

in the recipe for life

Look at that vein of calcite

Rocks

Nothing seems more lifeless
than a rock

It's inanimate, it's the
antithesis of a living thing

But we are beginning
to realize that rocks played

an absolutely fundamental role
in the origin of life

Aw, yeah

Hazen is out to expose
a secret relationship

between rocks and life
that helped drive

both the origin of life

and its evolution
into complex creatures

This is a very new
set of understandings

and the more we look,
the more we see

that life depends on rocks,
rocks depend on life

and this has been going on
for four billion years

As a geologist, it's no surprise
that Hazen is searching

for answers written in stone

But is he right?

Are rocks the missing
spark of life?

The history of Earth
is unimaginably long

If it were sped up to the
equivalent of a single day,

all of humankind
from the earliest skeletons

to the invention of the iPhone

would have occurred
in only the last four seconds

Dinosaurs were still
roaming Earth

about 20 minutes before that

But the creation of our planet

occurred more than
23 hours earlier...

Two cycles on this clock...
Or 4 5 billion years ago

Comprehending Earth's vast
history is a formidable task

There's four and a half
billion years of change

But you can divide it
into half a dozen ways

of describing Earth through time

Bob Hazen has come up
with another way to visualize

Earth's long history
that reveals

this special relationship
between rocks and life

He has divided it
into six stages,

each represented
by a different color

To understand how we ended up
with green Earth...

The planet we now know...

Requires us to turn
the clock back,

to before there was any life
at all

Stage one was the creation
of black Earth

Back in Morocco,

Hazen and Adam Aronson,
a meteorite expert,

seek out a small rock from
the beginning of our cosmos

Wow, look at this pile here

These are meteorites, rocks
that have fallen from space

This is Tamdackht

This is the one that
fell 20 kilometers

up the road from here

People saw it fall

A recent meteorite fall in
Siberia was captured in videos

that have shown up on YouTube

Other space rocks have ended up
for sale here in Morocco

So you'd buy this
without doing tests?

I would drop the cash right now

if he would give me a good price

Meteorites here can sell for
tens of thousands of dollars

That may seem a steep price
for a lump of rock,

but these are some
of the very oldest objects

in our solar system

This is the oldest object you
could ever hold in your hand

It's 4 6 billion years old

and it was formed
before earth formed

This is the very first
solid material,

the very first rock
in our solar system

and these came together
to build all the planets

Our Earth was created
out of the rocks and dust

present at the start
of our solar system

Over time, small fragments
of orbiting rock collided,

coming together into the planets
circling the sun

At first, Earth was molten

with temperatures
in the thousands of degrees

But in the cold vacuum of space

this hot rock
began to cool and change

Nothing, not a speck of dust,
is believed to have survived

from the period of black Earth

It was a hellishly
unpleasant time

Volcanoes spewed hot lava
from deep inside the planet

When it cooled,

it covered Earth with its first
rock, called basalt

And it was black

It seems
like a desolate landscape

But some ingredients
that life will need

are already here in these rocks

Look inside and you begin
to understand how intriguing

even an ordinary rock is

Every rock, you slice it open,
you look inside,

there's something special

Rocks are made up mostly of
minerals, which are crystals

like quartz or diamonds

Looking through a microscope
at super-thin slices of a rock

lets you see
its mineral composition

This is the rock peridotite,
made up of small crystals

including olivine and pyroxene

Even a simple black basalt rock
spewed from a volcano

becomes a patchwork
of colorful minerals

It's sort of like a fruitcake

You know, you slice it open,
there's nuts,

and there is dried fruit,
and maybe some lemon peel

It's made of lots
of little things

And it's not until you slice
into that fruitcake

that you see all the stuff
inside that makes it special

What makes them special
is not only their beauty

Minerals have remarkable
chemical and physical properties

and are a source
of many of the elements...

Nature's building blocks

That is why they're essential
in our modern world

to make everything
from skyscrapers taller

to mobile phones smaller

Extract the element molybdenum
from the mineral molybdenite

to make steel stronger,

or add a pinch of cobalt

and your iPhone battery
will last longer

Minerals are the fundamental
building block of societies

We wouldn't have televisions,
we wouldn't have automobiles,

we wouldn't have buildings

without the mineral riches
that we have

So were the remarkable
chemical properties of minerals

also key in creating life?

If so, Earth would need more
than it started with

It's estimated that the
meteorites that formed Earth

had only about 250 minerals,

sort of a chemical starter kit
containing many of the elements

Then in the intense heat
and pressures

in the creation of our planet,
new minerals began to form

This changed the appearance
of our Earth from black to gray

Yosemite National Park is a
relatively new piece of Earth

But the kind of rock that makes
up these dramatic cliffs

goes back much further

These huge walls are granite,

containing minerals
like quartz and feldspar

Granite became the foundation
of our continents,

leading Earth
into the gray period

At this point,
Earth is still a long way

from the glorious diversity
of plants and animals

that makes Yosemite
so picturesque

But the stage is set

for the next character
in our planet's story:

water,
which will turn Earth blue

Water plays a central role
in every model

for the origin of life

That's because water
is such a great solvent

All these different kinds
of molecules

can be floating around the water

and then they have the potential
to interact together

The starting point is the water

So when did Earth cool enough
to have liquid water,

this element key to life?

One of the biggest unknowns
in this whole idea

of going from black to gray
to a blue water-covered Earth

is how quickly it happened

The timing was a big mystery

The Pilbara in Western Australia

is one of the oldest places
on Earth,

and so one of the best places
to solve the mystery

of the planet's first oceans

Hazen joins an all-star team
of geologists

including Martin Van Kranendonk,

from the University
of New South Wales

and John Valley
of the University of Wisconsin

Valley is collecting rocks
that could hold clues

to when water first appeared

We can get zircons
and other minerals

that date all the way back
to 4 4 billion years old

Hopefully

Some rocks here contain
sand-sized grains

that weathered from
even older rocks

One in a million... literally...
Is a crystal called zircon,

one of the longest-lasting
materials in nature

Zircon is a popular gemstone,

but the microscopic zircon
found here

is even more precious

Zircon crystals
are especially amazing

Gemstone zircons of course
are valued,

but these tiny ones
that geologists value

are microscopic

They make a lousy ring, but
they tell an incredible story

To tell that story,

John Valley must first find
the tiny crystals...

The ultimate
needle in a haystack

If you want to find
a needle in a haystack,

the first thing you do
is you burn down the haystack

Then you'd sift through the ash
to look for the needle

Rocks are pulverized
into sand-sized grains

and sorted by weight
in a machine

developed to pan for gold

The gold that Valley is looking
for are heavy zircon crystals,

which get channeled
into different tracks

Then, grain by grain,
with a very steady hand,

thousands of small crystals
are sorted and analyzed

The chemical structure
of a zircon crystal

holds evidence of both
the environment

and the age when it formed

Some of these tiny crystals
go very far back,

just over 100 million years
after Earth formed

They are the oldest pieces
of Earth ever discovered,

so they could shed light on what
our young planet looked like

It's totally amazing to me

To hold this grain of sand
in the palm of your hand

is literally to see
back through time

It is a time machine

Valley expected these
crystal time machines

would confirm the long-held view
that the young Earth

was covered in molten lava,

still cooling after
its violent formation

I think the zircon on the left
looks very promising

So what he discovered
was shocking

because this type of zircon,
created 4 3 billion years ago,

could only have formed
in the presence of liquid water

But how could there be water

if Earth was still hot
and hell-like?

The implications were that
the early Earth had water

It was cooler and it was wet

It's starting to look very much
more familiar

And if water is a key
starting point for life,

could there be life
that early, too?

The science of the zircon
is telling us that the Earth

for a very, very long time
was a habitable environment

Not necessarily
that there was life then

We don't know that yet

But there's no reason why
there couldn't have been life

as early as 4 3 billion
years ago

So if life were possible that
early, it begs the question,

how did life begin?

In 1871, Charles Darwin

speculated in a letter
to a friend

that a warm little pond
might be life's birthplace

A warm soup of chemicals
bathed by energy from the sun

would have been, well,
comfortable for molecules

to come together in new ways
and create life

Darwin was way, way
ahead of his time

A nice little warm soup
is going to get you a long way

Jeff Bada of the Scripps
Institution of Oceanography

in San Diego,
has spent his career

working to understand the early
Earth's soup of chemicals

He began under the direction
of perhaps

the most famous scientist
in origin of life research...

Stanley Miller

There are in the history
of science turning points

where we suddenly see
the history of Earth

and life differently

In the early 1950s,
Stanley Miller,

the eager graduate student,
and Harold Urey,

the Nobel Prize winning mentor
at the University of Chicago,

conducted this
astonishing experiment

where they made
an early Earth environment

It looks like this sort of a
Frankenstein-type apparatus

But actually, it's a very
carefully thought out design

Bada sets up a modern-day test
of the 1950s experiment

on Miller's original
lab equipment

One flask contains water

That's to simulate the ocean

The other flask
has just got the gases in it

So this is the atmosphere

Just as it does in nature,

water from the ocean evaporates
and rises into the atmosphere,

where it condenses
and returns to the ocean

Miller simulated what he
believed to be the atmosphere

of early Earth with different
gases like ammonia and methane

Then, he added a spark of genius

Miller and Urey decided to use
a spark to simulate lightning

because that's such
a ubiquitous process

in the atmosphere of the earth

That was the real inspiration,

these little electric sparks

they acted like simulated
lightning

The energy from the spark
of lightning

breaks down
the gas and water molecules

so they can undergo
further chemical reactions

To their astonishment, when they
turned this apparatus on

after only a couple of days
you started seeing

this pink color developing

And then a few more days,
black, oily goo

is forming around the electrodes

The electrodes get covered
with new substances,

organic compounds
usually associated with life

And it wasn't just
any organic compound,

it was amino acids
that make proteins

The ingredients for life

Amino acids are the
building blocks of life

They form proteins,

which are the key component
of muscles and other tissues

People thought, "Aha!

This is a key step
in the origin of life"

And you really believe that
you can bring life to the dead?

That body is not dead

It has never lived

I created it

The experiment raised the fear
that a Frankenstein creation,

like in this classic film,
was just around the corner

It's moving

People were saying they made
Frankenstein in a test tube

It's alive!

Now I know what it feels
like to be God!

Had Miller and Urey cooked up
life in a test tube?

Many of the news headlines
were saying,

"Life created
in the laboratory!"

"Life created in a test tube!"

Well, of course that was wrong

The real news
was he'd made these compounds

that are part of life

By creating amino acids,
the Miller-Urey experiment

seemed to confirm
that Darwin was right...

Life must have begun
in a shallow pond

But then, 24 years later,
a shocking discovery

radically challenged that idea

On the dark ocean floor,

more than a mile
below the surface,

explorers found hot,
mineral-rich hydrothermal vents,

like underwater volcanoes

Temperatures reached
more than 600 degrees,

and yet here life was thriving,
not off the sun's energy,

but through chemical energy
from the vents

No one realized that life
could thrive without sunlight

Here you have
this extreme temperature

and this extreme pressure,

and so you have to shift
your perceptions

and realize that just because
it's extreme to us

doesn't mean it's extreme
to those microbes

Instead of the warm
shallow pond,

could this dark and unlikely
environment be where life began?

To answer that,
Hazen decided to try creating

life's building blocks in the
conditions of a deep sea vent

My first thought was gee,

why don't we do
a Miller-Urey experiment,

but do it at high temperature,
high pressures?

Hazen's laboratory

is at the Carnegie Institution
for Science,

which is famous for experiments
that simulate

the intense pressures
deep inside Earth

with powerful tools
called pressure bombs

They're called bombs
for a reason...

Because things can explode

Hazen and his colleagues
adapted these pressure bombs

to model the environment
of the deep sea vents

in a small gold tube

What they discovered
came as a surprise

Nothing happened

You can take basic gases...

Nitrogen, CO2,
maybe some sulfur compounds

You can mix those,
you can put them in a gold tube,

you can heat them up

You don't get much
that's very interesting

Simply squeezing and heating the
ingredients had little effect

Hazen was missing the spark,

like in the Miller-Urey
experiment,

the thing that kickstarts
the chemistry

So we said, "What's going on,
what's different?"

Well, look at the natural
environment,

there's all these rocks
and minerals

Let's try putting
some rocks and minerals in

They recreate
the early Earth cocktail,

but this time grind in powder
from rocks and minerals

But will Hazen's beloved rocks
do the trick?

They run the experiment again

And this time the atoms reform
into new organic molecules...

Including amino acids

As soon as you put
powdered rocks and minerals

into the gold capsules,

then all sorts of really amazing
things started happening

You made organic molecules,

they became more stable,
they lasted longer,

and it really pointed us
in the direction of saying,

"Aha, this has got to be
part of the story"

While scientists still argue

if life began in shallow ponds
or deep sea vents,

both sides wonder,

what part of the story did rocks
and minerals play?

One possible answer
may be found in London,

in the powerful properties
of mud

Most people will be familiar
with the material

It's very gungy

That's perhaps a British word

that refers to something
which is soft

and unpleasant, generally

Peter Coveney
of University College London

is busy playing in mud...
At a very sophisticated level

He has created
powerful computer simulations

that can track
the precise movement

of up to ten million atoms

Mud can contain clay,

which is made up of some
of Earth's most common minerals

What makes it so gungy

and perhaps essential
in the origin of life

can be seen deep
in its atomic makeup

You can see here the basic
structure of any clay

It's comprised of a large number
of stacked sheets

like a deck of cards

Sheets of clay
have spaces between them

that fill up with water
and other molecules

These extensive surface areas
can help create

more complex molecules,
potentially even RNA,

an essential part
of life's genetic code

One of the most
challenging questions

in the origin of life

is how we get
from the simple building blocks

to the complicated structures

we know are fundamental
to living systems

Clays provide a clear mechanism
for achieving that

These simulations show that
the secret to clay

lies in its surfaces

The surfaces of these minerals
are incredible

They do all sorts
of chemical tricks

Hazen says minerals, like clays,

illustrate a fascinating aspect
of chemistry,

because the surface
where reactions take place

can be as important
as the ingredients themselves

The most exquisite chemistry
occurs at surfaces

Your body, your cells
are almost entirely surfaces

on which chemistry takes place

So when we think
about the origin of life,

the minerals sort of replace
surfaces you have in your body

that do that chemical work

We are finally beginning
to understand the secret role

minerals could have played
in life's origin

They provided some
of the ingredients and surfaces

where important chemical
reactions take place

So when in Hazen's color phases
did all this happen?

One of the best places

to figure that out
is back in Australia,

where Hazen and team
are now searching for signs

of Earth's earliest life

I can't believe these rocks

are three and a half billion
years old

They look like they formed
last week

Martin Van Kranendonk
leads the team

to a very unusual rock formation

You get your eye casting up,
you see them,

all wrinkly, laminated, black

Yeah!

And then if you look
a bit further back,

you see a very large
domical structure

There's no obvious way

that a chemical or physical
process would form that

Exactly

These strange shapes

are fossilized remnants of life
called stromatolites,

beautifully preserved
in these ancient rocks

This is an amazing spot

We're actually looking down
on the surface

of the ancient Earth here

This was the seafloor

3 4 billion years ago,
and I can see it in action

It's like a snap frozen
instant of time

But billions of years
have taken their toll

To really understand
stromatolites,

we have to go
nearly 800 miles away

David Flannery, a geologist,
has come to Shark Bay

in search of their
very distant descendants

Just below the surface, he finds
a series of round, black mounds:

living stromatolites

Modern environments like these,

they're very rare,
but they are really the key

to interpreting what we see
in the very early fossil record

Without environments like these,
we wouldn't know

how stromatolites were built

Stromatolites
are something like coral,

a hard mineral structure that
has been built layer by layer

A closer look
reveals the builders

Microbes... single-celled life

The living part
of a stromatolite

is only the surface
where the living microbial mat

is building up the structure
layer by layer

at less than a millimeter
per year

The top layer of these
stromatolites is alive,

with microbes that perform
a remarkable trick

They capture minerals and sand
in the water

and biologically cement them
layer by layer

into the solid mounds

The results can be seen
in Shark Bay today

and in the ancient fossils

Yeah, let me introduce you
to this outcrop

It's just spectacular
to be able to see this

And this outcrop is unique

Van Kranendonk has dated
this stromatolite

to 3 5 billion years ago

This is the very oldest fossil
of life on Earth

We all want to know
where we come from,

where life originated,
how long ago, in what form,

and this is the oldest
direct evidence we have

for life on Earth

But while stromatolites

are the earliest fossil of life
we've found,

that does not make them
the very first living thing

In fact, Van Kranendonk thinks

that by the time
stromatolites appeared,

life's party was already
in full swing

There are whole communities
and colonies

that are building fantastically
complex structures,

so we've actually come in
pretty late to the game

There is a lot that's gone on
before us to get to this stage,

and it's this complexity
that tells us that life

probably originated on Earth
very early

So if these very early fossils

are too complex
to be the oldest form of life,

is it possible
to find something earlier?

That is what Ruth Blake,
a geologist at Yale University,

is trying to figure out

by turning
to the geological equivalent

of a crime scene investigation

The crime has been committed

The criminal is gone,

but they've left behind
some indicator

because they've changed
their environment

Blake is analyzing some
of the oldest rocks on Earth,

like this ground-up one
from Greenland

that formed
at the bottom of an ocean

She is looking
for a chemical signature of life

left by microbes,
including bacteria

What we start with is our ocean
trapped in a rock,

and our bio-signature
is somewhere in here

We have to get it out

In the lab, Blake and her team

dissolve these rocks
and extract molecules

that are the chemical signature
left behind by ancient microbes

All life, like these microbes,

consumes nutrients
to produce energy

The leftovers carry
the chemical footprint of life

Even today, we humans leave
behind chemical footprints

When we breathe, for example,
we're taking in oxygen

and we're exhaling CO2
and water vapor

That water vapor interacts
with your environment

Amazingly, rocks
from 3 5 billion years ago,

at the time of the stromatolites
in Australia,

also carry a strong
chemical footprint of life

But when Blake analyzes
the Greenland rocks

from 300 million years earlier,

she makes a tantalizing
discovery

As far back
as 3 5 billion years,

we see a strong biological
signature

And the older rocks
are approaching that,

but not quite there,

but we do believe that
we see something there

Blake believes she has detected
the faint signal of life

at 3 8 billion years ago,
only 700 million years

after Earth was created,
early in the blue phase

There is still much
that we don't know

about our early planet, but some
things are becoming clearer

If you could transport yourself
back in time

about four billion years,
parts of our Earth

might not look too different

than this Southern
California beach,

minus the surfers and poodle

You could stand on cliffs,
probably of granite,

overlooking oceans
that were increasingly rich

with minerals
and early microbial life

But you would quickly die
in a great deal of pain,

suffocating
in the heavy atmosphere

rich in nitrogen
and carbon dioxide,

but lacking in life-giving
free oxygen

Then something truly astonishing
happened

Those harmless-looking microbes

floating in the water
or on stromatolites

started to change everything,
turning Earth red

Wow

Oh, my God, this is amazing!

There aren't many places
on earth

you can see something like this

A remnant of red Earth
can be seen in Australia

at the Hamersley Basin
in Karijini National Park

In these rocks, Hazen finds

a startling consequence
of early life

as it began to thrive and evolve

What we're seeing here
is one of the greatest tricks

that life ever figured out

And that was
how to take sunlight

and convert it to energy

Microbes, like those in the
stromatolites at Shark Bay,

eventually began to live
off the sun's energy

through photosynthesis

That led to a dramatic rise

in a gas that Earth
was not accustomed to:

oxygen

While to us, oxygen
is a life-giving benign gas,

to a world not accustomed to it,

oxygen created a dangerously
corrosive cocktail

The early oceans were filled
with dissolved iron

The new oxygen reacted
with that iron,

and it began to rust

and sank to the bottom
of the sea

These little microbes,
they're microscopic things,

and you wouldn't think
they could do all that much

But when they produce
that oxygen

and the oxygen reacts
with the iron in the oceans,

you get the world's
largest deposits of iron...

Thousands of feet covering
hundreds of square miles

These formations
cover a vast area

with trillions of tons
of iron ore

That is an unimaginable
consequence

of trillions upon trillions
of microbes breathing

It's a fundamental change
in the chemistry of Earth

It's a consequence
of the rise of oxygen

The rise in oxygen
that rusted iron

and sent Earth
into the red phase

also created many new minerals

As a mineralogist,
when I look at Earth history,

I see big transitions

I see the moon forming impact,

I see the formation of oceans
and so forth

But nothing, nothing matches

what life and oxygen did
to create new minerals

Some estimate that the
meteorites that formed Earth

began with only
about 250 minerals

Today, there are more than 5,000

Hazen believes that two-thirds
of all the minerals

that now make up our planet

were created by the introduction
of oxygen

And most of that was, in turn,
created by life

Amethyst

It's mindboggling

Rocks create life,
life creates rocks

They're intertwined in ways that
are just now coming into focus

But the road ahead
for life and for rocks

would not be easy

As we head into the next phase
of Earth,

new continents formed
and broke apart,

which may have created dramatic
extremes in the climate

Earth plunged into an icy
freeze, turning it white

In these frozen conditions,
life was nearly wiped out

Fortunately, active volcanoes

still poked through
the icy veneer,

billowing out carbon dioxide,
or CO2

Like a thermal blanket
around our Earth,

this kept heat in
and rescued life

Life all but shut down

And then the CO2 rises and rises

and the greenhouse effect
gets hotter and hotter,

and suddenly the planet melts

Cycles of these snowball
hothouse conditions

had profound consequences
for life

One result was more oxygen,

which eventually allowed
for bigger animals

The dramatic changes
during white Earth

would bring us
to the present phase

starting about
540 million years ago...

A living planet

filled with diverse plants
and spectacular creatures

But those life-forms
are pitted against each other

in a survival of the fittest,

and rocks can make
the difference

between life and death

That struggle can be seen
back in Morocco,

at the edge
of the Anti-Atlas Mountains

Here, Bob Hazen and Adam Aronson

are looking for evidence
of an evolutionary trick

that shows once again
how life and rocks

took a big leap forward together

520 million years ago,

this valley was a shallow ocean
filled with new forms of life

This is when the diversity
of life on Earth exploded,

all thriving in a living sea

So if you were a scuba diver
and you dove down to this reef,

you'd see all kinds of life
swimming around,

really amazing,
probably very colorful, too

There is one creature that
dominates this ancient reef

that Hazen wants to find

Nothing there

Nothing there

And nothing there

Fossil hunting is a game of luck
and persistence,

but it doesn't take long for
Hazen to strike geologic gold

Whoa!

Jeez, look at that

That is amazing

The trilobite

Hey, look, there's
another head there,

and the head there, two more

Boy, this is rich rock

The trilobites here are amazing

because these are the oldest
animals that you can find

that are preserved as
what you think of as a fossil

that you can hold in your hand

Some trilobites were like
horseshoe crabs

scurrying about the ocean floor

The reason they are found
as fossils today

is because they developed

an astonishing
evolutionary trick

shells

Trilobite shells were made
of calcium carbonate,

the same mineral
found in limestone,

the rock that built the pyramids

In effect, life itself
began to make rocks

for its own advantage

And the idea went viral

If you had a shell, you're going
to survive a lot longer

than that soft-bodied animal
that doesn't have a shell

The trilobite had an advantage

It's survival of the fittest

The trilobite's mineral shell

heralded a new phase
in the evolution of animals,

catapulting our planet
into the present stage,

green earth, one that is rich
in diverse life

From humans back to trilobites,
we owe our evolution

and survival
to the world of minerals...

With shells, then eventually
with bones and teeth

that paved the way for life
to grow taller and stronger

All are evidence of life
co-opting minerals

for its own evolutionary
advantage

We've thought for centuries,

"Animals, minerals, they're
separate kingdoms, right?"

But it turns out they overlap,

they're intertwined,
they co-evolved

That life makes minerals,

and minerals have led
to new life-forms

You can't separate the two

Life and rocks
are totally intertwined

through billions of years
of Earth history

One of Hazen's favorite places

to see this intertwined history
of life and minerals

is at the Calvert Cliffs
along the Chesapeake Bay

He and his wife Margee

pick up shells and shark teeth
from a time

18 million years ago when
massive sea creatures swam here

That's nice, isn't that pretty?

You find teeth

along the beach that are five,
six, sometimes seven inches long

with serrated edges...
Razor-sharp teeth

These were immense creatures,

sharks that may have been
50 or 60 feet long

These giants of the sea

would have dwarfed today's
great whites

And it was the bones and teeth
created with minerals

that enabled them to grow
so large and powerful

They were feeding on whales

Dolphins would have been a snack

They are just one small part
of a story of co-evolution

stretching back
to Earth's beginning

The life, the rocks,
it's all part of the same story

Step by step,
throughout Earth's evolution,

minerals and life
have sparked chemical reactions

that sculpted the planet
into what we see today

and helped create
the life we know

At this place, you get a sense
of the immensity of time

and the constancy of change

Life is creating
and sculpting our surroundings

in ways that are quite wonderful

And just to recognize the power
of life to transform a planet

Of course, humans transform
the planet too

We build cities, we build roads,

we change the composition
of the atmosphere

and change the composition
of the oceans

There are going to be
global changes

These changes whose consequences
are now beginning to unfold

are the latest chapter
in Earth's epic story...

A story that began

four and a half billion
years ago with a rock