Ecology and Types of Interactions - notes
I. Ecologists have described ____________ main ways that species and individuals affect each other.
A. ___________________- When two or more individuals or populations try to use the same limited
resource.
1) _______________________ – scarce resources like water, food, space, even mates.
2)_________________________________–the number of individuals that an environment can
support; controlled by competing for limited resources and
What has caused this population to level out?
What is the carrying capacity of the deer population?
predator/prey interactions.
B. ___________________- The interaction of one individual eating another.
1) _____________- the organism that is eaten. Prey adaptations include advantages that help prey
_________ themselves or ______________ predators.
2) ______________- organism that eats the prey. Predator adaptations include advantages over the
prey that help predators catch their prey.
i. _______________________ - the ability of some creatures to imitate others, either by sound or
appearance for protective purposes
ii._______________________ - Protective coloring or another feature that conceals an animal
and enables it to blend into its surroundings
iii. ________________________ - Bright colors and patterns that warn potential predators of the
potential risk that would come from attacking or eating it.
Types of Consumers (Heterotrophs)
__________________ - consumer that eats plants.
__________________ - consumer that eats animals.
__________________ - consumer that eats both plants and animals.
__________________ -animals that feed on the bodies of dead animals.
__________________-organisms that get their energy by breaking down the remains of dead organisms.
C. ____________________- A long-term association between two or more species. There are three
types we will be discussing.
1) __________________- A relationship in which both organisms benefit from each other. + +
Ex: ____________________________________________________________
2) __________________- A relationship in which one organism benefits and the other
is unaffected. + 0 Ex: ___________________________________________________
3) __________________- A relationship in which one organism benefits while the
other is harmed. + - Ex: ________________________________________________
 ________________- benefits in the relationship.
 ________________- is harmed in the relationship.
II. Evolution is tied to the need for organisms to get energy.
A. __________________________- the process in which organisms produce offspring which are
biologically different than their ancestors, yet are more capable of surviving and producing offspring in the
environment.
Graphing Practice
1. Time is represented on the __________-axis.
2. The number of individuals is represented on the __________-axis.
3. At which point on the curve (I, II, III) is the population increasing at the fastest rate?_________
4. At which point on the curve (I, II, III) is the population leveling off?______________________
5. At which point on the curve (A or B) has the population reached the carrying capacity or the
maximum population density for its environment? _____________________________________
1. What do you think happened in 1880 that may have
Caused the population of sheep to level off?
2. About how many sheep can this population hold?
3. Why do you think the population grew so fast
from 1840- 1880?
4. What happens when the population goes over
the carrying capacity?
Peppered Moth Simulation
Objectives:
Describe the importance of coloration in avoiding predation
Relate environmental change to changes in organisms
Explain how natural selection causes populations to change
Materials
Sheet of white paper
Newspaper
Forceps
Colored Pencils
Clock with Second Hand
30 newspaper circles (made with hole punch)
30 white circles (made with hole punch)
Purpose: In this lab, you will simulate how predators locate prey in different environments. You will
analyze how color affects an organism's ability to survive in certain environments.
Industrial Melanism is a term used to describe the adaptation of a population in response to
pollution. One example of rapid industrial melanism occurred in populations of peppered moths in
the area of Manchester, England from 1845 to 1890. Before the industrial revolution, the trunks of
the trees in the forest around Manchester were light grayish-green due to the presence of lichens.
Most of the peppered moths in the area were light colored with dark spots. As the industrial
revolution progressed, the tree trunks became covered with soot and turned dark. Over a period of
45 years, the dark variety of the peppered moth became more common.
Procedure:
1. Place a sheet of white paper on the table and have one person spread 30 white circles and 30
newspaper circles over the surface while the other person isn't looking.
2. The "predator" will then use forceps to pick up as many of the circles as he can in 15 seconds.
3. This trial will be repeated with white circles on a newspaper background, newspaper circles on a
white background, and newspaper circles on a newspaper background. Record the data in chart
below.
Starting Population
Number Picked up
Trial
Background
Newspaper
White
1
white
30
30
2
white
30
30
3
newspaper
30
30
4
newspaper
30
30
White
Newspaper
Analysis
1. What did the experiment show about how prey are selected by predators?
2. What moth coloration is the best adaptation for a dark (newspaper) background? How do you
know?
3. What would you expect the next generation of moths to look like after trial 1? What about the
next generation after trial 3?
4. How does the simulation model natural selection?
5. Examine the table and construct a graph. Plot the years of the study on the X-axis, and the
number of moths captured on the Y axis. You should have 2 lines on your graph - one for light
moths, and one for dark moths.
Year
# of Light
Moths
Captured
# of Dark
Moths
Captured
2
537
112
3
484
198
4
392
210
5
246
281
6
225
337
7
193
412
8
147
503
9
84
550
10
56
599
6. Explain in your own
words what the graph
shows.
7. What are the 5
principles of natural
selection as stated by
Charles Darwin?
Deer: Predation or Starvation
Introduction: In 1970 the deer population of an island forest
reserve about 518 square kilometers in size was about 2000
animals. Although the island had excellent vegetation for feeding,
the food supply obviously had limits. Thus the forest management personnel feared
that overgrazing might lead to mass starvation. Since the area was too remote for
hunters, the wildlife service decided to bring in natural predators to control the deer
population. It was hoped that natural predation would keep the deer population from
becoming too large and also increase the deer quality (or health), as predators often
eliminate the weaker members of the herd. In 1971, ten wolves were flown into the
island.
The results of this program are shown in the following table. The Population Change is
the number of deer born minus the number of deer that died during that year. Fill out
the last column for each year (the first has been calculated for you).
Year
Wolf
Population
Deer
Population
Deer
Offspring
Deer
Predation Starvation Population
Change
1971
10
2,000
800
400
100
1972
12
2,300
920
480
240
1973
16
2,500
1,000
640
500
1974
22
2,360
944
880
180
1975
28
2,224
996
1,120
26
1976
24
2,094
836
960
2
1977
21
1,968
788
840
0
1978
18
1,916
766
720
0
1979
19
1,952
780
760
0
1980
19
1,972
790
760
0
+300
1. Graph the deer and wolf populations on the graph below. Use one color to show
deer populations and another color to show wolf populations.
Analysis
1. Describe what happened to the deer and wolf populations between 1971 and 1980.
_______________________________________________________________________________________
2. What do you think would have happened to the deer on the island had wolves NOT been
introduced?______________________________________________________________________________
3. The carrying capacity of a biological species in an environment is the maximum population size of the
species that the environment can sustain indefinitely, given the food, habitat, water and other necessities
available in the environment. What would you say the deer population carrying capacity is by looking at
your graph? How about the wolf population?
Deer= _____________ Wolf=______________
4. Most biology textbooks describe that predators and prey exist in a balance. This "balance of nature"
hypothesis has been criticized by some scientists because it suggests a relationship between predators and
prey that is good and necessary. Opponents of this hypothesis propose the following questions:
“Why is death by predators more natural or "right" then death by starvation?
How does one determine when an ecosystem is in "balance"?
Do predators really kill only the old and sick prey? What evidence is there for this
statement?”
What is your opinion of the balance of nature hypothesis? Would the deer on the island be better off, worse
off, or about the same without the wolves. Defend your position.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
__________________
Name _______________________________
Predators could be Superweed Fix by Rebecca Morelle
A Superweed spreading
throughout the UK.
1. What plant was first introduced as an ornament plant but now is
causing big problems in the U.K?
2. What is the definition of bio-control?
Appetite for knotweed
1. Where is the knotplant native? (Where did it come from?)
2. What did researchers find were predators of this plant?
3. Which of these predators were ruled out to be used in the bio-control
program?
4. Which two predators did scientist narrow their research down to?
5. How does sap-sucking psyllid insect control the knotweed?
Phenomenal Growth
1. Why was the knotweed introduced in the U.K. for horticulture
purposes?
2. How fast does the invasive plant grow?
3. What problems is the plant causing?
4. What is wrong with the current methods of getting rid of the plant?
Name ___________________
Animals Regulate Their Numbers by Own Populations Density
Written in Science Daily by Zoolologist from the University of Toronto
“No populations of
organisms increases
without limit.”
1. What certain environmental conditions can change reproductive output
according to Tim Karels?
2. Why does lower reproduction help with survival?
The artic ground
squirrel…
1. What biome do the artic ground squirrels live in?
2. Describe the 4 groups that were set up for the experiment?
1.
2.
3.
4.
3. What happened in the high-density populations?
The researchers…
1. Why do researchers believe female squirrels shut down reproduction?
2. What are the cost of reproduction for these females?
Karels and
Boonstra…
1. Because of high-density populations, what happened to the plants in the
community?
2. How did this affect the squirrel population?
Your opinion…
Do you think most animals would be able to adapt to control their own population
densities like the ground squirrel has?
How does this article create an argument against the use of biological control
methods?
Name ___________________________ Date _______________ Period _______
Bio-Control Argument
Your task is to write and argumentative essay that either speaks for or against the use of biological control
methods to balance ecosystems. As you know, a healthy ecosystem is maintained by several important
relationships among organisms, and the balance of these ecosystems relies on the interactions of
predator/prey relationships. Often times these relationships are threatened by human interactions or natural
disasters, and without these relationships some populations can get out of control.
Is it our duty, knowing the importance of a balanced food web, and thus ecosystem, to intervene with the
natural forces that drive the evolution of species with the use of bio-control methods?
Scientists have been struggling with the debate of whether they should allow nature to run its course even if
it means the extinction of species, or utilize methods such as introducing predators to help maintain balance
within an ecosystem.
In your essay you will need to include:
 A description of biological control methods and how they are used
 An explanation about your position on the ideas of using biological control methods
 Counter arguments to your position made by those that oppose your ideas
 Evidence that supports your ideas from articles read in class using quotes and citations.
This packet will help with organizing your notes and research throughout the research in designing your
argument.
Described the ideas behind biocontrol and why they are used
3pts
Stated a clear position or claim for or against the use of biocontrol and other 3 pts
methods for controlling populations
Supported argument with substantial evidence from research done in class
3 pts
Made acceptable counter arguments
Used proper vocabulary learned throughout the unit
Organized ideas well
Well-written and easy to read
Included proper references to articles read in class.
Turned in all work with the proper pre-writing materials
3 pts
2 pts
2 pt
2 pts
1 pt
1 pt
___/20 pts
Extra credit will be given to evidence that supports your position from one or more articles that were not
supplied by your teacher.
The work done during this project supports the Life Science GPS for the 7th grade
S7L1: Students will investigate the diversity of living organisms and how they can be compared scientifically.
S7L3: Students will recognize how biological traits are passed on to successive generations.
S7L4: Students will examine the dependence of organisms on one another and their environments.
S7L5: Students will examine the evolution of living organisms through inherited characteristics that promote survival of
organisms and the survival of successive generations of their offspring.
I promise to put fourth my best effort on this project and turn in the best work of my ability ____________________________
Parent Signature _____________________________
Vocabulary
It will be important that when writing your argumentative essay, that you use the proper vocabulary that will
help your readers understand your position on the use of biological control methods.
1. Population-
2. Carrying Capacity-
3. Limiting Factors-
4. Competition-
5. Predator-
6. Prey-
7. Biocontrol-
8. Natural Selection-
What are your first thoughts about the use of introducing species into an environment to balance out another
species’ population?
What are some other ways humans regulate populations?
Article Title:
Author:
Source:
Evidence For Biocontrol
Evidence Against Biocontrol
Quotes and citations from the article:
Additional notes or vocabulary taken from the article:
Did this article support the idea of using biocontrols or were the ideas expressed in the article against it?
Article Title:
Author:
Source:
Evidence For Biocontrol
Evidence Against Biocontrol
Quotes and citations from the article:
Additional notes or vocabulary taken from the article:
Did this article support the idea of using biocontrols or were the ideas expressed in the article against it?
Article Title:
Author:
Source:
Evidence For Biocontrol
Evidence Against Biocontrol
Quotes and citations from the article:
Additional notes or vocabulary taken from the article:
Did this article support the idea of using biocontrols or were the ideas expressed in the article against it?
Article Title:
Author:
Source:
Evidence For Biocontrol
Evidence Against Biocontrol
Quotes and citations from the article:
Additional notes or vocabulary taken from the article:
Did this article support the idea of using biocontrols or were the ideas expressed in the article against it?
Pre-writing Concept Map- Organize your argument and include ideas and evidence that you will include in
your paper into a concept map on this page.