Original subtitles

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It's famous for its grizzly bears,

its wolves, bison and its geothermal activity.

All of greater Yellowstone

is actually still an active volcano today.

The geysers, hot springs and thermal pools

signal the unrest that continues just below the surface.

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There's a lot of volcanic activity underground

beneath the GYE and so that expresses itself

in many different ways at the surface.

For many years scientists believed

these pools were devoid of life,

but a fantastic alien world exists

in the waters of Yellowstone's hotspots.

Yellowstone was the first place these were discovered.

The thermal pools are filled with clues

about the earliest life on earth

and even life on distant planets.

We study modern organisms that represent ancient life,

or that give us an idea of where alien life

might be able to exist and how it could exist.

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In 1966, scientists discovered organisms

in Yellowstone's boiling hot springs

and called them thermophiles.

A very famous microbiologist started sampling,

started doing standard microbiological tests

but at higher temperatures and really, really discovered

that organisms were living in these hot springs.

These thermophiles are thriving

in an environment that would be fatal

to most other forms of life.

Thermal pools in and around Yellowstone

are a living laboratory where scientists are even able

to research potential life on distant planets.

Understanding sort of the distribution

of microbial life in extreme environments on our planet

gives us an idea of potentially where else

they could exist on other planetary bodies.

Montana State University's

Thermal Biology Institute studies bacteria, archaea,

and viruses that hide in the springs and pools.

One of the pools they're investigating

is LaDuke Hot Springs.

The field work here,

there's a lot of unique safety issues.

Stepping into a hot springs would be very dangerous,

you can burn yourself very badly.

It's so dangerous that we can't show

how they actually collect their samples.

It's definitely a case of don't try this at home.

We are not going in to these hot springs

with big shovels and digging up truck fulls of material.

We're taking the smallest possible samples that we can

to get the analysis that we wanna get.

Brent is like a bio prospector

as he investigates hot spring biology.

In the pools there's a very large number

of different organisms, so multiple species

of bacteria and archaea.

And then each of those has probably

five or 10 viruses that infect those.

They can provide clues as to

how organisms lived long, long ago

and what types of metabolisms they had.

The rainbow-like colors seen in many areas

come from heat-loving bacteria.

So the photosynthetic organisms

give you the greens and the bright oranges.

Some yellow come from sulfur precipitation

caused by the microbes.

Some of the orange is minerals,

you can get different colored minerals as well.

So it's basically microbes and minerals

interacting in the hot springs that give you the colors.

Brilliant blue in the center

comes from clear water reflecting back blue light,

just like the sky.

The wild, chromatic beauty attracts tourists

but it also draws scientists

that believe these extreme thermal conditions

might replicate those found on other planets.

Dr. Luke McKay is a microbial ecologist

and an astrobiologist.

I'm looking for organisms with

what I call early evolved metabolisms,

metabolisms that originated long, long ago

shortly after the origin of life.

Brent and Luke know

that the invisible microbes that they hunt

are elusive and diverse.

When we show up at a thermal environment,

typically the first thing we do

is measure the temperature and the pH of the system.

8.14.

Depending on the environment and the type

of thermal feature it is,

we'll take different types of samples for chemical analysis

to understand what types of chemical molecules,

what types of chemistry is the hot spring composed of,

because that will determine

what types of microbes live in the hot spring.

Both bacteria and archaea inhabit the pools

in different proportions and both target viruses.

And so, depending on the hot spring

and the chemistry of the hot spring,

the bacteria or archaea

will use different chemistry, and so,

if you have one hot spring that supports

the metabolism of a lot of different archaea

then you'll have a lot of archaea there.

And pretty much anywhere where you're gonna have

a lot of archaea and bacteria

you're also gonna have a lot of viruses,

and they're gonna be in any of the hot springs.

These microbes are all part

of the tree of life.

All life on earth can be categorized

into one of the three domains of life.

Those are archaea, bacteria and eurkya.

And bacteria, on the tree of life,

is easily the most diverse of the three domains.

Archaea is smaller and eurkya is even smaller than that

in terms of, you know, if you can imagine an actual tree

it would be like most of the branches

are taken up by bacteria.

It's crazy because when we hear

what organisms are in the main carrier,

we think it's insanely diverse,

because it's us, it's humans,

it's all the animals, insects,

it's all the plants, all the fungi, protists,

but in terms of their DNA, it's actually

a very small fraction of the overall diversity of life.

Most of that diversity is captured

within the microbial world.

Single celled archaea

were originally classified with bacteria,

but now have a branch of their own.

Bacteria and archaea are different.

They're branches of life

that separated many, many billions of years ago.

But then, when when we started

to get molecular information,

genomic or genetic information, in sequencing genes

and comparing genes, we started to realize

that bacteria and archaea are incredibly different

from one another.

Their genes are very dissimilar in many cases.

This investigation requires extensive time

in the field and in the lab.

In TBI we're working on

a couple of different aspects of thermophiles.

One is very fundamental.

So we're taking samples from the hot springs

and we've got groups of organisms

that no one's ever grown in a laboratory,

and nobody knows how to grow them.

We find them very common in the hot springs

and can't figure out how to reproduce that in the lab.

And so we're doing everything we can

to learn about those micro organisms.

If we can grow organisms in the lab we can understand

so much about what they're doing

and you can formulate hypothesis based

on what you see in the hot spring and then test those

in the tube in the lab.

I take a sample from a hot spring

and I extract all the DNA of all the genomes,

of all the organisms, all the microorganisms

in that hot spring sample.

And then I sequence that DNA.

And then the next step is the computer analysis

of trying to understand how to

take all of that genomic information

and isolate different individual microbes.

And then there are the strange viruses

found in the streaming geysers and pools.

You have thermophilic bacteria,

you also have thermophilic archaea

that both live in these hot springs,

and then you have the viruses that infect

both the archaea and the bacteria

that live in the hot springs.

Like bacteria, the word virus

often conjures up images of sickness and death.

But none of the heat loving viruses in Yellowstone

affect our health because our bodies are too cold.

So the viruses in the springs are dependent

on those specific bacteria or archaea,

so they don't infect humans.

All have evolved

from the earliest forms of life on embryonic earth.

But together they suggest that life

may have arisen in super hot environments.

How did life originate here on earth?

And what was the evolutionary history of life?

How did life colonize certain environments

that are very extreme or distinct from other environments?

Some archaea, bacteria and viruses

in extreme environments still live in the same way

as our earliest microbial ancestors

and use the same sources of energy.

We oftentimes find organisms, microbes,

with early evolved or deep evolutionary roots.

In other words, they branch off

at a very, very early point on the tree of life.

And so these are the types of organisms

that are likely, they're not the same

as what was existing four billion years ago,

but they may be more similar to that than anything else.

And so if we understand their sort of modern day cousins

of those ancient organisms,

we can understand more about those ancient organisms.

A new virus

found in Yellowstone's thermal pools by Rebecca Hochstein

and Martin Lawrence has a structure so ancient

that scientists think it may be connected

to the root of the universal tree of life

according to a new study published

by the National Academy of Sciences.

It affects only archaea and it's spindle shaped.

It seems to be part of a rare superfamily.

Every time we go and sample, we find DNA

from organisms that nobody's ever grown,

nobody's ever named.

And so just the diversity of unknown organisms out there

is to me the most exciting.

This is actually like

a very active area of research.

And as new genomic information comes in

on different organisms, we are able to sequence new genomes

and we're able to get new sequences to compare

and to place on the tree of life.

New branches start to arise.

We start to actually discover new branches of life

that we didn't know about before.

The possibilities have experts

in many fields excited.

The main goal of my research

is to understand what organisms are in these hot springs,

but also as an engineer, what can we do with these,

how can they benefit society?

How can we use them to do

any sort of biotechnological task that we set at hand?

As they investigate the ways

that life likely evolved they're inching closer

to finding new places where life might be found.

So as we start to gather data

about the chemistry of Mars or the chemistry of Titan,

or Enceladus or Europa,

all of these exoplanets in our own solar system

that are interesting places where life

may have at least at one point colonized,

then we can understand a lot about those environments

by studying environments on Earth

that are sort of exotic and interesting.

Yellowstone's thermal pools may hold the keys

to the origin of life on our planet and beyond.

There is so much we don't know

and that we're still learning constantly.

Perhaps one day soon

Yellowstone's thermophiles would reveal the answers

to one of the most burning questions in science.

Are we alone in the universe?

I have no evidence to say that we are not alone.

I have not discovered alien life,

but I think it is incredibly probable

that we are not alone.

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