Fossil Record and Evolution

Initial Publication Date: July 3, 2015

Time required to complete this unit:

3 weeks, or 12.5 hours, or 750 minutes (estimated)

Please note this page may be edited at any time.

Earth Science Content:

Key Terms: paleontology, evolution, fossilization, fossil record, index fossil, taphonomy, cross-cutting relationships, unconformities, fossil succession, rock superposition, original horizontality, geologic time, relative dating, speciation, mass extinction, adaptive radiation


Our Earth has been around for approximately 4.6 billion years. Fossils, or rocks with evidence that life, show that life formed on Earth nearly four billion years ago. The fossil record helps scientists to understand the history of change over time. We find fossils such as sea shells, imprints of plants and animals, and burrows from worms that crawled through the soil long before man existed.

In the high Himalayan peaks we find fossils of life forms that lived in oceans long ago. In many places we see evidence that the Earth's atmosphere had to evolve before living things could live on land. In other places, the rock record reveals mass extinctions that occurred when environmental conditions changed so rapidly that organisms could not keep pace with the rate of change. All of these fossils tell us something about the evolution of life on our planet and the evolution of the planet itself. Due to the Earth's dynamic processes life has adapted to fit available niches. Coevolution occurs between the physical and chemical interactions of Earth's geosphere, hydrosphere, atmosphere, and biosphere. Today, life on Earth exists in a myriad of forms and occupies a wide range of environments. This unit takes us on a journey through the the rock record to learn how fossils document the history of life on Earth and how life on Earth has modified our planet.

Developed by the DIG Texas Blueprints Rio Grande Valley Development Team. Updated by Grace Musser, 2020.

Quick Links

Screen Shot 2020-06-29 at 1.39.58 PM.png
Screen Shot 2020-07-06 at 3.50.32 PM.png
TMM Logo-03-no-margin.png

Students will be able to (do)

  • Evaluate relative dating methods using original horizontality, rock superposition, lateral continuity, cross-cutting relationships, unconformities, index fossils, and biozones based on fossil succession to determine chronological order.
  • Analyze and evaluate a variety of fossil types such as transitional fossils, proposed transitional fossils, fossil lineages, and significant fossil deposits with regard to their appearance, completeness, and alignment with scientific explanations in light of this fossil data.
  • Evaluate the significance of the terminal Permian and Cretaceous mass extinction events, including adaptive radiations of organisms after the events.

Students will know

  • Scientific dating methods of fossils and rock sequences are used to construct chronology of Earth's history expressed in the geologic time scale.
  • Fossils provide evidence for geologic and biological evolution.
  • Taphonomy is the study of how fossils decay and become fossilized. Processes that affect organisms are disarticulation, dispersal, accumulation, fossilization, and mechanical alteration
  • Sedimentation, fossilization, and speciation affect the degree of completeness of the fossil record.


The activities we have selected are congruent with the Next Generation Science Standards (NGSS), and are arranged to build upon one another. Therefore, to follow the storyline we recommend that teachers complete the activities in the order provided. To open an activity in a new tab or window, right click the activity link and select the preferred option.

Deep History of Life on Earth

View Activity

Howard Hughes Medical Institute's (HHMI) biointeractive, the Deep History of Life on Earth, provides an overview of the 3 billion year history of life on Earth. The interactive emphasizes that deep time and Earth history are keys to understanding the present.

Instructional Strategies: Reading

Resource Type: Visualization (static visualization, animation, simulation)

Time Required: 50 minutes

Chanaging Planet: Past, Present, Future

View Activity

This video lecture is the first in HHMI's 2012 Holiday Lecture series on Changing Planet: Past, Present, Future. In his talk entitled, The Deep History of a Living Planet, Dr. Andrew Knoll describes life forms that have existed on our planet since its origin. The history of life in the fossil record represents the most recent 15 percent of the entire history of life on Earth. The deeper history is microbial. Life on Mars is addressed.

Instructional Strategies: Lecture

Resource Type: Visualization (static visualization, animation, simulation) , Video

Time Required: 88 minutes

The Fossil Record

View Activity

Students research the diverse fossils of the Cambrian-aged Burgess Shale, which was deposited in an ancient ocean. They build physical models of selected organisms and create a diorama to showcase their models. Students gain an appreciation of how the visual representation of life from Earth's early history is a combination of scientific knowledge and artistic interpretation.

Instructional Strategies: Modeling

Resource Type: Laboratory investigation, experiment or demonstration

Time Required: 120 minutes

Taphonomy: Dead and Fossilized is a physical board game; the player is a time traveler whose mission is to create the best fossil collection. The goal is teach about the process of fossilization.

Let's Go on a Field Trip!

Studies that examine how geologists think and learn about the Earth point to the value of field experiences in helping students develop practices that constitute geologic reasoning.

We encourage teachers to take students into the field as much as possible to help learners to see features that are important to professional practice. Indeed, many geoscientists report that fieldwork was a key factor influencing their choice of geoscience as a career. For your area, museums and geology departments at the local university or college may offer exhibits and tours, or there may be easily accessible fossil field trips or outcrop locations.


Oftentimes it is difficult to learn how to get into a geoscience career. Below we have curated resources and stories from several paleontologists to give students an idea about how one can become a paleontologist. We want to emphasize that being a geoscientist, including a paleontologist, is typically not about being the best in one's class or having a science-specific skillset--successful geoscientists usually are interdisciplinary, creative, and have perseverance even when things do not go according to plan.

Scaffolding Notes

Teachers develop their own individual plan for how they will teach the unit. The learning activities and educational resources in this unit are intended to complement other instructional activities led by the teacher. Many of the selected learning experiences provide links to excellent background preparatory materials, additional hands-on resources, teaching tips, and cross-curricular connections.

Teachers will need to create their own multimedia presentations, deliver lectures and assign ancillary work to their students in order to set the stage for effective use of the learning activities contained herein. Please be sure to allocate time to review the activities and background material prior to using the learning experiences in this unit and to probe students for their prior knowledge before starting an activity.

In addition, although some activities may incorporate assessments, teachers may need to create their own assessments to ensure that are appropriate for the students they teach.

Asterisks (*) indicate teacher resource and background information recommendations for activity support.


Next Generation Science Standards

We anticipate that students should be able to achieve the NGSS Performance Expectation(s) listed after completing the activities in this unit. However, we have not carried out educational research to verify this.

Additional Resources