( music playing )
- Are you ready? -
Greetings! Bill Nye here.
I am very excited to tell you
that I am today's celebrity substitute.
What if I told you
that cloning could cause the end of the human race?
I'm Ji-Yun Kim.
I'm from Oakland, California, where I teach Biology.
And today we're going to be studying...
But I have a special guest to help me teach this lesson.
Today's celebrity substitute is Bill Nye.
- Hi, Bill. - Greetings, Ms. Kim.
- How are you doing? - I'm fabulous.
We're quarantined. I'm here in the kitchen.
- I'm in my bedroom. - That's right.
Last time, though, I thought it was so fun
walking through the history of Earth's timeline.
- I'm exhausted. - ( laughs )
- I walked 3,000 miles. - You did.
- I'm whupped. - Dedication.
But anyway, today we're gonna talk about something else, yeah?
We're moving on to genetic variation
and natural selection.
Well, that make me want a banana.
Hmm.
Bill:
Ji-Yun:
And that's what enables farmers
to raise a tremendous number of bananas on a plantation,
but it also could put our banana supply at risk.
And in order to understand how this cloned banana
could wipe out all bananas forever
we need to understand genetic variation.
Genetic variation is things that change in nature--
whether you have brown eyes, blue eyes--
are a result of the random nature of genes
when organisms like you and me
and funguses and oak trees reproduce.
But what happens in nature,
and this is what Charles Darwin discovered,
was that sometimes the variation
gives you an advantage,
and sometimes it doesn't.
So Charles Darwin was traveling around--
you probably heard this story--
in the islands that we call the Galápagos.
And he would get a bird and spend time with the bird
studying the shape of its beak.
And these are the famous, famous finches
of the Galápagos Islands.
Finches play a pivotal role
in the history of studying evolution.
When Charles Darwin made his famous voyage to the Galápagos Islands,
he noticed that there was a surprising variation
in the size and shape of the beaks of finches
from one island to the next.
And that observation played a huge part
in developing the theory of evolution.
Ms. Kim has what I think is a very cool demonstration
that shows us the nature of getting an advantage
by natural selection.
I believe you have some pinto beans
in front of you somewhere.
Well, sure. Who doesn't?
So this is actually a simulation that I do
with my students in my own classroom
to demonstrate this concept
of genetic variation and competition,
and how that eventually can lead to the natural selection
of the traits that are more advantageous.
You and I, Bill, we're gonna be finches.
And we're gonna have beaks in the form
of different types of forks.
So I know you have some forks
laying around somewhere, right?
Oh! Let's see how many beans we can move from our plates
into our cups in 30 seconds.
One fork only, Bill.
- ( squawks ) -
Go!
I'm a finch scooping up my beans.
I'm a bean-scooping finch.
I'm using a fork to get my seeds.
I'm surviving on a Galápagosian Island.
I'm beaking around with the fork.
I'm competing with other finches
- as fast as I can. - And stop.
Counting beans.
( Bill vocalizing )
- 159. - 174.
What? You beat me!
So we can pretty clearly see that some of these beaks
were better suited to collecting this food than others.
If we imagine these as different types of finches
competing for food on an island,
let's just say things don't look too good for this finch here.
- I think the key was the scoopy fork. - Right.
So just think, if your beak was just the right shape,
you'd have an advantage
over other finches on your island.
What we've seen from this demonstration are two things.
The first is called survival of the fittest,
which is the continued existence of organisms
that are best adapted to their environment,
with the extinction of others.
The second is variation, which is the genetic differences
within and among a species or population.
- That is a cool demo. - It's a very popular one with the kids, too.
I love it.
Darwin also talked about artificial selection,
and humans do artificial selection all the time.
That's why we have farm food,
because farmers have artificially selected
for the plants that taste the best,
that grow the fastest,
that are the most drought resistant.
So this banana, the kind of banana that we all enjoy,
is called a Cavendish,
named after Steve Harrelson.
No! It was named after a guy named Cavendish.
But before these was another bigger
and what people say tastier,
more banana-like banana.
And people called it the Big Mike.
The Big Mike was wiped out by a fungus
and we don't have them anymore.
So farmers found another banana
that we call the Cavendish
that can thrive despite that fungus.
But keep in mind right now, these are all cloned.
If the bananas are all exactly alike,
and there's a germ that can attack this one,
it could attack all of these.
One of the advantages that you and I have
being big animals is that we have variation.
It allows is to fight off germs.
If you are a big animal,
your enemies are not gonna be
lions and tigers and bears.
What's really scary? Flying monkeys. That's right.
If you're not scared of flying monkeys,
there's something wrong with you.
All right, but the thing that's gonna get you,
and we're all living through this right now-- germs.
Germs are what get us big animals.
So by having these genes
that are a new combination every time,
we have the advantage
of having a new combination of genes
that the germ, like this virus,
may not be able to attack.
So how could the whole human race
be wiped out from cloning?
In science fiction stories,
people talk about cloning people all the time.
"We're gonna clone them.
We're gonna make armies of clones
who are gonna be soldiers to take over the world."
You don't wanna do that.
Because instead of coming up
with a new combination of genes
with a mom and a dad,
you're not coming up with a new variation.
So if everybody were exactly the same,
something like the Coronavirus could wipe us all out.
Because everyone on Earth would have the same weaknesses.
And we don't want that.
Science!
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