CHAPTER 1 –ENVIRONMENTAL CHANGE AND
TRAIT DISTRIBUTION
1.4.1: WARM-UP
Observing Populations at Two Generations
The histograms below show the distribution of fur-level traits in a population at two different
points in time. Review the two histograms and answer the questions below.
1.Do the two histograms show the same amount of
variation in the population at both generations?
2.Do the two histograms show the same distribution of
traits at both generations?
YES NO YES NO
The distribution of the traits changed over time.
1.4.1: WARM-UP
Observing Populations at Two Generations
The histograms below show the distribution of fur-level traits in a population at two different
points in time. Review the two histograms and answer the questions below.
1.Do the two histograms show
the same amount of variation
in the population at both
generations?
2.Do the two histograms show
the same distribution of traits at
both generations?
NO NO
1.4.1: WARM-UP
•At Generation 50, the distribution was
different since most of the ostrilopes
had a high amount of fur.
•There was also less variation since
there were only 4 fur traits.
•The population started with most
ostrilopeshaving low amount of fur.
•The population at this time had a high
variation –7 different fur traits.
Whydid the distribution changed from mostly individuals with traits for low
and medium levels of fur to mostly individuals with high levels of fur?
What makes the distribution of traits in a population
change?
Investigation
Question:
In the next activity, you will
use the Natural Selection
Sim to begin thinking about
what made the distribution
of fur traits in the Ostrilope
population change over
time.
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Let’s examine some more
controls in the SIM
•Temperature Slider
-Observe the changing visuals.
-Only make ONE temperature
change to make conclusions.
MILD TEMP.
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Let’s examine some more
controls in the SIM
•Temperature Slider
-Observe the changing visuals.
-Only make ONE temperature
change to make conclusions.
MILD TEMP.COLD TEMP.
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Let’s examine some more
controls in the SIM
•Temperature Slider
-Observe the changing visuals.
-Only make ONE temperature
change to make conclusions.
MILD TEMP.COLD TEMP.HOT TEMP.
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
•Traits Histogram Window Run
-Run Sim by pressing NEXT
-Then hit “RUN” in the build
setup menu.
-Collect a few generations of data
-Open Traits Histogram Window
(Bottom Left icon)
-Observe real-time histograms of
different features
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
•Traits Histogram Window Run
-Run Sim by pressing NEXT
-Then hit “RUN” in the build
setup menu.
-Collect a few generations of data
-Open Traits Histogram Window
(Bottom Left icon)
-Observe real-time histograms of
different features
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
•Traits Histogram Window Run
-Run Sim by pressing NEXT
-Then hit “RUN” in the build
setup menu.
-Collect a few generations of data
-Open Traits Histogram Window
(Bottom Left icon)
-Observe real-time histograms of
different features
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
•Traits Histogram Window Run
-Run Sim by pressing NEXT
-Then hit “RUN” in the build
setup menu.
-Collect a few generations of data
-Open Traits Histogram Window
(Bottom Left icon)
-Observe real-time histograms of
different features
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
•Traits Histogram Window Run
-Run Sim by pressing NEXT
-Then hit “RUN” in the build
setup menu.
-Collect a few generations of data
-Open Traits Histogram Window
(Bottom Left icon)
-Observe real-time histograms of
different features
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
•Traits Histogram Window Run
-Run Sim by pressing NEXT
-Then hit “RUN” in the build
setup menu.
-Collect a few generations of data
-Open Traits Histogram Window
(Bottom Left icon)
-Observe real-time histograms of
different features
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
•Speed Controls
-Use drop down to collect many
generations of data more quickly.
1.4.2: SIM –UTILIZE SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
•Histograms in Analyze
-Use Analyze in Build Setup
menu.
-Move generation slider.
-Note the stripes show the
starting generation
histogram.
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Starting histogram –Fur and
Temperature A Mode
•Press Build, then Rebuild
•Click on Ostrilope
•Look at starting Ostrilopepopulation
Note that it has the same distribution of fur
traits as in the Generation 1 Histogram
from the Warm-Up.
These ostrilopeshave been living in a warm
environment, but that students are going to
change the environment to be colder.
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Starting histogram –Fur and
Temperature A Mode
•Press Build, then Rebuild
•Click on Ostrilope
•Look at starting Ostrilopepopulation
Note that it has the same distribution of fur
traits as in the Generation 1 Histogram
from the Warm-Up.
These ostrilopeshave been living in a warm
environment, but that students are going to
change the environment to be colder.
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Starting histogram –Fur and
Temperature A Mode
•Press Build, then Rebuild
•Click on Ostrilope
•Look at starting Ostrilopepopulation
Note that it has the same distribution of fur
traits as in the Generation 1 Histogram
from the Warm-Up.
These ostrilopeshave been living in a warm
environment, but that students are going to
change the environment to be colder.
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Starting histogram –Fur and
Temperature A Mode
•Press Build, then Rebuild
•Click on Ostrilope
•Look at starting Ostrilopepopulation
Note that it has the same distribution of fur
traits as in the Generation 1 Histogram
from the Warm-Up.
These ostrilopeshave been living in a warm
environment, but that students are going to
change the environment to be colder.
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Set the environment to cold (Level 1),
using the Temperature slider, and observe
what happens over 50 generations.
Zoom into the environment and select
different ostrilopesto observe individuals
with different traits.
After 50 generations have passed, students
should press ANALYZE to compare the
Generation 50 histogram with the
Generation 1 histogram.
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Set the environment to cold (Level 1),
using the Temperature slider, and observe
what happens over 50 generations.
Zoom into the environment and select
different ostrilopesto observe individuals
with different traits.
After 50 generations have passed, students
should press ANALYZE to compare the
Generation 50 histogram with the
Generation 1 histogram.
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Set the environment to cold (Level 1),
using the Temperature slider, and observe
what happens over 50 generations.
Zoom into the environment and select
different ostrilopesto observe individuals
with different traits.
After 50 generations have passed, students
should press ANALYZE to compare the
Generation 50 histogram with the
Generation 1 histogram.
Each bar tells us how many
individuals in the population have a
particular trait.
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Launch the Sim and make sure you do the following:
1.Begin by setting the environment to cold (Level 1).
2.Observe individuals with different fur traits while the Sim is running.
3.Use the Traits Histogram Window while the Sim is running.
4.Press ANALYZE to compare histograms.
5.Upload a screenshot of the fur-trait histogram for Population A after 50 generations.
6.Answer the questions on their Amplify Science screens.
7.Time Permitting: Reset SIM and repeat your test to see if you get the same results.
Entire Screen Specific Area of the Screen
1.4.2: SIM –FUR AND TEMP A
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Discuss your responses to the questions with a partner.
1.4.2: SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Let’s review your work
The high fur-level trait became more common because
individuals with this trait could survive in the cold
environment.
"The population started with ostrilopesthat had low,
medium, and high levels of fur. I saw that the ostrilopeswith
the low level of fur shivered and died in the cold
environment, but the ones with the high level of fur
survived. "
1.4.2: SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Use your interpretation of the data to
hypothesize that the change shown in the
data was caused by the environmental
change –cold environment.
When a bar gets shorter, it means that
individuals died because they did not have
enough fur to survive in the cold
environment.
1.4.2: SIM
OBSERVING FUR TRAITS AND TEMPERATURE IN THE SIM
Traits for high fur became more common
and the traits for low fur became less
common.
•The ostrilopeswith lower fur-level traits
shivered and died in the cold
environment.
•The ostrilopeswith higher fur-level traits
survived in the cold environment. More
fur helped them survive, and they
became more common.
environment:everything (living and nonliving) that
surrounds an organism
Each of theseenvironmentsincludes many living things, such as plants and animals, and
nonliving things, such as rocks and water.
From left to right: Craters of the Moon National Monument, Idaho; Denali National Park,
Alaska; Guadalupe Mountains National Park, Texas; Channel Islands National Park, California.
adaptive trait: a trait that makes it more likely
that an individual will survive in a specific environment
non-adaptive trait:a trait that makes it less
likely that an individual will survive in a specific
environment
1.4.2: SIM
INTRODUCING ADAPTIVE AND NON -ADAPTIVE TRAITS
Higher fur-level traits
Lower fur-level traits
No, they shivered and died
What were theadaptive traitsin this Sim mode?
In other words, which traits helped individual
ostrilopessurvive best in the cold
environment?
What were thenon-adaptive traitsin this Sim
mode? In other words, which traits made it less
likely that an individual ostrilopewould survive
in the cold environment?
Were individuals with the non-adaptive traits
able to change to an adaptive trait in the middle
of their lifetime?
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Show how and why Population A changed after
the environment changed from warm to cold.
GOAL
Fur vs. Temp A
You will be learning how to model
your ideas about changes in the
distribution of traits in populations
using the natural selection
simulation model.
Remember: Scientists create models to
communicate ideas about how things
work to other people.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Types of Models:
•Physical models, like a globe or a model
of a cell.
•Computer programs, like a computer
model that predicts weather or
theNatural SelectionSimulation.
•Visual representations, like a food web or
a diagram of the water cycle.
You will be using a special tool called a
Modeling Tool to make visual models that
show your thinking about why populations
change over time.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Histograms:
There are two
histograms that
represent the
same population
at two different
points in time.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Timeline:
There is a timeline
at the bottom of
the image that
shows what points
in time these
histograms
represent.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Environment
labels:
There are labels
below each
histogram that
describe aspects
of the
environment and
whether the
environment is
changing.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Trait labels:
There is a legend
that shows
symbols and what
those symbols
mean.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Examine the Starting Population Histogram
The environment is changing from warm to cold, just like
in the previous Sim activity.
Which Ostrilopeswould be more likely to survive and
which would be less likely to survive in the cold
environment?
More likely to
survive
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
These histograms are the same as the histograms you saw in the Warm-Up.
In the Sim and the Warm-Up, we observed that the distribution of traits changed over
time.
This example modeled the change we saw in the Sim.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
We learned that traits for higher fur levels are adaptive traits
in a cold environment because they help ostrilopessurvive in
cold environments.
Lower fur-level traits make it difficult to survive in a cold
environment.
This means traits for lower fur levels are non-adaptive traits
in cold environments.
You will continue to investigate what causes the
distribution of traits in a population to change as
you create another model.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
You will receive one
copy of the Modeling
Tool:
Fur and Temperature,
Population B
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
POPULATION A POPULATION B
Share what similarities and differences
you notice between Population B and
Population A and their environments.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
POPULATION A POPULATION B
•Like Population A, most
of the ostrilopesin
Population B have low
fur-level traits.
•There is much less
variation in fur-level traits
in Population B compared
to Population A.
•Both populations
experience an
environment that gets
colder suddenly.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
In our next activity, we
will test our predictions
using the SIM.
Let’s discuss making
predictions.
We do not yet know how
the distribution of traits in
Population B will change as
a result of the environment
becoming cold.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
We will make a visual
model to predict how
Population B will change in
a cold environment.
You will be able to check
your predictions in the Sim
in a few minutes.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Turn to a partner and
discuss the following.
Do you think Population B
will respond differently than
Population A did to an
environment that changes
from warm to cold?
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Complete your models
individually.
You do not have to make
perfect predictions, but you
should show your best
guess at what might happen
to this population by
shading in the bars for the
Population After 50
Generations Histogram.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Note: The predictions are
what you think will actually
happen in the subsequent
Simulation activity.
1.4.3: MODELING TOOL
MODELING CHANGES TO THE DISTRIBUTION OF TRAITS
Models should only show fur
traits that were already present
in the population (Fur-Trait
Levels 1 or 2 only).
Two possible proficient models
are:
1.The population will die out,
and thus Histogram 2 would
be left blank.
2.The trait distribution will shift
so that ostrilopeswith higher
fur levels became more
common (shown below).
Possible Prediction about Histogram 2
1.4.4TESTING PREDICTIONS IN THE SIM
Open Fur and Temperature B
mode in theNatural
SelectionSimulation.
Press the Ostrilopeicon and
point out the Fur-Trait Histogram
for the ostrilopepopulation.
Note that it has the same
distribution of fur traits as the
Generation 1 Histogram from the
Modeling Tool activity.
1.4.4TESTING PREDICTIONS IN THE SIM
Open Fur and Temperature B
mode in theNatural
SelectionSimulation.
Press the Ostrilopeicon and
point out the Fur-Trait Histogram
for the ostrilopepopulation.
Note that it has the same
distribution of fur traits as the
Generation 1 Histogram from the
Modeling Tool activity.
1.4.4TESTING PREDICTIONS IN THE SIM
Setting Up The Sim activity.
•Set the temperature of the
environment to cold (Level 1)
and observe what happens over
50 generations.
•While running the Sim, you
should zoom into the
environment and observe several
individuals with different traits.
•When complete, press ANALYZE
to compare the Generation 50
Histogram with the Generation 1
Histogram.
1.4.4TESTING PREDICTIONS IN THE SIM
Setting Up The Sim activity.
•Set the temperature of the
environment to cold (Level 1)
and observe what happens over
50 generations.
•While running the Sim, you
should zoom into the
environment and observe several
individuals with different traits.
•When complete, press ANALYZE
to compare the Generation 50
Histogram with the Generation 1
Histogram.
1.4.4TESTING PREDICTIONS IN THE SIM
Setting Up The Sim activity.
•Set the temperature of the
environment to cold (Level 1)
and observe what happens over
50 generations.
•While running the Sim, you
should zoom into the
environment and observe several
individuals with different traits.
•When complete, press ANALYZE
to compare the Generation 50
Histogram with the Generation 1
Histogram.
1.4.4TESTING PREDICTIONS IN THE SIM
Entire Screen
Specific Area
of the Screen
1.4.4TESTING PREDICTIONS IN THE SIM
Discuss with a partner whether
your predictions are correct.
Did population B change the
way you had predicted?
Individuals cannot change traits mid-
life, so the population died out.
1.4.4TESTING PREDICTIONS IN THE SIM
Did Population B change in the
way you predicted? Why or why
not?
Population B died out because it did
not have high levels of fur that were
required for a cold environment.
1.4.4TESTING PREDICTIONS IN THE SIM
1.4.4TESTING PREDICTIONS IN THE SIM
POPULATION A:
Individuals with high fur levels were
able to survive in the cold environment.
The individuals with low fur levels
shivered and died.
Since more individuals with high fur
levels survived, the high fur-level trait
became more common in Population A
over time, and the low fur-level trait
became less common.
The high fur-level trait was an adaptive
trait.
1.4.4TESTING PREDICTIONS IN THE SIM
POPULATION B:
In the second Sim, the distribution of
traits in Population B could not shift like
Population A did -toward more
individuals with high fur level.
This is because new traits cannot
appear in a population just because
they would be helpful for survival.
Since Population B did not start out
with variationthat included individuals
with the adaptive trait of a high fur
level, none of the individuals could
survive.
1.4.5HOMEWORK
READ AND ANNOTATE THREE ARTICLES ABOUT DIFFERENT
ORGANISMS IN OREGON STATE PARK.
In order to help Dr. Alex Young and to apply your understanding of variation, traits, and
changes in trait distribution, you will be reading articles about different organisms living
in Oregon State Park.