[ on-screen text ] This is a short film about the people and places
of the Cuatro Ciénegas Basin in Coahuila, México
The Cuatro Ciénegas Basin - its water and microbial, plant
and animal communities - are a treasure of México
All of this unique life has been uncovered
through the work of Mexican scientists with international collaborations
This work makes possible
a deeper understanding of the history of all of life on earth
My name is Valeria Souza.
I work as a researcher at UNAM - the National University of Mexico,
that is a very large university.
This is probably the most important site that we have in the world right now
to understand the origin of diversity.
This place has an amazing geology that you can see just in front of you.
We have that kind of tsunami of rocks that uplifted,
because the mountain that is over that edge
is like an arrow.
It has an active fault with magma underneath.
And, it's pushing all the marine sediments that are from this valley up
and then it's flipped and makes a heart shape -
a 3,000 meter mountain.
So, all this amazing geology is an explanation of
why Cuatro Ciénegas is a singularity -
because these marine sediments
store the conditions of the ancient sea.
They store the magma... that is rich in sulfur,
that takes us all the way back to the Archean,
and it stores the minerals that formed in sand.
These minerals are very old.
Also, it is a sediment that is devoid of the most basic element for life,
that is, phosphorus.
So, this site is amazingly poor in phosphorus,
and that makes for a very... skewed stoichiometry.
Most of life now cannot live in a skewed stoichiometry -
we need 60 nitrogens for each phosphorus.
Here, we have 100 nitrogens - at least - for each phosphorus,
in some places 200 nitrogens for each phosphorus.
So, how they can make basic things, such as ribosomes or DNA,
is because they are really good at stealing phosphorus from anybody else,
including rocks.
So, they have an amazing array of strategies
to deal with the lack of phosphorus, and they did that since the Archean.
So, here we have stromatolites and microbial mats,
whose ancestry goes back to the Precambrian in some cases.
And, we are going to a site where we think we have
the boundary between the Archean and the Precambrian.
Since this is a blue pool,
we are talking about the moment where animals turned the planet blue,
and that was in the Ediacaran in the late Precambrian.
My name is Maria Kalambokidis,
and i'm an intern for a year, working in Valeria's lab in UNAM,
in the Department of Evolutionary Ecology.
And, right now, we're at Pozas Azules, at the site of the Archaean domes.
So, here you have a microbial mat that created a bubble
through the activity of the methanogens.
It created a bubble and then it eventually burst,
creating this perimeter.
So, we sampled the microbial mats that are still present there.
And, right now, they're hidden beneath the salt crust,
because it's so dry.
My research is looking at the evolutionary resilience
of the microbial mats at Cuatro Ciénegas.
So, the microbial mats create a codependent community
where each layer is sort of representing the history of metabolisms on Earth.
So, you start with methanogens,
which create nutrients for the next layer of sulfur-oxidizing bacteria,
all the way up until photosynthesis.
So, through this community,
they've become really dependent on each other
and they evolve together,
creating a really resilient community in Cuatro Ciénegas
that has existed for many millennia.
I was interested in the microbial mats
because they're evolutionary resilient and they've existed so long here,
but also because they've existed in an environment
that many other organisms couldn't exist.
For example, a really low nutrient content,
in particular, low in phosphorus,
which is thought to be necessary for the building blocks of life.
So, they've existed for so long,
they're able to exist in extreme environments.
Therefore, it creates a sort of living laboratory of organisms
that are alive today and indicative of communities that existed long ago.
So, in origin of life research and in astrobiology,
usually you're looking for signs of life - like biosignatures on another planet,
or you're breaking open old rocks
to see if there are compounds indicative of life.
But, in Cuatro Ciénegas, and in these mats,
we think that we have the organisms that formed the same communities...
that existed long ago.
So, as a biologist, it's really exciting
to actually be able to study it alive today.
[ from Spanish ] The big questions why so many species???
on planet Earth or in this place ???the history of survival???
The origin of life was probably very easy.
The origin of life was probably ?????? millions of ways possible???
On this planet, life survived???
???? the rocks and transformed all of the minerals.???
My name is Gabriela Olmedo-Álvarez, and I work at Cinvestav.
Cinvestav means: "center of research for advanced studies."
I'm in Mexico,
right in the middle of Mexico - in Irapuato.
I'm the director of Cinvestav in Irapuato, although I am also a researcher.
And, I've been working for 15 years, close to Valeria Souza,
in trying to decipher what are the keys that allow
so much diversity of microorganisms inhabit these places.
And, if you are looking at the pond behind me -
that's a beautiful pond, and it looks like it doesn't have much,
because it doesn't have a lot of nutrients.
That is why it's so interesting -
it doesn't have nutrients, but it has lots of different bacteria,
and has evidence of very old life.
It also has these stone-like things that are stromatolites.
Stromatolites are evidence of the first types of life on the planet,
but here they are still alive.
They are still, you know, blooming,
and it's very interesting because these are very, very old types of life.
And, that is possible precisely because there are no nutrients.
So, other larger things cannot compete with it,
and that allows these to remain for centuries and millions of years.
But if we walk just a few meters away, maybe just 200 meters,
we'll find a very different scenery.
We'll find these very salty crusts,
and these salty crusts are full of life also -
a very special life with lots of salt and with a low pH.
So, it's a weird life that we do not understand,
and that's sort of one of the focuses that we have for this trip -
to be able to sample what things are living there.
And, we'll take them to the lab to figure out
how some bacteria or archaea can live
with these very, very extreme environments.
In the system called "Pozas Rojas,"
because these ponds are fluctuating environments,
they get very saline in the summer because the water evaporates.
It is deep water, not rain water,
so each one becomes a more vivid color than in winter,
where water doesn't evaporate as much -
so they get like the juiciness concentrated in the summer.
The life that lives here is very diverse -
there's microbial mass that we have sequenced.
There's a very large biodiversity... and there are like islands.
There are nine small islands of these tiny pozas
and a big lagoon.
So, you can compare the diversity in each one of them
separately and then... the big poza in the middle.
But, this was perturbed by a hurricane in 2010
and it became a complete lake, all of its...
It kind of drained all the nutrients and all the water
from the... east side of the valley.
The biology changed
because the pozas became connected with the lake water,
and also the nutrients changed.
It was - before the hurricane - it was the site with less phosphorus.
Now, it is a site that nearly has a balance of stoichiometry.
So, it is very interesting how the life...
got habituated to this richer environment.
What is even more interesting is that what was a very primitive...
site... it became a more Holocene site.
For example, the Vibrio that lives here,
they didn't radiate since the Holocene in Cuatro Ciénegas,
which is at the same time as the fishes came from the Río Bravo shelf.
So, they are very interesting, and they are always changing,
and that makes us really happy - and we are following their change.
So, I'm sure that the deep aquifer
still has the deep, ancient bacteria.
It shows that the lake that...
shaped here, that came here,
brought newer creatures from everywhere
that were bacteria more used to nutrients.
And, maybe there are pockets of nutrients in different parts of the valley.
What makes Cuatro Ciénegas unique is precisely the lack of nutrients.
Maybe they are going to become - each time that we sample -
more and more imbalanced and return to their ancient selves.
But, it will take time.
My name is Jorge Valdivia, and I am a full-time professor
at the Universidad Nacional Autónoma de México.
[...] of my doctoral studies in the Cuatro Ciénegas valley.
I was working with the genus bacillus
and the project was focused on knowing the relationship that existed
between the number of copies of the ribosomal operon
and with the available phosphorus.
It is known that the valley of Cuatro Ciénegas
is an extremely oligotrophic site.
With these conditions... they are homologous
to what... the conditions in the past [...] origin of life.
Then, the interesting thing to find out was
how a genus that is characterized by
having many copies of the ribosomal operon
can adapt to these conditions of extreme oligotrophy.
We wanted to work in the isolates of the main sites in the valley,
and we wanted to quantify the genome level -
how many ribosomal operons they had.
We set them to grow with water from the site
to replicate the natural conditions in which they are found living,
and what we observe is that there is a zero correlation
with respect to the hypothesis of the growth rate.
A good indication are the viruses.
Viruses are the most ferocious hunters in the world.
And, like ferocious hunters, each one has their own favorite prey.
And, Cuatro Ciénegas is the most diverse place on the planet for viruses
at the tiniest scale.
And, the favorite food of those viruses are bacteria
My name is Nahui Medina,
and right now I'm a PhD student in Nuevo León in Monterrey.
So, right now I'm doing this amazing project about Archaeas and extremophiles.
What we do right now is try to isolate every single microorganism that we can,
and we do this with amazing people in the lab,
trying to create strategies
to make these microorganisms live in the lab.
This is pretty much interesting because
Archaeas, you know, in Ancient Greek, is about "ancient," you know...
This means that it could help us to know how they lived
and try to understand...how life is...
what begun... at that moment... it's pretty interesting...
They are so beautiful because they have so many colors -
red, pink, and like a... yellowish, some of them.
So, it's a pretty amazing project we're doing right now.
Maybe because it's in a place where...
the whole ecosystem, and the whole habitat is...
it's not in another place, you know...
you cannot find... the species that are in here.
So, it's very... interesting
because the microorganisms or the prokaryotes are living here.
There's just living here and that's it.
You cannot find them in another place in the world.
So, that's what we're doing and we're so happy to do it.
Here we are in Poza Azul Two,
that is one of the most beautiful pozas in all the valley.
What we can see behind us is a very big stromatolite shelf.
So, these blue pozas
take us back to 600 million years ago
when the animals changed the chemistry of the ocean
and the ocean turned blue -
and that's called the Ediacaran Era.
So, in Cuatro Ciénegas, we have kind of different timeframes -
different moments in geology that got preserved.
And, that's really interesting because it's not just a metaphor,
it's not just that it looks like...
the Ediacaran, and when the ocean turned blue.
and still the stromatolite shelf were being eaten by the first [embryos??]
[that was their due?]
But also, it's that this lineage has survived -
survived for the longest time.
In the Archaean domes that are 50 metres over there,
we have evidence that the Archaean - a world of methane and CO2 -
is preserved inside domes that are built by bacteria
that protect the ancient anaerobic bacteria from the oxygen input,
while they are doing photosynthesis.
This kind of cooperation and construction of the whole niche is pretty unique.
We know that stromatolite were world-builders -
they made the ocean blue,
they transformed every element that came from the start and made life complex.
For the fact is that, here in Cuatro Ciénegas,
we have a window - a true window - of those lost worlds is really incredible.
Because you walk... meters and you find
three billion years... of time.
And, you can have lineages that are very, very divergent
from the ones we know now,
how they assemble their nutrients and how they work.
We can cultivate them, we can study them using metagenomics.
But, for them to be studied, we need water.
And, this water here is precious - it's not just any water.
So, water that comes from that mountain that has a magmatic heart,
that magmatic heart is responsible for the Jurassic.
So, what happened is - humans - we are really silly,
and we think we can manage nature.
When there's agriculture in the desert...
where the water comes comes from - the deep aquifer.
And, it is not just any aquifer -
it's an aquifer that has stored the conditions of the early sea,
and we are losing it.
Then we have the tragedy of Churince where there's no longer water.
It only looks like that.
And now, it's a field of dead turtles and dead fishes.
Maybe there's some hope that we can recover it
if we close all the channels that are taking out the water
from this ecosystem.