Gerry Garbulsky: It is the year 1837,
our next speaker is 28 years old.

He is just back from 
an incredible voyage,

that would later change
our conception of life.

Please welcome Charles Darwin himself.

(Applause)

Charles Darwin: Dear colleagues, friends.

I took this invitation to tell you
about an idea that little by little

has been developing in my mind.

I consider it a dangerous idea.

Just because I know
you are people I can trust,

open minded people that will appreciate
how delicate this matter is,

I dare to expose it, yet incomplete.

It’s an idea that concerns me,

and, somehow, it’s turning into
a burden too heavy

to be borne alone.

I always considered 
my academic studies

were nothing but a waste of time.

I really had no idea 
how my life would turn,

until 6 years ago I got a letter 
that would change it forever.

My dear friend and mentor Henslow
told me that Capitan Fitz-Roy

was about to start 
an expedition around the world

and was willing to share 
part of his cabin

with a young naturalist, without salary.

That would be the beginning
of an adventure that would fulfill...

Fulfill? It would exceed all my dreams
since I was a little boy!

The expedition took longer than expected.
It ended up taking five years.

And even so, I couldn’t get used to 
the boat rocking movement.

But, the natural wonders I saw,
what I learned in that trip.

I took notes almost every day,

returned with so many journals 
I expect to publish as soon as possible.

As a kid I loved nature, loved it,
collected minerals, insects.

I remember once, I found 
a spectacular beetle,

very different from the ones I had.

And I caught it with a hand,

and another one appeared 
and I caught it with the other hand,

finally a third beetle appeared
and I couldn’t think of a better idea

than putting one of them 
into my mouth in order to free one hand.

At that moment, the beetle
spat a horrible liquid,

very acid, I had to spit it out
and lost the other beetles.

Imagine what it meant to me, then,

to have access to that place
in the boat of Fitz-Roy.

Besides, before we left, 
professor Henslow

gave me a geology book.

I must admit that,
when I was studying in Edinburgh,

geology always seemed boring to me.

I even swore I would never read
a book about it again.

But, as it was a gift from him
I agreed to take it and read it.

The book is "Principles of Geology" 
by Charles Lyell.

An author I admired 
from the first page.

And now I boast about counting him
among my closest friends.

Lyell says that when we face
any geological formation,

like a canyon or valley,

we shouldn’t explain it through
extraordinary causes,

like a singular flood 
or the caprice of the gods.

No. All the past events, no matter 
how extraordinary they may seem

should be explained through 
ordinary causes.

For example, a canyon or a valley,
through the action of an ordinary river

that slowly and constantly erodes it
for a long time.

The key was time.

Imagine how long it takes for
a little riverbed to form a canyon.

The Earth, my friends, is much older
than we thought.

Time and raindrops.

Multiplying the drops 
by thousand downpours,

and multiplying the action
of a river by thousand years,

Lyell turns geology
into a mature discipline.

He simply teaches us to recognize

and decode in the rocks 
the message of time.

He teaches us a new perspective to see 
the geological formations we already knew.

As if they were the wrinkles in the face
of an old world.

The impact the book had on me was such

that every time I faced 
a landscape never seen by Lyell,

I saw it through his eyes.

Although nature wasn’t the same after him,

it would still be the object
of my passion.

So, it occurred to me to ask myself 
if this approach

couldn’t be applied to other fields.

That is, if the repetition
of little events

through huge periods,
makes them effective.

Maybe, time has created new things
in unforeseen spheres.

That is, Lyell explains the origin
of a canyon

with processes as simple as erosion.

So, is it possible to explain
in a similar way

the mystery of all mysteries?

That is to say, the origin of the species.

But, which are the forms,
the forces, that are still working

and have shaped life?

Which is the erosion that has created

the wonderful diversity of species 
that inhabits our planet?

No doubt, not even one,
that the naturalist

who finds which such processes are,
will be the Newton of natural history.

But, while I was asking myself
these questions during the trip

I started to notice
certain signs in nature.

Without being able to understand
their meanings and implications.

Like a detective arriving
at the crime scene

and doesn't know how it was committed.

I’m talking of the dangerous idea

I’m here to tell you about.

For example, in the Galapagos archipelago

I noticed that in each island
different turtles inhabited,

with a different aspect, but above all
with a different flavor

More than one proudly recognized
the island the dinner came from

with just a bite.

Many believed that it just was
a caprice of the creator.

I was concerned about it.

I needed to find another answer.

I had clues for a new idea.

But this idea didn't mature during 
the trip, but later.

It was by accident.

I sent my complete collection of birds
from the trip to an expert ornithologist

to have them catalogued.

In the sample, there were a series 
of little birds, chaffinches,

I collected in the four islands
I visited in Galapagos.

In each island, the chaffinches 
showed different modifications.

The idea I came up with, 
the most reasonable one,

was that the birds came
from the continent

and have adapted to
the different environments

of each island.

We were dogmatically taught that a species
can never be transformed into another one.

However, the expert told me
that despite their resemblance

they weren’t varieties of the same species

but different species.

The modifications the chaffinches
suffered in each island

achieved what we considered impossible;

the species change.

Can the ordinary mechanisms
that generate transformations

in each species create different species

if we give them enough time?

I thought how taxonomists
group life forms:

varieties into species, 
species into kinds,

kinds into families.

The “family" idea started
to go around in my head.

And if it was just about that?

If the term "relationship" was more
than an expression

but a real thing instead?

If the whole life on Earth
was part of a big family?

Maybe, the complete biodiversity

is the product of the descendant

of some ancient ancestors.

Perhaps, and this may be
a little risky,

there is a single ancestor for all of us.

Imagine. The history of Earth,
the history of life on Earth

would be like the history of a tree.

A tree whose branches represent

the varieties of all the families

that inhabited and inhabit our planet.

A family tree that grows
imperceptibly day by day.

And this is where the idea
becomes even more dangerous.

If we follow the implicit logic
of this thought,

we, human beings,

would also be part of this big family,

with moths, orangutans,
and Galapagos chaffinches.

We would be a little branch
in the leafy tree of life.

We wouldn’t be the result
of the direct action of the creator.

We’d no longer be
the center of creation,

but just descendants of an
animal form already extinct.

But as always, this leads us
to new questions.

If we all are part of a big family,

it’s inevitable to want to know
how our ancestors were.

Perhaps in the future, we may be lucky
and able to find their fossils.

But, how can we know how they moved,
what they thought,

laughed, cried, what they dreamed of?

Lyell taught me to read the past
in the geological strata.

I wondered in which stratum we naturalists

should read our own past.

We bear the footprints
with which, in the future,

we could rescue our ancestors.

The forces we are searching for
left a scene full of clues.

And the answer, like the erosion,
is in the full eye of everyone.

You just have to be open minded
to find it.

Think about it:

If someone meets with me,
my brother and my cousin Francis

in a room, they could suspect
we are family.

They could even dare say my brother
is closer to me than my cousin.

All this, just thanks to

the detailed observation
of the physical resemblance.

So, observe the wing of this bat.

It has the same bones, in the same
disposition as our hand.

And these similarities can also be found

in the structure of a bird's wing,

or even in an extinct reptile.

From my point of view, 
these similarities occur

because they are inherited 
from a common organism:

the organism from which they descend.

And these similarities reflect
a genealogical relationship.

Birds, mammals and reptiles are family.

And we can also deduce that bats

are closer to us than reptiles or birds.

Like my brother is closer to me

than my cousin.

And another very important thing:

if someone observes
my cousin, my brother and me,

they could imagine,
even without meeting him,

characteristics of my grandfather.

By examining these bones,

we can know characteristics
of the organism they descend from.

For example, that it had a spine,

that certain bones were
connected with other ones, etc.

And, isn’t it possible to apply this
method further than to bones?

Don’t the yawns, that many times

our loyal dogs pass on us,

talk of our ancestors?

Isn’t it meaningful

that in our anger gestures
we show our teeth?

Like wanting to show the huge canines
we no longer have.

Maybe, it’s a gesture dogs and humans
inherited from a common ancestor.

And the dogs that keep us company at home,

and we consider members of our family,

who would have thought
that they really are our family.

And who would have thought
that partridges are too,

in which both human and dogs 
buried our teeth.

I know I have to find an explanation,

in Lyell’s way,

that tells how they are produced,

these modifications,

These ramifications in the tree of life.

How come my dear chaffinches

got their beaks modified, in each island

to be able to eat the food
available there?

What is missing is the natural mechanism

that generates the beautiful adaptations 
of the organisms

to their environment.

To be honest, I have no idea
which this mechanism is.

Anyway, all this radically changes

the way we see ourselves.

That’s why the idea is so dangerous.

It’s against the foundation

of our moral values.

How could I share this idea
with people who still think

that we are the center of creation?

How could I share it with an audience

that doesn’t even recognize
a common origin for all human beings

and in this way pretends
to justify slavery?

How would they take my idea that we have
an origin in common with primates?

Beyond the seriousness of this statement

I was comforted that this conception

gives arguments to those of us

who are horrified by slavery.

I remember how terribly upset I was

when I saw the unfair treatment
black people received in Brazil,

or the natives in Argentina.

I see from here that some of you
look at me flabbergasted,

others even show me their canines.

Another ones, curiously,
seem satisfied with the idea.

It’s not necessary to convince me 
of how hard it is to digest this idea.

It’s like wasting almost all I learned
during my studies

and much of what you probably learned.

Well, the confession is made.

And I say confession because
having told you my idea,

for my conscience and fears,

is like having confessed a crime.

Thank you.

(Applause)