(bell ringing)
Now as you can see,
the flowers of these two plants are shaped quite differently.
Does anyone have any ideas about why the flowers of this orchid
might look different from other types of flowers,
like the ones on this cactus?
Ooh, Ms. Reyes, I know, I know!
(clears throat)
I think maybe Dimitri wants to be called on.
I bet it's bright and weird-looking
because it's poisonous.
You know, how like poison dart frogs are crazy colors?
It's called warning coloration.
Psh, it's not poisonous.
My mom got one of those at WalkeaMart!
It is true that many species can signal with their coloration.
Let's hear from some other people.
Shawna, what do you think?
(timidly): Oh.
Maybe the orchid looks so unusual
because it needs to attract attention?
MS. REYES: Very close, Shawna!
The orchid's unique appearance
attracts a very specific type of insect pollinator,
which carries pollen between the orchids to fertilize them.
But how did it know to make its flowers look like that?
Good question!
The relationship between orchids and insects
evolved over time through natural selection,
which is the process responsible
for nearly all of the diversity of life on Earth!
Oh!
That's what I thought.
Oh, yeah!
(bell rings)
What a glorious morning!
I'm feeling ripe with possibility today.
Oh hey, Blossom!
That lesson went great,
so I'm feeling pretty centered myself.
You know that I'm a big believer in following your bliss,
but in this instance,
we may need to take a few steps back.
Natural selection is a tricky topic.
It's easy to misunderstand and even easier to misrepresent.
How about this?
When the kids get back,
I'll guide you through some of the rough patches.
Sounds way groovy to me!
(coughs)
Oh excuse me, I'm sorry.
You totally bring that out in me.
And scientists discovered that Galapagos finches
had evolved differently-shaped beaks
to adapt to the particular environments
of different islands, allowing them
to exploit the resources that were available there.
The finches with short, thick beaks
are adapted to feed on large seeds,
while those with long, narrow beaks have evolved
to feed on cactus pulp,
allowing them to thrive in more desert-like conditions.
I don't know about you, but I think that went pretty well.
Hmm.
Here's an idea.
Let's take a look at what Shawna took from that.
Then we can see if we're heading down the right path.
SHAWNA: The finches that can't reach food
with their short little beaks evolve longer ones so they can.
Gah!
Okay, individual organisms
don't just sprout the traits they need.
Natural selection whittles down existing variation
over many generations.
New variation can arise
through mutation and genetic recombination,
but even then, it's only sometimes beneficial.
I know, my dear.
You're talking to an orchid here.
Hey, that rhymed!
Poetry truly is everywhere.
Anyway, when you said "the finches,"
Shawna thought you meant individual finches.
Of course I know you meant their population,
but the word is ambiguous.
Next time, make sure you specify
individual, population, or species,
and ask your students to do the same.
And don't worry.
This is thorny stuff.
Kinda like my friend over here.
I guess he took a vow of silence.
I admire your commitment, my prickly pal.
Why don't we see how a different student
interpreted your lesson.
JUSTINE: The warbler finch
better bulk up that beak over time
if it wants to use those resources.
And then it can pass that new awesome beak to its babies!
Another misconception!
Beaks aren't like biceps.
They can't just change size because an organism works at it.
And the traits organisms acquire through experience or practice
are almost never passed down to their offspring.
This is tricky.
(taking a deep breath)
Go to your happy place.
Yes.
I always thought evolution was pretty straightforward.
Darwin, the Galapagos, survival of the fittest...
What's to misrepresent?
A lot, unfortunately.
When you said "they adapted," Justine thought it was something
the finches were actively trying to do,
like when you adapt to a new school after a move
or when you put on a coat in the winter.
You and I know that "adaptation"
has a special meaning in biology,
but students who haven't learned this stuff yet
will rely on the definitions they already know.
Shall we dive back in?
Okay.
Natural selection is sometimes called survival of the fittest.
The "fittest" individuals in a population
are most likely to survive in the environment,
and therefore most likely
to pass on their genes to their offspring.
In this way, populations can become
more and more "fit" over time.
MS. REYES: This is horrifying.
ORCHID: I know.
Dimitri doesn't yet understand that sometimes,
it can be an advantage to be small or spindly--
say, if it makes it easier to hide from predators
or find enough food when there are limited resources.
Uh, no, I meant all the snakes and spiders!
I'm gonna have nightmares for a month!
(shuddering)
Understanding where your students are losing their way
is a powerful thing.
If they don't understand the definition
of the word "fitness" in an evolutionary context,
they might think you mean big, healthy, and strong,
as it's used in normal conversation.
While we're on the topic,
I'd steer clear of that "survival of the fittest" bit;
it's quite misleading.
But I've been hearing that phrase my whole life,
even from scientists.
How can it be wrong?
Yes, unfortunately even experts sometimes use it as shorthand,
but they often don't realize
it can be misleading to students.
That's because the process of natural selection
is really all about reproduction, not survival.
An organism that lives a long time without reproducing
doesn't contribute its genes to the next generation,
and therefore isn't really that "fit" at all,
biologically speaking.
Well, speaking of "fit,"
getting my students to understand
how some individuals can be better adapted than others
if they're all the same species
might just put me on the edge of having one.
That is another tricky one for sure.
The whole process of evolution hinges on the natural variation
that occurs between individuals in a population
and between populations of a species.
Just ask your students to look carefully
at what they see out the window in the world around them.
You can see it everywhere.
No two oaks in a park, pigeons on a wire,
or kids in a classroom are exactly the same.
In an evolutionary context, these differences
give individuals advantages or disadvantages
in different environmental conditions,
which affects their ability to survive,
and most critically, to reproduce.
Let's go back in time and try it again.
Can we do that?
Can an orchid talk?
Maybe the orchid looks so unusual
because it needs to attract attention?
You may be onto something, Shawna.
Can you explain what you mean by attracting attention?
Maybe it's good for the orchid if bugs hang around it.
So it makes itself look stranger so the bugs will come.
It's so clear now.
Shawna is thinking about the orchid
the same way she was thinking about the finches.
She thinks individual organisms can choose to develop
whatever traits they need to thrive in their environment.
Looks like I'm gonna have to watch my wording
and my assumptions.
Isn't it wonderful?
By asking the students questions throughout the lesson
and having them explain their thinking,
you're learning what their misconceptions are
and gaining the tools to help correct them.
This is great!
And we've only just scratched the surface.
There are also misconceptions about common ancestry,
phylogenetic trees, deep time...
Blossom, Blossom...
Okay, I guess there's still a lot to learn,
but at least I'll never be bored.
Are you up for another lesson?
Of course, my dear.
Hey, you wanna take the next one?
Oh well, I tried.
To discover more about how kids learn science
and the types of misconceptions they might have,
visit us online
at ScienceEducation.SI.edu/ GoodThinking.
More videos from the Smithsonian Good Thinking series
can be found over here.
Namaste!