Developing an Explanation for Mouse Fur Color

Contributor
Paul Beardsley
Type Category
Instructional Materials
Types
Article , Case Study , Data , 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

This lesson from HHMI BioInteractive is based on the classic study of the evolution of fur color in rock pocket mouse populations. It supports the short film, “The Making of the Fittest: Natural Selection and Adaptation.”  The creator uses the evolution of the fur color of the rock pocket mouse as the phenomenon for this activity and uses it to address three of the four mechanisms that contribute to population adaptation through natural selection. Students summarize the evidence for evolution by natural selection presented in the film and in figures from a scientific paper. The goal is to understand how to collect and analyze evidence that supports each of the major conditions for evolution by natural selection in order to develop a full explanation for how populations change over time.  This activity includes:  educator materials, student handout, additional evidence and an explanation table.

Intended Audience

Learner
Educational Level
  • High School
Language
English
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

HS-LS4-4 Construct an explanation based on evidence for how natural selection leads to adaptation of populations.

Clarification Statement: Emphasis is on using data to provide evidence for how specific biotic and abiotic differences in ecosystems (such as ranges of seasonal temperature, long-term climate change, acidity, light, geographic barriers, or evolution of other organisms) contribute to a change in gene frequency over time, leading to adaptation of populations.

Assessment Boundary: none

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

Comments about Including the Performance Expectation
The activity guides students through a series of questions that helps them figure how the rock pocket mouse population has shifted over time. At the end of this lesson students will use what they have learned in order to explain a difference in the color of the population. One concept a teacher could choose to incorporate more in this section is the idea that given the right circumstances the population could shift back. An example, for an extension activity that a teacher could include if the environment shifted again could be Color Variation Over Time Rock Pocket Mouse Populations also reviewed and found at: http://www.hhmi.org/biointeractive/color-variation-over-time-rock-pocket-mouse-populations

HS-LS4-2 Construct an explanation based on evidence that the process of evolution primarily results from four factors: (1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

Clarification Statement: Emphasis is on using evidence to explain the influence each of the four factors has on number of organisms, behaviors, morphology, or physiology in terms of ability to compete for limited resources and subsequent survival of individuals and adaptation of species. Examples of evidence could include mathematical models such as simple distribution graphs and proportional reasoning.

Assessment Boundary: Assessment does not include other mechanisms of evolution, such as genetic drift, gene flow through migration, and co-evolution.

This resource appears to be designed to build towards this performance expectation, though the resource developer has not explicitly stated so.

Comments about Including the Performance Expectation
The student activity addresses three of the four pieces of the performance expectation explicitly, however only briefly mentions competition for limited resources as it relates to the amount of space the mice have versus their rate of reproduction. Students use a chart in order to identify and document these four mechanisms of natural selection and later use this data as evidence to support their reasoning. As this lesson is designed to be completed in one class period discussion pieces are limited, however, a teacher could incorporate a more explicit component to address limited resources in order to deepen their understanding about natural selection. An example would be how limiting space be a resource and why would that be important. Another suggestion would be to ask students which of the four mechanisms was most responsible for the shift in fur color in order to argue from evidence. Students could engage in this practice and use the information from the movie as evidence to support their claim.

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
During the lesson students are asked to both use and represent data in order to figure out how the mechanisms of natural selection has played a role in species adaptation. As students go through this lesson they are asked to make claims and then use their data to back them up. As more information is introduced they incorporate this new data into their explanation and adjust their claim if necessary. To enhance this lesson a teacher could choose to use the additional data sets that are located on the website. This could be done is several ways including: (1) give the new data sets to all the student to analyze or (2) give groups of students a different data set and then have them share out what they have learned in order to incorporate a peer-to-peer learning opportunity.

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

Comments about Including the Science and Engineering Practice
The activity does address the full element of this practice and students will use the different ideas and data sets in order to create an explanation. Throughout the lesson students will make observations and analyze data from different sources in order to make a claim for natural selection. Students are asked to go back and revise their ideas after new information is given and to also consider what else they might need to know. At the end of the lesson students to apply what they have learned to a new situation. To enrich this lesson a teacher may want to add a discussion piece in order to make the students ideas public. This could also be an opportunity to have students argue from evidence. Allowing students to argue from evidence would also give the teacher a chance to check for understanding and common misconceptions. However this would potentially lengthen the lesson, as this lesson is meant to be taught in a 50 min time period. There are also other enrichment suggestions list in the educator guide.

Disciplinary Core Ideas

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
There is explicit evidence that this lesson addresses three parts of the performance expectation as written, however there is very little information about the limited resource. It is referenced in the video and in the chart (p 5 More offspring are born than can survive, resulting in competition among individuals within a population.) The questions call out the individual pieces of the three pieces within the element and then students use these pieces in order to build their explanation of adaptation. This lesson also addresses the misconception that it is not an individual's need to change that causes adaptation to appear in a population. To expand on the concept of adaptation, a teacher could also use the peppered moth scenario, as their population shift was also due to an environmental shift. This activity would reinforce the concept of (3)competition for an environment's limited supply of the resources that individuals need in order to survive and reproduce, as sometimes based on another population's need for resources.

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

Comments about Including the Disciplinary Core Idea
This lesson looks how natural selection occurs in a changing environment. Students view a short movie about the Rock Pocket Mouse and some additional data in order to figure out how a shift in their population occurred. Students discover how both (1) variation in the genetic information between organisms in a population and (2) variation in the expression of that genetic information -that is, trait variation- that leads to differences in performance among individuals. This lesson also incorporates how the predator/prey relationship plays a role in this evolutionary shift. To expand on this concept a teacher could choose to look at data sets from other populations. At the end of the lesson the author suggests looking at the biology of skin color in order to apply what what they have learned from the Rock Pocket Mouse to a new population. Another suggestion would be to look at the peppered moth population, that can be found at the following link: v https://www.biologycorner.com/worksheets/pepperedmoth.html

Crosscutting Concepts

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

Comments about Including the Crosscutting Concept
Although cause and effect relationships are investigated through the entire lesson, the teacher is not explicitly called to identify the cross-cutting concept of cause and effect in the lesson. This lesson does call out the common misconceptions that individuals can change based on needs or want and gives students data in order to correct this common misunderstanding using the data sets. In order to improve this lesson a teacher could explicitly call out the cause and effect relationships within this lesson and also address correlation versus causation. The shift (cause/effect) in the fur color was not due to the mice needing / wanting to change, but was due to the fact the light colored mice were more visible to predators leading to more dark colored mice surviving and reproducing. A teacher could also address correlation to environment; living on the dark lava did not cause the mice to become dark in color but instead just made them less visible to prey.

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

Comments about Including the Crosscutting Concept
Throughout the lessons patterns are explicitly called out in order for students to identify relationships within the data sets. Students then use this data to build understanding in order to develop an explanation of natural selection. They look at data at several scales looking at evidence from a macro (organisms) to micro (alleles) view in order to explain this phenomena. To emphasize the use of patterns, teachers may want to ask students how they are used at each scale within the system. A teacher may also want to introduce a new population to give students an additional point of reference when it comes to using patterns within the same system at different scales.

Resource Quality

  • Alignment to the Dimensions of the NGSS: The creator uses fur color of the rock pocket mouse as the phenomenon for this activity and uses it to address each of the mechanisms that contribute to population adaptation through natural selection. Throughout the lesson students are asked to use the three dimensions in concert with each other in order to build a explanation for this phenomena. Students gather and analyze data to identify patterns in order to identify cause/effect relations leading to a change in an organism's population. They use this information to build an explanation for adaptation through natural selection and then apply what they have learned to another population of mice and human skin color. In order to improve this lesson a teacher could choose to use explicit language about the cross-cutting concept of cause and effect. This lesson identifies cause and effect relationships, however never directly calls out the process or addresses causation versus correlation. A teacher could easily address this by having a class discussion about how the shift (cause/effect) in the fur color was not due to the mice needing / wanting to change, but was due to the fact that the light colored mice were more visible to predators leading to more dark colored mice surviving. A teacher could also address correlation to environment; living on the dark lava did not cause the mice to become dark in color but instead just made them less visible to prey.

  • Instructional Supports: The educator material includes specific steps a teacher could take in order to provide student support. There is also a recommendation as to how to support the topic of evolution to ensure that different worldviews are respected and a link to the reading, Cultural and Religious Sensitivity Teaching Strategies, is included. There is a Spanish version of the print materials as well as a transcript of the video. The lesson includes several extension options as well as optional data sets, however no specific instructional supports are given for English Language Learners or students with special needs. In order to meet the needs of all your students a teacher could add additional supports including: a transcript of the video broken into sections as a reference so students that may struggle with listening skills may refer back, allow students who may need extra time to watch the video independently, and provide writing guides or graphic organizers for extended response questions. An example, for an extension activity that a teacher could include if the environment shifted again could be Color Variation Over Time Rock Pocket Mouse Populations also reviewed and found at: http://www.hhmi.org/biointeractive/color-variation-over-time-rock-pocket-mouse-populations

  • Monitoring Student Progress: As this is only a one day lesson, some of these monitoring pieces do not apply, however this activity does include an answer key. There are also several opportunities for teachers to gather formative assessment data. To more effectively monitor student progress, teachers may want to use a teacher checklist of ‘look fors’ when participating in a whole class discussion to identify student understanding and misconceptions, check student questions/ chart before letting them move to the next part and end the lesson with a quick quiz or exit ticket at the end in order to check for understanding.

  • Quality of Technological Interactivity: - none -