 ( music playing )
- Are you ready?
- ♪ Celebrity ♪
 ♪ Substitute ♪
Greetings!
Bill Nye here.
 I am very excited
 to tell you
 that I am today's
 celebrity substitute.
How does this jar of mud
become me?
And how does something
as absurdly unlikely
as evolution
become inevitable?
I'm Ji-Yun Kim,
I'm a Biology teacher
in Oakland, California,
and to answer those questions,
we're going to be studying
the timeline of Earth's history.
I have a very special guest
to help me teach this lesson.
Today's celebrity substitute
is Bill Nye.
- Greetings.
  Greetings, everyone.
- Hi, Bill.
- Hi, Ji. Good to see you.
- How are you doing?
I'm fabulous.
We're quarantined,
and I'm living off
the land up here.
I do have a garden,
and I got quite a bit
of food out of it.
I'm really excited about
getting to do this with you
because evolution,
I find it spirals
through everything
in Biology content.
And it's such
a complex concept for
a lot of my students,
so when I teach it,
it takes a real long time.
So-- yeah, exactly.
It's a lot.
So I'm really excited
about getting this chance
to teach it in some way
this year
since I haven't gotten
to touch it at all.
I can't say enough
how amazing this idea is.
Because when it comes
to living things
like you and me...
- Right.
- ...evolution explains it all.
- Right.
- It's the story behind
  every living thing.
- Where should we start?
- Oh, well, it's always good
  with the discoverer,
which was two guys--
Charles Darwin
and Alfred Russel Wallace.
They both had the same idea
about the same time.
But I think the reason
you hear so much more
about Darwin
is he wrote the book--
"The Origin Of Species."
The conclusion that
both of these guys drew
was that if you go
far enough back in time,
everybody came from
a common ancestor.
And we're talking about
everybody.
You, me, every human
you've ever met.
Every dog, every mushroom,
everybody has
a common ancestor.
- Just looking at species...
- Right.
...looking around,
looking at roses,
looking at bees and birds.
How could there
be enough time
for all these
species to emerge?
But through extraordinary,
extraordinary careful science,
we know that the Earth
is 4.5 billion years old.
Right.
It's just such a huge number.
I've never been able
to really understand it.
It is, like, huge.
It's, like, so huge.
Mm-hmm.
I can't wait to get into it,
but since
we're talking about time,
I wonder if you have time
for a little surprise?
Two students of mine
who are big fans of yours
are on the line.
Do you mind if Selena
and Michelo join this lesson?
They have no idea that
you're teaching it with me.
I mean, it sounds cool.
It sounds great. Let's go.
Hi, Selena. Hi, Michelo.
- Hi, Miss Kim.
- Hello, Miss Kim.
You know that we're here
to kind of go through
a lesson about evolution.
- Yeah.
- What I haven't told you
is that we actually
have a very special
substitute teacher
here with us.
So I just want to introduce you
to this wonderful celebrity.
- Bill Nye.
- Hi, you guys.
( laughing )
Oh! Hi!
- Hi.
- Hi.
Ji-Yun: You guys okay?
You two okay?
- Selena's a little-- 
- Yeah, yeah! Um...
- Yeah.
- Selena, I've never
  seen you so quiet.
- Uh, I'm shocked right now.
- I can tell.
A little warning
would have been nice.
Do you have any questions
for Bill?
Why is it important
to know about evolution?
There's two questions
that everybody asks.
- ( phone ringing )
- Oh, listen to this,
  you guys.
I don't know if you remember
this technology.
Can you see this?
This is a phone.
- Yeah.
- Yeah.
Have you ever used a phone
with a cord before,
Selena and Michelo?
I don't think so.
It's just like this,
only it has a wire on it
and it's big.
So you said why is evolution
important, right?
- Both: Yeah.
- So everybody wants
  to know about ourselves.
And I claim
there's two questions
that everybody asks.
"Are we alone in the universe?"
And then the other question is,
"Where did we all come from?"
Where did we all--
what are we doing here?
How did we get--
what is going on?
What is it that let us
be on the Earth right now?
That's-- if you want
to know anything,
you have to learn evolution.
Does that answer
your question?
Both: Yeah.
Nice to finally meet you.
- Thank you.
- Thank you, Bill.
- Very cool.
- Thank you so much
  for being here today.
We're going to get going,
but I hope you enjoy
the lesson that
we're about to teach.
- And I'll see you soon.
- See you soon.
- Bye, guys. Thanks.
- Thank you. Bye.
So I'm really excited about
teaching evolution, personally.
The fact that I get
to do it in this really
cool way with you,
I got really excited
about it, you know?
Well, it's gonna be fun.
Well, where should we start?
I have come up with
this exciting demonstration
involving a map
of our beloved country,
the United States.
Our journey begins in Boston,
and we are gonna walk
all the way to Los Angeles
over the course of
four and a half billion years.
So on the map you're using,
Boston is the formation
of the Earth,
and Los Angeles is now.
Bill: Yeah, yeah.
So, from Boston to Los Angeles
is very close to 3,000 miles.
And so that means that each
meter represents 1,000 years.
We start the clock
4.5 billion years ago.
Stars have exploded.
All this dust
is tossed out into space.
Whoa, dude. Dude.
Even the dust has gravity,
and it pulls itself together.
It starts to spin
into a disc.
The little whirlpools
form in the disc
and that's a planet.
And here we are.
So the Earth formed.
We go about 30 million years.
The Earth gets hit
with another one
of these objects,
and our beloved moon forms.
And we will put the moon here
at about Worcester,
Massachusetts.
Even though it looks like
it's spelled "wor-kester,"
they say Worcester.
( Boston accent )
"Did you park in Worcester?"
"I parked it. I parked it,
I unparked it-- in Worcester."
( normal voice ) So, uh, now,
we're walking along here
and we're waiting for something
exciting to happen.
- Let's say oceans form.
- ( gasps )
And the oceans formed
right around here,
in what would now
be maybe Pennsylvania.
At some point
in Earth's history,
the atmosphere had a bunch
of gasses in it,
and eventually the temperature
of the Earth cooled down.
And as it cooled down,
the water vapor in the air
actually condensed
and formed our oceans.
Bill:
So this would be water
and all these different salts.
And this is
a big block of salt.
And in the same way
that this salt
formed these crazy,
beautiful crystals,
maybe, perhaps,
a set of atoms came together
that enabled themselves
when hit with lightning
or sunlight or something
to make copies of themselves.
We're in Pennsylvania
when the soup formed,
the oceans cooled off.
But if you keep going
all the way
to what would be
western Pennsylvania,
these crystals started
to organize
into self-replicating
living things.
Oh, here.
A dramatic representation
of self-replicating
single-celled organisms.
So somewhere along the line
with enough "bzzz!"
and enough "brzz!",
something happened
that enabled chemicals
not just to form crystals,
but to form things that
made copies of themselves.
And this was
the beginning of life.
What are the chances
of that even happening?
Well, let's say the chances
are really, really small.
So we've been going
about a billion years,
and we've barely gotten
to the Great Lakes.
Another big fraction
of a billion years passes
and these organizing
organisms get a nucleus.
So that's cool, but look!
Here's a miniature one.
That would happen
in about St. Louis.
We've gone over
a billion years,
and we've just--
all we've got is
the little bacterium.
Just one little--
a little thing.
There are no giraffes
running around.
There's just little--
little cells.
All right, so,
we're walking along,
and eventually
these things with nuclei
get really, really complicated
and become big dinosaurs.
That started way over here.
We're on Route 66.
Then all the other
animals emerge.
And then,
people built these pyramids.
We like to think about
the Roman Empire, don't we?
"Sure, we do. Yes, we love
the Roman Empire, Bill."
That's right here,
my kitchen,
this would have taken place.
And then
the U.S. was formed.
And then sending people
to the moon.
( imitating explosions )
Understand,
we have walked 3,000 miles,
4,500 kilometers,
four and a half billion years.
We've walked across the U.S.
We get all the way
to my kitchen,
and all of human history
is right here
within about a meter
of where I'm standing.
I mean, understand
when people talk about four
and a half billion years.
So, what about that question
I asked at the beginning
of the lesson?
How did this jar of mud
become me?
If you had enough time
and enough sparks
from lightning storms,
from thunderstorms,
hitting Ms. Ji's
primordial soup,
there may be
a combination of chemicals
that when hit
with the right "bzzz!"--
jolt of lightning,
for example--
become self-replicating.
What a world.
Thank you so much, Bill.
Be safe out there.
- Carry on.
- Bye, Bill.
Time to take a break.
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