Phylogenetic trees and the Classification of Fossils: How Should Biologists Classify the Seymouria?

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

This resource is from “Argument-Driven Inquiry in Life Science” by Patrick J. Enderle, Ruth Bickel, Leeanne Gleim, Ellen Granger, Jonathon Grooms, Melanie Hester, Ashley Murphey, Victor Sampson, and Sherry A. Southerland.

Students examine skeletal replicas or pictures of a Seymouria fossil as well as skeletons of a frog, lizard, pigeon, bat,  and rat to determine the evolutionary relationships of these organisms. They decide which characteristics of the specimens they will compare and how to quantify the differences and similarities in the skeletons.  From the data that they collect students  look for patterns about how the life forms have changed over time and construct an argument for how biologists should classify the Seymouria.  This 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.

A reading about phylogenetic trees and how they represent evolutionary relationships between species introduces the lab so that students should be able to construct a cladogram for the specimens in the lab.  

“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-LS4-1 Analyze and interpret data for patterns in the fossil record that document the existence, diversity, extinction, and change of life forms throughout the history of life on Earth under the assumption that natural laws operate today as in the past.

Clarification Statement: Emphasis is on finding patterns of changes in the level of complexity of anatomical structures in organisms and the chronological order of fossil appearance in the rock layers.

Assessment Boundary: Assessment does not include the names of individual species or geological eras in the fossil record.

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

Comments about Including the Performance Expectation
Students examine skeletal replicas or pictures of a Seymouria fossil, frog, lizard, pigeon, bat and rat to determine the evolutionary relationships of these organisms. They decide which characteristics of the specimens they will compare and how to quantify the differences and similarities in the skeletons. From the data that they collect they look for patterns about how the life forms have changed over time and construct an argument for how biologists should classify the Seymouria. A reading about phylogenetic trees and how they represent evolutionary relationships between species introduces the lab so that students should be able to construct a cladogram for the specimens in the lab. By doing this, students analyze and interpret data for patterns in the fossil record, compare it to living organisms, and see how life forms changed throughout the history of life on Earth. There is only one fossil specimen as a part of the lab. Having other specimens for students to examine might help them to see the diversity of life that existed instead of only comparing one fossil to five extant organisms. The lab does, however, help students to see how fossil forms are related to those living today and that some life forms are younger than others.

MS-LS4-2 Apply scientific ideas to construct an explanation for the anatomical similarities and differences among modern organisms and between modern and fossil organisms to infer evolutionary relationships.

Clarification Statement: Emphasis is on explanations of the evolutionary relationships among organisms in terms of similarity or differences of the gross appearance of anatomical structures.

Assessment Boundary: none

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

Comments about Including the Performance Expectation
Students examine skeletal replicas or pictures of a Seymouria fossil, as well as a frog, lizard, pigeon, bat and rat to determine the evolutionary relationships of these organisms. They decide which characteristics of the specimens that they will compare and how to quantify the differences and similarities in the skeletons. From the data that they collect they look for patterns about how the life forms have changed over time and construct an explanation for how biologists should classify the Seymouria to show how it is related evolutionarily to the other specimens. A reading about phylogenetic trees and how they represent evolutionary relationships between species introduces the lab so that students should be able to construct a cladogram for the specimens in the lab.

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
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 about how biologists classify the Seymouria. 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 analyze the data on characteristics of the skeletons to answer the question about how biologists should classify the Seymouria, 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
Students determine how they will quantify the differences and similarities in the specimens and make a data table. If they have not had experience in choosing the data that they will collect there may need to be some teacher guidance. This will also be the case if students have not had experience with constructing data tables. If they get to this point and struggle with the analysis, the teacher may want to provide them with some options of how to organize and analyze the data.

Disciplinary Core Ideas

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

Comments about Including the Disciplinary Core Idea
This lab engages students in the task of examining anatomical similarities and differences in one fossil and five organisms living today. After collecting data from skeletons of these creatures they construct an explanation about their evolutionary history and determine how biologists should classify the fossil, Seymouria. There is an introductory reading on phylogenetic trees and students can use this tool as a representation of the lines of evolutionary descent with the organisms they examined.

Crosscutting Concepts

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

Comments about Including the Crosscutting Concept
Students examine the structure of each skeleton in the activity and they compare and contrast them to infer evolutionary relationships. Function is not stressed in the lab, but could be incorporated by asking students what function they think each shared derived characteristic has and how it helped the organism to survive.

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

Comments about Including the Crosscutting Concept
After students collect the data on the six skeletons, they need to analyze it by looking for the patterns in the data. This helps them to see the relationships between the skeletal characteristics and to answer the question of how Seymouria should be classified. The practice of finding patterns in the data leads students to see how to reconstruct the evolutionary history and the infer lines of evolutionary descent. The way the activity is written for students emphasizes the idea of looking for patterns in the data, but explicit discussion by the teacher in this part of the lab will help students to internalize how this crosscutting concept is an essential part of the investigation.

Resource Quality

  • Alignment to the Dimensions of the NGSS: Students engage in three dimensional learning in this activity. The disciplinary core idea about comparing the skeletal characteristics of five living and one fossil organism is done through students planning and carrying out an investigation using skeletons or pictures of the organisms, 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: This resource does not have a technology component.