Unbelievable as it seems
we can transfer heredity through
the substance of DNA.
It's possible for a lot of people to become
successful.
You have to have the right genes.
For the first time, scientists have successfully
repaired a faulty gene in human embryos.
They used a process known as gene editing.
It could help eliminate deadly genetic diseases
but some say it's too much like playing God
and opening a dangerous Pandora's Box.
If this was going to be your baby would you
have gone ahead with this?
This story begins in the 1850s
in a small monastery.
And with this monk, Gregor Mendel.
While he's experimenting with pea plants,
he identifies that traits like color and height
pass from one generation to the next.
He's the first to establish the principle
of inheritance.
After Mendel dies the other monks in the abbey
take the notes of his astonishing discovery,
put them into a pile, and burn them.
Well there's no question that Mendel
was ahead of his time.
I guess you'd say the scientific community
was not ready to hear what he was saying.
It's fraught with anxiety because there's
this idea that you may be playing God
you may be trying to determine the future and
taking control of things that people should
not have control over.
So other scientists rediscover what Mendel
already knew and in 1905 the word 'genetics'
appears for the first time.
Research on DNA is one of the
great new challenges in science.
Skip forward to 1953 and
scientists at Cambridge University
discover that DNA has a double helix structure.
DNA is a code.
The structure of DNA showed exactly how that
code was put together.
Once you knew what the structure was, you
could begin to introduce other chemicals
you could take things apart, you could put
them back together.
All those types of things you could suddenly
start studying.
In the 1970s American biochemist Paul Berg
isolates DNA from different sources
then he cuts and splices them together.
The result is recombinant DNA.
He writes a letter about the
"potential biohazards" of what he's
just discovered.
All gene editing experiments stop until 1975
and the Asilomar Conference in California.
A group of around 140 scientists, physicians
and lawyers
come up with practical and ethical guidelines.
It was almost like a nuclear treaty
for biotechnology.
Scientists were looking at recombinant DNA
with the idea of doing positive things.
Somebody else could take these
and start using them
to make poisons to make 
bioterrorist weapons.
So they felt like the time it was time to
take a step back, create some rules
and that's what they did.
By 1994 the first genetically engineered food
hits the shelves.
Controversy is swirling around an updated
variety of the humble tomato.
It's called the Flavr Savr.
2012 is the year of a landmark discovery.
It's called CRISPR
CRISPR
CRISPR Cas9
There's a dispute about who actually discovered
this tool for editing the human genome.
But now scientists can cut out faulty sections
of DNA and replace them with healthy ones.
It's cheap, it's easy to use.
I've watched people use CRISPR
in a neighborhood laboratory
and these were folks that were
no more scientists than you and I.
That that's exciting because that gives you
all kinds of power to do experimentation.
The concerns are that people might use this
say to increase the strength of their offspring
or to choose eye color,
to try to affect personality.
The number of gene editing advances using
CRISPR is growing worldwide
and soon China steps up its efforts 
to dominate the biotechnology sphere.
And in 2018 this happens.
Irresponsible, disturbing, inappropriate,
that's how two of the inventors of a
gene editing tool are describing
a Chinese scientist's experiment
that helped create genetically edited babies.
From what I've read he had relatively high-minded
ideals about what he was doing and I think
his impression was that it was going to be
welcomed.
The audience that he sat in front of was really
pretty horrified and eventually
the Chinese government really
started to turn against him.
The interesting thing is that every time a
new technology comes along everybody talks
about it as though it's a Pandora's Box
and that these evils are going
to fly out with a good.
And that is true.
There's always risk but that's the story of
science.
The whole idea is to open up these boxes and
to see what's inside.
And each time you open up a box, 
there's another box inside of it.
And that's going, what's going to happen with
CRISPR is the revelations will continue and
the controversies will continue.
That's just the way science goes.
