Scientific Method
Science is something you know and something you do.
Body of knowledge and getting answers about the natural world.
Pure science seeks to answer questions about how the natural world works.
Applied science uses the information from the pure sciences to solve problems
1. Which of the following is considered a pure science?
a. Environmental science
b. Medicine
c. Engineering
d. Biology
2. Which of the following is considered an applied science?
a. Ecology
b. Forest Conservation
c. Physics
d. Chemistry
Scientific Method
Observations all science begins with good observations!
Questions -the most important part is to ask a good question.
Hypothesis must be testable
Design and experiment
Collect and analyze data
Draw conclusions
Suppose you observed that a cricket outside your window seems to be chirping every night, but some nights it chirps faster than others. A friend of yours told you once that you can use the sound of a cricket chirp to tell the temperature. Curious, you decide to design an experiment.
3. What was the initial observation?
4. Write a hypothesis:
To set up the experiment, you go out to your yard and capture a few crickets. You bring them inside and place them in a container. The goal in designing an experiment is to eliminate all the variables except the one you are testing. This means all your cricket subject must be housed in the same environment (same lighting, same food, same water..etc). Okay, so you get that set up and take the temperature of your room. Now you must wait for the crickets to start chirping. You count how many times the cricket chirps for a 5 minute period.
Now you have to compare that number with the chirps that occur at different temperatures. You may use a heating pad, or ice or any other way to lower or raise their temperature. You would then take data for 5 minutes at the new temperature.
In your experiment, the INDEPENDENT VARIABLE is the thing you changed
5. What is the independent variable in the experiment above?
TheDEPENDENT VARIABLE is what you are measuring that happens as a result of that change
6. What is the dependent variable in the experiment above?
Mark Capture and Recapture
Often it is not possible to directly count all of the organisms in a habitat to determine the size of a population. In these cases an estimate of the population size can be made by marking a segment of the population at one time and later recapturing the organisms (hence "Mark and recapture techniques").
The procedure for estimating population size begins with the capture of individuals at the study site. The organisms are then marked in some way so that they can later be identified by the investigator. Typical marking methods include ear tags, leg bands, dyes or paints, and clipping of fins or toes (ouch!). These animals are then returned to the habitat and allowed sufficient time to mix with the other members of the population, thus establishing an as yet unknown ratio of marked to unmarked animals in the total population. After an appropriate period of time, a second sample is collected to determine the ratio of marked to unmarked animals in the total population.
7. Assume that 50 animals were captured, marked, and returned to a population during the first sampling period. On returning to the field, 60 animals are captured. Of these 60, 5 are marked. What is the estimated size of this population?
8. In order to estimate the population of geese in Northern Wisconsin, ecologists marked 10 geese and then released them back into the population. Three years later 12 geese were captured and 2 of those had a mark. What is the estimated size of the population?
There are three assumptions of the mark and recapture technique:
I. Marked and unmarked animals are captured randomly. Field mice may become trap-happy or trap-shy. If your marks make the animals more conspicuous, you may collect too many marked animals during the recapture phase of the survey.
II. Marked animals are subject to the same mortality rate as unmarked organisms. Fish marked at sea may be weakened and suffer higher mortality or marks may make your study animal more conspicuous to predators.
III. Marks must not be lost or overlooked. Leg rings can be lost by birds or arthropods may molt and lose the mark.
9. A biologist wanted to estimate the size of a rabbit population in the Shenandoah Forest. She captured rabbits using traditional metal traps filled with alfalfa grass. She marked each rabbit by dying its tail a bright orange color. Did the biologist take all of the assumptions into account above? Explain any problems with each assumption (I III) above.
Ecological Experiments and Data
Observation: Watching the organism or group of organisms in their natural environment or a lab setting and collecting data on what you see, hear, smell, or otherwise observe. More informal experiment.
Benefits: In the field (natural environment), can observe natural behavior
Limitations: Hard to control experiment, hard to collect quantitative data
Experiment: Controlled experiment set up to test one variable at a time. All other factors are closely controlled.
Benefits: Can set-up and control experiment, focus on one thing to collect data from.
Limitations: Not natural environment, cant replicate all cases.
Modeling: using computer programs to predict future events or what-if scenarios.
Benefits: predict future or what if events, dont disturb environment.
Limitations: Must include as many factors as possible in model, hard to measure all components to include, lots of assumptions must be made.
10. Which of the following is not a fundamental way of testing a hypothesis?
a. Modeling
b. Field observation
c. Experimentation
d. Elimination prediction
11. The behavioral ecology lab we did in class used what method to test the hypothesis?
a. Modeling
b. Field observation
c. Experimentation
d. Elimination prediction
12. The behavioral ecology lab we did in class was useful for
a. Predicting animal behavior.
b. Quantifying animal behavior.
c. Altering animal behavior.
d. Capturing and recapturing animal behavior.
13. Which of the following using a model to test their hypothesis?
a. A scientist spends 3 hours recording squirrel behavior during the fall.
b. A scientist collects detailed data on which temperatures cause crickets to chirp the fastest.
c. A scientist records whale sounds in an attempt to understand how they communicate.
d. A scientist uses mathematical equations and current temperature data to predict what will happen if we continue to emit carbon dioxide at current rates.
14. What is one way to collect data from past events?
a. Capture-recapture
b. Scan Sampling
c. Behavioral Ecology
d. Sediment Core Examination
Levels of Study and Organization
15. A scientist studying how UV radiation affects algal grown in all of the oceans is primarily conducting his study at what level?
a. Populations
b. Ecosystems
c. Communities
d. Biosphere
16. You collect the following specimen from your local park: grass, crickets, worms, maple leaves, and spiders. Together these make up the local
a. Ecosystem
b. Population
c. Community
d. Biosphere
17. Which of the following is an abiotic factor that can limit the plant growth in a local ecosystem?
a. The amount of nitrogen available in the soil.
b. The number of local deer that feed on the plants.
c. The type of insects that eat the leaves.
d. The presence of fungi that is parasitic to the plants.
18. What do we call the group of all living and non-living things in a given area.
a. Habitat
b. Ecosystem
c. Population
d. Community
Plant Defense
Know the following types of plant defenses! There are three main categories. Be able to list an example of each.
PHYSICAL DEFENSES
Spines, thorns, hairs
Cutins, waxes, suberins
SECONDARY METABOLITES
Bad taste - limolene in lemons
Scent to warn - mint
Poison kills insects
Prevent germination of other plants allelopathic like pine needles
Attract predators of herbivores wasp and caterpillar
Hypersensitive response plants kill infected cells off
Mutualistic Relationships ant and acacia
19. Cherry tree sap that can trap insects when they try to feed on the bark is this type of defense.
a. Physical defense
b. Mutualistic relationship
c. Hypersensitive defense
d. Allelopathic defense
20. Describe how a plant can use a wasp for protection.
21. Ants and the acacia tree have a mutualistic relationship. Explain how each species benefits from this relationship.
Animal Adaptations
Examples of Adaptations1. Camouflage (Cryptic) 2. Disruptive Markings3. Warning Coloration4. Mating Coloration5. Batesian Mimicry 6. MullerianMimicry7. Automimicry
Which type of adaptation is described by each statement below?
22. A lizard that has tail that closely resembles its head in order to confuse predators is using this type of adaptation.
23. A brightly colored bird that uses his feathers to attract a female and reproduce is using which adaptation.
