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Peer Review

Connecting Concepts: Ecology/Population Dynamics

by Jan Cheetham , Robert Jeanne


Overall Numeric Rating:

4 stars
Content Quality: 5 stars
Effectiveness: 4.5 stars
Ease of Use: 4.5 stars
Reviewed: Sep 16, 2005 by Biology Editorial Board
Overview: Ecology/Population Dynamics is one of a series of interactive web-based lessons designed to give introductory undergraduate biology students opportunities to connect biology concepts. Each lesson is a series of screens that breaks the topic down into simple steps and then illustrates the connections between the steps to present the completed concept or process. Population dynamics is highly mathematical and very difficult for introductory biology students to understand. This site can be used as a supplement to the lecture to allow students to review the topic at their own pace and as many times as desired.This simulation/tutorial consists of three topics. In topic 1, students conduct a study of a zebra mussel population in a fictitious lake and present their findings during a virtual teleconference. Students will: 1) review qualitative descriptions of growth curves for the exponential and logistic models, selecting one to test at the lake; 2) collect and plot data, and determine which of the models the data fits; 3) answer questions about populations at other localities by calculating rmax, t, and N using their data. In topic 2, students review the math and biology behind the logistic growth model with the help of a fish population. Students will: 1) complete interactive explorations of density-dependence and carrying capacity, the difference between r (realized intrinsic rate of increase or per capita, growth rate), rmax, (maximum intrinsic rate of increase and dN/dt (population growth rate), how growth rate changes over time while r decreases; and 2) summarize and compare properties of exponential and logistic growth. In topic 3, students follow the growth of the Kruger National Park elephant population from 1903-1996. While following the history of the population, students calculate values using the logistic equation. Students will complete a case study in which they: 1) learn the biological and sociopolitical history of the KNP elephants; 2) calculate dN/dt, N, and 1-(N/K) over time; 3) explain how assumptions of logistic growth affect the shape of the curve; and 4) evaluate how well the KNP population fits the logistic model. A very good help screen is provided to help students use the lessons. The larger site containing the entire series will be very useful at the introductory level.
Type of Material: Tutorial
Recommended Uses: This site could be used in many ways. 1. As the basis of a classroom lecture presentation. 2. As an out-of-class assignment before the topic is covered in class. 3. As a study tool for students after topic is presented in class.
Technical Requirements: Flash 6.0
Identify Major Learning Goals: The major focus of this lesson is to help students understand exponential and logistic growth models and the mathematics behind the models. Each of the three lesson topics addresses a portion of the larger process and contains specific learning objectives.
Target Student Population: Undergraduate
Prerequisite Knowledge or Skills: Students will need to have a basic understanding of calculus (differential equations). Students will also be expected to have read the text assignments on this topic.

Evaluation and Observation

Content Quality

Rating: 5 stars

  • Good combination of the math behind exponential and logistic growth and applications.
  • Nice animations and stories linked to the topic.
  • Very relevant to most introductory biology courses.
  • The lesson requires students to work with data from hypothetical situations to illustrate exponential and logistic growth curves.
  • The lesson includes manipulating data tables, graphs, and using the equations that describe growth to calculate specific parameters.
  • Questions asked throughout lessons help student get feedback on understanding of concepts/process.
  • Animations clearly connect the different parts of each process into a coherent whole.

  • None

Potential Effectiveness as a Teaching Tool

Rating: 4.5 stars

  • Written at an appropriate level for most undergraduates.
  • Questions are interactive, and more than just multiple choice, there are also boxes for students to enter calculations, and some matching.
  • Questions get at fundamental understanding of population equations and their application to solve real problems.
  • Manipulation of data as part of lesson makes it an excellent learning tool.
  • Clearly demonstrates relationships between elements of each concept.
  • The site can be used in several ways—as a direct teaching tool in a distance learning course, as a lecture outline, as a review and study tool for students after topic covered in class.
  • Some of the questions asked promote problem solving by student.
  • Some of the questions asked will be very challenging for introductory students.

  • Completion of plans for links to assessments and image/animation data bases will greatly enhance the usefulness of the site.
  • The math required may be beyond the skill level of many students.

Ease of Use for Both Students and Faculty

Rating: 4.5 stars

  • Well organized, no dead links, load quickly.
  • Could easily make assignments based on the tutorial.
  • Instructions clear, especially when manipulating components and entering animations.
  • Instructors manual available; summarizes the contents of each of the lesson topics.
  • Glossary available for selected terms.

  • Somewhat frustrating to navigate once you are in a section, it would be nice to have a linked outline of some sort.

Other Issues and Comments: This series of lessons has outstanding potential for use by faculty and students everywhere. The concepts are broken down to simple parts and then reassembled by an interactive process and use of data manipulation.

Creative Commons:
Creative Commons License
This work is licensed under a Attribution-NonCommercial-NoDerivs 3.0 United States