Original subtitles

[water rushing]

$4' [Man vocalizing]

[Male narrator] As human beings,

we are instinctively drawn

toward the grandeur of the natural world,

to spectacular displays that inspire us

with their magnitude and power.

♪ J' [Choir singing in African language]

During moments like these,

we are understandably filled

with the genuine sense of awe.

Yet nature's most stunning revelations

aren't always defined by sheer force

or physical scale.

For often, in secluded corners of our planet,

many of Earth's greatest wonders

take center stage.

Wonders of rare beauty and complexity,

creativity, and design...

wonders born on the gossamer wings of an insect

weighing less than an ounce.

$4' [Choir continues]

[Man] As you watch a butterfly,

to describe what you're looking at,

you can't really put it into words.

And I said to myself,

I want to be part of that.

That is the coolest thing.

That's biology. That's also magic.

When you hold a living butterfly in your hand

for the first time--

Maybe you've netted it

or picked it off a flower or something,

and here's this incredibly beautiful organism,

intricately shaped

with its feet and antennae

and all these things moving at once.

Every one of these 20,000 species

have different color patterns,

and every one of them has different shaped wings.

The diversity is just so magnificent.

If I was the greatest artist in the world,

there was no way I could come up with all of these patterns.

I mean, it would be just absolutely impossible.

If you open the work of a lepidopterist--

someone who studies butterflies,

somewhere in that writing

you're going to find the language of astonishment.

The fact that it goes through a caterpillar stage,

and then becomes this mysterious Chrysalis

out of which this flying creature emerges,

has captured the imagination of people since antiquity.

[Narrator] Throughout history,

butterflies have touched the human mind and soul

on levels both scientific and philosophical.

3500 years ago,

Egyptian artists studied their anatomies

and then rendered them as icons of beauty and perfection of form.

In Aztec and Mayan folklore,

the insects symbolized life and death.

And to the ancient Greeks,

"psyche"-- the word for butterfly--

literally meant, "the soul".

Today, terms like "magical" and "miraculous"

are often used to describe their mysterious life cycles.

For almost every butterfly,

it is a cycle that begins

often hidden from the eyes of the world.

Depending upon its species,

a female butterfly can la y hundreds of eggs during her brief lifetime.

Each initiates an extraordinary process of growth and transformation.

[Paul Nelson] The eggs are remarkable in themselves.

They have species-specific architectures,

some of which are just astonishing.

For instance, if you look at a Monarch egg, it has a beautiful symmetrical structure.

It looks like a little miniature dome or cathedral.

Ranging in size from a pinhead

to the width of a child's finger nail,

each egg is attached to a plant

by an adhesive fluid secreted by the butterfly.

They are lined with a coating of wax that helps keep them moist and viable.

Each egg is deposited on a specific species of plant called a "host."

These host plants are the only source of food a butterfly's offspring will eat,

so accurate identification of their leaves and branches is crucial.

And the females are well equipped for the task.

[Ron Boender] The percepfion flmat they have

of the odor of those plants is just overwhelming.

So they can find those plants for miles.

And then once it gets near its host plant,

it can tell that the odor

is getting stronger and stronger.

Then it begins to focus on leaf shape.

Instinctively it knows what leaf shape its host plant has.

And it begins to taste.

And it tastes with its feet, with its forelegs.

They drum the leaves, they scratch the leaves,

and then they use their proboscis to taste the scratch.

They also smell with their antennae.

So they've got the legs,

they've got their proboscis,

they've got their antennae.

They have all these mechanisms to make sure that it's the right plant.

If it's the wrong plant, their caterpillars are going to die.

Butterflies just don't make mistakes.

I mean, it's just amazing.

It's just one of the greatest wonders of nature

to watch how this female can do all of this from such great distances.

In many species, the eggs hatch within a week.

Then the newly emerged caterpillar-- or larva--

wastes no time embarking on the second stage of its journey to adulthood.

[Ron Bo e n d e r] We Call them "eating machines"

because that's their only purpose in life

is to just eat and grow, eat and grow.

A really hungry, busy caterpillar,

you can actually hear it eating.

It sort of reminds you of corn on the cob

because it bites along, and then it bites along some more.

It's just munch, munch, munch.

Slice and chew. Slice and chew.

To build up the raw materials for the next stage of life.

A caterpillar could gain in weight so fast

that it would be eating its own weight

in leafy material every day.

Equipped with powerful jaws and a digestive tract

that extends the length of its body,

this stomach-with-legs can multiply its birth-weight

more than 3,000 times in less than two weeks.

[Paul Nelson] To show you how remarkable this weight gain is,

imagine you had an eight-pound human baby,

and he multiplied his weight 3,000 times as he was growing.

That would be a 24,000 pound child.

That's a big kid.

A caterpillar's growth is punctuated by violent surges of transition called molts.

[Ann Gauger] Imagine flue outer skin of a gterpillar

as being sort of like a wetsuit.

It's got a little but of stretch to it, but limited.

It's waterproof so they don't dehydrate.

Now, as the caterpillar grows,

it fills out that wetsuit,

and eventually it reaches a point

where it can't grow any more.

Then it has to make a new larger version on the inside.

A molt begins when a caterpillar spins,

and then grasps, a silk pad,

anchors its body securely with small barbs on its legs,

and splits its skin near the capsule covering its head.

[Paul Nelson] There are censors in the cuticle,

in the skin of the caterpillar,

that are strain detectors.

They detect the amount of pressure

or strain being put on the skin.

And when that is too great,

they send a signal to the brain of the caterpillar,

which then releases a hormone that causes molting.

A caterpillar will undergo four or five molts.

Its rapidly growing body is composed of two distinct cell populations:

the larval cells that form all of its organs

and enable it to function

and the imaginal cells that ensure its future as a butterfly.

[Paul Nelson] In the later instars of the caterpillar,

I one can in to see at are called imagfimafl dfiswg

Now, these are the precursor cell populations

for what will become wings and legs, or sensory structures in the adult.

Most of these imaginal cell clusters develop in pairs

and are positioned throughout the caterpillar's body

in locations that correspond to the organs they will eventually help form in the adult.

[ H H Ga u g e r] I m a g I n a I discs are p re CU rso rs

that are there and waiting.

They're set aside to make adult structures.

And at a certain point in development,

those cells are triggered to start to grow.

As the end of the larval stage approaches,

the caterpillar stops eating,

finds a secluded spot,

and spins another silk pad.

When finished, it attaches itself with a pair of claspers on the end of its body...

then hangs, almost motionless.

[Rona B e n d e r] It will hang there for a day or so,

usually in a "J" position.

All kinds of chemical reactions occur within that caterpillar.

It changes color, and you have no idea what's going on inside there

until all of a sudden, it pumps the fluids so that the skin begins to split.

The caterpillar's final molt

marks the beginning of the third stage of a butterfly's development

and the appearance of a remarkable structure called a chrysalis.

As the old skin is pushed away,

the cremaster, a thin extension on the top of the Chrysalis,

works its way into position to permanently grasp the silk pad.

With a scanning electron microscope,

the cremaster is magnified more than 500 times.

[Ron Boender] The caterpillar has microscopic hooks on the cremaster

and it attaches those hooks

to that silk pad that it puts

on the bottom of a leaf or twig.

And it begins to spin.

And this caterpillar spins and spins and spins

because it wants to get rid of that old skin that it has.

During the hour that follows,

the Chrysalis hardens and takes its final form,

as one of the most fascinating processes in nature is set into motion--

the metamorphosis from caterpillar into butterfly.

[Paul Nelson] What you see in a Chrysalis

is not a shapeless mass,

but in fact something very much like a mold for the adult butterfly.

Ham Emmefl] You see the wing pads

where the adult wings are going to form.

You see the head and the compound eyes appear,

visible through the outer case of the pupal shell.

Abdominal segments are very clearly separated from the thoracic segments

where the wings are going to be attached.

All of this is astoundingly new

compared to the caterpillar

where everything looked sort of the same

down the whole length of the body.

This transition from an earth-bound, plant-eating arthropod

with limited vision and mobility

into a beautiful winged insect that feeds on nectar,

navigates with exceptional senses,

and can fly 50 miles in a day,

is truly a marvel of the natural world.

Exactly how it happens is still very much a mystery.

Yet innovative research at the level of molecules and cells

provides intriguing new clues.

[Paul Nelson] There is some continuity of tissues

from caterpillar to adult butterfly,

but most of what was there in the caterpillar

is going to disappear

and be turned into new structures

that have no analog in the caterpillar.

For instance, there's nothing like

the compound eye of the adult butterfly

present in the caterpillar.

There's nothing like the proboscis present in the caterpillar,

or the long articulated legs in the caterpillar.

So these are all novel structures that are going to be built.

[Ann G-auger] In a metamorphic insect, w h at ou' got is two b o d y p I a n S.

You have to first form one functional body plan,

and then you have to switch gears and form a new body plan.

I am amazed by development

when it goes from egg to caterpillar,

because it's such and intricate process.

But then you have to enter into the Chrysalis stage,

and you have to get it right again.

So it's like the problem squared.

The creation of a butterfly begins with the partial destruction of the caterpillar.

Inside the Chrysalis, larval cells

that formed the caterpillar's limbs and organs

are systematically digested and broken down.

[Paul Nelson] You've got to get rid of or digest the caterpillar tissues.

They won't work for the adult.

In fact, the cells themselves disappear,

but then their components are recycled

and are turned into a kind of soup

out of which the adult structures will be built.

Throughout this process, the imaginal cells,

the foundation of the adult insect's body,

are preserved to differentiate and multiply.

[Ann Gauger] Now, cell death is programmed;

It's not something that happens by accident.

If you kill the wrong cells, you're in deep trouble.

[Paul Nelson] It's very carefully engineered.

You're going to save some of the cell populations,

so you got to know where you're gonna end up before you start.

You don't want to digest everything,

just the things that need to be eliminated.

Then the I magi nal discs rapidly beg I n" t proliferate,

and you can trace a continuous pathway into the pattern on the wing.

This timeless drama of death and renewal

is performed in the seclusion of the Chrysalis

without audience or applause.

During the past two decades,

scientists have worked diligently to pull back the curtain.

[Richard Stringer] I've been at this about 15 years,

and the possibility of somehow getting in there

to photograph what's inside the chrysalis--

that question was out there all along.

And it occurred to me that

magnetic resonance imaging

might be a perfect tool to use

to see what goes on inside a Chrysalis.

The challenge of visually documenting a butterfly's development

led biologist Richard Stringer to Duke University

and its Center for In Vivo Microscopy.

There, over a 10-day period,

Monarch butterfly chrysalises were scanned

throughout a complete cycle of metamorphosis.

Each scan visually sliced the Chrysalis into more than 200 sections.

Eight hours into the first day,

Stringer observed significant changes.

Even though it was very early in the development of the Chrysalis,

you could already see things forming

that were going to be part of the butterfly

including the head, including the brain,

including leg muscles, wings, antennae.

The longer it scanned, the more detail you get.

Stringer's magnetic resonance data was later used to create

a three-dimensional dissection of the butterfly's body

as it took shape within the Chrysalis.

On day one,

the caterpillar's massive digestive tract

is still nearly full-size.

By the tenth day,

hours prior to the butterfly's emergence,

the tract has been totally reconstructed.

It is now about 25% of its original volume,

ideal for the adult insect that will feed almost exclusively on nectar.

During this transformation,

the butterfly's reproductive organs,

non-existent in the caterpillar,

develop completely...

...while its tube-like heart is remodeled

to fit and function within the abdomen of the butterfly.

In the front of the Chrysalis,

dramatic anatomical changes continue.

The caterpillar's simple eyes,

capable only of discerning darkness and light,

are replaced by large,

complex organs of vision.

A muscular system that will power flight and locomotion

is built from both imaginal and recycled larval cells.

The butterfly's six legs, two antennae, and feeding tube

are individually formed while tightly compacted into a mass

against the wall of the Chrysalis.

And four wings,

each with elaborate networks of veins and scales,

are shaped, decorated, and refined in less than two weeks.

[Richard Stringer] It's like a different organism.

And as the week goes on,

transitions have to take place in the heart,

transitions have to take place in the antennae,

transitions have to take place in the reproductive organs.

You've got a big orchestra in there.

You've got a great big orchestra, and you've got a conductor,

some conducting force that's responsible for it all.

I can say without any doubt that it was the most amazing thing I'd ever seen.

Caterpillar into butterfly.

The transformation to an entirely new way of living is nearly complete.

During the first moments after emergence,

the butterfly makes final preparations to fly and eat,

as it finishes construction of its proboscis and wings.

[Thomas Emmel] The proboscis is a straw-like tongue,

hollow in the middle.

And the butterfly has muscles in its head

which can create a suction,

a sort of a suction pump,

and draw nectar up.

Within the Chrysalis,

the proboscis developed as two separate pieces.

Now, immediately following emergence,

the butterfly must assemble them into a single unit

or die of starvation.

[Ron Boender] ifs two half-straws.

There's a channel on one side,

and has to get it into the channel, the other side.

Yo u 'll 3 eve: t little a p p e n d a g e s on their head called pal pi.

And those palpi seem to protect the proboscis

and help that proboscis get put together.

As the butterfly knits together the proboscis,

its wings also take on their final structure.

[Ron Boender] When the butterfly comes out of the Chrysalis,

the wings are like velvet.

They're soft, they're pliable.

There's veins. The wings are filled with veins.

[Paul Nelson] What the butterfly does is,

using its abdominal muscles,

p u m p s h e 0l

into the veins, into the wings,

and they quickly expand to their full size and shape.

Each of the butterfly's four wings

is covered with thousands of microscopic scales

that are positioned like shingles on a rooftop.

These scales are not only arranged for aerodynamic efficiency

and spectacular patterns,

they also act as solar panels,

collecting heat to warm the flight muscles of the cold-blooded insect.

A butterfly's eyes are also formed from a vast network of component parts.

Thousands of hexagonal light receptors work in unison

to produce a mosaic view of the insect's environment...

...while the spherical shape of each compound eye

creates a field of view more than 180-degrees wide.

Ham Emmefl] They have four-coflom vision systems, pigment systemsg

which enable them to see from the ultraviolet to infrared.

Butterflies have better color vision than humans.

The butterfly's antennae, legs, and feet complete its sensory system.

The antennae, that control balance and equilibrium in flight,

recognize the aromas most important to the butterfly.

Their clubbed ends are covered with scales

that can detect the scent of a host plant

or prospective mate more than a mile away.

A butterfly has three pairs of jointed legs

with scales and fine hairs

that sense vibrations. ..

And possibly sound.

While its legs and claws are lined with nerve cells

that react upon touch to a leaf's distinct flavor.

This heightened sense of taste is activated

whenever the insect scratches the surface of a plant.

Some of the best biologists and chemists in the world

are now studying the process of metamorphosis

on a series of new levels,

trying to integrate this with the advances and techniques

that we have for molecular biology,

to modern imaging systems.

[Paul Nelson] In the case of butterflies,

it's like a fine piece of art.

You can appreciate it at a sort of technical level

in terms of what was required to get the pigment on the canvas and so forth.

But what's going on is so much richer than that,

and so much more significant than that.

[ N n Ga u g e r] just the b a re 0 u tl I n e s

of a few of the processes involved for metamorphosis.

It's a mystery. It's like a black box.

Input larva, black box, output butterfly.

What happened?

What happened?

And we only know a thousandth of what's going on

inside those insects,

inside that pinhead brain,

and all of the things that it can do.

The way it can navigate,

the way it can migrate,

the way it can find the females.

The way it can find the plant.

It's one of the great wonders of the world.

As science probes deeper into the life cycles

of the 20,000 species of butterflies

known to inhabit the earth,

one story stands unique from any other.

It is an epic saga that unfolds across a continent,

and a journey to the heart of the beauty and mystery

that epitomize metamorphosis.

For more than 30 years,

researchers from throughout the world,

including biologist Thomas Emmel,

have traveled to a secluded forest

to study a phenomenon unparalleled in nature...

the Monarch butterfly's migration to Mexico.

[Thomas E m mel] I've g 0 n e do eve ry ye a r si n Ce 1981 ,

and many years made a number of trips--

two, three, four trips a year.

Here's a butterfly species that does something truly spectacular.

Just imagine, 300 million Monarchs in one site

that have flown 2500, 3000 miles

to end up in these tiny twelve areas

that still exist in the Trans-Volcanic range of south central Mexico.

The Monarch's migration begins each September,

when most of the North American population

east of the Rocky Mountains

departs for central Mexico.

Their journey can span more than 2500 miles,

and is critical for two reasons:

Monarchs are tropical butterflies,

unable to endure the freezing winter temperatures

of the Midwest and Canada,

and their life-cycle depends upon the milkweed.

More than 100 species of milkweed grow throughout the United States

during the spring and summer.

It is the only plant a female Monarch will select to host her eggs.

Milkweed leaves contain cardiac glycosides,

toxic chemicals that can cause illness or death.

After hatching, the caterpillar eats the plants

and stores their poisons in its outer layer of skin.

Then, during metamorphosis,

the glycosides are transferred from caterpillar to adult.

And whenever the Monarch spreads its wings,

their distinctive pattern sends a warning to predators:

Don't eat me. I taste terrible.

Like the Monarch,

milkweed cannot survive the harsh North American winter,

and by the end of August, it goes to seed.

[Tom Emmel] And at that point, the Monarch stops all reproductive activity.

If it's a female, no more eggs.

If it's a male, no more sperm.

They still feed, are active,

but they show no interest in sex or reproduction.

With no milkweed for their eggs until spring,

the Monarchs devote themselves entirely to preparation for a transcontinental flight.

They spend the final weeks of summer

feeding on nectar to build reserves

of carbohydrates and fats,

the fuel for their journey.

Monarchs born in the spring or early summer have a life-span of only two-to-four weeks.

But the generation that emerges in August

is genetically programmed to live up to nine months,

a provision crucial to survival.

[Thomas Emmel] The last generation of the summer,

the one that's going to live all winter and into the following spring

is really an interesting problem for biologists

because here you have two, three generations

preceding that generation

where the adult lives at most

two weeks, three weeks, four weeks, and then dies.

And now, all of a sudden,

a generation is produced

that's going to live nine months,

nine times as long.

It's thought that there's a genetic difference

comprised of about six genes

that are unique in this generation

that enable it to live that long.

Often called, the "Methuselah generation,"

their longevity will enable the butterflies to fly south for eight weeks,

endure four months of winter,

and then start the return trip north

to establish a new generation of Monarchs in the spring.

With the approach of autumn,

the angle of the sun at mid-day drops below 56 degrees.

The shortening days are the butterfly's cue to begin their migration.

A network of sensory organs

will enable them to navigate throughout the journey south.

[Thomas Emmel] The question is how the butterfly figures out what direction to go.

We're looking at several things.

The butterfly is able to detect day length

through tiny organs on its antennae.

It's able to detect the position of the sun

above the horizon by visual senses,

and also compensate with a biological time-clock in its brain

for the movement of that sun

from early in the morning on the eastern horizon

to the western horizon at the end of the day when it sets.

So, they're moving south,

following the sun's directions,

and they're adjusting their flight each day.

From as far north as Canada, Michigan, and Maine,

the Monarchs travel an average of 50 miles a day,

as they glide on currents of warm thermal air.

By mid-October, their primary migration routes converge,

as most of the butterflies funnel into southern Texas

before crossing the border.

Some, however, take a more direct route, across the Gulf of Mexico.

In late October, on evenings following the passage of a cold weather front,

Monarchs descend upon the gas and oil rigs throughout the gulf.

Perhaps attracted by the lights,

the butterflies interrupt the longest non-stop leg of their journey.

Here, among the pipes, ropes, and heavy machinery, they rest for the night.

In 1993, biologist Gary Ross and a team of volunteers

documented Monarchs on more than twenty platforms during a two-week period.

At daybreak, the butterflies warmed their flight muscles,

calculated their bearing by the position of the sun,

and then resumed their journey.

After crossing the southern border of Texas,

the eastern Monarch population merges into a fly-way about 50 miles wide.

During this leg of their migration south,

they follow the geography of the Sierra Madre-Oriental mountain range.

Then, near a region called the Sierra Gorda,

they abruptly change direction and cut through a pass,

heading southwest toward the interior of Mexico.

[Thomas Emmel] A n d t h e re the f I n d t h e e n d of t h e d e s e rt

and the start of a transverse mountain range

that runs west-east, and that's the Trans-Volcanic range.

The Trans-Volcanic is the tallest range in Mexico.

Its mountains contain rich deposits of heavy metals

that may play an important role in the Monarch's navigation.

[Thomas E m m e I] Gold, iron, manganese, copper--

all of these metals created an anomalous magnetic field.

And this seems to be important in bringing the Monarchs in,

because the Monarchs have tiny particles of the mineral magnetite in their body

at the base of the wing, and in the thorax and the abdomen.

And these are believed to help them navigate

to precisely this mountain range

because there's a very strong magnetic anomaly

as one approaches this range,

due to all these heavy metals near the surface.

So the particles of magnetite rotate like a little bar magnet inside a cell,

and that cues the Monarch that it needs to head in a certain direction.

[birds cawing]

Until late in the 20th century,

the only people to ever observe the butterfly's arrival in Mexico

were the farmers and miners

who lived and worked in these volcanic mountains.

Then, on January 2, 1975,

in a forest 70 miles west of Mexico City,

a spectacular discovery opened the door for the rest of the world.

$4' [choir vocalizes]

Millions of Monarch butterflies

had gathered in a forest of Oyamel firs,

10,000 feet above sea level.

Fredrick Urquhart, a Canadian biologist

who devoted his career to the Search for this colony,

described it as "a glorious, incredible place

"where butterflies swirl through the air like autumn leaves,

"shimmering against the mountain sky

and drifting across our vision in a blizzard of orange and black."

Science now glimpsed the true magnitude of the eastern Monarch's migration.

[Thomas Emmel] One of the really remarkable things about this migration

is that all of these individuals have never made the trip before.

It was their grandparents or great-grandparents, two, three, four generations ago.

They have no leader who has made the trip before.

Umflfike hoopimg Cranes or Samdhiflfl Cranesg

they don't have an older experienced adult

to take the lead and show them where to go,

where to stop at night.

But in the end, it ends up on the very same trees,

same area, same slope of the mountain

that its parents or grandparents left from the previous year.

Since 1975,

a dozen permanent over-wintering colonies

have been discovered in these mountains.

Each maintains a critically balanced microclimate

that helps sustain the Monarchs until spring.

Average temperatures in the colonies

range from 35 to 60 degrees Fahrenheit--

warm enough to protect the insects from freezing

and cool enough to minimize their expenditure of energy.

For more than four months,

hundreds of millions of butterflies

live in a state of semi-hibernation

while slowly consuming the reserves of nutrients

they accumulated during the summer.

The bark and needles on the fir trees provide stable footholds.

And by flocking in roosts, several layers deep,

they can endure days or weeks of inclement weather.

[thunder rumbles in distance]

34' [Woman vocalizes]

$4' [choir vocalizes]

With the arrival of spring,

the insects prepare to depart the over-wintering sites.

After the sun warms the colony,

the Monarchs leave their roosts for a few hours each day.

They travel short distances in search of nectar and water

that will nourish them during their journey north.

At lower elevations, they feed on the new bloom of wild flowers

and draw moisture from the damp grass

and the rivulets that run down from the mountains.

The lengthening days also trigger a change in the Monarch's biology.

In early March,

the butterfly's reproductive organs become active

as the males produce sperm and the females, eggs.

After mating, they leave the colonies and head north,

ready to establish a new generation.

The Monarch's departure from Mexico coincides with the appearance

of a new crop of milkweed in southern Texas.

When the females find the host plants, they lay their eggs.

Their life-cycle now complete, they will soon die.

Throughout the spring and summer,

successive generations of Monarchs,

each living about four weeks,

follow the milkweed as it grows progressively

across the Midwest and into southern Canada.

Then, in late August,

near a dairy farm in Minnesota

or a Iakeshore in Ontario,

butterflies from a new "Methuselah generation" emerge,

ready to undertake the great migration once again.

[Thomas Emmel] The series of steps that the Monarch takes during this trip,

both coming south and going north again in the spring,

is truly astounding.

Here's an insect moving by the billions between three countries.

To imagine a tiny brain the size of a Monarch brain

being able to carry all the information that it needs to make this 2500-mile trip,

adjusting daily for the movement of the sun as it drops lower on the horizon,

getting near the over-wintering site in Mexico,

and somehow ending up in the same mountain range

that their grandparents came from the previous spring.

But that tiny brain puts all of this together.

It is a wonderful mystery that's going to attract scientists' attention

for many, many decades or centuries to come,

and we are only beginning to understand how miraculous this is.

[Paul Nelson] It's impossible to look at a caterpillar turning into a butterfly

and not ask "how".

Their metamorphosis, their migration, their Iifecycle.

How did this happen?

How is it regulated? How is it controlled?

This astonishing remarkable transformation.

A biologist who encounters

a puzzle like metamorphosis

is going to view that puzzle

through an analytical filter, a lens.

It's a way of trying to understand the problem.

And for most biologists,

that lens is going to be an undirected evolutionary process.

Since the late 19th century,

most explanations for the life-cycle of a butterfly

or any other organism

have shared a basic premise:

to be considered scientific,

they must rely exclusively upon undirected natural causes.

This view was first published by Charles Darwin in his theory of evolution

through random variation and natural selection.

And, today, it is widely accepted as a foundation of modern biology.

But can such a theory account for the origin of metamorphosis?

[Paul Nelson] On the evolutionary view of life,

in particular on the Darwinian view of life,

everything that an organism does,

every feature that it has,

all of its details ultimately relate to the requirements of natural selection.

So, to build the first butterflies,

natural selection would have had to work entirely through genetic mutations.

They're the raw materials of evolution.

A mutation is an error in the DNA of a living organism.

An alteration of the genetic code.

The theory of natural selection contends

that the accumulation of mutations

over enormous periods of time

fuel the evolution of all complex life on earth.

[Ann Gauger] Generally speaking, mutations are mistakes.

It's a change to the DNA.

And these mutations happen in a random way.

They're not guided or directed

to happen in the right order,

in the right sequence, in the right time.

[Paul Nelson] There's no foresight involved in this process,

no vision of what the organism needs in the future.

Now, there's a real problem with that,

especially when you consider the single most important element of metamorphosis--

the Chrysalis.

A butterfly Chrysalis connects two fundamentally different ways of living.

It is both a bridge and a workshop

where one type of organism is transformed into another.

[engine whirring]

The magnitude of this transformation

has been compared to a Model T Ford--

[tires screech]

...that suddenly encases itself within a garage.

[metal slams, objects clatter]

[mechanical whirring]

Inside, most of the car breaks down

into fragments of metal, rubber, and glass.

[clattering]

These pieces then reorganize themselves

into components more complex

than any that previously existed in the Model T.

After several days, the garage door bursts open

and a radically different mode of transportation lifts off into the sky.

[engine powers up]

[blades whirring]

[Paul Nelson] Now, an analogy like that is pure whimsy.

But, even if it were somehow possible,

I don't think turning a car into a helicopter,

would be nearly as impressive

as the actual transformation that takes place inside a Chrysalis.

From the moment the Chrysalis is formed,

caterpillar tissues are destroyed and then recycled to help build wings,

compound eyes, reproductive organs,

and navigational systems of stunning beauty and efficiency.

Yet despite the importance of cell death in the Chrysalis,

the origin of the process defies the basic logic of natural selection.

[Paul Nelson] One of the fundamental requirements

of natural selection is reproduction.

You've got to be able to make copies of yourself, in particular of your genes.

You've got to be able pass them on.

But a Chrysalis,

unless it represents a bridge to something yet to come,

is really a casket.

If you're a caterpillar, you're entering your own grave.

Turning most of your body into a molecular soup would be suicide.

[Ann G-auger] A caterpillar, unless it makes it through to the adult,

is no good because it can't reproduce.

You're not going to have offspring, so you're a dead-end street, evolutionarily.

So it wouldn't be any benefit at all to kill yourself,

unless you've got a hidden plan up your sleeve.

You know, like, "Okay, I know I can commit suicide,

because there's a new me waiting to happen."

[Paul Nelson] The caterpillar is not going to enter the Chrysalis,

without simultaneously knowing,

"I've got a plan for getting out of this.

"I'm heading towards the adult butterfly.

"I'm going to reconstitute these tissues in the adult form,

emerge, and go on my way."

But that's not how natural selection operates.

It can't look into the future

and somehow anticipate

what an evolving organism is going to need

in a week, or a month,

or a thousand years from now.

So, if the first caterpillars were evolving into existence--

without foresight, it's highly unlikely natural selection would retain

a destructive process like cell death.

This absence of foresight is not the only challenge to Darwinian theory.

Biologists have long recognized

that natural selection cannot succeed

by taking large evolutionary leaps.

Instead, the process can only move forward

through a series of small, incremental steps.

[Paul Nelson] In evolution, it's the smaller scale changes

that have a better chance of being passed on

because they're relatively limited in their scope.

That means they're disrupting less,

and they're more likely to be tolerated by the organism.

But when it comes to the origin of metamorphosis,

the notion of gradual evolutionary change comes to a dead end.

By its very nature,

metamorphosis is an all-or-nothing proposition.

And throughout biological history,

its success has hinged upon the immediate availability

of a full set of instructions--

including genes, proteins,

and the developmental program required to integrate them.

[ n“ n G a u g e r] It all has to be in place ahead of time.

It needs to have the genes in place.

The regulatory elements that are going to turn the genes on and off--

it has to have am the cells preprogrammed

to do what they're going to do when the time comes,

so they respond to the signals they get in the right way.

The larval cells have to know they're going to die.

You gotta remember, the caterpillar isn't thinking about things.

It's not saying, "Okay, now it's time to dissolve my epidermis,"

and, "Okay, what about that gut?

Got to get working on that gut."

No.

It has to happen rapidly and in a coordinated fashion.

Once you're committed to the Chrysalis stage,

there's no going back.

You have to complete the transition.

[Paul Nelson] A caterpillar that's equipped to go 10%

or 25% of the way through metamorphosis

is no-way through metamorphosis.

Part way into a process

that requires getting out the other side

as a fully-formed adult, doesn't work.

A In“: G a u g e r] You have to recreate ad u It legs,

adult antennae, adult eyes.

You have to change the shape of the brain

and the connections between the antennae and the eyes.

You have to reformat the gut

so that it switches from eating plant material to eating nectar.

How many mutations does it take,

and how do you coordinate all of that?

If you get the eyes right but the gut wrong,

it's a failure as a butterfly.

If you get the wings right and the legs right

but the muscles don't attach,

that butterfly's going nowhere.

It's dead.

You begin to see the depths of the problem.

So for evolution to have created

this sort of pathway, gradually,

it would take a miracle.

[Paul Nelson] Metamorphosis,

if it came into existence at all by an undirected process,

had to have done so in one fell-swoop.

Natural selection, by definition,

I would say, cannot build that kind of process.

To create a process like metamorphosis,

you'd need a totally different type of cause.

Something that could see a distant target,

keep that target in focus,

and provide all the resources necessary

to hit the bulls-eye on the first shot--

I think the only cause that could have accomplished that is an intelligent agent.

From a philosophical perspective,

the suggestion of intelligent design

as the explanation for the origin and development of life

contradicts the assumptions of many biologists.

But when considered objectively, evidence may be plentiful

within the walls of a Chrysalis

or on a Monarch's wings.

Metamorphosis not only challenges the Darwinian picture of life,

in fact it points, in a positive way,

toward the truth of intelligent design.

If you saw a mechanical device of the sophistication of a butterfly,

you would not, for a moment, hesitate to ascribe that to intelligence,

because the butterfly is so much more sophisticated,

almost beyond our comprehension,

than anything that we make.

Planning, foresight, artistry, engineering--

Normally in our experience,

when we see those criteria fulfilled,

when we see those indicators,

we say, "That's positive evidence of intelligent design."

To build a butterfly, you need a cause

that can visualize a long-range objective,

and then direct every step of the process

that's required to make it happen.

Only intelligence, universally in our experience,

is capable of doing that.

You also need a cause that can re-use lower-level component parts

to construct a different higher-level system.

For butterflies, the same genes and proteins that build you a caterpillar

can be reused to give you an adult flying insect.

As Nobel Prize winning geneticist B a rbara CCI I n to C k n ote d,

"it's astounding that two brilliantly designed organisms

share a single genome."

To build a butterfly, you have to be able

to assemble a network of elaborate sub-structures

like wings, navigational systems,

and a proboscis...

and then integrate all these systems into a very complex organism.

And you need a cause with an artist's eye

for color and pattern and shape...

a sense of beauty and aesthetics

that extends way beyond utilitarian purposes

like camouflage or species recognition.

There may well be in butterflies

aspects of beauty that are there

not for the sake of reproduction or survival,

but for us to appreciate.

[ N n G a U 9 e F] A lot of people I know who study biology

do it because they find it beautiful.

Natural selection had no reason to produce beauty.

Beauty is a sign of the transcendent.

It's purely gratuitous.

We all recognize it.

We just have to acknowledge what it points to.

[Paul Nelson] As human beings, we have a unique gift

that enables us to evaluate evidence and then arrive at logical conclusions.

That's what science is all about.

When you see certain effects in nature,

it's your responsibility as an investigator

to find the cause that will explain the effect.

When you process all the evidence revealed through metamorphosis,

and then you ask yourself-- in your own experience,

what kind of cause could bring about these results?

I think the only reasonable answer

is an intelligence that transcends the natural world.

A designer with foresight

and a sense of engineering and artistry...

and the ability to light up the sky on a summer afternoon

with magnificent evidence that life on earth

is the product of something greater

than a blind, undirected process.

$4' [Woman vocalizing]

$4' [choir vocalizing]