Primary Type: Lesson Plan
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 43470
Back to the Past with the Geologic Time Scale
This lesson introduces the geologic time scale and the concept of time segments being divided by major events in Earth's history. It gives students
an opportunity to place various fossils into appropriate periods, observe the change in the complexity of fossils and draw conclusions regarding the
change. Students complete a brace map including the eras and periods showing their understanding of parts to the whole within the geologic time
scale. On day 2, students research an organism of their choice and trace it back to their most basic relative. Students then create a final product,
such as a brochure, timeline or a poster, demonstrating the change of the organism over time. Students will be provided with a rubric that will guide
them while they work on the final product.
Subject(s): Science
Grade Level(s): 7
Intended Audience: Educators
Suggested Technology: Document Camera,
Computers for Students, Internet Connection, Basic
Calculators, Overhead Projector, Microsoft Office
Instructional Time: 2 Hour(s) 30 Minute(s)
Resource supports reading in content area: Yes
Freely Available: Yes
Keywords: geologic time scale, fossils, fossil record, era, period, history of Earth
Resource Collection: CPALMS Lesson Plan Development Initiative
ATTACHMENTS
Geologic Time Scale Reference Chart.docx
Geologic Time Scale Project.xls
Geologic Time Scale Brace Map Key.docx
Geologic Time Scale worksheet(1).docx
History of the.docx
Geologic Time Scale worksheet answer key (1).docx
LESSON CONTENT
Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
Students will be able to explain and diagram the divisions of time in the history of life on Earth. They will become familiar with the vocabulary used to name each of the
time segments. Students will demonstrate that the geologic time scale does not divide the age of Earth into equal parts as our clock or calendar does. Students will be
able to explain that the divisions of the geologic time scale depend on events in the history of the Earth. Students will explain that the types of organisms living on Earth
changed over long periods of time according to the evidence provided by the fossil record.
Prior Knowledge: What prior knowledge should students have for this lesson?
Students should be familiar with the concept of fossils, relative and absolute age of rocks, layers of Earth, continental drift, Pangaea, and the concept of creating time
lines.
Students should have prior experience with thinking maps, specifically brace maps. However, the teacher should review the concept of brace maps before students
page 1 of 4 start their independent work.
Guiding Questions: What are the guiding questions for this lesson?
Did humans and dinosaurs live on Earth at the same time?
How is the age of life on Earth measured in the geologic time scale?
How does physical evidence support scientific theories that Earth has evolved over geologic time due to natural processes?
Teaching Phase: How will the teacher present the concept or skill to students?
Teacher will pose a question: Did humans and dinosaurs live on Earth at the same time? (The answer is "No").
Teacher will wait for students to respond and start a class discussion.
Ask students questions about how old the earth is and when did life first appear on Earth?
What kind of living things were there?
Ask specific questions such as, were the animals of today around when Earth first formed?
When did reptiles start appearing? When was the first human on Earth?
If they already hypothesized that animals have changed over time, then ask, why?
What is different about Earth now, than it was then? Based on student responses, the teacher will be able to see if students are familiar with scientific vocabulary
related to the Geologic Time Scale. Students may bring up the Flintstones or the Jurassic Park, Ice Age, or the Land Before Time.
The teacher can then talk about how we have been figuring out how old the Earth is based on our collection of fossils and where they have appeared in rock
formations. Scientists have pieced together a history of Earth based on these and other findings.
This will be a great starting point to introduce the geologic time scale reference table.
Geologic Time Scale Reference Chart.docx
Ask students to take a few minutes to review the chart before asking questions.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
Teacher will explain the organization of the geologic time scale by asking probing questions, such as "What is the name of the period we live in right now?" or "Which
segment of time lasted the longest amount of time?"
Next the teacher should hand out the Geologic Time worksheet and review the questions. Ask students how they might go about answering the questions to determine
if they understand what they are being asked to do.
Question #1: Students should focus on the time divisions between the eras and subtract to find out how long each era lasted (Mesozoic Era lasted 185 million
years, because 251 - 66 = 185).
Question #2: Students create a pie chart to show the percentage of time each Era of geologic time represents in the geologic time scale. A pie chart is used to
compare the different parts that make up a whole amount. Students use the data they have input in the data table in #1 to create the pie chart. 100% = 360
"degrees". 1% = 3.6 "degrees". Students can use a protractor to create a pie chart. Other students may be able to estimate the size of each section on the pie
chart without using the protractor. (75% is 3/4 of the circle, 12.5% is about 1/2 of the remaining pie. 75+12.5=87.5 which is acceptable for 88%)
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the
lesson?
Day 1: Students will complete the worksheet questions 1 - 5 and complete a thinking map.
Geologic Time Scale worksheet.docx
Geologic Time Scale worksheet answer key (1).docx
Geologic Time Scale Brace Map Key.docx
Day 2: Each student will choose an animal or another organism and will trace it back to their most basic relative. Students use computers with internet access to
research the evolutionary path the organism made through geologic time. The teacher may provide links to the websites to save time and to ensure quality research.
Some links are provided below. Sites for students should be free of ads and should be from research sites if at all possible.
The final product can be a brochure, a timeline, or a poster.
History of the.docx
Students will have an opportunity to finish the project at home and use the rubric to guide them as they work on the project.Geologic Time Scale Project.xls
The point of this activity is to find how the animals they are familiar with have changed over time. Some discoveries will be made that students will be surprised to
find. Some suggestions to research would include dogs, cats, alligators, shark, manatees, dolphins, horses and even a chicken.
Horse: http://www.amnh.org/exhibitions/past-exhibitions/horse/the-evolution-of-horses
Dogs: http://www.pbs.org/wgbh/evolution/library/01/5/l_015_02.html
Cats: http://en.wikipedia.org/wiki/Cat
Alligators: http://news.sciencemag.org/sciencenow/2013/03/ancient-alligator-ancestors-unea.html (this site has ads)
Birds: http://www.pbs.org/lifeofbirds/evolution/
Manatees: http://www.manateebrain.org/07evolution/
Sharks: http://www.shark.ch/Information/Evolution/
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
page 2 of 4 This entire lesson is designed to assist students in organizing their knowledge of the geologic time scale. The brace map, the data table and the pie chart will help
students to organize their knowledge.
In addition, from the final product students will be able to put a story together regarding the history of Earth. Animals have changed over time as evidenced by the
fossil record. All animals (and all living things) have changed at different times and at different rates.
Summative Assessment
The activities in this lesson will lead to summative assessment and demonstrating mastery including:
Students are able to interpret the geologic time scale by understanding that each segment lasted various amounts of time.
Students will be able to use the reference chart to calculate the length of time of each of the Eras and Precambrian Time.
Students will be able to complete the pie chart that shows the proportion each of the segments of time represents in the entire age of the Earth.
Students will demonstrate their understanding of the organization and relationships of the Eras and Periods in the Geologic Time Scale by completing a thinking
map.
The completion of the brace map shows that students understand the parts to the whole relationship in the geologic time scale.
Students will place fossils of various organisms in the correct Periods using the reference chart.
Students are able to make observations regarding the complexity of the fossils as we move through the geologic time scale from Precambrian Time to present and
draw a conclusion based on their observations.
Each of the 5 questions on the activity sheet is worth 20 points.
Formative Assessment
The teacher will walk around, spot-check students' work and ask probing questions if students are not progressing adequately. Sample questions:
How will you calculate the amount of time each of the time sections lasted?
Do we need to focus on the time divisions between the periods or eras in order to complete the data table in #1?
Do you remember what a pie chart shows?
Do you remember what a brace map looks like?
If multiple students are having the same reoccurring difficulty, the teacher can stop the independent work session and address the whole class to clarify the issue.
Feedback to Students
The teacher will ask probing questions regarding interpreting the Geologic Time Scale Reference Chart, filling out the data table, setting up the pie chart, and filling out
the brace map. Students will have an opportunity to ask their teacher to look over their progress and to identify errors during the lesson before they turn their
completed assignment in.
ACCOMMODATIONS & RECOMMENDATIONS
Accommodations: Students will be able to use a protractor and a calculator to complete the pie chart.
Students will get teacher's assistance to complete the calculation and the pie chart if necessary. A template of a brace map can be provided if necessary.
Students can be paired up if necessary to assist in the calculation and creation of the pie chart as well as diagramming of the brace map.
The teacher can control the reading level by printing out selected articles for research for low level readers.
Extensions: Students can be challenged to provide another way to present the geologic time scale besides the pie chart and the brace map.
Students may say that the geologic time scale could be represented by a bar graph, a layered cake or stairs.
Encourage creative and innovative analogies.
Students can be asked to make a model of the geologic time scale based on their analogy.
Suggested Technology: Document Camera, Computers for Students, Internet Connection, Basic Calculators, Overhead Projector, Microsoft Office
Special Materials Needed:
Day 1: Prepare copies of the geologic time scale worksheet for each student. Provide a class set of the geologic time scale reference chart. Each student will need a
blank piece of paper to complete the thinking map. Art supplies can be available for students who would like to add color or drawings to their thinking maps and pie
charts.
Day 2-3: Students will have computers with internet access to research an organism of their choice and trace it back through the geologic time to its most basic
relative. Students then work on a final product such as a brochure, a timeline or a poster to show the change of the organism over time as seen in the fossil record.
Further Recommendations: This can be an introductory lesson to the geologic time scale unit or a single lesson unit based on your curricular needs.
Additional Information/Instructions
By Author/Submitter
Students will be able to understand the "big picture" of the geologic time scale only after one lesson! Use this lesson plan as an introduction to the geologic time scale unit or
as a single lesson unit based on your curricular needs.
page 3 of 4 MAFS.K12.MP.1.1 Make sense of problems and persevere in solving them.
SOURCE AND ACCESS INFORMATION
Contributed by: Slavka Roselip
Name of Author/Source: Slavka Roselip
District/Organization of Contributor(s): Brevard
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
SC.7.E.6.4:
MAFS.7.RP.1.2:
Description
Explain and give examples of how physical evidence supports scientific theories that Earth has evolved over geologic
time due to natural processes.
Recognize and represent proportional relationships between quantities.
a. Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or
graphing on a coordinate plane and observing whether the graph is a straight line through the origin.
b. Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of
proportional relationships.
c. Represent proportional relationships by equations. For example, if total cost t is proportional to the number n of
items purchased at a constant price p, the relationship between the total cost and the number of items can be
expressed as t = pn.
d. Explain what a point (x, y) on the graph of a proportional relationship means in terms of the situation, with special
attention to the points (0, 0) and (1, r) where r is the unit rate.
Remarks/Examples:
Examples of Opportunities for In-Depth Focus
Students in grade 7 grow in their ability to recognize, represent, and analyze proportional relationships in various
ways, including by using tables, graphs, and equations.
Attached Resources
Teaching Idea
Name
Description
The Earth is 4.6 billion years old. That's a hard number to conceptualize. What does 4.6 billion look like, and what
happened during all those hundreds of millions of years between the formation of our planet and now?
This BLOSSOMS lesson will help students conceptualize the enormity of geologic time and learn about important events
in Earth's history. Students will also learn how geologic time can help explain seemingly incomprehensible processes, like
the formation of the Himalayan Mountains from a flat plain to their current height, and the evolution of a tiny group of
reptiles into enormous dinosaurs.
MIT BLOSSOMS - Geologic
Time: The Ticking of Our
Planet’s 4.6 Billion Year Clock: The lesson will take approximately 45 minutes. Students should have a basic understanding of biology, and a familiarity
with geology is helpful but not necessary. The supplies required include a measuring tape that is at least 5 meters long,
a 5 meter long piece of string, ribbon, or rope, index cards or other stiff pieces of paper, and calculators.
During the breaks, students will construct a geologic timeline of their own in the classroom and do simple calculations to
determine how long amounts of time can lead to impressive changes in the height of the Himalayan Mountains and the
size of a group of reptiles.
page 4 of 4