Lab 17: Mechanisms of Evolution: Why Does a Specific Version of a Trait Become More Common in a Population Over Time?

Contributor
National Science Teachers Association
Type Category
Instructional Materials
Types
Lesson/Lesson Plan
Note
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.

Reviews

Description

Lab 17:  Mechanisms of Evolution:  Why Does a Specific Version of a Trait Become More Common in a Population Over Time? is one of a series of lab investigations for the middle school student from the book, “Argument-Driven Inquiry in Life Science:  Lab Investigations for Grades 6-8”.   Using the online NetLogo simulation, Bug Hunt Camouflage, students explore how the frequency of different versions of the body color of a bug causes a change in the population of bugs over time in two different environments.  From this, they then develop a model that explains how the trait became more common in the population over several generations.  Students then engage in argumentation with other groups in the classroom based on the data that they have collected from their investigation in the NetLogo simulation and their analysis of the data.  “Checkout Questions” are provided to facilitate student reflection on what was learned.  Students are assigned a short investigation report to finish processing their experience.  Significant background information is provided for teachers and to a lesser degree in the student hand-out in the introduction. The standards addressed in the lesson are also included in the teacher’s notes.

Intended Audience

Educator and learner
Educational Level
  • Grade 8
  • Grade 7
  • Grade 6
  • Middle School
Language
English
Access Restrictions

Available for purchase - The right to view, keep, and/or download material upon payment of a one-time fee.

Performance Expectations

MS-LS4-4 Construct an explanation based on evidence that describes how genetic variations of traits in a population increase some individuals’ probability of surviving and reproducing in a specific environment.

Clarification Statement: Emphasis is on using simple probability statements and proportional reasoning to construct explanations.

Assessment Boundary: none

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
The lab aligns very well with this performance expectation since students are participating in an online simulation where they determine what data about frequency of different versions of the body color of a bug they collect and how they analyze it. There are four different environments and the color of the bugs differs in terms of its hue, saturation and brightness and its heritable. Students design an investigation to determine the answer to the question “Why does a specific version of a trait become more common in a population over time?” After they analyze the data to see which bugs survive and reproduce better in a specific environment with a predator present, they develop a model, test it and see if they can make accurate predictions about how the bug color trait changes over several generations under different conditions. An argument is written in the form of claim, evidence and justification of the evidence and an argumentation session is held between groups in the class.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
After participating in the simulation, students are asked to develop a conceptual model to explain why a specific version of the body color trait becomes more common in the population over several generations. They then are asked to think about how this model can be used to explain other situations in nature.

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
This activity provides an opportunity for students to participate in argumentation. A simplified graphic organizer, “Argumentation Presentation on a Whiteboard” scaffolds students through the argumentation process. Students are given the chance to choose and develop their argument. Several questions are provided for the students to assess whether their argument is convincing, and students share their work with others in a round-robin format. During the round-robin, one member of the group stays with the group’s work and explains it to others, as they visit. The remaining group members go to other groups and listen and critique their arguments, resulting in a process during which every team evaluates each other’s work.

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
After students construct a data table that best helps them make sense of their data and think about the patterns they see, a scientific explanation is written based on the evidence. Students identify the guiding question, their claim, their evidence and their justification of the evidence. This is written on a whiteboard and used in the argumentation session of the activity. The protocol for writing an explanation is included in every activity in the book and is an excellent way to have students understand the process of how scientists report their findings after analyzing their data. The justification aspect, explaining why their evidence is important and how it relates to the claim, is important for students to articulate their thinking.

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
Instructions on how to complete the activity are provided to assist students in the design process for the investigation about traits in a population that they will carry out. Students decide how to plan their investigation with guiding questions and the NetLogo simulation. Teachers are encouraged to facilitate student development of a data table so students can realize the maximum benefit of an exercise in experimental design. If students are unfamiliar with the experimental design process, the teacher will need to provide instruction and model how to design good experiments and collect appropriate data.

Disciplinary Core Ideas

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
By using the Bug Hunt Camouflage simulation students are able to plan an investigation to test survival rates of bug color that is determined by genes in a population. As they run the simulation they are able to see that those that are camouflaged have a greater probability of surviving and reproducing than others when a predator is present. By switching the environment, a different variation of color survives and reproduces better in the population. Since students can simulate many generations they can see the distribution of traits change in the population of bugs and result in adaptations.

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
By using the Bug Hunt Camouflage simulation students are able to plan an investigation to test survival rates of bug color that is determined by genes in a population. As they run the simulation they are able to see that those that are camouflaged have a greater probability of surviving and reproducing than others when a predator is present. By switching the environment, a different variation of color survives and reproduces better in the population. Students then construct an explanation based on the evidence that they have collected and then argue their explanation with other groups in the class.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
In the lab handout, students are asked to think about the importance of looking for patterns in nature. As they run the simulation they find what patterns occur with population changes with different environmental backgrounds. The checkout questions include a question about why identification of patterns is useful in science and asks students to use an example from their investigation.

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
Students collect data to show how a change in environment, the cause, has an effect on the coloration of bugs in a population over time. This is not explained to the students in the lab, so the teacher will need to make it more explicit and add questions about cause and effect to the Checkout questions.

Resource Quality

  • Alignment to the Dimensions of the NGSS: Students engage in three dimensional learning in this activity. The disciplinary core idea about natural selection is done through students planning and carrying out an investigation using a simulation of different colored bugs in different environments, developing a model to explain their data, constructing an explanation based on finding patterns in that evidence and then arguing their claim. The disciplinary core ideas, practices and crosscutting concepts are integrated in what the students do in this lab.

  • Instructional Supports: By using student-collected data, this activity provides an excellent, scientifically accurate context in which students can engage in three-dimensional learning. Several guiding questions are provided to facilitate students through the experimental design process as well as the argumentation session. Students have opportunities to build on feedback from other students as to whether their answer to the research question is the most valid and acceptable, and there is scaffolding in the form of a graphic organizer support students.

  • Monitoring Student Progress: A “Checkout Questions” page is provided for a more immediate summative assessment (6 questions total). Students are also assigned a two-page “Investigative Report”. The report is divided into three sections and three major questions are provided for students to address in the report, which includes the results of their argumentation session. There is no rubric or sample answers provided.

  • Quality of Technological Interactivity: The simulation is older, but still includes the elements needed to have students construct and explanation about “natural” phenomena. One problem is that it was written in Java and will not operate on many web browsers. A fix for this problem is to download Netlogo which is free from https://ccl.northwestern.edu/netlogo/