Evolutionary Relationships in Mammals (Genetics and Evolution)

Contributor
Victor Sampson & Sharon Schleigh
Type Category
Instructional Materials
Types
Student Guide , Instructor Guide/Manual , Lesson/Lesson Plan , Activity
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 is one of 30 lessons from the NSTA Press book Scientific Argumentation in Biology. The lesson engages students in an argumentation cycle in which they use evidence from their analysis of the amino acid sequences 1-40 for the hemoglobin subunit alpha protein for nine mammals (elk, caribou, cow, pallid bat, big-eared bat, golden hamster, mouse, musk shrew, and nine banded armadillo) to make an argument for which of these mammals are the most closely related. Students create a cladogram that shows the branching of lineages of the nine mammals. As they construct their argument, students build and apply knowledge of modern phylogenetics, which classifies organisms based on evolutionary history. The lesson includes an introductory reading on Darwin’s idea of descent with modification, an example of homologous structures in vertebrate limbs, and instructions on how to create a cladogram. Subsequently, students are asked to examine the relatedness of the 9 mammals, constructing their own cladogram, based on the amino acid sequence 1-40 for the hemoglobin subunit alpha protein. Students strengthen their understanding that common ancestry and biological evolution are supported by multiple lines of empirical evidence by reading about homologous structures in vertebrate limbs and using the amino acid sequences as evidence to make their argument for relatedness. Teachers are encouraged to refer to the preface, introduction, student assessment samples, and appendix provided in the full book for important background on the practice of argumentation and resources for classroom implementation.

Intended Audience

Educator and learner
Educational Level
  • High 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

HS-LS4-1 Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence.

Clarification Statement: Emphasis is on a conceptual understanding of the role each line of evidence has relating to common ancestry and biological evolution. Examples of evidence could include similarities in DNA sequences, anatomical structures, and order of appearance of structures in embryological development.

Assessment Boundary: none

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

Comments about Including the Performance Expectation
Students should be familiar with the principle of descent with modification, phylogenetics, and how to create a cladogram, before starting the activity. In the lesson students are asked to answer the question “Which of these mammals are the most closely related?” Students apply their understanding of phylogenetics to create a cladogram to answer the question. As students prepare their initial arguments with claim, evidence, and justification of evidence, and again as they write their final individual argument to answer the question, they communicate scientific information that common ancestry and biological evolution are supported by evidence from amino acid sequences, in this particular case amino acid sequences 1-40 for the hemoglobin subunit alpha protein for nine mammals. The preface, introduction, student assessment samples, and appendix of the full book provide the teacher with background on how to support students in their small group work and class discussions as they progress through the argumentation cycle. The opening reading for this particular lesson is long and information-dense. Teachers should consider providing support for students to help them make sense of the reading. Teachers can use partner reading strategies, such as the “Think Aloud” routine. With this routine, one student is reading aloud and at the same time comments on what they are thinking as they are processing the text, while the other student listens, comments, and asks questions. Students can also mark up the text with comments and questions as they read, or they can use a reading log (e.g. a T- chart with one column titled “Important ideas and information from the text” and the other column titled “My thoughts and questions”). Teachers can also assign paragraphs to students to read aloud, and ask volunteers to restate what was being read, and encourage students to ask questions of what was being read.

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
By engaging in the argumentation cycle, answering their research question (Which of the mammals are most closely related?), providing a claim, supporting the claim with evidence from the data (using amino acid sequences 1-40 for the hemoglobin subunit alpha protein for nine mammals to create a cladogram), and then justifying their evidence, students both construct an explanation based on evidence and engage in argument from evidence. Students begin to work in small groups, creating their whiteboard with claim, evidence, and justification of the evidence, and then share their arguments with others. Utilizing what they learned through this process, students then individually construct a written argument to answer the question.

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

Comments about Including the Science and Engineering Practice
As students analyze the amino acid sequences 1-40 for the hemoglobin subunit alpha protein for nine mammals and create a cladogram, they are essentially constructing a model of the relatedness between these 9 mammals. Like all models, cladograms contain approximations and assumptions in representing relatedness. In this case, the relatedness is based only on the similarities and differences of the amino acid sequences 1-40 for the hemoglobin subunit alpha protein, which limits the validity and predictability of the model students create. As students share their cladograms and the associated arguments for relatedness with each other, the teacher can help students see that models are only approximations of the phenomena, and that there is more than one way to construct a model (cladogram) based on the how one interprets the evidence. One way of doing that is asking students to evaluate the merits and limitations of two different models (cladograms), both describing the relatedness of the same system of 9 mammals, and have a discussion of which of the models best fits the evidence, and why, or whether there are several different potential models (cladograms) that fit equally well. This activity also provides the opportunity to point out that as models are based on evidence, models need to be modified when new evidence is uncovered that the model cannot explain.

Disciplinary Core Ideas

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

Comments about Including the Disciplinary Core Idea
This lesson explicitly addresses the disciplinary core idea by asking students to use evidence from their analysis of the amino acid sequences 1-40 for the hemoglobin subunit alpha protein for nine mammals (elk, caribou, cow, pallid bat, big-eared bat, golden hamster, mouse, musk shrew, and nine banded armadillo) to make an argument for which of these mammals are the most closely related. Teachers should support students in making connections between the amino acid sequences, their cladogram and their argument for relatedness, by asking probing questions, encouraging students to ask questions of each other, and using the argumentation framework/cycle provided. A helpful resource for students to learn about how DNA sequences can be used to generate phylogenetic trees from DNA sequences is a “Click and Learn” activity from Howard Hughes Medical Institute. This Click and Learn explains how DNA sequences can be used to generate phylogenetic trees, and how to interpret them. http://www.hhmi.org/biointeractive/creating-phylogenetic-trees-dna-sequences

Crosscutting Concepts

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

Comments about Including the Crosscutting Concept
When constructing their cladogram and making their argument for which of the 9 mammals are most closely related, students use patterns of similarities and differences between amino acid sequences 1-40 for the hemoglobin subunit alpha protein for nine mammals as empirical evidence to determine the relatedness of the 9 mammals. Due to the large number of data, students may need support on how to approach making the multiple comparisons between each of the amino acid sequences 1-40 for the hemoglobin subunit alpha protein for the nine mammals to identify and use the patterns to construct their cladogram and make their argument. Talking with students about the use of the patterns in the data also provides a good opportunity for teachers to help students make connections to the nature of science.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This lesson engages students in the practice of argumentation and modeling and the crosscutting concept of patterns in order to make sense of the phenomenon of relatedness of 9 mammals, based on their amino acid sequences 1-40 for the hemoglobin subunit alpha protein. As students examine the data, construct their cladogram, and prepare and make their argument to answer the question, “Which of these mammals are the most closely related?” they are actively engaged in a practice (modeling) to make sense of the disciplinary core idea of evidence of common ancestry, while being confronted with the importance of a crosscutting concepts (patterns) to help them create their model. Teachers are advised to familiarize themselves with Sampson and Schleigh's argumentation framework, suggested teacher behaviors, and assessment approaches before implementing this lesson in the classroom. While other lessons in the book do not include instructional materials that directly present the core concepts targeted by the lesson, this particular lesson includes background information on decent with modification and construction of cladograms.

  • Instructional Supports: This lesson engages students in the scenario of making an argument for relatedness based on authentic molecular evidence, an approach that scientists use in their work in the real world. Starting with the context of nine mammals, and asking the question of how they are related, motivates students to engage in the task in order to find an answer to the question. The activity builds on students’ prior knowledge during the introduction, when it makes the connection of shared anatomical features, something students should be familiar with, to the molecular evidence for relatedness. The information on homologous structures, molecular evidence, and how to create a cladogram is grade-appropriate and accurate. Throughout the activity, students have multiple opportunities to compare their own thinking with the thinking of their small group members and others in the class. The argumentation cycle utilized in the lesson, allows students to express, clarify, justify, interpret, and represent their ideas and respond to peer and teacher feedback, both orally, and in writing with their final individual written argument. The lesson does not include guidance for teachers on how to support differentiated instruction, connect instruction to the students’ home, neighborhood, community and culture, or how to support English language learners or students who have special needs. The preface, introduction, assessment chapter, and appendix of the full book provide critical instructional support information for teachers who wish to implement this lesson. Successful implementation requires skillful facilitation by the teacher throughout the argumentation cycle.

  • Monitoring Student Progress: Constant monitoring and feedback are built in to Sampson and Schleigh's argumentation framework, which elicits direct, observable evidence of three-dimensional learning at multiple points throughout the lesson, relying on skillful teacher interactions with students. An assessment rubric and a scored sample rubric are provided. Supportive teacher questioning is critical to student success in this and similar lessons. Teachers should monitor and provide feedback to students as they construct their cladograms and initial arguments, present and critique arguments, and draft final written arguments. Teachers can also model and guide students in providing constructive peer feedback. Teachers should consider allowing students to revise and improve final written arguments based on teacher and peer feedback.

  • Quality of Technological Interactivity: This is not a technology-based lesson. Technology may be incorporated in supporting instruction. For example, students can use the Click and Learn activity that explains how DNA sequences can be used to generate phylogenetic trees, and how to interpret them. http://www.hhmi.org/biointeractive/creating-phylogenetic-trees-dna-sequences