The advancement of "de-extinction" technologies, while capturing public imagination for resurrecting extinct species, holds a far more significant and immediate potential for conserving currently endangered species through genetic rescue.
Look at this. This is rare footage from
1933. You see this dog looking animal
pacing back and forth in a cage. That's
a Tasmanian tiger. One of the very last
of its kind. It died in 1936. And the
species was ultimately declared extinct.
But now scientists are trying to bring
them back. And it's not alone. You might
have seen headlines about direwolves or
woolly mammoths or dodo birds or
passenger pigeons or dinosaurs.
deextinction has become a new and urgent
scientific debate that we should all
know about. But when I took a deep dive
into what's really going on here, I
realized that we're getting this
conversation very, very wrong. Because
we're on the cusp of a huge genetic
breakthrough. But the most huge if true
thing happening here isn't actually
bringing back extinct animals. It's what
this means for all the animals alive
today. And very few people seem to know
about it. >> Deextinction.
>> Deextinction.
>> The extinction.
>> Trying to bring back creatures from the past.
past.
>> We can do this.
>> Resurrect the woolly mammoth. >> Direwolf.
>> Direwolf. >> Tasmanian.
>> Tasmanian.
>> It sounds like something out of a
science fiction movie.
>> It's no longer science fiction.
>> That's the future. [Music]
>> All right. Imagine you're a mad
scientist and you want to bring back an
extinct animal. Here's the recipe. Step
one, choose your animal. like a mammoth.
Now, from here, you need to choose one
of three paths, and for each, you'll
need different ingredients. You could
try to take a close- living relative of
the animal that you chose and breed a
bunch of them together until you get an
animal with traits that roughly match
the one that you wanted. This is the
same basic process that made my dog Thor
out of a wolf. But instead of trying to
make something new and adorable, you're
trying to make something old. It's
called back breeding, and it can work.
Like with this guy, it's called a quaga.
>> I actually have a little uh toy quaga
right here. It's a subspecies of zebra
native to South Africa.
>> They have stripes on the head and neck
and the stripes fade away along the body.
body.
>> It was hunted to extinction by 1883, but
we've already been able to bring a
version of it back using back breeding.
This is a really exciting approach and
it can work for both animals and plants,
but it is incredibly slow. It takes many
generations of zebra to get there and
it's a guessing game. You don't know
which genes will appear when and which
will go away. In reality,
>> it's a cool method that's been done, but
probably pretty limited.
>> Okay, but how about option two? I
remember in Jurassic Park, they pulled
dinosaur DNA from blood inside a
fossilized mosquito.
>> Bingo. Dino DNA.
>> And then they cloned the animal based on
that DNA.
>> It's all part of the miracle of cloning.
>> Cool. Let's do that. In real life,
though, the ingredients that you need
for this method aren't just the extinct
animals DNA. You need a whole living
cell. Because cloning is actually a very
specific scientific technique.
>> The long name is sematic cell nuclear
transfer. It means removing the nucleus
out of an egg cell and replacing it with
the nucleus of a body or sematic cell of
the animal you want to clone. And then
you put that egg with its new nucleus
into an animal where it can grow. And
this actually works almost.
almost.
>> People tried this in the early 2000s
with an extinct species called the
bukardo. These animals are so cool. But
by 2000, there was only one Bicardo
left. But luckily, this was 4 years
after Dolly the sheep was famously
successfully cloned. So, in an attempt
to save the species, some quick-thinking
biologists put tissue samples from the
remaining Bicardo in storage. And then
they were able to take the nucleus from
those cells and put them into the cells
of domestic goat hybrids. And in 2003, a
baby Bicardo was born. Unfortunately,
their first clone that was born had a
malformed lung and didn't survive. Um,
this hasn't been tried again.
>> So, we are able to clone animals when we
have living cells, which is wild. But
unlike the bicardo, nobody carefully
preserved the whole cells of a mammoth.
The biggest challenge is needing those
living cells in the first place. Because
it turns out that cells have a shelf
life. Once an animal dies, their cells
are typically pretty shortlived, dying
off within hours or days. But freezing
can dramatically slow this process,
which is why there's been hope that
animals found preserved in ice, like
this 40,000-year-old baby mammoth, might
have some usable cells. But so far, no
revivable cells have been found. So
cloning is hard. But we've got one more
option, and this one is by far the most popular.
popular.
>> For the 99.99%
of extinct species, we have to use the
third method, gene editing. If you
imagine DNA as a group of blocks, each
block here could represent a gene. Like
this one tells me the shape of the
skull, and this one tells me ear size,
and maybe this one tells me thick woolly
coat. And then stacked together, they
give me the instructions for how to
build this specific animal. The
challenge is like living cells have a
shelf life. So does DNA. Once an animal
dies, the DNA in its cells starts to
break down into tinier and tinier and
tinier fragments until eventually
there's nothing left. That's why right
now we can't bring back animals that
went extinct too long ago, like the
dinosaurs. Too much time has passed and
their DNA is way too fragmented. But if
we use an animal that died off fairly
recently or was frozen in just the right
way, scientists can figure out what some
of those key missing pieces are and
replicate this stack of blocks in
another animal. This is gene editing.
You compare the stack of DNA blocks of
the extinct animal with the blocks of a
close living relative to see where the
two are different and edit the DNA in
the living relative. So, it resembles
the DNA in the extinct one. This is what
they're trying to do with woolly
mammoths and direwolves,
but they won't be exactly like the
extinct animal. In fact, people online
were really quick to point out that
these actually aren't really direwolves
at all. It's better to think of them as
genetically modified greywolves. But the
thing is, that was intentional.
Scientists are choosing which exact
traits to manipulate to get the outcomes
that they want. and they want to do it
by making the least amount of edits
possible. I asked the scientist in
charge of the direwolf project why I'm
thinking about deextinction and I'm also
thinking about animal welfare. Every
time we change the sequence of DNA in a
genetic background, there's a risk that
something happens that we didn't
predict. I want healthy animals in the
end. Therefore, my goal is the fewest
number of changes necessary to
de-extinct those important
characteristics. So deextinction might
have a branding problem because people
on one side are looking at the literal
definition and saying that's not
de-extinction and they're right that's
not the exact animal. But then on the
other side of this you have scientists
who are saying bringing back exact
replicas isn't really the point. They're
not trying to deextinct the exact
animal. They're trying to deextinct what
the animal did. In the end the whole
direwolf or not direwolf debate doesn't
really matter. Branding them this way
makes for a good headline, but it's not
technically accurate. And while the
effort to bring back a version of a
direwolf or a woolly mammoth is totally
cool, I think it's a distraction from
what is the real huge, if true, use of
this technology. But first, let me show
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special. It's not just that it's built
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durability, or that it has a lifetime
warranty against yellowing. Those things
are important, but what's even more
important is their mission to tackle
plastic waste. Every year, 19 to 23
million tons of plastic waste leaks into
lakes and rivers and oceans. First, they
plan to become plastic neutral. So, they
built a closed loop model. The phone
cases are 100% recyclable. You can send
back your old phone case and they break
it down and repurpose it into a brand
new one, giving it a second or third or
more life. It's even got a QR code on
the inside so you can track the
product's life cycle. But what they
really wanted was to tackle all plastic
waste, not just modern plastic, but also
legacy and future plastic, too. What if
you could take plastic waste out of the
ocean, and then use or upcycle it?
That's exactly what they do. They've
built a solar powered floating platform
that uses water jets to create pressure
differences that guide floating garbage
into its collection area. It's like a
robot vacuum for ocean cleanup. This is
new. They're testing it right now, but
it's the kind of effort that I find
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There have been five times in the
history of Earth where over 75% of all
life was lost. And many scientists say
we're going through a sixth right now.
And while prior mass extinctions were
caused by natural disasters, this one
seems to be caused by us. But hang on,
even if you don't care about animals and
biodiversity, this sucks for us. This
has huge impacts on our food and our
homes and everything we rely on to
survive. And here's the optimistic part.
The same tools that we've been talking
about to bring back extinct animals can
also be used to help animals not go
extinct in the first place. This is the
part that got me most excited, and this
is what I don't see enough people
talking about. It's called genetic
rescue. Meet the blackfooted ferret.
This adorable little guy is in need of
genetic rescue because
>> every living blackfooted ferret alive
today are first cousins. >> Yikes.
>> Yikes.
This little guy nearly went extinct in
1979. Because of humans, the population
crashed. But fortunately, they've
started to come back. The problem now is
that this new group of blackfooted ferrets,
ferrets,
>> it has really, really low diversity.
Very small gene pool.
>> Scientists call this the bottleneck
effect. If your group doesn't have
enough genetic variety, you're
vulnerable to things like disease and
weird genetic mutations. This is a
problem facing dozens of species whose
populations put them at risk for genetic
bottlenecking. But today, scientists are
exploring gene editing to create more
genetic diversity in some of those groups.
groups.
>> We can take DNA from a museum stuffed
animal from a 100 years ago, sequence
its DNA, and then edit it into living
blackfooted ferrets.
One way to get diversity back, which we
are working on.
>> Another great example of using minimal
gene editing to save a species, is this
little guy, the northern qu from
Australia. Look how cute he is. But
they're expected to be extinct in the
wild within the next 10 years because of
this guy, this toad. This is the cane
toad, and it's an invasive species. It's
got a deadly toxin on its skin. So what
happens is
>> so our carnivorous little qual will eat
the cane toad and they die instantly
from that toxin.
>> But scientists found that it's just one
single letter of genetic code that makes
them either die from eating a cane toad
or completely resistant. Just one
letter. So they're working on a way to
introduce that one change into the
population and make coals that are able
to eat cane toads without dying, saving
an entire species. In theory, you could
do a lot of this. Not just making key
animals poison resistant, but also
disease resistant or heat resistant.
There are projects to do this on coral
reefs. Huge if true. But then why are we
trying to deextinct animals at all? That
brings us back to the Tasmanian tiger.
Humans hunted these tigers until there
were none left in the wild. But they
didn't understand what would happen
next. Without the tiger, Tasmania lost
its only apex predator, a keystone
species, meaning it has a huge impact on
its ecosystem. And without them,
>> there's been an explosion of walabeees
and kangaroos there. They're eating all
the shrubs, they're eating all the
bushes, you know, that's impacting the
bird populations. It's changing the landscape,
landscape,
>> which means that now other species are
at risk, like the Tasmanian devil.
>> They developed this incredibly strange
disease, and it's actually like a cancer
tumor that grows on their face, and they
spread it from animal to animal. Apex
predators used to reduce diseases like
this. By eating sick members of the
population by killing all the Tasmanian
tigers, we created a butterfly effect
that's rippling through the food chain
to this day. So, some are proposing
>> the only way we'll ever be able to bring
that ecosystem back into balance is to
put the Tasmanian tiger back into it.
>> Tasmania is an island cut off from other
natural predators. And many scientists
agree that there's no other living
species that could replace what the
thyloine could do here. But could we
actually do this? Well, they're
following the recipe. They've identified
the animal. They've sequenced the DNA.
As for close relatives, this is the
closest living animal to the thyloine.
Their genetic makeup is 99.9% identical.
identical.
>> And then you just edit that.1% where
they're different. And that will turn
that then into a Tasmanian tiger or a
thyloine cell. >> Wait.1%.
>> Wait.1%.
That's actually a lot genetically. And
that's the bit that's going to take a
really, really long time um to get that
bit done.
>> At this point though, you might be
wondering, whoa, whoa, whoa, whoa, whoa.
Did we not learn our lesson from
Jurassic Park?
What are the consequences of actually
doing this? When is it okay to use this
technology? And when is it not? In other
words, how do we get this right? What
happens when you drop a predator back
into an environment that hasn't seen it
in decades? Well, in this case, it seems
like a lot of the animals remember them.
>> We made some replica thyloines and we
took them out into the bush in Tasmania.
We saw that they absolutely without
doubt, even though it's been over a
hundred years since they were really
there. All of those animals remember the
thyloine. If there's a fox or a goat,
they don't really care. But if they see
the thyloine, they are out of it.
>> But what about the thyloine's instincts?
How would it know to behave right like a
predator? How much of an animal is
nature versus nurture? There's real
debate here.
>> I frankly don't think that it will ever
happen that we will see thyloines into
the wild.
>> But advocates for the thyloine would argue
argue
>> those behaviors are really hardwired in
any animal's brain. The best example of
this would be domestic cats. These are a
pounce predator animal that have been
living in our houses now for hundreds of
generations, eating tinned cat food or
little crispy biscuits. But if you
wiggle a feather in front of them or a
mouse runs across the floor, they
immediately know that they are a pounce
predator and they will pounce and kill
and eat that that animal.
>> We don't really know until we try. And
they're trying. This is all hard, but
it's not like we're creating things that
are suddenly going to just be released
into the wild.
>> You would have them in a very large
enclosure. you would really study them
very very closely and make sure that
they have taken on all of the behaviors
so that by the time we get a population
that we could think about releasing into
the wild, we know that they're going to
be able to really thrive once again.
>> What this all means, best case, is we're
still decades away from a wild Tasmanian
tiger, but this technology is coming and
we need to be part of that conversation
right now. It's obviously fun to imagine
Jurassic Park or bringing back a
direwolf, but as we have this
conversation, we got to be careful.
We're talking about manipulating
billions of years of evolution. There
are huge stakes, ethical stakes about
using animals as lab experiments,
environmental stakes that could
accidentally devastate entire
ecosystems, and of course, the stakes of
not doing absolutely everything we can.
To me personally, the most huge, if
true, optimistic bit of all of this
isn't actually bringing back animals
from the past. It's using all of this
incredible science and technology to
help keep the animals and the world that
we live in now healthy.
>> I would love people to go away from this
and be like, deextinction science is
conservation science and we absolutely
have to use it.
>> We are living in a world that we changed
before we understood the consequences.
The real debate about de-extinction
isn't what's a direwolf. It's what
responsibility do we have to the world
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