(upbeat music)
- Hi, scientists, I'm Miss Alaskey,
eighth grade science teacher
at Asa Mercer international Middle School.
For those of you that are my students,
I've missed you these
last couple of weeks.
And thanks for those of you
that have been checking in
with me on Schoology.
For those of you that are not my students,
I'm sure your teachers miss you as well.
Today we're gonna start
our Natural Selection Unit,
one of my favorite units
'cause we're looking
at populations and how
they change over time.
So today, we're gonna
start with lesson 1.2:
The Mystery of the poisonous Newts.
What you need for this lesson
is something to write with,
and something to write on.
Optional materials, if you have a someone
that you can check in with,
maybe a family member
in the house with you,
or a friend, or a relative
that you can text, or Snapchat.
If you have a copy of the
Rough-Skinned Newts article,
that's great.
If you have a computer, go
ahead with log into Amplify.
And for an activity near the end,
if you have 12 small
objects that can be sorted,
it could be coins, it
could be building cubes,
any small thing that has differences.
We're gonna start with a little warm up,
get you thinking about our unit.
So I want you to look at these frogs
and then describe the group
of frogs in the image.
So you can write this down, you can talk
with whoever you're checking in with;
however you want to
record, what do you notice?
Right, now you've had a
chance to get your ideas down.
I'm gonna talk a little
bit about what I noticed.
So one thing that I notice,
is I know these are frogs
based on the shape of their body,
and their legs, and they look
a little bit shiny or slimy.
Some things that I noticed
is all these frogs have
at least two different colors,
but not all their colors are the same.
So I notice some of the ones
at the top are kind of brown,
with the some yellow or green,
in the middle there more orange,
some of them with brown,
teal or yellow spots,
and then down to the bottom,
there are some a little more reddish,
and they seem to have
black or orange spots.
A very important word for
this unit is population.
So population is a group of
the same type of organism
living in the same area.
So we can talk about populations
like the human population of Seattle,
or the human population in Washington Dc,
and that's how many people
live in those areas.
We can also talk about
populations of animals,
like the seals that live
in the Pacific Ocean,
or we can talk about populations of plant
like these cedar trees
around Mount Rainier.
The population we're gonna be talking
about in this unit are
the rough-skinned newts.
So a wildlife biologist is a scientist
who studies interactions of organisms
with one another and their environment.
As you watch this video,
listen to why this group is interested
in rough-skinned newts.
(adventurous music)
(rapid foot stomps)
(branches crackling)
- Shawn
- [Shawn] Over here.
(bouncy music)
Finally it's down here.
- Uh-huh, and you're sure this time.
- Hurry up take a picture
before he gets away.
(phone camera shutters)
What did I tell you a poisonous newt.
- This isn't prove anything,
doesn't even look poisonous.
- But I read about this guy
that died from anyone one,
and this looks just like it.
His friends dared him.
- That's horrible, but I
doubt this is the same kind.
- Let's go back and ask those rangers,
if you don't believe me.
- All right, race ya.
- Seriously.
(feet stamping)
(bouncy music)
(feet stamping)
- Woo, is everything okay guys?
- There aren't any poisonous
newts in this park, are there?
- What we just found one
and we took a picture,
show her.
- Yep, that's a rough-skinned
newt, and they are poisonous.
- Well, poisonous to bugs maybe,
but he's trying to tell me
that these are the type
that can kill people,
is that true?
- Rough- skinned newts
have dangerous poison
all over their skin and it
is true people have died
from eating them.
- See, I told you, I read about a guy
that ate a rough-skinned newt,
and he was all dizzy and
his body went fully numb,
and he was dead in 20 minutes.
- Unfortunately, that really happened.
- We were just a couple
feet away from one,
we're lucky to be alive.
- Oh, you weren't in any real danger,
rough-skinned newts are very shy,
just don't bother them
and they won't bother you.
- So are you like a newt expert?
- Well, sort of, I'm a
wildlife biologist here
at the park and we're researching
the rough-skinned newts.
- Why are they so poisonous?
- A lot of visitors
have the same question,
and so far we have some interesting clues.
We know that the newt population
has changed over time.
But there're more individuals
with very high levels of poison now
than there were in the past.
- These newts have gotten
more poisonous over time?
- That's right.
- Hm-mh, I wonder how
they got so poisonous.
- Excellent question,
that's one of the things
we're trying to find out.
Actually if you guys don't
mind could you show me
where you found that newt?
- Yeah.
- Sure.
- Why do you wanna see the place?
- So I can mark it on down,
and return it to the main conservation.
- Cool.
(music chimes)
- So you heard in the
video Dr. Alex Young say
that the newts become
more poisonous over time.
So I want you to take a moment and think,
you can write down, share your idea
with whoever you're checking in with?
What do you think caused
the newt population
to become more poisonous?
Dr. Alex Young needs
some help figuring out
how the newts became
more poisonous over time.
She's been gathering some ideas,
and the two most common
things that you hear,
are claim number one, that some
newts became more poisonous
because they wanted to,
the newts do seem like smart creature
or claim number two, that's
something in the environment
caused the newts to become more poisonous.
Over the course of this unit,
we'll gather some evidence
and figure it out.
As I said, one of the important words
that we'll use in this
unit a lot is population.
We're gonna look at a lot
of different populations,
and an important thing is to be able
to describe traits within a population.
So what we have here is one butterfly,
and so what I noticed
is the wings are broken
into four parts.
On the left side, the wing
is light yellow and peach,
and then it has a brown on
the top part of the wing.
The right wing is much darker.
So the bottom has a darker yellow,
the top is a darker peach,
and then there's that thick brown edge
on the top right wing, and
instead of having brown dot,
it has a blue dot.
So what you're going to do is,
I'm gonna give you two more butterflies
and with whoever you're talking with,
whether you're checking
in digitally with someone,
or there's someone in the room with you,
I want you to discuss how can
we describe the population
by talking about these two butterflies?
What did you notice
about these butterflies?
What Similarities and what
differences did you notice
in this population?
This leads us to our second important word
of the unit, "Trait".
Trait is a specific characteristic
of an individual organism.
So when we look at these butterflies,
and we look at their wings color,
each individual has its trait.
Some of them have solid pale yellow.
Some of them have a solid, darker yellow,
and some of them have a yellow and brown.
Those are the traits of the
individuals in this population.
If you have a copy of the article,
"The Rough Skinned Newt,"
or are logged into Amplify,
follow along as I read it to you.
While we're reading, I
want you to think about,
what are you learning
about the newt population?
Rough- skinned newts may
not appear dangerous:
they are no longer than 20
centimeters (eight inches),
with stubby legs and teeth
that look like tiny bumps.
However, some of these newts
are the most poisonous animals
in the Pacific Northwest.
One rough-skinned newt can
have enough poison in its body
to kill dozens of humans.
That's crazy, an eight inch long newt!
That means if I took a regular
eight and a half by 11 piece
of paper, and I laid a newt
across the short edge of it,
it wouldn't even be that big,
and it can kill dozens of people.
Rough-skinned newts have brown
bumpy skin on their backs,
with bright orange skin on their bellies.
When threatened by predators,
newts curl their bodies
to show the orange undersides
of their necks and tails.
The orange color warns
predators to stay away,
and most predators do.
The only predators that
regularly eat rough-skinned newts
are common garter snakes.
I wonder what's special
about garter snakes
that allows them to eat poisonous newts.
Newts hatch in the water, but they spend
most of their lives on land,
often hiding under fallen leaves or bark.
At night, they hunt for insects,
tiny fish and other small prey.
When they are ready to mate,
rough-skinned newts returned to the water.
Where males and females
swim together in pairs.
The females lay poisonous
eggs and attach them
to underwater plants.
I bet having poisonous eggs makes it
so that the eggs are
less likely to get eaten.
Now that we've read the article,
take a moment and record
two things you learned
about our newt population.
We're moving on to natural selection 1.3:
Exploring Variation and
Distribution in Populations.
I wanna introduce you
to our digital model,
"The Natural Selection Simulation."
The reason scientists use
digital models like the same
that we're about to use,
is that it allows them
to look at things that
are too big or too small
or in our case take a really long time.
We wanna look at populations
and how they change.
It takes hundreds of thousands
and millions of years
for the population change,
but we can see changes
in a very short amount
of time in a SIM.
If you're able to log in, go
ahead to 1.3 activity two,
and launch "The Natural
Selection Simulation"
and follow along.
We're gonna explore the SIM and get to see
what tools it has.
If you're trying this exploration at home,
what I want you to consider is,
what are the different buttons do?
What do you notice about
what you can change?
Are there any questions?
If you're not able to log in, don't worry,
I'll take you through the SIM.
This is my cat Akimbo
he's decided to join us
for the next little part
while we explore the SIM.
There are four main things
that you need to know
about the SIM.
The first two are in the "Build Mode".
There're two different
things that you can build,
you can build abiotic and biotic.
So abiotic factors are
all the nonliving parts
of the SIM, the temperature, the rainfall,
and the surface color.
The second thing to
know in the Build Mode,
is that you can change the biotic factors.
We have three organisms
in our environment.
We have Thornpalm,
Ostrilopes, and Carnithons.
We'll look at all of them
closer in a little bit.
The thing to know though, is
they have different traits,
and we'll look at
differences in those traits.
The third piece to the
SIM is the "Run Mode."
This is where you see
what has happens based
on the environment that you set up.
And the final step is the "Analyze Phase".
This is where you look at your populations
and their different traits,
and you can see how they
change over time as well.
Now we've seen the tools in
the SIM, let's try it out.
So I click on Run, and I can
see our different organisms.
So I've got Ostrilopes,
they're the little bird like creatures.
Carnithons are the big red meat eaters,
and the Thornpalms are the trees.
So these organisms aren't real,
but they're based on real organisms.
The idea being that you have a plant
that does photosynthesis, an
organism that eats plants,
and an organism that eats other animals.
They need energy in order to survive,
and they also reproduce.
So we can use these organisms
to look at changes over time.
Now we're going to try
some missions in the SIM.
Again, if you're logged in, go ahead,
pause this video and try them on your own,
but if you're not logged in, don't worry,
I'll take you through
the missions right now.
Our first three missions are
all about the Thornpalms.
So I'm going to turn off the Ostrilopes
and the Carnithons so that I
can focus on our Thornpalms.
Okay, so my first mission
with the Thornpalms is
to have all of them have medium thorns.
And so I look at their thorn size,
and I can see all of
them have medium thorns.
So I'm gonna look around at them
and I can see these little spikes on them,
and the size thorns that they have.
So the second mission is to have
many different sizes of thorns.
Okay, so I look down here
and I see this little bar
that says, "variation".
I move it over to low variation.
Now I can see that I have a
few different thorn sizes.
If I move it over to medium, then I have
even more different thorn sizes,
then move it over to high then I can see
that I have all the
different thorns sizes.
So I look at this, and now
this one has thorn size 10,
so I can see it's really spiky,
kind of reminds me of my cousin
when I had a Mohawk.
Right, and here's another,
this one has thorn size seven.
Thorn, another thorn size seven, right.
And so I can see that we
have a different size thorn.
This one is a thorn size four,
and I can see it has barely
any spikes on it at all.
Our third mission with the Thornpalms
is to have many short Thornpalms,
a few that are medium
and none that are tall.
So I'm gonna leave them
with a lot of variety
with the thorn size, and
I'm gonna switch to height.
So right now they're all the same height.
If I wanna have many that are short,
a few that are medium,
and none that are tall,
I'm gonna bump up my variation
a little bit to medium.
But now it's kind of spread out
and most of them are medium,
but I want most of them to be short.
So I'm gonna drag this
over, and then you can see
that more of them are now gonna be short,
a few of them will be medium
and none will be tall.
So now I look at this one, and
it's short little Thornpalm,
and so I can see this, these differences
in the height of the Thornpalms.
Our next two missions
are with the Ostrilopes,
so I'm to get rid of the Thornpalms
and I'm going to bring
our Ostrilopes back.
So our first one is to change
the color of the Ostrilopes,
So I'm gonna switch to the color,
and I can see right now I
have no variation in color.
So they're all color number five,
So I look at this color number
five looks like a green.
So I wanna have blue, green and yellow.
So if I move the variation up more,
now you can see this one's yellow.
So this is color number eight, okay,
so yellow is a higher number.
Green, still yellow is number five.
So that's in the middle is green.
See if I can find some other colors.
Oh, here's kind of a blue,
so this is color number three.
So what I figured out is the low numbers,
these are blues.
The middle numbers are greens
and high numbers are yellows.
Then I wanna make it so
that one of my features
with Ostrilopes has a lot of variation,
and one feature has no variation.
So I'm gonna try armor,
so right now the armor has no variation.
So I'm gonna make it to have
a lot of variation, okay?
So and then when I look at the Ostrilopes,
I can see these little spikes on the rack,
how much armor it has.
I can't really see the spikes on that one.
Here we go, there's is a
big spikes on that one.
So that is the armor nine, right?
So it's got some big spikes on it.
So I have lots of variation in the armor.
And then neck length, I have no variation.
So all of their necks are the same length.
Our last two missions
are with the Carnithons.
So I'm going to remove the ostrilopes
and bring the Carnithons back.
I'm gonna zoom out a little bit
until I can find some
Carnithons, there we go.
(computer mouse clicks)
Okay, and what I wanna look
at is having a lot of fur
and some with medium fur,
so I already figured this
out with the Ostrilopes
that in order to get that I wanna move
to medium variation, and this time instead
of moving in the distribution
to the left, like I did before,
this time I'm gonna move it to the right.
And so I can see the
Carnithons now have a bunch
of fur on them, and some of them have
a little bit less, right?
So most of them have a lot fur,
and a little, some of them have less fur.
Okay, and our last challenge
with the Carnithons
is to have the maximum variation possible.
So I'm gonna go with poison resistance,
and I'm going to go with
the maximum variation.
And so they each have a different amount
of poison level resistance.
So this one is a level nine, which means
that it can withstand a lot of poison.
This one's eight, so it can
also withstand a lot of poison.
See if we can find on
poison resistance two,
which means that it can't stand up
too much of the Ostrilopes poison.
Those are all the missions for today,
but in future lessons,
we'll look at the organisms
interacting with each other.
And see how their populations
has changed over time.
As he watched the video,
listen for why we use histograms
and what it shows us about variation.
(Xylophone music)
- [Narrator] Biologists use
graphs called histograms
to show variation in
populations of organisms.
Let's look at a population of Ostrilopes
to understand how histograms
can show variation.
If you look at the
Ostrilopes, you can see that
although they are all
from the same population,
they're all different from each other.
They have different traits,
for example, the Ostrilopes vary in color
from yellow, to green, to blue,
and they have different
amounts of fur on their bodies.
Their necks range from
very short, to very long.
These are examples of variation
in the Ostrilopes population.
If the population is broken
into groups according
to a single feature, (beep)
such as the length of their neck,
and they line up according to the trait
of how long their necks are,
we can see how many
individuals have short necks,
and how many have medium,
long, and very long necks.
The lines of organisms
are like bars in a graph.
The taller the bar in the graph,
the more organisms that
have that neck length.
This type of graph is
called a "Histogram".
This is the same histogram
represented in a different way.
It shows the same variation in neck length
within the Ostrilopes population.
If the Ostrilopes are grouped
by a different feature,
the shape of the histogram will change.
Now the Ostrilopes are
lining up according to color.
You could count how many
Astra Lopes or each color
by looking at every individual
Ostrilope one by one,
but using the histogram is easier.
One quick look shows that
most of the Ostrilopes
in this population are
blue, some are yellow,
and a small amount of green.
Histograms help biologists
understand the variation
of traits in a population.
They're also useful for comparing
two or more populations,
or for investigating how
populations change over time.
(xylophone music)
(chiming music)
- Hopefully that video helped
add to your understanding
of three more important words,
"Variation, Distribution
and Histogram."
Variation is any difference in traits
between individual organisms.
You saw lots of variation
of the Ostrilopes, right?
Their are different colors,
their different neck lengths,
all the things are
differences in their traits.
Distribution is the number of
individuals with each trait
in a population.
So when we look at the distribution
of our Ostrilopes color,
we can see Most of them are blue,
many of them are yellow, and
very few of them are green.
And our final important
word for today "Histogram".
So a histogram is a graph that uses bars
to show how characteristics
or values are distributed
within a group.
It's much easier to look
at changes in populations,
if you can visually represent
what population looked like
before and what it looked like afterwards.
We'll use histograms a lot to
show variation in populations.
Let's practice making some histograms.
For this, you'll need a piece
of paper with a grid on it.
I just use piece of lined
paper and draw a grid on it,
and 12 small objects that you can sort,
you can get coins, or
Legos, or building cubes,
something, anything will work
as long as there is variation
in your materials.
Here are my materials that I have
that I'm gonna to use to
practice making histograms.
You can see I grabbed 12 random coins,
and then I made a grid
on a piece of paper.
So whatever materials
you have, works great.
Hey, so we're gonna start
by making a histogram
that shows no variation.
So if I wanna think about something
that all of my materials have in common,
one of the things they all have
in common is they are metal.
Okay, and so I would sort
this into one column,
showing them that all of them are metal.
It is totally fine, if your
material go up your paper,
if your histogram is not big enough,
especially when we're doing things
where they are all one
thing, it's totally fine.
Then if I wanna show low variation,
I might do something like a sort by color.
So then I sort them into columns
based on what color they are.
And you see I have super low variation
because they're either silver or copper.
Or if I want to increase my variation,
I might sort them by their value,
and so my pennies are all worth one cent.
My nickels are worth five,
my dimes are worth 10,
and my quarters were worth 25,
and so I can increase
the amount of variation
that I show based on
the trait that I select.
Keep using your materials,
try making different histograms,
showing different amounts of variation.
We'll use histograms a lot
as we look at what happens
to our populations and
how they change over time.
We'll end today with our first Key Concept
for Natural Selection.
Make sure you record this, a
population can be described
by the traits present and
by the number of individuals
who have each trait.
Again, a population can be
described by the traits present
and by the number of
individuals who have each trait.
You saw this today with our butterflies
and the variety of traits that they had
with their wing color.
You saw this with our ostrilopes, right?
Their different neck
lengths, different colors,
different fur amounts.
Saw this with our Thornpalms
and our Carnithons.
So anytime you're looking at a population,
you're looking at, what traits they have,
and how many have each of those traits?
Thanks for joining me Today,
as we started natural selection.
I hope you'll join me next time
when we look at what happens to Ostrilopes
when their environment changes?
See you next time.
(upbeat music)
