[Music]
[Narrator]: Every year,
Science chooses one fantastic discovery as its Breakthrough of the Year.
Before we get to it, here are a few of the runners-up.
DNA from fossils has transformed what we know about evolution.
Now, scientists are digging up DNA from an entirely different place: the soil itself.
In Spain, DNA extracted from a cave floor
revealed that three groups of Neanderthals had once occupied it—
and only one remained at the end of the last Ice Age.
In a cave in the country of Georgia,
scientists found a female genome
from a previously unknown line of Neanderthals.
And in another cave in northern Mexico,
12,000-year-old DNA from four black bears revealed
that their descendants migrated to Alaska as the climate warmed.
New techniques that sift nuclear DNA from ancient soil made these findings possible.
As the method spreads
expect many more answers to questions about Earth’s ancient past.
NASA’s InSight spacecraft
is bringing the interior of Mars into focus like never before.
Soon after its 2018 arrival,
the lander detected a handful of marsquakes.
These underground tremors revealed that the thin martian crust
has at least two layers—maybe as many as three
That thin shell would have made it easy for the planet to shed heat early in its history.
One layer down, Mars’ mantle is also thinner than expected,
lacking an insulating lower half.
At the planet’s center is a huge liquid nickle-iron core.
But InSight is running out of time.
It has just a few months to hear more quakes before
Martian dust covers its solar panels—and it powers down forever.
In 2021, psychedelic drugs got a big boost in mainstream medicine.
One major study found that patients with post-traumatic stress disorder
improved so much on the drug MDMA and talk therapy
that two-thirds no longer had the disorder after two months.
The results brought excitement and caution.
Nearly all participants correctly guessed
that they had received the drug—rather than the placebo—
perhaps due to its psychoactive effects.
That might have enhanced their expectations—and their odds—of improving.
Still, if another ongoing study can confirm these results,
the treatment may be up for approval by the U.S. Food and Drug Administration
as early as 2023.
A new weapon is joining the fight against COVID-19:
antiviral pills that can prevent
symptoms and death if taken early enough.
This fall, drug makers Pfizer and Merck
released clinical trial results—still under peer review—
that hinted at early success.
Merck’s antiviral reduced the risk of hospitalization or death
by 30% in high-risk, unvaccinated individuals.
Meanwhile, Pfizer’s two-drug approach reduced hospitalization
by 89% in the same group.
There are concerns that the results may not be as good as they appear—
and that off-target effects in Merck’s pill
could cause troublesome mutations.
The pills are also no replacement for a vaccine.
But if they become widely available,
they could reduce death, blunt breakthrough infections,
and even cut transmission of SARS-CoV-2 worldwide.
And now, the Breakthrough of the Year…
For more than 50 years, scientists have tried to understand how proteins—
the building blocks of biology—
transform from simple chains of amino acids
into precisely-folded 3D structures.
Those structures determine how proteins interact with other molecules—
and could reveal everything from unknown drug targets to new insights into basic biology.
This year, the power of artificial intelligence
improved those predictions by magnitudes.
Before AI entered the scene, scientists used experimental techniques
to map proteins atom by atom.
Researchers have used these methods to uncover the structures of more than 180,000 proteins.
But such work is slow and expensive.
To speed things up, scientists started using computers
to predict the shapes that proteins might take.
For the last two decades, those predictions have gotten better,
but they still had room for improvement.
Then, AI changed everything.
AlphaFold, a program developed by Google’s sister company, DeepMind,
outshone every team at a major competition in 2018.
And in 2020, AlphaFold2 showed that it could predict
proteins as well as experimental techniques—a major milestone.
And this year, researchers at DeepMind
solved 350,000 human protein structures—
44% of all known human proteins,
and a really good fraction of the 200 million thought to exist.
Other researchers are using AI to predict how proteins come together and interact
for a wide variety of applications.
Even now, AlphaFold2 is modeling the spike protein in the new Omicron variant of SARS-CoV-2—
and scientists are eagerly awaiting results.
[Music]