Islands of Creation

Narrator: Today the earth is home to over 10 million species

of plants and animals,

living in virtually every habitat imaginable...

But despite this vast diversity,

scientists agree that every organism on the planet

shares a single common ancestor.

Which raises a compelling question:

Man: A question that Darwin himself never answered.

Man: Where do species really come from?

Narrator: How does one species split into two?

Charles Darwin called this "the mystery of mysteries."

In the jungles of the Solomon Islands,

scientist al uy is trying to solve this mystery.

Using tools Darwin could only dream of,

he's doing something once thought impossible...

Catching evolution in the act of creating a new species.

Al uy: We actually have the mutations

that create the new species.

Narrator: But while on the verge of an amazing discovery,

uy's work is in danger.

With the Solomon Islands under threat,

he must gather the evidence

that will prove the existence of a new species

before it's lost.

Narrator: There's an ancient story

told in the Solomon Islands

about how the world came to be.

It describes how a serpent spirit called agunua

created the land, sea and sky.

He created the first man as a brother for himself.

Agunua gave him a single yam

and told him to cut the yam into pieces

and scatter the pieces on the earth.

From the pieces of the yam grew every kind of plant and animal,

and that was the beginning of all life on earth.

For millennia, creation stories like that

were at the heart of many cultures,

explaining not only the origin of life,

but, in some cases, when it began.

As recently as the 1800s, many devout westerners

believed the earth was just 10,000 years old...

With all life on the planet unchanged

from the moment of its divine creation.

Then, in 1859, came a revolutionary book.

Charles Darwin's "origin of species"

suggested the earth was more than 10,000 years old,

as many scientists then believed.

But he also said that plants and animals changed over time

through a process he called natural selection.

Darwin went on to claim that all organisms...

Every living thing on earth... Came from one common ancestor.

He portrayed this bold idea in the form of a family tree,

with every place the tree branches

signifying the birth of a new species.

Making sense of the earth's diversity

means understanding what happens

at these branching points.

Today scientists call this process "speciation."

Everywhere around us we see the results of speciation...

Including the human species evolving from other primates.

But exactly how this diversity of species came about

remains a mystery.

Darwin explained how an existing species

could adapt to its environment,

but his theory was still incomplete.

Christopher filardi: Darwin did this incredible job

of describing how species change over time,

but in his book, right,

"the origin of species,"

it sort of left a question Mark about where those lines started.

That is, where do species really come from?

Narrator: By the early 20th century,

biologists believed that the answers

to how new species appear

would be found in the Solomon Islands...

An archipelago of islands in the south pacific.

It was here in the late 1920s

that Dr. Ernst mayr took one of the major steps

toward completing Darwin's theory.

Jared diamond: Ernst mayr is usually considered

the greatest evolutionary biologist since Darwin,

and he's especially known in the 20th century

for having essentially solved the problem

of how species originate...

The theme of Darwin's book,

but a question that Darwin himself never answered.

Ernst was a medical student,

but while studying medicine at university, he also got a phd

studying the expansion of a Finch in Europe.

And then he wanted to study birds.

He had never been out of Europe, and several European museums

then arranged for him to go to the solomons.

Filardi: What's incredible about the Solomon Islands

is that they're really the galapagos

that Charles Darwin was looking for.

Narrator: In the late 1920s,

the Solomon Islands were known for their pristine beauty

and exotic species of plants and animals.

Here was an evolutionary experiment

millions of years in the making.

Mayr spent two years collecting hundreds of bird specimens

from all the major islands.

Studying them at the American museum of natural history,

he detected a pattern in a bird called the monarch flycatcher.

Monarch flycatchers appear throughout the solomons,

but from island to island,

the birds vary, most noticeably in color.

Some were Chestnut-colored brown birds.

Others were completely black.

Today, Dr. Chris filardi

oversees Ernst mayr's flycatcher specimens from the 1920s.

It was this collection

that led mayr to suspect the black monarchs

were transforming into a new species...

Putting him in the unique position

of witnessing evolution as it was happening.

Diamond: It's something that rarely happens

fast enough to be observed.

Usually, though, speciation occurs slowly

over hundreds of thousands of years.

We humans cannot observe it directly.

Instead we have to reconstruct it...

By finding different cases which represent intermediate stages

in the process of speciation.

Narrator: In the wake of Darwin's theory

that organisms changed over time,

Ernst mayr developed a concept that defined what a species was.

It would come down to a simple three-letter word: Sex.

Diamond: Mayr said a species is a group of populations

that interbreed with each other but not with other populations.

And so, for example, humans constitute a species,

because Europeans, Chinese, africans

and aboriginal Australians, given the opportunity,

have always interbred with each other.

But humans are a species distinct from chimpanzees

because there's no recorded case of humans interbreeding

or attempting to interbreed with chimpanzees.

Narrator: Mayr's definition...

Called the biological species concept...

Helped scientists draw the lines

that separate one species from another.

But the reasons why closely related species

did not interbreed remained elusive.

More than a century and a half after Darwin,

biologist al uy is following in his and Ernst mayr's footsteps...

Exploring the Solomon Islands

in a quest to discover the origin of species.

It's a quest that began when he was a boy.

Uy: I was born in the Philippines

right outside the capital, Manila...

And moved to the United States when I was 13 years old.

I've always been interested in biodiversity.

I think that's a natural curiosity

that most people have, you know, why is the earth so diverse...

And where did that come from?

So I think a very important part of human nature

is we are always interested to figure out

what is our place in life

and what is our place in the grand scheme of things.

Narrator: In trying to figure out the grand scheme of things,

uy looked to Ernst mayr.

Uy: Ernst mayr inspired generations of scientists

and the way scientists think.

He helped me, as a young scientist,

truly understand how evolution works

and to start addressing

some of the pressing questions in evolutionary biology.

Narrator: Armed with the biological species concept,

uy is in the solomons to test

whether two bird populations are splitting into separate species.

His subject... The monarch flycatcher.

Uy: We know from mayr's descriptions

that populations from different islands look different...

But the question then is does it matter to them

that in the one island they're brown-bellied

and the other island they're fully black?

And now we can really, as scientists,

come up with experiments and studies that test the process

of how you get that differences between populations.

Narrator: Are the black monarch flycatchers

becoming a separate species from the brown ones?

If so, what's causing it to happen?

Answering these questions promises to bring uy

closer than ever to unlocking

the elusive secrets of speciation.

Scientists have identified 96 separate species of flycatchers

living in habitats from Sub-Saharan Africa

to the Solomon Islands.

These species have evolved from a single common ancestor

that lived millions of years ago.

But no scientist has witnessed a population of monarchs

in the process of becoming a new species...

Until now.

Uy: Speciation, or the origin of species,

is a complex process.

To understand how new species arise,

you need data to connect the dots.

And these data basically come together to form a story.

Narrator: Al uy's first challenge in the solomons

was figuring out whether