[electronic beeping]
[static fizzling]
[female narrator] September 2012.
Under a parking lot in the English city of Leicester,
archaeologists find a mysterious skeleton,
its spine oddly twisted.
DNA from the bones confirms
these are the mortal remains of Richard III, king of England.
His funeral, 530 years after he was killed in battle.
What's more, most portraits show him with dark hair and eyes.
But his DNA reveals Richard III
likely had fair hair as a child and blue eyes.
Genetics can be full of surprises.
DNA is the blueprint to life,
the stuff that determines nearly everything about you,
from how you look to whether or not you're a thrill-seeker.
But that just takes up 1.2% of your DNA.
Scientists still don't know what's in the remaining 98.8%.
Our closest evolutionary relatives,
chimpanzees,
share 96% of the same DNA as us.
But we also share about 60% of the same DNA...
-[chimpanzee screeches] -...as bananas.
The ability to read DNA
is arguably one of the most important technological advances
of the 20th century.
But, in our rush to understand and manipulate DNA,
are we sowing the seeds of our own destruction?
Are we unleashing a real Frankenstein's monster?
[growls]
For centuries,
humans have known that we get more than our looks from our parents.
But no one ever knew how.
By the 1950s, biologists know
that DNA exists and that it contains the code of life.
[man] This is a close-up of the DNA molecule,
magnified more than 100,000 times.
Unbelievable as it seems,
we can transfer heredity through the substance of DNA.
Well, gee, what kind of stuff is DNA?
[narrator] In 1952, when British chemist Rosalind Franklin
uses X-rays to magnify DNA,
she makes a startling discovery.
DNA is actually shaped like a spiral.
A year later,
Franklin's photo lands on the desk of James Watson and Francis Crick,
who realize what they're seeing is actually a double helix...
which helps them work out DNA's molecular structure.
So what is this stuff?
DNA stands for deoxyribonucleic acid.
Let's break it down.
Inside every cell in your body,
in the nucleus, you'll find the genome,
twenty-three pairs of squiggly chromosomes.
Half are from your mother,
half are from your father.
And each chromosome contains a folded-up spiral ladder strand of DNA.
That ladder is made up of just four molecular bases
that always connect in pairs.
Adenine and thymine,
and then cytosine and guanine.
And certain sequences of those letters, what we call genes,
tell the cell to create certain proteins,
the molecules responsible for every function in your body.
[birds chirping]
DNA can be found in every living thing.
But it's also incredibly complex.
And it could end up fundamentally changing
our understanding of life
if only we can unlock its secrets.
In the 1960s,
before anyone fully understands how DNA operates,
scientists get an idea.
If they study families that share a unique genetic trait,
they should be able to locate that trait on their shared chromosomes.
Over the next few decades,
geneticists start combing through the DNA of families
with inherited diseases.
One example is Huntington's disease,
a rare neurological disorder that only shows up in adults.
So parents often pass it down to their children
before they even know they have it.
My daughter, she's at risk from the illness as well.
She's only 14.
And hopefully, one day, there will be a cure for her.
[narrator] In 1983,
researchers begin work on isolating where the disease is on the genome,
and they eventually discover
a gene marker for Huntington's on chromosome four.
It means they can spot the disease before its symptoms show,
so adults can know if they're putting their future children at risk.
One of the many researchers
rushing to isolate genetic diseases is
British scientist Alec Jeffreys.
But in 1984, he realizes something else.
Certain stretches of DNA produce a pattern,
rather like a bar code, that's unique to each person.
All it takes is a microscopic amount of DNA from any body tissue,
and scientists should be able to distinguish
and identify that individual.
He calls it "DNA fingerprinting."
And it will revolutionize the way crimes are solved.
In the summer of 1986,
the body of 15-year-old Dawn Ashworth is found in a wooded area
in Leicestershire.
[man] Dawn was subjected to a horrific sexual attack,
and I have no doubt that the person who committed that was
a very sick-minded individual indeed.
[narrator] What alarms the neighborhood is that, three years earlier, the body
of 15-year-old murder victim Lynda Mann was found just half a mile away.
Do they have a serial killer on the loose?
Detectives give Dr. Jeffreys
DNA samples recovered from both victims,
and he proves their suspicions are correct.
It's the same man.
[man] You can seen that the patterns in this track and this track
are, in fact, identical.
And therefore, it led us to the conclusion
that this semen has originated from the same man,
and therefore, the two murders are connected.
[narrator] But to investigators' surprise,
the sample doesn't match the suspect they already have in custody.
[man] You can see that the pattern from his blood stain is
quite different from that...
got from the semen that was taken from the vagina swabs from both girls.
[narrator] So police start collecting DNA samples
from over 5,000 men living in the area,
until they finally find a match.
And Colin Pitchfork becomes the first person
ever to be convicted based on DNA evidence.
DNA fingerprinting becomes the greatest advance
in forensics since actual fingerprinting.
By 1990, the use of DNA in police work
explodes all around the world.
Since it was launched,
America's national DNA index of criminals, called CODIS,
has helped in more than 465,000 investigations.
The chances of two unrelated individuals matching is one in 30 billion.
That's almost four times the world's population.
CODIS contains nearly 14 million offender DNA profiles.
As of October 2019, 367 convicted people
have been exonerated through DNA.
Throughout the 80s,
even before scientists fully understand how it works,
DNA is already proving useful for uncovering disease and solving crimes.
But to really understand DNA, in 1990,
scientists embark on one of the most ambitious projects ever,
creating a map of the human genome.
It's no small feat.
The human genome contains about 3.2 billion base pairs.
If you wrote out the entire sequence, it would fill 800 copies of the Bible.
If you stretch the DNA in one cell all the way out,
it would be about six feet long.
But all the DNA from the 37 trillion cells in your body
would stretch across the solar system and back again.
The effort to map the genome will end up costing around $2.7 billion.
Not so expensive for the secret to all of life.
Americans spend at least ten times more on pizza per year.
But even as some geneticists are struggling to decode DNA,
others don't want to wait.
They decide to start manipulating it.
Take a gene from one living thing that has the trait you want
and insert it into the DNA of another living thing
during reproduction.
And voilà, you've artificially engineered that genetic trait.
The technique proves especially good at boosting the efficiency of food crops.
[man] It will be possible to grow crops that have no cholesterol in the oil.
We'll be able to grow crops with higher vitamin content.
[narrator] In 1994, geneticists make a backwards copy of the gene
that ripens tomatoes
and create new tomatoes that don't ripen too quickly.
Other crops are modified to be genetically resistant to pests.
They're called "genetically modified organisms,"
GMOs.
And soon, they're everywhere.
As of 2018,
the top five countries growing GMOs in terms of crop area
are the United States, Brazil, Argentina,
Canada, and India.
Twelve countries in Africa are now testing crops
that have been modified for drought tolerance,
saline tolerance, and enhanced nutrients.
In the US, up to 92% of corn is genetically engineered...
and 94% of soybeans.
Estimates are that more than 75% of processed foods on supermarket shelves,
from soda to soup to condiments, have some genetically altered ingredients.
But as people begin to realize
the extent to which their food is genetically modified,
there are concerns.
What exactly are we eating?
Some of this, likely,
comes from soy which has been genetically modified.
So what's the big deal, genetically modified? Well, we don't know.
[woman] There's no scientific consensus as to whether these foods are okay or not.
And yet we are putting them into infant formula,
something we give to babies from the first day of their lives.
And yet they contain ingredients that have never been tested for safety.
[narrator] For now, there is no scientific evidence
that swapping out a plant's genes makes food harmful in any way.
But simply interfering with nature
at such a basic level makes people nervous.
Are geneticists messing with forces they don't fully understand?
-[bleating] -When scientists start tinkering
with the DNA of animals, the debate intensifies.
In 1996, Scottish scientists
take the nucleus of a white-faced sheep's udder cell
and inject it into the egg cell of a black-faced sheep,
then implant the egg into a surrogate mother.
One hundred and fifty days later,
the surrogate gives birth to a white-faced lamb,
an exact genetic copy of the mom who donated her udder cell.
Dolly the sheep is an instant celebrity,
the first mammal cloned
from an adult cell, a genetic twin to her mother.
If scientists can successfully clone a sheep like Dolly,
-then what about other forms of life? -[bleats]
The question is now being asked,
will they ultimately be able to clone human beings?
[narrator] The same technique does prove successful for cloning monkeys,
but what about humans?
It'd be one thing to modify the genes of a baby with a deadly disease,
but will people start designing their children,
making sure they have a higher IQ
or a certain eye color?
Scientists can now take cells
from a human embryo smaller than a pinhead,
and use them to grow genetically identical healthy body organs,
ones that could later replace sick ones.
[cameras clicking]
But meddling with human embryos proves extremely controversial.
The use of, uh... uh...
embryos to clone...
is wrong.
[stammers] We should not, as a society, grow life...
to destroy it.
[narrator] Human cloning is flat-out banned
in more than two dozen countries, but not the US.
And the debate rages on.
Meanwhile, after a full decade of research,
geneticists finally present the world with their first draft of a map
of the entire human genome.
[applauding]
President Bill Clinton makes the announcement.
With this profound new knowledge, humankind is on the verge of gaining
immense new power to heal.
Genome science will have a real impact on all our lives.
And even more on the lives of our children.
[applauding]
[narrator] It quickly accelerates new findings.
Genes are isolated with links to type 2 diabetes,
cardiovascular disease, schizophrenia, and more.
In a page out of science fiction,
people can now find out
if they're likely to get certain diseases before they happen,
and they start acting on it.
[crowd shouting]
In early 2013, actress Angelina Jolie
announces her decision to have a double mastectomy.
A defective BRCA1 gene
puts her at an 87% risk of developing breast cancer.
The procedure reduces the odds to 5%.
I've been very happy just to see the discussion
about women's health expanded, and that means the world to me.
And-- and after losing my mom to these issues, I'm very grateful for it.
[narrator] With celebrities raising awareness,
more people start wanting to know about their own DNA,
what diseases might be lurking there,
and what it might tell them about their genetic past.
In 2015, 23andMe, named after the number of chromosomes,
becomes the first FDA-approved company
to sell genetic testing directly to consumers.
DNA home kits become gift-wrapped bombshells.
Some discover long-lost siblings.
Many people, excited about the technology,
start uploading their genetic profiles
to sites that allow you to search for long-lost relatives.
It introduces another thorny issue...
privacy.
[indistinct chatter]
Law enforcement agencies quickly see the potential of this new DNA development
-to catch more criminals. -[siren blaring]
In early 2018,
California homicide detectives upload crime scene DNA of a suspect known
as the Golden State Killer.
Searching nearly one million profiles,
they get hits on several distant relatives of their suspect.
The matches are enough to lead them to a name,
Joseph DeAngelo.
And that April,
the 72-year-old former police officer is charged with the murders of 12 people.
[man] It was always gonna be DNA that solved this case.
There's gonna be discussions about privacy
and public nature of these databases, like there is on everything. That's fine.
Those are discussions for other people to have.
Um, our need is to solve crimes.
[narrator] But it raises difficult questions:
What if scientists discover a genetic predisposition
for criminal activity,
and the authorities decide to act on it?
What if government agencies start rounding up people
with a particular undesirable trait?
Your DNA holds all your secrets about your past and your possible future.
What might your employer do, or your future significant other,
if they knew your predisposition to certain diseases?
What if we start discriminating against people
for their unseen genetic traits?
We may have opened this Pandora's box
before fully understanding the consequences.
And let's not forget that 98.8% of the genome we still don't understand.
Manipulating DNA could give us longer, healthier, and even more enriching lives,
but it could also launch us into a dark new era.
Humanity's curiosity can take us to some dangerous places.
With genetics, our endless quest to know more and to control our lives
may just take us a step too far.
[electronic music playing]