The History of Life
Unit Design
Submitted December 2005
In partial fulfillment of requirements for EDUC 422
Time Allotted: 10 50-minute class periods
Related Textbook Material: Glencoe Dynamics of Life Chapter 14
- Unit Overview (Page 2)
- (Page 10)
Appendix A (Page 12)
(back)
Appendix B (Page 16)
Exobiology Worksheet (front)
Exobiology Worksheet (back)
Appendix C (Page 18)
Unit Overview
In this unit, students will study the history of life on earth in preparation for a study of evolution and classification. They will gain a working understanding of the currently understood time scale of geology, including geologic dating methods and the fossil record. Students will become familiar with several hypotheses for the origin of life. This unit will come at the beginning of the second semester of an introductory Biology course for 9th and 10th grade students. Students have already covered the characteristics of life, cells, cancer, and genetics. This unit is the beginning of a larger unit on evolution and classification of life.
Purpose of Unit
The guiding question for the overall evolution unit is “How did we get here, the way that we are?” This portion of the unit address specifically the very early history of that question: “How and when did life appear?” It is also a very controversial topic that should engage the students’ interest.
Major Concepts
Learning Goals
Identify the different types of fossils and how they are formed.
Explain how fossils provide evidence about the nature of ancient life (Michigan Benchmarks LE III.4-1e)
Summarize the major events of the Geologic Time Scale.
Correlate the Geologic Time Scale with biological events.
Analyze early experiments that support the concept of biogenesis.
Relate hypotheses about the origin of cells to the environmental conditions of early Earth.
Sequence the steps by which small molecules may have produced living cells.
Compare and contrast modern theories of the origin of life.
Instructional Sequence
Day 1.
Instructional Objective: Introduce unit and establish purpose.
Procedure: Teacher introduces unit. Students locate and identify key terms in the text.
Resource Materials: Glencoe’s Dynamics of Life Chapter 14.
Evaluation: Have students turn in flashcards when completed.
Day 2.
Instructional Objective: Identify the different types of fossils and how they are formed.
Explain how fossils provide evidence about the nature of ancient life (Michigan Benchmarks LE III.4-1e)
Procedure: Teacher presents lecture notes while students complete accompanying handout. Students work on completing a worksheet that will be due for homework.
Resource Materials: PowerPoint notes from Glencoe’s Dynamics of Life, 14.1 with accompanying student handout. Worksheet from 14.1 (Glencoe).
Evaluation: Have students explain the differences between different types of fossils and the significance of these fossils for determining the history of the Earth.
Day 3.
Instructional Objective: Summarize the major events of the Geologic Time Scale.
Procedure: Student Inquiry—Relative Dating. Students mimic relative dating techniques through an interactive activity and relate the task to Geologic Dating.
Resource Materials: Relative Dating Activity.
Evaluation: Have students relate the dating techniques to geology and identify the key events of the history of the Earth.
Day 4.
Instructional Objective: Analyze early experiments that support the concept of biogenesis. Relate hypotheses about the origin of cells to the environmental conditions of early Earth.
Procedure: Teacher presents lecture notes while students complete accompanying handout (continued from Day 2). Students work on completing a Critical Thinking worksheet about the origins of life.
Resource Materials: PowerPoint notes from Glencoe’s Dynamics of Life, 14.2 with accompanying student handout. Critical Thinking worksheet.
Evaluation: Have students identify environmental conditions of pre-biotic Earth and explain the most common hypothesis for how life could have begun.
Day 5.
Instructional Objective:Correlate the Geologic Time Scale with biological events.
Procedure:Students watch video linking geology and biologic history while answering questions on an accompanying handout. Students discuss video and go through video questions together.
Resource Materials: Video (United Streaming). Guiding questions to accompany video.
Evaluation: Have students explain the relationship between major biologic and geologic events.
Day 6.
Instructional Objective: Relate hypotheses about the origin of cells to the environmental conditions of early Earth.
Procedure: Students review conditions of pre-biotic Earth and try to identify the biotic capabilities of a hypothetical meteorite’s originating planet. Students then play a game in which they must identify the home planet of a fictional character by analyzing the characteristics of several planets. Worksheet must be completed for homework.
Resource Materials: Meteorite data. Planet information. Worksheet.
Evaluation:Students should be able to distinguish conditions supporting life and conditions not supporting life.
Day 7.
Instructional Objective: Sequence the steps by which small molecules may have produced living cells.
Procedure: Teacher presents lecture notes while students complete accompanying handout (continued from Day 4). Students work on a worksheet to be completed for homework. Assign groups for project beginning the next day.
Resource Materials: Lecture notes from Glencoe’s Dynamics of Life 14.2 and accompanying handout. Worksheet for homework.
Evaluation: Have students explain the major concepts involved in the formation of cells.
Days 8-10.
Instructional Objective: Compare and contrast modern theories of the origin of life.
Procedure: Students work in groups to research different theories of the origin of life and present them to other groups in the form of a mock debate. Discuss and summarize results of each group on final day.
Resource Materials: Compilation of resources for each group. Assignment and Data Form.
Assessment Program
This unit will include two quizzes (part of a pattern of weekly Friday quizzes) whose intent is to assess student progress and understanding of a small portion of material before moving on to the next section. Graded assignments will also include a set of vocabulary flashcards to be completed during class on the first day of the unit, as well as three in-class worksheets, a small group activity, a lab write-up, and group evaluations from the debate. Each lesson will begin with a prior knowledge check through a Question of the Day (or What Do You Know?) that will be discussed as a group before beginning the lesson. Student response will be elicited throughout lecture presentations of notes to encourage participation and engagement in the learning process. Please see attached assessments for more detail.
Rationale
This unit has been designed as an introduction to the origin of life as scientists currently understand it. It will come at the beginning of the semester and will also be the students’ first introduction to me as a teacher. I have included a series of lecture notes that will be spread across portions of three different days during this two-week span of instruction. For every lecture, I will provide students with guiding notes to keep their attention and focus during a potentially disengaging activity. Most lessons will include a simple worksheet to check student understanding and to help them focus on important concepts as the material progresses. All assignments will be accompanied by class time students will be encouraged to utilize wisely. To keep the instruction from falling into monotony, I have designed several interactive lessons to engage student interest and participation. I have also taken into consideration the diverse learning styles of my students and have provided opportunities for them to work in groups on projects and to request additional assistance during class time when they have assignments to work on.
One overarching consideration of this unit is the fact that evolution and the origin of life is such a hot topic right now. I want to be very careful to respect my students’ personal beliefs about these issues without compromising the scientific integrity of the lessons. In the mock debate that I have designed, I hope that students will understand the fact that even among scientists there is debate and continuing discussion of these various theories. It will also give them the chance to explore a belief that may be different from their own, with the intent not of trying to convert them, but to provide them exposure to more theories so that they can better defend their own position. It is my hope that this unit will provide a solid foundation for a continuing study of evolution and other macro biology topics in the second semester of our course.
Barbara Fleming
Biology I
Romulus High School
2005-2006
Evolution: History of Life
Inquiry: Can I Get a Date?
Lesson Overview
This is a one-day lesson designed for first-year Biology students to acquaint them with the manner in which scientists use rock layers and fossils to determine relative dates on the geologic time scale. In this activity, adapted for a high school classroom from Barber and Bartos at Berkeley, students are asked to sequence cards with symbols representing fossils, arranging them in age order. They will then construct a model of the timeline the fossils lived in. With the aid of a guide, students will then assign each fossil to an era of geologic time. The activity should take a full 50-minute class period.
Purpose
The purpose of this lab is to help students understand how scientists use relative dating to analyze evidence of ancient life and the changes it has undergone.
Objectives
At the completion of this lesson, students should be able to show how fossils can be used to give relative dates to rock layers and how rock layers of known age can be used to identify the ages of fossils. This is related to Michigan Benchmark LE III.4-1(e): Explain how fossils provide evidence about the nature of ancient life.
Instructional Sequence
7 min. Class introduction.
8 min. Introduce lab activity and assign groups.
35 min.Conduct Inquiry and work on lab questions.
Materials
For each group of 2 students:
• Card Set
For each student:
• Lab worksheet
Student Prior Knowledge and Preconceptions
Students should have a basic knowledge of the structure of Earth and be aware of the fact that the surface of the planet has many layers. They should know what fossils are, how they form, and what evidence they provide for ancient life. Students should be familiar with the time scale of geology and be able to identify major eras and events.
Students may think that each rock layer would contain unique fossils without overlapping. They may think that rock layers are always straight and level so that relative dates are easy to find without “all this work.”
Instructional Activities
To introduce the lab, read the opening paragraph aloud (or have a student or two help out!). Explain briefly what students will find at their lab stations. Assign students in pairs to each lab station (larger groups or single participants can work if necessary, but two is optimal for this activity).
With the instructions provided at each lab station, students should be able to conduct the inquiry independently. Be available to help with questions and/or ASK questions to make sure that students are understanding the task. Before each group can move on to Part II, check the results from Part I. If they are struggling with Part I or are off task, remind them 10 minutes into the session to be wrapping up the first section so that they can finish the whole task during the class period.
Any work that is not completed in class should be assigned as homework.
Assessment
The primary assessment of student understanding of the concepts in the inquiry is the completed lab worksheet (see attached). Additional formative assessments will be made throughout the lab as students display the progress of their work to the teacher before moving on to the next section.
Resources
See materials.
Sources
Barber, M. & Bartos, D.S. Who’s on First? A relative dating activity.
Rationale
I chose to do this inquiry because I thought it would be an interesting way for the students to try their hands at some relative dating techniques. This seems to be a difficult topic on which to do much inquiry, so the experience is rather far-removed from first-hand. It is pushing the limit of being inquiry, but it does require more manipulation than most classroom activities. It is also a very simplified activity. I chose to use abstract images instead of real fossil pictures mostly because it was easier for me to create and name them, but also because I think that the fun pictures will be of more interest to the students than real fossil images. In making this decision, I am also committing myself to making explicit the link between the inquiry activity and real geologic dating techniques, which I will do in lectures surrounding this topic.
Barbara Fleming
Biology I
Romulus High School
2005-2006
Evolution: History of Life
Exobiology: What does a planet need to support life?
Lesson Overview
This is an interactive lesson. Students are asked at the beginning of class to analyze the characteristics of a meteorite to see if the originating planet could really support life. As a class, they will discover that there is not conclusive evidence for life on this planet. Now the class begins a role-play activity. The class represents a private detective agency that is searching for an escaped Marvin the Martian, accused of trying to blow up the Earth. Now that they’ve determined that life is not supported on Mars, they know that Marvin is an imposter and are trying to find his real home planet; to do so they must discover the properties of several newly discovered planets and analyze their ability to support life.
Purpose
There is a lot of interest in the media and in popular culture concerning the possibility of extraterrestrial life. This lesson gives the students a chance to explore this possibility in a fun and interactive manner while learning the science behind the field of exobiology.
Materials
Lesson Worksheets
Video
Learning Performances
At the completion of the lesson, students should be able to
- Identify the conditions necessary to support the development of life
- Differentiate between pre-biotic and biotic conditions
- Analyze data of planetary conditions to predict the possibility of life
Performances linked to Michigan Standards III.4: All students will explain how scientists construct and scientifically test theories concerning the origin of life; and V.4: We learn about neighboring and remote celestial bodies through our observations and exploration of space.
Instructional Activities
15 minutes Introduction
Open class with outline of activities for the day. Present Question of the Day (on the overhead): What are the characteristics of pre-biotic Earth that made it possible for life to develop? Sunlight, atmosphere, carbon, oxygen, source of energy, organic molecules, water. Call on enough students to get a sufficient number of correct responses. It is important that these ideas be fresh in the students’ minds for the forthcoming lesson, so allow for extra time to elicit any omitted responses and to explain alternative conceptions.
35 minutes Exobiology Worksheet
Introduce lesson by showing a video of Marvin the Martian. Pass out and explain the lesson worksheet (Exobiology: Where is Marvin?). Give students up to 20 minutes to complete. This should be more than enough time. If time permits, go through the answers as a class. The worksheet asks the students to use their knowledge of pre-biotic Earth to analyze data from a meteorite rock sample. They must write an explanation of why this rock could or could not have come from a life-supporting planet.
Assessment
Formative assessments will occur during the Question of the Day as students share their responses with the class and clarifications are made. These will of course depend on what responses are received. This assessment uses random selection to identify students who must respond, so it should induce all students to answer the question.
The homework will be graded on completion, but the answers will be carefully analyzed to determine what level each student is at in reasoning and communication abilities about the origin of life.
Sources
Rationale
I chose to do this lesson because I think that exploring the idea of extraterrestrial life is an interesting and engaging way for students to think about the issues surrounding the origin of life on Earth. This lesson fits as a transition point between the history of Earth and the origins of life, tying together these two ideas. I don’t like to lecture every day, so I designed this is a different sort of activity to get all of the students involved with the material.
Barbara Fleming
Biology I
Romulus High School
2005-2006
Evolution: History of Life
Origins of Life Debate Project
Lesson Overview
This lesson is designed to acquaint students with several of the various scientific theories on the origins of life on Earth. Rather than being presented by the teacher, students will be doing research and conducting a debate over two class periods in a Jigsaw format. Day one will find students collecting research in homogeneous groups (grouped by theory). Day two will feature heterogeneous groups in which the debates will occur. Each student will be responsible for submitting a completed chart summarizing the features of each theory.
Purpose
Evolution is a very controversial topic. It is debated in the news, in the court, and in religious circles. At the heart of this debate is the discussion of how life formed originally. This lesson exposes students not only to the science and religion debate, but also introduces conflicting theories among scientists. Hopefully, students will be engaged by the controversy.
Materials
Instructional Activities
The first day of this lesson is designed for students to do research on their assigned theory of life’s origin on Earth. The most prevalent theory has already been presented by the teacher, so the remaining theories will be divided up among the students. Based on an average class size of 25, groups will be designed to Jigsaw using 5 groups of 5 students each. All groups will be assigned at random to prevent students from feeling like they should be emotionally involved with the topic they will be advocating for. The five theories that will be addressed are creation by a Higher Power, exobiological transference, deep sea vents, RNA world, and the bubble hypothesis. These are all explored in the students’ textbooks, but they will be conducting research in the Media Center on computers. Students will each have a research collection form to fill out during class and receive a teacher signature as an exit-ticket. Students who are off-task or disruptive will receive a 0 for the day. All students doing research on the same topic are encouraged to work together as a scientific team, trying to convince others of their theory.
The second day, groups will be mixed so that one student from each theory is represented in each of the final groups. Each student in the group will be given an opportunity to convince his classmates that his theory is the correct one. He should present evidence to support the theory. Other students may ask questions or pose counter-arguments, but each student must have an opportunity to speak. To facilitate and assess this requirement, each student must fill out a Theory Organization Chart, which will include the essential information from each theory. This chart is due at the end of the hour.
Assessment
The primary assessment for this lesson is participation and the chart turned in at the end of the second period. This is designed to show the thoughtfulness of each student’s work. Some students may present incomplete information to their group. In that instance, the group members will be instructed to record that information on the chart and it will be verified by the teacher. Students will complete a brief group evaluation for each of the two groups they participate in.
Sources
Glencoe’s Dynamics of Life Chapter 14.
Rationale
I chose to design this lesson in this manner because I wanted to provide students with a way to deal with a potentially difficult topic. Many students resent having a teacher present a scientific theory with which they disagree for moral reasons, yet they are reluctant to say anything. In this lesson, students learn that it’s ok to disagree with scientific theories; scientists do it all the time! In fact, it’s how we learn new things. I have watched students debate in similar ways before and I know that this can be a difficult thing to do, but I think that this is a way for students to practice their scientific communication skills without the pressure of being in front of the class. I have also included a group evaluation form on which students can provide a confidential evaluation of group members in both assigned groups. This helps me get a better idea of what is happening in each group when I am not present.
