Science fiction sometimes has a way of predicting the future.
I was 18 when Jurassic Park came out.
It was this incredible cinematic experience.
And it put this idea in people's heads, maybe
we can bring dinosaurs back from the dead.
It was inspired by a 1991 finding
of DNA fragments found in
a 40 million year old bee that was preserved in amber.
So they started to think, "Maybe we'll find a mosquito and inside its belly,
we might be able to find DNA fragments of a dinosaur."
Bang. Clone dinosaur.
But no, that wasn't the case.
Over time, they discovered that amber doesn't preserve DNA as well as they'd originally thought.
And the truth is DNA sequences that are long enough and clean enough
to be used for cloning purposes
probably can't be older than 1.5 million years old.
But the question of whether we can bring back
more recently extinct species, that is alive and kicking.
So what if we could resurrect the extinct?
Extinction is a fact of life. 99% of things that have ever lived are extinct.
Animals usually become extinct through what they call an extinction vortex,
the environment changes, greater pressure from predators.
The population starts to shrink, you get inbreeding,
fewer viable offspring, you end up with a population that's just not going to survive.
We've had five major mass extinctions. What's unusual about now is that we've
entered into a sixth extinction. And this is being caused by us.
Not only is it being caused by us, but it's happening much faster than ever before in history.
It's estimated that about a million species are at risk of extinction.
A quarter of all mammals, a 10th of all birds, and 40% of all amphibians.
And we are fools if we think we can live without this biodiversity.
De-extinction is a terrible word.
It suggests that extinction is no longer a problem.
It suggests that we can make it temporary. But to be clear, the technology is extraordinary.
There are three techniques.
Back breeding is something that humanity has done, basically forever.
Breeding organisms together over successional generations that have
the skin deep traits you want to recreate in one single organism,
kind of like how we bred dogs from wolves but going backwards in time.
Cloning is more complicated.
The transfer of nuclear DNA from the endangered or extinct donor species
to the egg of a surrogate species, which is closely related and not endangered.
It has been used, technically, to bring back a species called the Pyrenean ibex.
After many, many hundreds of failed attempts, eventually,
one little animal grew to term, and this little baby was born, and the room held its breath
because this was the first time ever an animal had been brought back from extinction.
For a very short period of time, that actually went extinct.
A few minutes after she was born, she started to develop breathing problems and died.
So this means it's also the first species ever to have gone extinct twice.
So in theory, you could use that to bring an extinct species back from the dead.
Unfortunately, it only works if the nuclear DNA from the
donor species was taken while it was alive. You can't use dead material as a donor source.
So it can't work for a frozen mammoth.
CRISPR-cas9 is kind of like cut, copy and paste in a word processor but for DNA.
This is a tooth from a woolly mammoth.
In here, there will be cells that still contain DNA from the woolly mammoth that it came from.
CRISPR-cas9, its use in de-extinction is to take DNA that are still okay
and copy them into the genome of a closely related species, say, an Asian elephant.
Use the Asian elephant as a scaffold and have bits of the idea of a mammoth bolted on to it.
Thick, shaggy, iconic woolly mammoth hair, for example, or bigger fattier skin that would
allow it to stay warmer in colder temperatures, smaller ears that allow less heat to escape.
So scientists could actually use something like this as a starting point for de-extinction.
Now, that sounds fascinating, crazy science fiction.
But the question is, is that de-extinction?
It's really important to recognise that you can't, in fact, reverse extinction.
Once that little weave of the evolutionary tree has been snipped,
you can't weave it back together again.
What's done is done. You can't turn back the clock.
What we're really talking about is creating a novel organism
to fulfil the role in the ecosystem that an extinct animal fulfilled.
And that's a very different thing to bringing an animal back from the dead.
There are some good reasons to try to de-extinct some species.
When certain species go extinct, they leave an ecological hole in the landscape that is damaging.
And if we can bring that animal back, we can start to restore levels of biodiversity.
There's this really famous story of the wolves of Yellowstone Park.
They were exterminated from Yellowstone about 100 years ago. But in 1995, they were reintroduced.
Nobody could believe what was going to happen.
They're being there influenced many other flora and fauna.
An entire kind of cascade of effects.
The wolf kills led to opportunities right the way throughout the ecosystem.
This is the dream scenario.
Mammoths are a really good example of this.
They were involved in maintaining a habitat called the mammoth grassland,
which no longer exists because the mammoths don't exist.
The thought is that if you bought the woolly mammoth back,
they could turn the mossy, unproductive tundra into a rich and luscious grassland.
That grassland was very effective at pulling carbon dioxide out of the air.
So de-extinction might be a big part of a response to global warming.
De-extinction is a grand experiment filled with manifold uncertainties.
This is not a plug and play. Would it just regenerate the forest ecosystem?
Or would it push that ecosystem into some new state that we've never seen before?
These systems are so incredibly dynamic, there will be unpredictable consequences.
We have to assume those will be there right from the get-go.
I think it would be ethically acceptable to put a de-extinct mammoth back into that environment.
Those environments, they're already in terrible, terrible trouble and
they are going to change beyond recognition anyway.
However, we can have a better go at achieving the same effect
by using species that exist already today without the whole de-extinction thing.
There's a really famous quote from Jurassic Park where Jeff Goldblum's character says,
"You were so preoccupied with whether or not you could, you didn't stop to think if you should."
I think de-extinction comes from a profoundly emotional place.
We've responded with this kind of,
"Wow, wouldn't it be so fantastic and exciting or troubling? Or it's Jurassic Park," you know.
The trouble with this narrative is it's all about us again.
If we just stand there and say, "Look how amazing we've been", then we're bringing
these animals into a world in which they have no safeguards, no real, intrinsic moral status.
People might want to sell, patent and profit from various forms of de-extinct creatures.
And we know that this has a rollback effect to cause
huge biodiversity problems, public health issues.
I mean, look at the pandemic and the reality that we're in now.
There's really nothing to stop them being purely the subject to the whims of whatever
economic system that happened to be there, we could well be eating mammoth burgers
in these new Pleistocene parks.
Obviously, I would love to see a woolly mammoth. I mean, who wouldn't love to see a mammoth?
But the word is dangerous.
It has consequences. It pretends that we can solve extinction,
so it doesn't really matter if we cause a species to go extinct.
But what we mustn't do as conservationists is be just simply anti-technology.
In doing all of this science and developing this technology, we will learn so much
about the way that cells and embryos develop. It could lead to new treatments for disorders,
it could also generate knowledge that could be useful to the field of conservation.
For example, some species that are really on the edge, tiny populations, are very inbred,
they have very little genetic diversity. CRISPR can be used to re-engineer that diversity back in.
What would it mean to engineer coral reefs so that they're more stress-tolerant
and can withstand warming waters with climate change?
So you can actually use all these techniques to stop things going extinct in the first place.
That to me is a better use of the technology than de-extinction.