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  • 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.