From Ecosystems To Speciation
Time: 8 classes, 45-50 min each
Introductory High School Biology
Students will develop an understanding of how populations interact with each other within a community, discussing ideas concerning carrying capacity, competition, and interdependence. From there students will use models to explain the connection between genetic drift, natural selection, and speciation.
Lesson 1: Students will gather information from real-world case study (the Isle Royale wolf & moose ecosystem) and develop questions about factors that might be influencing population size changes.
Lesson 2: Students will look at single population of organisms and investigate how population growth is influenced by limiting factors such as resources. Using this NetLogo model they will be able to visualize some of the factors that lead to the formation of a carrying capacity for organism within a defined area. Students will then simulate how carrying capacity is affected by the introduction of a predator to the system and will also be able to see the dynamic interaction between these two organisms over the course of a large time scale.
Lesson 3: Students will describe how consumer/producer interactions for limited resources necessary for survival leads to the emergence of a competition for those resources, even when there is no intentional effort being made by individuals to outcompete each other.
Lesson 4: Students will explain how populations indirectly compete against each other, by applying the concepts of stability and change in population sizes over time, direct and indirect interactions between individuals, and immediate and delayed outcomes in two different ecosystems, each more complex than those modeled previously computer.
Lesson 5: Students experiment with a population of bacteria growing in an environment with sugar as an energy source. The population of bacteria consist of different types represented with different colors. Different types of bacteria have different number of flagella; however, in this model there is no selective advantage of having more number of flagella. Students explore this model to investigate the phenomenon of genetic drift. They discover that even though there is no selective advantage of having more or less flagella, eventually only one type survives in the population. This happens because of statistical selection, also referred to as genetic drift.
Lesson 6: In this activity students engage in simulated natural selection to discover how natural selection emerges from mechanisms: a) variation in heritable traits in a population and b) interactions in the environment give individuals with some variations a competitive advantage over other individuals. Another purpose of this lesson is to describe the outcome of natural selection as an increase in the proportion of individuals with advantageous heritable trait variations in a population over multiple generations.
Lesson 7 and Lesson 8: The purpose of the activities in these lessons is to understand how new species can form from old species through the mechanisms of evolution covered so far in the unit (mutation, genetic drift, changes in environmental conditions, and natural selection).
- Life Science
- [HS-LS4] Biological Evolution: Unity and Diversity
- [HS-LS2] Ecosystems: Interactions, Energy, and Dynamics
- NGSS Crosscutting Concept
- Stability and Change
- NGSS Practice
- Using Models
- Conducting Investigations
- Analyzing Data
Computational Thinking in STEM
- Modeling and Simulation Practices
- Using Computational Models to Find and Test Solutions
- Using Computational Models to Understand a Concept
- Computational Problem Solving Practices
- Troubleshooting and Debugging
- Data Practices
- Analyzing Data
- Manipulating Data
- Visualizing Data
- Systems Thinking Practices
- Investigating a Complex System as a Whole
- Thinking in Levels
- Understanding the Relationships within a System
Computational Thinking in Science and Math
Lesson 1: Introduction to Ecosystems and Models