Using the data from Lab 2: Interactions Within and Between Communities, write a formal lab report. This report should include an introduction, methodology, results, and conclusion sections and should be created based on the standard scientific journal format. Examples of a formal lab report can be found in the “Writing a Lab Report” lesson. Examples are linked in the Lesson Toolbox as well.
Below are some guidelines for what to include in each section.
Title: The title should describe the experiment in ten words or fewer. The title must convey an accurate description of the overall topic and the variables being tested.
Introduction: The introduction should briefly describe the foundational concepts and background information used in the experiment. This information must come from outside sources and use proper citations in APA format with in-text citations. The introduction should provide a clear sense of the experiment’s importance and the research that has been conducted by other scientists. In addition, the introduction should include a clear statement of the hypothesis for the experiment and the scientific rationale for this hypothesis. For example, this is a hypothesis from an experiment on the effect of pesticides: “The hypothesis was that increasing pesticide concentration would increase the number of insects that died in the 48-hour window. This is because the pesticide is a potent neurotoxin, and higher concentrations would cause increased damage to the central nervous system.” The introduction section should be one or two paragraphs and must include outside sources to support the ideas that are introduced.
For more information about writing an introduction to a science lab, click here. For more information about writing a hypothesis, click here.
Materials and Methods: The materials and methods section includes a list of tools and materials used. The methods should be written out in paragraph form. Make sure to include enough details so that someone could replicate the work based on this section. Include any changes from the outlined procedure and any mistakes that occurred in the process.
For more information about writing the materials section of a lab report, click here.
Results: The results section should present the raw data from the assignment in a table and in a graph created in Excel, Google Sheets, or a similar program. Include the data’s units, and label the graphs and tables appropriately. Include a clear written description of the controls. For help with Excel, see: https://blog.hubspot.com/marketing/how-to-build-excel-graph.
For more information about writing the results section of the lab report, click here.
Discussion: The discussion section should explain and elaborate on the results. If unexpected results were obtained, then explain them and identify any possible confounding variables. Address the following questions:
What trends do the graphs show?
Are there any negligible factors that may affect the results if the experiment were performed in the real world?
Within the discussion, you must include your conclusion. The conclusion section is based on evidence obtained throughout the experiment. The conclusion summarizes the study’s purpose and results, and it is used to persuade the audience of the work’s significance. Explain why you accepted or rejected your hypothesis using data from the experiment, and include a brief summary of the data, where necessary, to help the reader understand the results and conclusions.
For more information about writing the discussion section of a lab report, click here. For more information about writing a conclusion for a lab report, click here.
Self-Evaluation
Self-evaluation is an important skill to learn in your everyday life. No level of personal growth comes without understanding how to first self-evaluate. In every assignment you do, be it for this course or any other, you should be self-evaluating your work. Use the list below to double-check your work before submitting.
Review Your Formatting – Go back and review the “Writing a Lab Report” lesson in Module 1 to evaluate the formatting on your assignment. Review the “Resources” tab to ensure you are using best practices and adhering to the guidelines presented.
Check the Criteria – Print out the rubric for this assignment, and read through your work carefully. A good practice is to grade yourself using the rubric to ensure you’ve executed all assignment expectations.
Get a Fresh Perspective (If Available) – Give your assignment to someone else who can critically evaluate it. Make sure to provide them with the assignment description and the rubric (if available). After they have graded your work, discuss their perspective and see if there is room for improvement.
Lab 1: Population Demographics, Dynamics, Growth, and Control
Access to the following website: https://smartgraphs-activities.concord.org/activities/225-african-lions-modeling-populations/student_preview/index.html
Lab 2: Interactions Within and Between Communities
Access to the following websites: http://virtualbiologylab.org/pdf/BarnacleCompetitionDirections.pdf.
http://virtualbiologylab.org/ModelsHTML5/BarnacleCompetition/BarnacleCompetitionModel.html
Compare and contrast competition and predation.
What is logistic growth?
Compare and contrast a fundamental niche and a realized niche.
Lab 1: Population Demographics, Dynamics, Growth, and Control
Click on the following link for an activity that begins by modeling a population of African lions: https://smartgraphs-activities.concord.org/activities/225-african-lions-modeling-populations/student_preview/index.html
Answer each question correctly to move on. As you answer these questions, take notes here to help you track your understanding.
What is ecology? Give an example of something an ecologist would study.
After the crater lion population crashed to 12 lions in 1963, what do you think happened to cause the population to decrease so rapidly?
Growing Bacteria
What prediction did you make?
Why did you make this prediction?
What is exponential growth, and when does it occur?
Exponential Growth and Lions
Look at the lion population from 1963 to 1975. Do you think this rate of growth will continue to increase?
Why or why not?
Limiting Factors
What is a limiting factor?
What is the difference between density dependent and density independent?
Use the graph to draw your prediction about the lion population from 1980-2012, and describe it here.
The Lion Population Rebounds
Compare your carrying capacity prediction to the real data.
What do you notice?
If there are differences, what could have caused them?
Human Population
Look at the graph of World Population Projects and Estimates. Do you think Earth’s population will reach carrying capacity?
What might be some limiting factors?
Lab 2: Interactions Within and Between Communities
In this simulation, you will explore the niches of two species of barnacles: Chthamalus and Balanus. A fundamental niche is the entire set of conditions under which a species or population can survive and successfully reproduce. A realized niche is the actual set of conditions that they inhabit. Meaning that after interactions with other species have been taken into account, the realized niche is the unique habitat that only they utilize. Connell (1961) used this example to demonstrate how the fundamental niche of Chthamalus barnacles was restricted to a small realized niche because of the competition with the Balanus barnacles.
Prior to opening the simulation, read through the basic directions and background information here: http://virtualbiologylab.org/pdf/BarnacleCompetitionDirections.pdf.
After reading through the PDF, access the simulation here: http://virtualbiologylab.org/ModelsHTML5/BarnacleCompetition/BarnacleCompetitionModel.html
Go through the tutorial to learn about the various parameters and how to adjust them. (keep in mind C is “white” and B is “orange”; Thais is the predatory snail). Return to “Home” when completed.
Click “Run Experiments” to go to the simulation.Be sure to answer the associated questions as you work through the activity.
Run the experiment for 20 days by adjusting the controls. You can speed up the time using the blue buttons at the bottom.
Is there a species that settles and grows on a wider range of rock?
Which one can handle being exposed to air during low tide?
How is this difference reflected in their growth rates?
Include a picture of your data collection from the left half of the screen at the end of 20 days.
Reset the experiment, and click the right arrow to go to the experimental design page. Increase the sea level to “2” and observe what happens to the data after 11 days.
What is different about the data measures here compared to the scenario depicted in step 6?
Why do you think this happened?
Reset the experiment, and click the right arrow to go to the experimental design page. Increase the Thais density to “10” and observe what happens to the data after 11 days.
Which species did the Thais prey on more?
How did this affect the other species?
Create your own experimental design to run for 20 days. This will be the experiment that you will use to write your lab report for this module.
What did you change?
What do you predict will happen to each species, and why?
Did your results match your prediction?
Why or why not?
Post-Lab Questions
Why did the realized niche for each barnacle species not match its fundamental niche?
How do competition and predation limit the distribution of each barnacle species?
What would you do to increase the population of African lions?
