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Imagine you were alive back in the 1980's and were told
the computers would soon take over everything.
>From shopping to dating and the stock market.
That billions of people would be connected via a kind of web.
That you would own a handheld device
orders of magnitude more powerful than supercomputers.
It would seem absurd but then all of it happened.
Science fiction became our reality that we don't even think about it
We're at a similar point today with genetic engineering.
So let's talk about it.
Where it came from? What we're doing right now?
And about a recent breakthrough that will change how we live
and what we perceive as "normal" forever.
Humans have been engineering life for thousands of years. Through selective breeding
we strengthened useful traits and plants and animals.
We became very good at this but never truly understood how it works.
Until we discovered the code of life: deoxyribonucleic acid, DNA,
a complex molecule the guide of the growth, development function
and reproduction of everything alive.
Information is encoded in the structure of the molecule.
Four nucleotides are paired and make up a code that carries instructions.
Change the instructions and you change the being carrying it.
As soon as DNA was discovered people try to tinker with it.
In the 1960's, scientists bombarded plants with radiation
to cause random mutations in the genetic code.
The idea was to get a useful plant variation by pure chance.
Sometimes, it actually worked too.
In the 70's, scientists inserted DNA snippets into bacteria, plants and animals
to study and modify them for research, medicine, agriculture and for fun.
The earliest genetically modified animal was born in 1974,
making mice a standard tool for research, saving millions of lives.
In the 80's, we got commercial.
first patent was given for a microbe engineered to absorb oil today we
produce many chemicals by means of engineered life like life-saving
clotting factors growth hormones and insulin, all things we had to harvest
from the organs of animals before that. The first food modified in the lab went
on sale in 1994: the Flavr Savr tomato, a tomato given a much longer shelf life
where an extra gene that suppresses the build-up of a rotting enzyme. But GM food
and the controversy surrounding them deserve a video of their own.
In the 1990's there was also a brief foray into human engineering. To treat
maternal infertility, babies were made to carry genetic information from
three humans making them the first humans ever to have three genetic
parents. Today there are super muscled pigs, fast-growing salmon, featherless
chickens and see-through frogs. On the fun side, we made things glow in the dark
fluorescent zebrafish are available for as little as ten dollars.
All of this is already very impressive but until recently,
gene editing was extremely expensive, complicated and took a long time to do.
This has now changed with a revolutionary new technology now
entering the stage: CRISPR. Overnight, the costs of engineering have shrunk by 99%
Instead of a year.
it takes a few weeks to conduct experiments and basically everybody with
a lab can do it. It's hard to get across how big a technical revolution CRISPR is.
It literally has the potential to change humanity forever.
Why did this sudden revolution happen and how does it work?
Bacteria and viruses have been fighting since the dawn of life.
So-called bacteriophages, or phages, hunt bacteria.
In the ocean, phages kill 40% of them every single day.
Phages do this by inserting their own genetic code into
the bacteria and taking them over to use them as factories.
The bacteria try to resist, but fail most of the time
because their protection tools are too weak.
But sometimes, bacteria survive an attack. Only if they do so can they activate
their most effective antivirus system. They save a part of the virus DNA in
their own genetic code in a DNA archive called CRISPR.
Here it's stored safely until it's needed.
When the virus attacks again, the bacterium quickly makes an RNA copy
from the DNA archive and arms a secret weapon, a protein called Cas9.
The protein now scans the bacterium's inside for signs of the virus invader by
comparing every bit of DNA it finds to the sample from the archive.
When it finds a 100-percent perfect match
it's activated and cuts out the virus DNA making it useless, protecting the
bacterium against the attack.
What's special is that Cas9 is very precise, almost like a DNA surgeon.
The revolution began when scientists figured out that the CRISPR system is programmable.
You can just give it a copy of DNA you want to modify and put the
system into a living cell. If the old techniques of genetic manipulation were
like a map, CRISPR is like a GPS system. Aside from being precise cheap and easy,
CRISPR offers the ability to edit life cells to switch genes on and
off and target and study particular DNA sequences.
It also works for every type of cell: microorganisms, plants
animals or humans. But despite the revolution CRISPR is for science,
it's still just a first generation tool. More precise tools are already being
created and used as we speak.
In 2015, scientists use CRISPR to cut the HIV virus out of living cells from patients
in the lab, proving that it was possible. Only about a year later they carried out
a larger scale project with rats that had the HIV virus in basically all of
their body cells. By simply injecting CRISPR into the rats tails, they were
able to remove more than 50% of the virus from cells all over the body.
In a few decades, a CRISPR therapy might cure HIV and other retroviruses.
Viruses that hide inside human DNA like herpes could be eradicated this way.
CRISPR could also defeat one of our worst enemies: cancer. Cancer occurs when
cells refused to die and keep multiplying while concealing themselves
from the immune system. CRISPR gives us the means to edit your immune cells and
make them better cancer hunters. Getting rid of cancer might eventually mean
getting just a couple of injections of a few thousand of your own cells that have
been engineered in the lab to heal you for good.
The first clinical trial for a CRISPR cancer treatment on human patients was
approved in early 2016 in the US. Not even a month later, Chinese
scientists announced that they would treat lung cancer patients with immune
cells modified by CRISPR in August 2016. Things are picking up pace quickly.
And then there are genetic diseases. There are thousands of them and they range,
from merely annoying to deadly or entail decades of suffering. With a powerful
tool like CRISPR, we may be able to end this. Over 3,000 genetic diseases are
caused by a single incorrect letter in your DNA.
We are already building a modified version of Cas9 that is made to
change just a single letter, fixing the disease in the cell. In a decade or two
we could possibly cure thousands of diseases forever. But all of these
medical applications have one thing in common: they are limited to the
individual and die with them, except if you use them on reproductive cells or
very early embryos. But CRISPR can and probably will be used for much more:
the creation of modified humans, designer babies and will mean gradual but
irreversible changes to the human gene pool.
The means to edit the genome of a
human embryo already exists, though the technology is still in its early stages.
But it has already been attempted twice: in 2015 and 2016, Chinese scientists
experimented with human embryos and were partially successful on their second
attempt. They showed the enormous challenges we still face in gene editing
embryos but also that scientists are working on solving them.
This is like the computer in the seventies: there will be better computers.
Regardless of your personal take on genetic engineering, it will affect you.
Modified humans could alter the genome of our entire species because their
engineered traits will be passed on to that children and could spread over
generations slowly modifying the whole gene pool of humanity. It will start
slowly: the first designer babies will not be overly designed, it's most likely
that they will be created to eliminate deadly genetic disease running a family.
As the technology progresses and gets more refined, more and more people may argue
that not using genetic modification is unethical, because it condemns children
to preventable suffering and death and denies them to cure. But as soon as the
first engineered kid is born, a door is opened that can't be closed anymore.
Early on, vanity traits will mostly be left alone, but as genetic modification
becomes more accepted and our knowledge of our genetic code enhances,
the temptation will grow.
If you make your offspring immune to Alzheimer, why not also
give them an enhanced metabolism?
Why not throw in perfect eyesight? How about height or muscular structure?
Full hair? How about giving your child the gift of extraordinary intelligence? Huge changes
are made as a result of the personal decisions of millions of individuals
that accumulate. This is a slippery slope. Modified humans could become the new
standard, but as engineering becomes more normal and our knowledge improves, we
could solve the single biggest mortality risk factor: aging. Two-thirds of the
150,000 people who die today will die of age-related causes. Currently we think
aging is caused by the accumulation of damage to ourselves, like DNA breaks and
the system's responsible for fixing those wearing off over time. But there
are also genes that directly affect aging. A combination of genetic
engineering and other therapy could stop or slow down aging, maybe even reverse it.
We know from nature that there are animals immune to aging. Maybe we could
even borrow a few genes for ourselves. Some scientists even think biological
aging could be something that eventually just stops being a thing. We would still
die at some point, but instead of doing so in hospitals at age 90
we might be able to spend a few thousand years with our loved ones. Research into
this is in its infancy, and many scientists are rightly skeptical about
the end of aging. The challenges are enormous, and maybe it is unachievable.
But it is conceivable that people alive today might be the first to profit from
effective anti aging therapy. All we might need is for someone to convince a
smart billionaire to make it their next problem to solve. On a bigger scale we
certainly could solve many problems by having a modified population. Engineered
humans might be better equipped to cope with high-energy food, eliminating many
diseases of civilization like obesity.
In possession of a modified immune system with a library of potential
threat, we might become immune to most diseases that haunt us today.
Even further into the future we could engineer humans to be equipped for
extended space travel and to cope with different conditions on other planet,
which would be extremely helpful in keeping us alive in our hostile universe.
Still a few major challenges await us. Some technological, some ethical.
Many of you watching will feel uncomfortable and fear that we will create a world in
which we will reject non-perfect humans and preselect features and qualities
based on our idea of what's healthy.
The thing is we are already living in this world. Tests for dozens of genetic
diseases or complications have become standard for pregnant women
in much of the world.
Often, the mere suspicion of a genetic defect can lead to the end of pregnancy.
Take Down Syndrome for example: one of the most common genetic defects.
In Europe, about ninety percent of all pregnancies where it's detected are
terminated. The decision to terminate pregnancy is incredibly personal, but
it's important to acknowledge the reality that we are preselecting humans
based on medical conditions. There is also no use in pretending this will
change, so we have to act carefully and respectfully as we advance the
technology and can make more and more selections. But none of this will happen
soon: as powerful as CRISPR is, and it is, it's not infallible yet. Wrong edit
still happen as well as unknown errors that could occur anywhere in the DNA and
might go unnoticed. The gene edit might achieve the desired result
disabling a disease, but also might accidentally trigger unwanted changes.
We just don't know enough yet about the complex interplay of our genes to avoid
unpredictable consequences. Working on accuracy and monitoring methods is a
major concern as the first human trials begin. And since we've discussed a
possible positive future, there are darker visions too.
Imagine what a state like North Korea could do if they embraced genetic
engineering. Could a state cement its rule forever by forcing gene editing on
their subjects? What would stop a totalitarian regime from engineering an
army of modified super soldiers? It is doable in theory? Scenarios like this one
are far far off into the future, if they ever become possible at all. But the
basic proof of concept for genetic engineering like this already exists
today. The technology really is that powerful. One of this might be a tempting
reason to ban genetic editing and related research that would certainly
be a mistake.
Banning human genetic engineering would only lead to the science wandering off
to a place with jurisdiction and rules that we are uncomfortable with. Only by
participating can we make sure that further research is guided by caution,
reason, oversight and transparency.
Do you feel uncomfortable now? Most of us have
something wrong with them. In the future that lies ahead of us, would we have been
allowed to exist?
The technology is certainly a bit scary, but we have a lot to gain and genetic
engineering might just be a step in the natural evolution of intelligent
species in the universe. We might end disease, we could extend our life
expectancy by centuries and travel to the stars. There's no need to think small
when it comes to this topic.
Whatever your opinion on genetic engineering, the future is approaching no
matter what. What has been insane science fiction is about to become our new
reality, a reality full of opportunities and challenges.
Videos like this would not be possible without your donations on patreon.com
If you want to support is expanding complicated stuff and maybe get your own
bird in return you can do so here. If you want to learn more about CRISPR, we put
the sources and further reading in the description. More videos about the whole
topic area will follow. If you want to be notified when it happens,
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Subtitles by the Amara.org community


基因編輯工程將永遠改變一切(Genetic Engineering Will Change Everything Forever)

3791 分類 收藏
Harry Yeung 發佈於 2017 年 1 月 22 日
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