The American Chestnut tree was one of the most abundant
and dominant trees
in the Eastern United States Appalachian chain.
They were gorgeous trees.
It is actually the tree that inspired the Christmas song
"Chestnuts Roasting On An Open Fire".
It was a very heavily used resource by people.
In the late 1800s,
people brought Asian chestnuts to North America
as an ornamental tree, and they carried with them a disease,
a fungal blight and it infected
native American Chestnut trees
and just wiped them out completely.
Over 99% of the population was obliterated.
Fast forward nearly 100 years
and a team led by William Powell
at the State University of New York
was able to actually discover why the blight
kills the Chestnut tree.
And they have produced a strain of Chestnut trees,
that is 100% resistant to this fungal blight.
It really shows that there's no point of no return.
There's potentially no point you can get where you can't
end up recovering and healing the damage that's happened.
And that's the hope that biotechnology
brings to conservation.
The UN is issuing a dire warning on climate change.
Nearly a million species are at risk of extinction
because of humans.
We are doing irreparable harm to Earth's biodiversity.
And what is clear is that we're driving
species to extinction.
The human species has driven
the planet's biodiversity into an unprecedented decline.
The extinction rate is 1000 times higher
than it naturally would be
with as many as one million species at risk.
Many scientists say we are in a sixth mass extinction.
The decline in biodiversity is a crucial issue
that is largely overlooked in the public consciousness
in terms of how important it really is.
Our existence as humans is deeply intertwined
with the health and flourishing
of a number of non-human species.
If you destroy the environment,
it's going to turn around and bite back.
We need to radically rethink our relationship
to the natural world.
We need to understand that we are a deeply entrenched
part of it, certainly not separate from it.
This is part of what is killing other species,
and eventually us too.
Traditional conservation methods alone
are struggling to offset the speed at which
we're losing species and habitats.
Biotechnologies that have been developing in the wings
are now offering the hope of new, if not controversial,
ways of saving endangered species.
Genetic rescue traditionally has been the practice
of increasing a population's genetic diversity,
in a way to benefit it.
Usually when the population is exhibiting
some type of problem, like inbreeding or whatnot.
We're trying to increase genetic diversity
or increase the viability of the genetics of a population.
Then in that kind of very core definition,
biotechnologies offer a whole host of ways to do that.
Biotechnology offers everything from genetic insight
to restoring diversity with cloning
or technologies or doing gene editing,
to aid disease resistance, all the way to that moonshot
of using all those technologies to restore something
like a wooly mammoth or a passenger pigeon.
The process of resurrecting species like this
is known as de-extinction
and it's one of the more complex
and controversial applications of this biotechnology.
Because of biotechnology,
we can bring back those kinds of animals.
But of course it is a tedious work to do
but it is not impossible.
De-extinction is a scientific movement we could say,
an emerging space of researchers
who are trying to use a variety of different biotechnologies
in order to help recreate
close approximate versions of extinct species
so that they can create new animals
that mimic extinct species and can go back out
into the wild spaces where extinct species used to roam,
and carry out important ecological roles there
that have disappeared since a certain species went extinct.
The very first example of de-extinction,
if you call it that, is the bucardo,
which is a Pyrenean Ibex or kind of a mountain goat.
The last bucardo died in Spain, it was a single animal,
but they took some cells from its ear and preserved those.
And years later, they used those cells
to clone a bucardo using a domestic goat as the surrogate.
So they could create cells, implant an embryo in the goat
and the goat gave birth to a live Bucardo.
The species was brought back,
only to go extinct again just 10 minutes later,
due to lung defects.
The 2003 resurrection of the bucardo remains the closest
that anyone has gotten to true de-extinction,
at least for now.
In 2017, George Church's wooly mammoth project
captured the public's imagination
and brought de-extinction back into conversation.
So de-extinction is really just a little bit
of hybridization, using ancient DNA
and some modern synthetic DNA to achieve a goal
of say cold resistance or pathogen resistance.
Church hopes to adapt the genome
of the wooly mammoths closest living relative,
the Asian elephant, to include a number of mammoth traits.
In particular, how to thrive in the cold climate
of the Arctic.
We are using the tools of paleo genomics,
which is the ability to actually get DNA sequences
from those extinct species from 100s or 1000s of years ago,
and look at their genetic code,
compare it to their living relatives
and start to understand what are the unique fragments
of DNA that made them do what they did
in the environment.
Two, there's now something called gene editing,
which is most famously done with CRISPR Cas-9.
It's an enzyme and RNA combination,
that basically is a homing system that allows scientists
to target any region of DNA in a living cells genome
and make a cut and then make an edit to that area.
So we could take the hemoglobin gene
in an Asian elephants genome,
and cut it and overwrite in its place the hemoglobin
a wheel from a wooly mammoth, which will change
how it bonds oxygen at different temperatures.
And that's something that George Church's lab
has already done in culturing a Petri dish.
So it used to be a big deal to make one precise change
in the genome of an animal.
We've made 42 changes in pigs.
We now have 2000 adult pigs
that are called three point, version 3.0,
that are used for organ donations.
And that's being tested now in preclinical trials.
That shows we can do 42 in a cell and a lab,
and then move the nucleus into an egg
and bring it to term all the way to adulthood.
Thousands of times.
So we wanna do the same thing in elephants,
which are a little bit bigger than pigs,
little slower but otherwise it should be
a very similar procedure.
While altering the genome of living animals
like the Asian elephant could help bring a version
of extinct species back to life,
it could also help to rescue a species
which is itself endangered.
We want something that has all the advantages
of cold resistance, possibly resistance to pathogens
like the EEHV virus, that's almost extinction level
harm to the Asian elephant, which is an endangered species.
So you can consider it a hybrid
but it also, we can use synthetic biologies
to say alter tusk length to avoid poachers.
So there's a number of opportunities here
that is not limited to de-extinction of genes.
Church wants to re-introduce his hybrids
into the Arctic Tundra, which he hopes will preserve
an environment that's crucial to storing carbon.
Science has proven de-extinction is possible,
and the environmental argument for doing it is clear,
yet questions still remain.
Doing de-extinction, there's a whole lot of unknowns.
And especially when you're trying to think about a species
like a wooly mammoth
that's been gone for thousands of years.
What are the prospects for being able to put this back
in the appropriate kind of environment.
Does wooly mammoth habitat even exist anymore?
And if you go for very long extinctions,
the further back you go, the more uncertainty,
the less we know about the species
and the less likely there is to be a place for it now.
The technical ability is outrunning our ability
to think about is this a sensible or a useful thing to do.
And this is concern that, you know,
if we're dealing with something as fundamental
as the genetic makeup of species
and thinking about putting them back out into the wild,
you know, the genie's out of the bottle a bit.
What does it mean to take the tools
from synthetic biology and merge them
with the more traditional conservation biologists,
who are losing the game, as we're, you know,
also losing more species,
can really fruitful combination be born
from this hybridization of knowledge sets.
And indeed it seems to be happening.
There are interesting projects getting off the ground,
when you bring these two different ways
of looking at nature together, something that's engineerable
and something that's worth saving.