as you can see.

What that means is that,

day by day, I become a lot more reliant and trusting

of machines like this

than I am of this machine.

Like some of you, I suspect, I'm increasingly aware

of the frailties of the human body and brain.

And I look around at this technological revolution taking place.

And I kind of want to apply this same ingenuity to the human body

to upgrade myself.

After all, if we've gone from this

to this

in my lifetime,

why can't we go from this

to this?

Why can't I, why can't we all be stronger, smarter,

faster, longer lasting?

We've all seen great new inventions that are aimed at doing just that;

upgrading the human body.

High-tech replacements for our hands and arms,

our knees and legs, our eyes and ears,

even our brain.

Google has an ambition to connect the brain directly to the internet;

no typing or speaking required.

Think about that for a second, kind of creepy, kind of cool?

I'm sure it will happen if Google is going after it.

The main reason that we fantasize about these biological, these bionic upgrades

is that our own biological upgrades happen so infrequently,

at least that's what we were told in school, right?

Here's what we were taught:

Once upon a time we evolved from this

to this,

to this, to this,

to this.

And now, we are who we are.

This is Darwin's famous natural selection.

It is thought to be the one and only,

very slow upgrade mechanism that we have.

And what we were told was, we're stuck in place

we'll stay just like this until a random genetic mutation happens

and spreads throughout the entire species.

For most of the grand time scale of human existence,

we stay the same.

That's what we were taught.

But that turns out not to be the case.

If you look closely at science from the last few decades,

a very different lesson emerges.

Humans are self-upgradeable.

We are designed to upgrade on our own.

Not just every few hundred thousand years, but all the time.

We have a genetic operating system

whose function it is to constantly adapt to external conditions and needs.

Imagine if Apple held an event and said,

here's your new iPhone 6

and you're really gonna want to buy this one

because you'll never have to buy another one.

Next year this iPhone 6 will turn into an iPhone 7.

The year after that, it will turn into an iPhone 8,

not just the software,

the hardware itself will transform right in your hand

and into what you need it to be.

So, the screen will become bigger or smaller depending on what you need,

the glass will become more flexible or more rigid depending on what you need,

the case will become harder or softer or more grippy or smoother

depending on what you need.

That's what human beings do.

We constantly adapt

to our external conditions and needs using not one, but four

different biological upgrade mechanisms.

We've already talked about natural selection,

it's the slowest by far,

it's the only one we don't get to see in our own lifetime.

So let's talk about the other three.

First upgrade mechanism is homeostasis.

It's a biochemical system

that allows the body to adapt constantly,

second to second, minute to minute, hour to hour,

to environmental changes.

What's an example of homeostasis?

I am in my warm New York City apartment,

I decide to go outside,

it's freezing cold,

I'm in the middle of a freezing cold blizzard all of a sudden.

Immediately, my hypothalamus sends signals

to constrict the blood vessels close to my skin,

it activates my skeletal muscles to shiver and generate warmth,

the hair on my skin raises up to trap warm air,

glands secrete adrenaline and thyroxine to increase my metabolic rate.

I'm not even aware of it, but my body has just immediately

self-adjusted to a new environment,

it is instantly upgraded to deal with the cold.

That's homeostasis, upgrade mechanism number one.

So I'm outside

and I'm actually on my way to my son's school a few blocks away,

he's in the fifth grade and he's learning to play the violin,

and today I get to hear his first orchestra concert.

(Music)

You do too.

(Music continues)

I think if my fifth grade orchestra had been anywhere near that hip,

my life would have gone in a completely different direction.

So what's going on with my son as he is learning to play the violin?

He is experiencing and enjoying upgrade mechanism number two:

neuroplasticity.

You've all heard of neuroplasticity; it's the brain's way of becoming smarter

by building connections between neurons

and strengthening those connections.

And even though neurons are obviously very, very small,

all these connections actually physically change

the shape of your brain.

I can't emphasize this enough,

this involves every single skill you have ever learned or will ever learn,

and we know it from peer-reviewed science.

Using MRI scans, neuroscientists have seen the subtle physical changes

in the brains of musicians learning a new instrument,

cab drivers learning the geography of a different city,

meditation practitioners training their brain in a new way

and all sorts of athletes.

The brain is built to adapt to your needs,

that's what it's designed to do,

and that's upgrade mechanism number two.

So, we've got a problem here, what about this interval?

We seem to have every time scale covered,

we've got seconds, minutes, hours,

all the way up to millions and millions of years covered,

all these three mechanisms are working so well together,

but what about this interval here?

Generation to generation.

This is where the story gets a little strange

and, to me, very interesting,

because for a long time, scientists were quite convinced

there was no biological mechanism for adaptation

from generation to generation.

We have culture, we have education, we have events like this,

these things can do a tremendous amount in that time period,

but not these three biological mechanisms; natural selection is way too slow,

you can have a random genetic mutation

but you can't have it spread that quickly through the human species.

Neuroplasticity also doesn't apply here,

my son can change his brain dramatically in his lifetime,

but he can't change the brain of his future son

or grandson.

Or can he?

Because it turns out that there is a very peculiar biological mechanism

that fits right in this interval of generation to generation.

It's called epigenetic inheritance.

Epigenetic inheritance, by the way, was just discovered,

so if you haven't heard of it, forgive yourself,

it's a brand new discovery.

We've known of epigenetics, but epigenetic inheritance

is really brand new to science.

And what is it?

It is the understanding that anything in our lives,

anything we eat, breathe, our moods, behaviors and so forth,

affects our genes and that some of those effects on the genes

can actually get passed down to our children and grandchildren.

Now, this is going to sound nuts to you guys

because we're all raised to think about genes in a certain way,

which is that you can't change your genes.

And that's true, you can't change your genes.

The most fundamental thing about DNA is that it's stable.

50% of your DNA is a perfect replica from your mother,

the other 50% is a perfect replica from your father,

but DNA comes wrapped up in a protective package of proteins

called the epigenome.

"Epi" is Latin for "outside," so epigenome means outside the genome.

Here's an illustration of what the epigenome looks like

at a magnification of about 1 million.

You can see the double helix strands of DNA wrapped around

the epigenetic proteins.

Now, these proteins not only protect DNA,

they also influence gene expression,

which means they tell genes when to turn on and off.

So we've known for a long time that our lifestyle can influence our genes

through epigenetics,

what scientists just discovered

through many studies now in plants and animals

is that some of those effects can get passed down to our children.

And very recently we've seen

some really amazing population studies in humans

that suggest that the exact same thing is going on in us.

Now, admittedly, we do not have the perfect examples yet in human beings.

Why is that? We can't manipulate human breeding,

we can't clone humans,

we can't do with humans what we would ordinarily need to do

to do these studies,

but the scientists who study this are quite convinced

that epigenetic inheritance is real and ubiquitous.

So that brings us back to this marvelous chart.

Now it's complete, we see our four upgrade mechanisms,

each perfectly complementing one another

and covering the entire time scale of existence.

And, by the way, these ideas are not mine.

I, of course, am learning them from scientists.

Here are two scientists I wanted to give credit to and thanks to

for doing an early version of this time scale chart

and putting it all together.

Why am I so obsessed with this chart,

and I keep coming back to it?

It's just a dry list of words,

but I don't think I've ever seen

an illustration that better demonstrates how humans are built for adaptivity.

We are designed to upgrade on our own, we are self-upgradeable,

we are designed to change from moment to moment,

from month to month, and year to year,

from generation to generation, and over hundreds of thousands

and millions of years.

We don't just inherit our biology,

we also impact our biology.

That's an amazing opportunity,

and also a very serious burden.

So what can human beings transform themselves into?

It's easy for me to stand up here

and obsess about my own middle-aged problems,

my creaky bones, and fantasize about some new high-tech solution,

and we know those solutions will come.

But then I think about this chart, and I think about my son

and how he's gonna transform himself

over the course of his life,

and some of those changes will get passed on to his children

and to their children.

And thinking about that, I am filled with a hope

and a sense of awe for this very, very old technology

inside each one of us.

Thank you so much.

(Applause)