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Biodiversity
Targeted Idaho Core Standards:
R.S. 9-10.5
Analyze the structure of the relationships among concepts in a text, including relationships among key
terms (e.g., force, friction, reaction force, energy). This unit will look at the relationship among key
terms: genetic mutation, natural selection, and ecosystems.
W.S. 9-10.7
Conduct short as well as more sustained research projects to answer a question (including a selfgenerated question) or solve a problem; narrow or broaden the inquiry when appropriate; synthesize
multiple sources on the subject, demonstrating understanding of the subject under investigation.
Content Standards:
Standard 1: Nature of Sciences
Goal 1.1: Understand Systems, Order, and Organization
CL: D Content Limit: Students will be able to identify the components of a system and
explain that components work together to allow the system to
function as a whole.
CL: E Content Limit: Students will be able to identify the components of a system and
predict the role of each component in the system's function.
Goal 1.5: Understand Concepts of form and function.
Goal 1.6 Understand Scientific Inquiry and Develop Critical Thinking Skills
9-10.B.1.6.4 Formulate scientific explanations and models using logic and evidence.
9-10.B.1.6.5 Analyze alternative explanations and models.
CL: E When offered a variety of possible explanations, students will be able to identify
the most probable option to fit with the question stem.
Essential Question:
What would human life be like without
(you choose an organism) ?
Measurable Outcomes:
The student can:
Explain the difference between genotype and phenotype.
Identify the difference between dominant and recessive genes.
Solve a genetics problem involving mono-hybrid and di-hybrid crosses.
Describe when a change is a genetic mutation.
Use evidence to define a change as natural selection.
Build a food web.
Describe the relationships between predators and prey in an ecosystem.
Define the trophic levels in a food web.
Find organisms, populations, and communities in an ecosystem.
By the end of the unit the student will be able to build a food web, extract an organism from the
food web and explain how the removal of this organism effects the remainder of the organisms in
the food web and the human population.
Length of unit: block scheduling (80 – 90 minute classes) it will take 8 – 9 classes, 3 weeks.
With 50 – 60 minute classes this unit will take 14 – 15 classes, 3 weeks.
Instructional Sequence
Lesson One (1 – 2 class periods)
Hand out the worksheet on phenotypes.
Discuss the difference between phenotype and genotype. The definitions are printed at the top of the
worksheet.
The students will need some examples of the phenotypes to know if they have that phenotype.
Allow the students 15 – 20 minutes to collect the information from each other needed to fill out the
table.
Project a picture of human chromosomes. (http://www.zo.utexas.edu/faculty/sjasper/images/f9.4.jpg)
Genes come in pairs with one of each pair inherited from each parent. Each gene of the pair is an
allele. Therefore there is one gene for a specific characteristic inherited from each parent in a specific
position on a specific chromosome. One of these genes may be dominant, and one may be recessive. It
requires two recessive genes to produce the phenotype coded for by the gene; however, it only requires
one dominant gene to produce the dominant phenotype.
Hand out the sheet with the genetics definitions on it. Students who have difficulty reading will need
help putting the definitions in their own words.
Go to the website: file:///N:/Integrated%20Science/Genetics%20Practice%20Problems.htm and work
through the genetics problems as a class. Get through mono-hybrid, di-hybrid crosses, and incomplete
dominance. (Sex linked can be worked through if most of the class understands the first three types of
crosses.)
Hand out the genetics problems worksheets and move around the room helping students with
difficulties.
There is an answer sheet with the problem sheet.
Students who finish early can pick up the additional problem sheet with more challenging problems.
A phenotype is the expression of the genotype. The phenotype can be seen in the appearance of an
organism; however, the genotype is inside the organisms cells in the DNA.
Phenotype
Names of
My
people
with the
Phenotype
same
phenotype
Right or Left
Handed
Hitchhikers Thumb
widow's peak
Roman Nose
Attached Ear Lobe
Names of
people with
different
phenotype
total
(count
yourself)
% of people
with the
same
phenotype
% of people
with different
phenotypes
Tongue roller
PTC Taster
Use the papers on the
front table. One paper
for each student
Genetics Problems
In dogs, wire hair (S) is dominant to smooth hair (s). In a cross of a homozygous wire-haired dog with
a smooth-haired dog, what are the genotypes and phenotypes of all of the puppies.
If two of the puppies from the previous problem are allowed to mate, what are the genotypes and
phenotypes of their offspring?
Woodrats have a dominant trait of bringing home shiny objects (H) that is an allele to the recessive trait
of bringing home only dull objects (h). Suppose two heterozygous individuals mate, what are the
genotypes and phenotypes of all of the offspring?
In blackbirds long tails (L) are dominant over short tails (l). A female blackbird with a short tail mates
with a male blackbird with a long tail who had a short tailed parent. What are the phenotypes and
genotypes of all of their offspring?
Tongue rolling (T) is dominant to the inability to roll your tongue (t). A woman who can roll her
tongue marries a man who cannot roll his tongue. Their first child has his father's phenotype. What are
the genotypes of all three individuals?
In peas tall plants (T) are dominant over short plants (t). Also, round seeds ( R ) are dominant over
oval seeds (r). A heterozygous tall plant with round seeds is crossed with another heterozygous tall
plant with round seeds. What are the phenotypes, genotypes, and percentages of their offspring?
What are the genotypes, phenotypes and percentages of crossing a homozygous tall pea plant with oval
seeds, and short plant that is heterozygous for round seed shape?
Answers to Genetics Problems
In dogs, wire hair (S) is dominant to smooth hair (s). In a cross of a homozygous wire-haired dog with
a smooth-haired dog, what are the genotypes and phenotypes of all of the puppies.
S=wire
s=smooth
Homozygous wire-haired dog = SS
Smooth haired dog = ss
All puppies are Ss and have smooth hair, but are carriers of the smooth haired gene
If two of the puppies from the previous problem are allowed to mate, what are the genotypes and
phenotypes of their offspring?
Phenotypes
From the previous cross: Ss X Ss
S
s
25% Homozygous wire haired
S SS Ss
50% Heterozygous wire haired
s Ss ss
25% Smooth haired
Wood rats have a dominant trait of bringing home shiny objects (H) that is an allele to the recessive
trait of bringing home only dull objects (h). Suppose two heterozygous individuals mate, what are the
genotypes and phenotypes of all of the offspring?
Phenotypes
H=shiny
Hh X Hh
H h
25% Homozygous shiny
h=dull
H HH Hh
50% Heterozygous shiny
h Hh hh
25% dull
In blackbirds long tails (L) are dominant over short tails (l). A female blackbird with a short tail mates
with a male blackbird with a long tail who had a short tailed parent. What are the phenotypes and
genotypes of all of their offspring?
L=long
l=short
Female= ll
(Only one possibility from female parent
Male= Ll (can only receive an l from short tailed parent)
Phenotypes
L l
50% short
l Ll ll
50% long
Tongue rolling (T) is dominant to the inability to roll your tongue (t). A woman who can roll her
tongue marries a man who cannot roll his tongue. Their first child has his father's phenotype. What are
the genotypes of all three individuals?
T= rolling
t= non roller
Mother = Tt (she has to have a recessive gene because the first child has
his fathers phenotype tt and had to get one from the mother)
Father = tt
Child = tt
In peas tall plants (T) are dominant over short plants (t). Also, round seeds ( R ) are dominant over
oval seeds (r). A heterozygous tall plant with round seeds is crossed with another heterozygous tall
plant with round seeds. What are the phenotypes, genotypes, and percentages of their offspring?
T=tall
t=short
R=round
r=oval
Heterozygous means that there is one of each gene, dominant and recessive, even
though the phenotype is dominant.
Heterozygous Tall Plant = TtRr X TtRr
TR
Tr
tR
tr
Phenotypes
TR TTRR TTRr TtRR TtRr
9 tall round
Tr TTRr TTrr TtRr Ttrr
3 tall oval
tR TtRR TtRr ttRR ttRr
3 short round
tr TtRr Ttrr ttRr ttrr
1 short oval
What are the genotypes, phenotypes and percentages of crossing a homozygous tall pea plant with oval
seeds, and short plant that is heterozygous for round seed shape?
Homozygous Tall with oval seeds = Ttrr
Short plant heterozygous for seed shape = ttRR
50% tall round
50% short round
Tr
tR TtRr
tr
ttRr
Genetics Vocab
Heredity: characteristics passed from parent to
offspring in genes
Genes:
units of heredity that code for
particular traits
Alleles: two genes that control the same
characteristic
Homologs: various forms of the same gene
Genotype: the genes that make up an organism
Phenotype: the appearance of an organism
determined by the genotype
Dominant: a gene that is expressed when only
one copy is present
Recessive: genes that expressed only when two
copies are present
Lesson Two (1 – 2 class periods)
Check for understanding by having pairs of students go to the board to do the problems from the
previous day. (this is a formative assessment.)
If further understanding is required: hand out the genetics activity worksheet. You will need blank
pieces of paper, and enough scissors for each pair of students.
Hand out the genetics quiz for students to work on. Allow them to use the definitions paper from
yesterday. 15 – 20 minutes(the quiz is a formative assessment, they will hand it in when finished)
Define and discuss mutations and list the causes for mutations.
Mutations are changes in the genetic information. Some mutations happen naturally; however, they
can be caused by a number of things: radiation, chemicals, uv light. Sometimes the mutation is
beneficial, and sometimes the mutation is detrimental. Detrimental mutations usually mean that the
phenotype caused by the mutation will cause the death of the organism. Beneficial mutations mean that
the phenotype will give the organism some kind of an advantage thereby causing the change to be
passed on.
Hand out the Evolution Reading Document. Have the students underline the most important phrase in
each section to insure deeper reading.
Go to the evolution website (file:///N:/Integrated%20Science/evolution%20site.htm) and use the site to
guide the class discussion. Start with the page on “Development” and finish with the page on
“Misconceptions”.
Genetics Problems Worksheet (for further understanding)
Fold a sheet of paper 4 times. Unfold it and cut it into rectangles along the folds. (these will be your
alleles)
In rats black coat (B) is dominant over white coat (b).
Write a capital B on two of the sheets of paper you cut out.
Write a lower case b on two other sheets of paper that you have cut out.
A homozygous black rat mates with a homozygous white rat.
Genotype of the homozygous black rat ______
Genotype of the homozygous white rat ______
What is the phenotype and genotype of all of the offspring (f1)?
Genotype _______
Phenotype _________________
Two rats from the f1 generation mate.
What are the possible genotypes?
Genotype _______
Genotype _______
Genotype ______
What are the possible Phenotypes?
Phenotype _________________
Phenotype ________________
Why are there 3 genotypes and only 2 phenotypes?
Now try to solve the following problems.
In guinea pigs coats can be either coarse or smooth. Coarse coat ( T ) is dominant over smooth coat ( t
).
What are the phenotype and genotype possibilities for the following crosses:
Homozygous coarse and Heterozygous coarse.
Genotypes ________________________
Phenotypes ____________________________
Smooth coat and Heterozygous coarse.
Genotypes _________________________
Phenotypes_____________________________
Smooth coat and Heterozygous coarse.
Genotypes __________________________
Phenotypes_____________________________
Homozygous coarse and Smooth.
Genotypes __________________________
Phenotypes _____________________________
Genetics Worksheet Key
Fold a sheet of paper 4 times. Unfold it and cut it into rectangles along the folds. (these will be your
alleles)
In rats black coat (B) is dominant over white coat (b).
Write a capital B on two of the sheets of paper you cut out.
Write a lower case b on two other sheets of paper that you have cut out.
A homozygous black rat mates with a homozygous white rat.
Genotype of the homozygous black rat _BB___
Genotype of the homozygous white rat _bb___
What is the phenotype and genotype of all of the offspring (f1)?
Genotype __Bb___
Phenotype ___all black____
Two rats from the f1 generation mate.
What are the possible genotypes?
Genotype __BB___
Genotype __Bb___
Genotype _bb___
What are the possible Phenotypes?
Phenotype _____black______
Phenotype ______white_____
Why are there 3 genotypes and only 2 phenotypes?
Because the genotypes BB and Bb both code for the same phenotype
Now try to solve the following problems.
In guinea pigs coats can be either coarse or smooth. Coarse coat ( T ) is dominant over smooth coat ( t
).
What are the phenotype and genotype possibilities for the following crosses:
Homozygous coarse and Heterozygous coarse.
Genotypes _________TT and Tt _______
Phenotypes ________all coarse ____________
Smooth coat and Heterozygous coarse.
Genotypes _____tt and Tt ___________
Phenotypes_50% coarse and 50% smooth____
Smooth coat and Heterozygous coarse.
Genotypes _____tt and Tt ____________
Phenotypes_50% coarse and 50% smooth____
Homozygous coarse and Smooth.
Genotypes ______TT and tt__________
Phenotypes _______all coarse ____________
Genetics Quiz
You are a genetics counselor. An individual comes in to your office with some specifics characteristics
he/she desires for an offspring. You must explain to the individual the phenotypes and genotypes
required for their mate to produce the desired offspring. (Include terms: genotype, phenotype,
dominant, recessive, and heredity. Also include the possibilities or percentages of the phenotypic
characteristics.)
Offspring Phenotype: left handed, blue eyed, dark hair, attached ear lobe, widows peak, non-tongue
roller, PTC taster.
Individual in Your office Phenotype: non-taster, blonde hair, attached ear lobe, right handed, brown
eyed, widows peak, tongue roller.
You may work with one partner. Write your answers below (answers could include charts,
punnet squares, etc...)
Evolution Reading Document
Mutation:
Mutation is a change in DNA, the hereditary material of life. An organism's DNA affects how it looks,
how it behaves, and its physiology — all aspects of its life. So a change in an organism's DNA can
cause changes in all aspects of its life.
Mutations are random
Mutations can be beneficial, neutral, or harmful for the organism, but mutations do not "try" to supply
what the organism "needs." In this respect, mutations are random — whether a particular mutation
happens or not is unrelated to how useful that mutation would be.
Mutations happen for several reasons.
1.) DNA fails to copy accurately
Most of the mutations that we think matter to evolution are "naturally-occurring." For example,
when a cell divides, it makes a copy of its DNA — and sometimes the copy is not quite perfect.
That small difference from the original DNA sequence is a mutation.
2.) External influences can create mutations
Mutations can also be caused by exposure to specific chemicals or
radiation. These agents cause the DNA to break down. This is not
necessarily unnatural — even in the most isolated and pristine
environments, DNA breaks down. Nevertheless, when the cell repairs
the DNA, it might not do a perfect job of the repair. So the cell would
end up with DNA slightly different than the original DNA and hence,
a mutation.
Natural selection
Darwin's grand idea of evolution by natural selection is relatively simple but often misunderstood. To
find out how it works, imagine a population of beetles:
A.) There is variation in traits.
For example, some beetles are green and some are brown.
A.) There is differential reproduction.
Since the environment can't support unlimited population growth,
not all individuals get to reproduce to their full potential. In this
example, green beetles tend to get eaten by birds and survive to
reproduce less often than brown beetles do.
1.) There is heredity.
The surviving brown beetles have brown baby beetles because this trait has
a genetic basis.
4. End result:
The more advantageous trait, brown coloration, which allows the beetle to
have more offspring, becomes more common in the population. If this
process continues, eventually, all individuals in the population will be
brown.
If you have variation, differential reproduction, and heredity, you will have evolution by natural
selection as an outcome. It is as simple as that.
Adaptation
An adaptation is a feature that is common in a population because it provides some improved function.
Adaptations are well fitted to their function and are produced by natural selection.
Adaptations can take many forms: a behavior that allows better evasion of predators, a protein that
functions better at body temperature, or an anatomical feature that allows the organism to access a
valuable new resource — all of these might be adaptations. Many of the things that impress us most in
nature are thought to be adaptations.
Mimicry of leaves by insects is an adaptation for evading
predators. This example is a katydid from Costa Rica.
The creosote bush is a desert-dwelling plant that produces toxins
that prevent other plants from growing nearby, thus reducing
competition for nutrients and water.
Echolocation in bats is an adaptation for catching insects.
So what's not an adaptation? The answer: a lot of things. One
example is
vestigial structures. A vestigial structure is a feature that was an
adaptation for the organism's ancestor, but that evolved to be
non-functional because the organism's environment
changed.Fish species that live in completely dark caves have
vestigial, non-functional eyes. When their sighted ancestors
ended up living in caves, there was no longer any natural
selection that maintained the function of the fishes' eyes. So,
fish with better sight no longer out-competed fish with worse sight. Today, these fish still have eyes —
but they are not functional and are not an adaptation; they are just the by-products of the fishes' history.
. A vestigial structure is a feature that was an adaptation for the organism's ancestor, but that evolved to
be non-functional because the organism's environment changed.Fish species that live in completely
dark caves have vestigial, non-functional eyes. When their sighted ancestors ended up living in caves,
there was no longer any natural selection that maintained the function of the fishes' eyes. So, fish with
better sight no longer out-competed fish with worse sight. Today, these fish still have eyes — but they
are not functional and are not an adaptation; they are just the by-products of the fishes' history.
Survival of the Fittest
Survival
The ability of an organism to exist, grow and reproduce. It is not survival if the organism does not
reach a reproductive age and pass on its genetics.
Survival depends on superior genetics, and on the environment. The ability of an organism to be able
to adapt to its environment is a combination of both genetics and environmental change.
Examples:
The fastest zebras do not get eaten by the lions; therefore,
they pass on the genetic combinations that have made them
the fastest. Whereas the slower zebras are the first ones
that are caught and the genetics that have made them
slower are not passed on.
The bison with the thickest coats can survive the winter
because they lose less heat and don't need as much energy to
stay warm.
Genetic change happens slowly taking generations, however, environmental change can happen many
times within a generation. When environments change too quickly because of interference by another
species, or because of natural disasters. The ability of the organism to adapt becomes more difficult
and, therefore, the ability of an organism to survive also becomes more difficult.
Lesson Three (1 – 2 class periods)
Ask for questions about evolution.
Hand out the evolution quiz. 15 – 20 minutes (this is a formative assessment, they will hand it in when
finished)
View the Bill Nye Video on Evolution.
(https://www.youtube.com/watch?v=1xIi4RQiZW4)
This will also help students who are not clear on natural selection to understand evolution. (It is
designed for middle school students and is very basic.)
Hand out the worksheet on Natural Selection and go over the first example with the class.
In the example show how it was the change in the genetic material that causes the change in the
organism and that it takes decades (or many generations) for the resulting change to occur. This will
help the students to tie natural selection to genetics.
The students will have the remainder of the class time to work in discussion groups on the natural
selection worksheet.
The teacher should move around the room to help with questions and to help stimulate discussions.
Evolution Quiz
What is a mutation?
Name three things that can cause a mutation.
What happens to organisms that do not have beneficial mutations.
What do we call the area and conditions in which an organism lives?
What does an organism need to do to survive environmental changes?
How do we know when a species has survived?
Use the words survival, environment, and mutation to explain natural selection.
Define natural selection and describe how it relates to evolution.
Describe examples of things that cause evolutionary change.
Explain the differences between mutualism, commensalism, and parasitism.
Evolution Quiz Key
What is a mutation?
A change in the genetic code that creates a phenotype change in the organism.
Name three things that can cause a mutation.
Radiation, Chemicals, Some occur naturally
What happens to organisms that do not have beneficial mutations.
They will not reach reproductive age, therefore the mutations will not be passed on.
What do we call the area and conditions in which an organism lives?
Environment
What does an organism need to do to survive environmental changes?
Phenotypic changes caused by mutations that give the organism an advantage.
How do we know when a species has survived?
A species survives when their genetics are passed on to the next generation. The species has to reach
Reproductive age.
Use the words survival, environment, and mutation to explain natural selection.
Natural selection is the survival of organisms that have genetics mutations that give them an advantage
in their environment.
Define natural selection and describe how it relates to evolution.
Natural Selection is the survival of the fittest organisms that have adapted the best to their
environment.
Describe examples of things that cause evolutionary change.
Ice ages, earthquakes, floods, and other environmental changes will cause an evolutionary change.
Explain the differences between mutualism, commensalism, and parasitism.
Mutualism is two species living together and both of them benefit.
Commensalism is two species living together when one benefits and the other is unharmed.
Parasitism is two species living together when one benefits and the other is harmed.
Natural Selection Examples
Example 1: An animal is born with a slightly longer neck. This animal can reach the leaves on the
trees and is able to survive during drought conditions. Therefore, this animal passes on its genetics for
a longer neck and all of its offspring have longer necks. After decades of drought all of the
animalshave longer necks.
Example 2: During a decade of extremely cold weather one village of Eskimos builds thicker igloos
and wears thicker clothes. They are able to survive the cold weather; whereas another village did not
change their living quarters, or wear thicker clothes. The Esikimos in the first village survive, but the
Eskimos in the second village all die from exposure.
Example 3: The Fish and Game creates a bounty on coyotes. Many people go out and shoot
coyotes. The population of coyotes goes way down. This causes the population of rabbits to increase
dramatically.
Example 4: Gypsie Moths can be black or white. The birch trees where the moths live are white;
therefore, the black moths are easier for the birds to see and they usually get eaten resulting a larger
population of white moths. During the industrial revolution in England (where the moths live) they
burned a lot of coal. The soot turned the white birch trees black. The population of
white
moths decreased, and the population of black moths increased because now the birds could see the
white moths.
Example 5: During cold weather (we call it Winter) frogs bury themselves in the muddy shores of
lakes, ponds, and streams to hibernate until the weather warms up. Frog species one lives in an area
where the soil is not very deep and they can only bury themselves in shallow mud. Frog species two
lives where there is a lot of soft soil with leaves covering the top of the soil;
therefore, they
can bury themselves deeper in the mud and are covered with leaves. During an especially cold winter
all of the frogs in species one die from the cold; however, half of the frogs in species two survive.
Natural Selection
Example
1
2
3
4
5
Population
Change
Environmental
Change
Natural Selection
Or
Not
Why?
(evidence)
Lesson Four (1 – 2 class periods)
Go over the natural selection worksheet.
Have the students choose sides from their answers on the worksheet for examples 2 – 5.
They can discuss and use the evidence that they wrote onto the worksheet to defend their choice on the
worksheet.
(The teacher may have to play “devil's advocate” to begin the discussion. For example: On # 2 was it
the genetics of the Eskimos in the village that survived that allowed them to be more intelligent and
protect themselves from the weather? This will lead to further questions: for example, are the zebras in
the center of herd smarter than the zebras on the edge of the herd that are going to get eaten by lions?
If this is true are zebras becoming continually smarter because the dumb ones are getting eaten?)
These types of questions should lead the students to a deeper understanding of natural selection and
how it is tied to genetics and evolution.
This discussion could last for 15 – 30 minutes depending on the assessment of the teacher (formative
assessment) on the value of the discussion to meet the goal of understanding evolution and natural
selection.
Show the students an image of a food web.
(http://www.uic.edu/classes/bios/bios101/x311_files/images/image30.png)
Use the food web to indicate to the students the trophic levels, defining each level.
The trophic levels are: producers that make energy from the sun, primary consumers that eat the
producers, secondary consumers that eat the primary consumers (may also eat producers), tertiary
consumers that eat the secondary consumers (may also eat producers and secondary consumers), and
quartenary consumers that eat everything below them (may not eat producers).
Go to the website: (http://www.harcourtschool.com/activity/food/food_menu.html) Allow the students
to go to the board in groups and build the food webs.
Hand out the worksheet on the “Patawalonga and Torrens Waterwatch”.
http://waterwatchadelaide.net.au/uploads/file/pdfs/other_resources/Food_webs_incl_teacher_notes.pdf
This is a worksheet used for formative assessment and is taken home to work on and turn in next class.
Struggling students will need help with definitions as the remainder of the class works on the handout
these students can be grouped and the word search can be done as a group guided by the teacher. As
they do the word search they will indicate the trophic level to which the word belongs.
Find all of these food
web words in the grid
to the left.
Indicate the trophic
level for each
organism on the list.
carnivore
catch
decomposer
eat
energy
filter feeder
food chain
gather
graze
grow
harvest
herbivore
hunt
insectivore
parasite
pick
plant
predator
prey
scavenger
sunlight
food web
omnivore
trap
© 2005 www.bogglesworldesl.com
Lesson Five (1 – 2 class periods)
Students will hand in the “Patawalonga and Torrens Waterwatch” worksheets.
Write on the board: “What happens to the population of elk when wolves are introduced into the
ecosystem?”
Have the students write for 4 minutes about their opinions on the topic.
The teacher will need four pieces of paper with the following written on each paper: STRONGLY
AGREE, SOMEWHAT AGREE, SOMEWHAT DISAGREE, STRONGLE DISAGREE. These sheets
should be taped in the four corners of the room.
Do a four corners on the statement: The population of wolves in the ecosystem should be left alone
with no human interference.
As they form their groups they will require 3 minutes to discuss within their groups why they chose
that group.
Have the students choose a spokesperson and give each 1 minute to prove their point.
The discussion should lead the students in the direction of predator and prey relationships. As the
number of predators goes up, the number of prey goes down. Also as the number of prey decreases, the
number of predators will also decrease. The lab will show the relationship between the numbers of
predators and prey.
Lab: Predator and Prey Relationships
The teacher will need 100's of paper circles and 100's of washers (approximately 50 of each for
each group, groups can be as large as 4 or as small as 2). Colored pencils and rulers to
complete the graph on the back of the data sheet.
Hand out the predator/prey relationships lab sheet, and show the students how to complete the lab.
At the end of the lab the students will have the option to change their minds about the four corners
exercise.
Predator/Prey Relationships
The paper circles represent prey. The washers represent predators.
Rules
Each time the washer touches a paper the predator has killed the prey and two of the prey need to be
removed because they cannot reproduce.
Each time the washer misses the paper the predator has missed his kill and does not survive.
For each paper that “survives” add another paper.
For each washer that “survives” add another washer
Procedure
1: Spread six paper circles on a table at random positions.
2: Toss three washers onto the table attempting to land on the paper discs.
3: Use the rules above to adjust the number of papers and washers.
4: Each toss is one generation. Go through 10 generations and record the number of predators and prey
for each generation in the data table.
5: If the predators or prey run out within 5 generations start over at procedure 1.
6:Make a graph of the results plotting generations on the horizontal axis and number of predators and
prey on the vertical axis.
Data
GENERATIONS
1
2
3
4
5
6
7
8
9
10
PREDATORS
PREY
Graph
100
90
80
70
60
Predators/Prey
(red)
(blue)
50
40
30
20
10
0
1
2
3
4
5
Generations
6
7
8
9
10
Lesson Six (1 – 2 class periods)
Hand back the “Patawalonga dna Torrens Waterwatch” worksheets.
Show them how a food web is an example of an ecosystem by going back over “Patawalonga and
Torrens Waterwatch”. This will tie ecosystems to food webs.
Draw a circle on the board that represents the earth (approximately 70cm in diameter). Point out that
the living things on the Earth live from the depth of the deepest ocean to just above the top of the
highest mountain within the atmosphere. Ask a student or several students to come to the board and
mark where the lines should be both inside and outside the circles to encompass all living things.
The lines are probably within the circle drawn on the board! (The radius of the Earth is approximately
8000 miles. The depth of the ocean is approximately 7- 10 miles. The thickness of the atmosphere is
approximately 7 – 10 miles. This is 1/800 of the diameter of the circle drawn on the board.) All living
things on Earth live within 7 miles of the surface! This area is called the biosphere.
The biosphere is divided into sections: Go through and define the levels of the biosphere: organisms,
populations, communities, ecosystems, and biosphere.
Give the students some examples of ecosystems. Be sure to point out that a population requires at least
two organisms, a community requires at least two populations, and an ecosystem requires at least two
communities. Make sure that they understand that organisms can be any living thing (sometimes they
forget that plants and bugs are living things.
Hand out the worksheet on Ecosystems. They will go outside (weather permitting) to find at least two
ecosystems on the school campus.
The lawn is a great ecosystem. It has a community of plants: at least one kind of grass (population) and
weeds (population), the individual blade of grass and weed is an organism.
It has ants (population) and spiders (population) which make up another community of insects.
The two communities make up an ecosystem.
The students must find another ecosystem and answer the questions on the back of the sheet. (This is a
formative assessment)
Ecosystem I
Community I
Population I
Population II
Organism I
Organism II
Organism I
Organism II
Organism I
Organism II
Organism I
Organism II
Community II
Population I
Population II
Ecosystem II
Community I
Population I
Population II
Organism I
Organism II
Organism I
Organism II
Organism I
Organism II
Organism I
Organism II
Community II
Population I
Population II
What are the environmental factors that keep an organism from ecosystem I
from surviving in ecosystem II?
What organism in Ecosystem I is at the top of the food chain?
What organism in Ecosystem II is the producer for the food chain?
Create a food web using the organisms on one of your ecosystems.
Lesson Seven (1 class period with homework)
Collect or go over the ecosystem papers and answer any questions.
Hand out readings from: Evolution and Biodiversity The evolutionary basis of biodiversity and its
potential for adaptation to global change.
The readings are accompanied by questions.
These readings have a very high Lexile score (1300); however, the students should have enough
scaffolding to get through them and answer the questions.
The readings should also tie together the entire unit and help prepare the students for the summative
assessment.
Human perspectives on biodiversity
Stefaan Blancke, Department of Philosophy and Moral Science, Ghent University, Belgium
Not only does evolutionary theory have a massive impact on our modern understanding of biodiversity,
but also on our reasons for valuing it.
Of the many conceptual changes brought on by Darwin's theory of descent with modification,
there are at least three that have determined the way we look at biodiversity today. First instead of
interpreting species as imperfect images of an ideal type, Darwin was the first to fully appreciate the
omnipresence and importance of variations in nature. Since Darwin, we no longer consider species to
be immutable units, but varieties that are, as Darwin put it, “strongly marked and well-defined”. By
constantly providing alternatives or new possibilities, variation allows populations to adapt to a
changed or changing environment. Therefore, variation is a condition sine qua non not only for the
survival and reproduction of those populations, but in the end, also for the very existence and
preservation of biodiversity. Biodiversity, which is variation among species, can only occur by means
of variation within species. It is the product of evolution.
Second, because populations will continue to vary, to adapt and hence to evolve, biodiversity
should be considered to be a dynamic, and not a static, phenomenon. Except for a few isolated voices,
people before Darwin tended to think of nature's diversity to be a static order arranged in resemblance
of God's reason. But, today, we realize that biodiversity is in a constant flux. It itself varies
continuously, this indeed providing life as a whole with a strong potential to adapt to new
circumstances and to evolve. However, this dynamic character also poses important limits on what
kind of biodiversity we can expect to maintain. For instance, if we transplant a species into a different
environment in order to rescue it from extinction, the species will adapt to the new conditions and this
change. In general, thinking in essentialist terms about biodiversity – which we do intuitively – would
set our hopes too high. We can work hard to preserve nature's diversity, but we cannot expect to keep it
as it is.
Third, as species evolve by adapting to the environment, they cannot display any feature that is
“formed for the exclusive good of another species”. Some of Darwin's contemporaries still cherished
the idea that life on Earth was created solely to the service of humans. Darwin realized that if this
would be the case, “it would annihilate [his] theory”, but today, his theory still stands. Now, life on
Earth might have turned out not to be exclusively created for us, but in the end we are, as far as we can
tell, the only species that can value its diversity. And we have two very good reasons to do so. First,
how will people later judge our generation if we do not attempt to preserve a minimum of diversity,
especially because we know perfectly well how to accomplish this? They would rightly blame us for
leaving them with a less interesting and less fascinating world. And second, as species adapt to each
other, they form a “web of complex relations”, in which too much interruption might have unpredicted
but severe consequences for human lives and society. These two reasons alone should be sufficient to
make our moral instinct – initially evolved to deal with kin and tribe – encompass nature's diversity.
What does variation allow populations to do?
What does Stefaan Blancke think is the key to biodiversity?
How do we know that biodiversity is in constant flux?
Why should we, as humans, do everything we can to maintain biodiversity?
Understanding evolutionary processes during past Quaternary climatic cycles: Can it be applied
to the future?
John Stewart, Natural History Museum, UK
Climate change affected ecological community make-up during the Quaternary which was probably
both the cause of, and was caused by, evolutionary processes such as species evolution, adaptation and
extinction of species and populations.
The Quaternary, the last 2.6 million years, with its regular and extreme climatic oscillations at different
amplitudes and the accompanying ecological variation would appear to be a likely time for species
evolution.
Despite this, it has been claimed that Quaternary climate change has acted in such a way as to
decrease the opportunities for species formation rather than be the principle driver of modern species
evolution. This is because the differentiation that occurs because of endemism in allopatry during
glacials would be undone in the subsequent interglacials by the interbreeding of the formerly allopatric
populations (Coope, 1978; Bennett, 2004; Klicka & Zink, 1977 versus Avise & Walker, 1998; Lister,
2004). The opinions seem to be driven by the nature of the fossil record of each organism type studied.
(For example the difference between two closely related modern birds will often be in their plumage
and song which do not preserve and not in their osteology).
In contrast there is much evidence for ecological change during the Quaternary and in particular
the existence of non-analogue communities – organisms living together in the past that do not live in
sympatry today (Graham, 1990; Williams & Jackson, 2007). These non-analogue communities have
also been shown to become less analogue with deeper time (Stewart, 2008). Therefore, it is clear that
in each subsequent oscillation the environment did not return to the state it was in at the equivalent
stage of the preceding oscillation.
It seems likely that the ever changing mixtures of organisms will have had an evolutionary
effect on the organisms making up changing communities. This effect has been called the “New
Neighbour Hypothesis” (Hewitt, 1996, 2000; Stewart 2009) and suggests that the Quaternary probably
involved more evolution than often claimed. If this is the case the existence of non-analogue
communities which become progressively more non analogue with deeper time maybe act in part as a
proxy for this evolution that may not be visible in the fossils of certain organisms.
The cause of non-analogue communities is generally believed to be because of the
individualistic nature of species. This is that species respond to climate change by expanding or
contracting their geographical range and not whole ecological communities of species.
The implication of the individualistic nature of species is important to conservation biology as it
implies that species are unlikely to respond as communities in the future. This already being observed
with the arrival in Britain of birds that have never lived here before such as the little egret and the cattle
egret (whether caused by climate change or not) (Stewart 2004) and through the detailed study of
woodland ecologies in Southern England (Kieth et al.,2009). This in turn suggests that we should
expect the unexpected much as it has been suggested that we should expect non-analogue climates in
the future (Williams and Jackson, 2007).
Studies of ancient DNA from the fossils of extant mammals during the late Pleistocene shows
that animal species that lived in non-analogue communities in the past were often made up of extinct
genetic clades (with no living descendents) (Dalen et al.,2007). This may in part explain the fact that
they lived in non-analogue associations in the past. It has alos been shown that at times these extinct
populations were subsequently replaced by allopatyric conspecific populations (Leonard et al., 2007).
The latter implies that population turnover is a process that can take place due to climate change
and that widespread genetic populations can become extinct and be replaced by less widespread
population. This may not always, or even generally, be the case as it depends on the availability of a
suitably adapted population to replace the extinct one.
Finally, many cold adapted species are likely to have evolved from more temperate ones during
the Quaternary as the cold environments are relatively new (Stewart et al., 2010). The most obvious
example is the polar bear which nests within the brown bear phylogenetic tree. This is in addition to
the speciation scenario that has been invoked by the differentiation within temperate species while in
different southern refugia (Hewitt 1996; Lister 2004).
What we need to know now is more about the genetic make-up of the populations of animals
living in different ecological community combinations. The hypothesis is that organisms living in nonanalogue combinations are made up of extinct populations. The results would give us a better
understanding of the relationship between ecology and evolution driven by climate change.
What is the Quaternary?
Cite examples to explain climate oscillation.
Why does the author think that climate has reduced the opportunity for species
formation?(Paragraph III)
What are non-analogue communities?
What is meant by the individualistic nature of species?
What probably happens to the gap left by non-analogic species that become extinct?
Why would the author think that organisms living in non-analogic combinations are made up of
extinct populations?
Final Lesson 1 class period
Answer any questions from the readings.
Discuss how everything is related in the biosphere.
Hand out the summative assessment.
They will have the remainder of the class time to work on the summative assessment, and they can take
it with them and hand it in the next time.
Summative Assessment
What would my life be like without ____(you choose an organism)
?
Build a food web that includes you, your chosen organism, and at least two more trophic
levels. Be sure to put more than one organism on each of the trophic levels. (The food
web can be build on a poster, a web site, or on a piece of paper.)
Build another food web with your chosen organism taken out and answer the following
questions:
1. How does the elimination of this organism affect the environment?
2. How does the elimination of this organism affect the trophic levels below the
organism?
3. What kind of a mutation to another organism in the food web allow it to survive and
keep the food web from collapsing?
4. Could another organism with a mutation replace the eliminated organism in the food
web?
5. Name ways that the other organisms in the food web would be able to adapt in order
to survive and how many generations it would take to make this adaptation.
Explain what happens to biodiversity with the organism missing and how this change
affects your life. Include the following terms in your explanation: (producers,
consumers, secondary consumers, tertiary consumers, population, community,
ecosystem, recessive genes, dominant genes, natural selection, adaptation, survival,
mutation, environment)
Grading Rubric for Summative Assessment
Questions:
There are 5 questions each worth 8 points for a total of 40% of the grade.
2 points
4 points
6 points
8 points
Attempted
Not correct
No evidence
Attempted
Partially correct
No evidence
Partially correct
Evidence cited
Totally correct
Evidence cited
example: The
elimination of the
organism does not affect
the environment.
example: The
elimination of the
organism affects the
environment adversely.
example: The
elimination of the
organism will change
the next trophic level
because as we saw in
the predator/prey lab the
predators will die if the
prey (organism) is
eliminated.
example: Because the
organism is a predator of
the trophic level below
and a prey organism of
the trophic level above
the elimination of the
organism will change
the entire food web. As
we see on the graphical
analysis of a
predator/prey
relationship, when the
prey is removed the
predators suffer and
their numbers are
reduced.
There are 15 vocabulary words worth 4 points each for a total of 60% of the grade.
1 point
2 points
3 points
simply written out of
context.
written in context but
not defined
example: All students example: Producers
are the producers of the make energy.
answers on this test
4 points
written in context and
defined
written in context and
defined through example
or evidence
example: Producers are
at the base of the food
web and begin the
production of energy
that flows through the
food web.
example: Biodiversity
depends on the health of
the producers because
they are the organisms
that create the energy
the flows through the
trophic levels; therefore
we will find them at the
base of all food webs.
With 40% from the answers to the questions and 60% from the answer to the question that
includes the vocabulary words, there is a total of 100% on the summative assessment.