- [Man] Good girl.
- [Barbara] Okay, going in with the probe.
- [Man] Okay.
- [Narrator] This is Doctor Barbara Durrant.
She's working to save a species,
and holy crap she's sticking her arm all the way in.
Wow, let's go back to the beginning and get some context.
(tape rewinding)
This is a zoo, a frozen zoo.
- [Barbara] So, I can pull some of these out.
This is a South African Cheetah,
this is a Mountain Yellow-Legged Frog,
this is a Sumatran Tiger, also an endangered species.
So, every species in here has its own unique
and interesting story.
- [Narrator] Inside these tanks of liquid nitrogen,
the genetic legacy of thousands of species is preserved.
Nope, not dinosaurs!
That's Jurassic Park.
But yeah, same idea I guess.
Anyway, this is the Northern White Rhino.
It's not a dinosaur, but it is extinct.
Functionally extinct.
There are two surviving female specimens,
but neither can reproduce.
This extinction is the result of human activity,
mainly poaching.
However, because of the work being done
here at the frozen zoo,
and with the cooperation of some Southern White Rhinos,
this may not be the end of the line
for the Northern White Rhino.
In fact, with a little luck,
this could be a very short extinction.
- [Man] Come on, Wallace!
Come on Amani!
Good, hustle.
- [Barbara] This is just the most wonderful job
anybody could ever have.
- [Man] Good girl.
- [Barbara] I think the interaction with the animals
is my favorite part.
I also love being in the lab and doing the basic science.
Uh oh. (laughs)
I'll have to look for that later.
Okay, so, now.
- [Narrator] This is Doctor Barbara Durrant.
She's the director of San Diego Zoo's
Reproductive Sciences Department,
and entrusted with the care of their frozen zoo.
- [Barbara] It's a unique collection
of cell lines, sperm, embryos, DNA
from over 10,000 individual animals.
The reason that we have a frozen zoo
is because species are going extinct every day.
Without this reservoir,
we don't have hope of bringing them back.
- [Narrator] Now, Doctor Durrant and her team are working
with the genetic data in their frozen zoo
to do something that has never been done before:
bring a species back from extinction.
- [Barbara] Okay, this is Northern White Rhino right here.
I would say the project
to bring the Northern White Rhinos back
is the most ambitious project that we've undertaken.
This species was poached to extinction.
We would call the Northern White Rhino functionally extinct
because there are two living Northern White Rhinos.
They're both females.
But they have been determined to be
incapable of reproduction.
And there's no male,
so that makes it a little bit more difficult.
However, we can actually bring the Northern White Rhino
back from extinction with the living cells
that we have in the frozen zoo.
- [Narrator] Much of the samples in the frozen zoo
are tissues like skin cells.
Recent advances in technology have allowed researchers
to convert skin cells into stem cells,
and stem cells can transform into any other kind of cell.
- [Barbara] Our aim is for those cells
to become sperm and eggs, so those are the next steps.
This means that they can create fertilized eggs...
No, not those kinds of eggs.
Rhinos are mammals,
please stop putting Jurassic Park references in here.
Once they can reliably create
fertilized Northern White Rhino embryos,
they can be gestated in these lovely ladies,
a group of Southern White Rhinos
that are helping to bring the Northern White Rhinos back.
(metal gate creaking)
- [Man] Good job.
- [Barbara] When we first started
doing the reproductive research with the rhinos,
we needed them to be calm and comfortable
so that we could do our research noninvasively.
And that means we're not anesthetizing these animals,
we're training them.
- [Man] All right, let's go!
- [Barbara] This is a voluntary process for these animals.
If they're not comfortable on any given day,
we stop, we open the gate, and we release them.
- [Man] Not having it?
All right.
Well, unfortunately,
I don't think she's up for it right now.
I was actually personally impressed
with how quickly they did take to training.
Over the years of the program,
we've done between 700-800 ultrasounds.
We've collected quite a bit of data
and that's all because they're participating
in those sessions.
- [Barbara] The process that we use
to visualize the reproductive tract
is called trans-rectal ultrasound.
Okay, going in with the probe.
So, we are actually going into the rectum
because the rectum is above the reproductive tract.
See, ovary's right down in there,
but I don't have good view of it yet.
The reason that we're doing all this training
and the ultrasound
is so that we can understand the reproductive cycle
in very minute detail.
There it is.
If we know when the animal is going to ovulate,
we can time an artificial insemination for maximum success.
The ultimate goal for these Southern White Rhinos
is to be recipients for Northern White Rhino embryos
that we would produce in the lab.
So, all of this background work has to be done
for the end goal to be achieved of having females
that are capable of carrying a Northern White embryo
to term.
- [Narrator] Right now these Southern White Rhinos
are being evaluated to make sure they're ready
to carry the first new generation of Northern White Rhinos.
There's enough genetic diversity preserved in the frozen zoo
to create a self-sustaining population
of Northern White Rhinos in the wild.
- [Barbara] This is a very long term project.
We're talking decades.
I feel a very strong personal obligation to do this work.
Because humans have driven so many of these species
to the brink of extinction,
we have the responsibility to bring these animals back.
The hardest part of this project
is developing the technologies.
No other species has been brought back
from the brink of extinction
with these kinds of cellular techniques.
If this project succeeds,
we will have shown the pathways to make this possible
for a number of other species,
and that would be a tremendous achievement
for the human race.
But it is bittersweet
to think that I won't see the end of this project.
Maybe I will!
Might live to be 100.
- [Man] I mean, (laughs) I hope we all do!
- [Barbara] I might be alive,
but I might not be aware of it. (laughs)
(uplifting music)
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