Natural Selection

Concord Consortium
Type Category
Instructional Materials
Interactive Simulation
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.



Students are introduced to the concept of interdependence in an ecosystem and its effect on the evolution of populations through a family of rabbits that include five offspring: one small rabbit, three medium sized rabbits, and one large rabbit. Each size of rabbit eats a different type of grass. All three types of rabbits are thriving in the environment until a dam is introduced. The dam reduces the amount of water that flows into the bottom half of the environment. The grass that the large rabbit eats needs less water, so the large grass and large rabbit continue to do well in the environment. The small and medium-sized grasses need more water to thrive, so they begin to die out, causing the population of the small and medium-sized rabbits to die out. When students remove the dam, they observe the ecosystem slowly return to its original state. A Teacher's Guide link can be found near the the download button. The guide includes lesson plans, answers to the questions in the activity, and detailed instructions on using the features of the simulation. This activity is number eight out of a ten part series of evolution readiness education activities by the Concord Consortium.

Intended Audience

Educational Level
  • Grade 5
  • Grade 4
  • Grade 3
  • Upper Elementary
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

3-LS4-2 Use evidence to construct an explanation for how the variations in characteristics among individuals of the same species may provide advantages in surviving, finding mates, and reproducing.

Clarification Statement: Examples of cause and effect relationships could be plants that have larger thorns than other plants may be less likely to be eaten by predators; and, animals that have better camouflage coloration than other animals may be more likely to survive and therefore more likely to leave offspring.

Assessment Boundary: none

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

Comments about Including the Performance Expectation
Running the simulation presents evidence that students can use to construct an explanation for why the larger rabbit survived and the smaller rabbits begin to disappear from the ecosystem below the dam. At the end of the simulation, the dam is removed, the small and medium grasses return, and the small and medium-sized rabbits begin to repopulate the area, which helps the students to see that they were correct about the cause-effect relationship. An optional way to use this resource is to project the simulation (page 4 of the activity) to the whole class and have students construct predictions about what is happening and why before starting at the beginning and completing the simulation in smaller groups. To more completely address the standard, the teacher would need to include information on characteristics that would give plants and animals advantages to finding mates and reproducing not included in this resource.

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
Since observing this scenario with a real rabbit population would take many years, this simulation offers the students a model that helps them describe what is happening (short answer and multiple choice questions embedded in the simulation) and to predict what will happen next. An extension of this activity could be that students could design their own natural selection simulation with another type of animal. This extension would satisfy the 'develop' portion of the Practice. The teacher should lead a discussion about what the limitations of the model might be, and what the simulation shows as well as what it is missing. When having that discussion, the teacher could bring in the crosscutting concept of systems by asking, "What components would this system have that are not shown in this simulation?"

Disciplinary Core Ideas

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

Comments about Including the Disciplinary Core Idea
Both the rabbit population and the grass population are affected by the change in the dam, which reinforces the core idea of how a change in the habitat affects the organisms living in the habitat. The suggested extension idea (having the students come up with a scenario with another type habitat and animal) would make the activity even a stronger fit for the Core Idea. Students could present their ideas to the class, which would give them a large variety of animal populations and habitat examples.

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
The components of the system (amount of water, grass, and rabbits) change as the dam is first added to the system, and then later removed. Teachers may need to explicitly deconstruct the term "ecosystem" to uncover that the relationships between the dam, plants, and rabbits are an interconnected system.

Resource Quality

  • Alignment to the Dimensions of the NGSS: The simulation supports students in making sense of how a variation in characteristics among individuals of the same species in an ecosystem (the size of the rabbit offspring) may have an advantage of surviving a particular environment (a change in the amount of water getting to the grass in the area). Since watching an actual population of rabbits over many years would not be practical, this model allows the students to see the effects that the change in the rabbits' environment has on the population in a short period of time. This simulation allows students to construct an argument based on their observations of the model and the embedded questions.

  • Instructional Supports: The simulation engages students in an authentic and meaningful scenario that reflects what would happen when there is a change in the environment in the real world. The resource poses the focus question "what makes a trait more likely to be passes on to a new generation?" driving the investigation, and student discourse to come to consensus at the end of the simulation. The resource develops understanding of the Disciplinary Core Idea by building on students' prior knowledge and provides opportunities to express their ideas to respond to peer and teacher feedback. The beginning of the lesson has an extended period a reading for this grade level, so teachers with struggling readers might want to do the activity whole-group on an interactive white board. Students are asked to respond to written questions throughout the activity, with answers to all questions available in the Teacher's Guide. The activity does feature some supports for differentiation: the simulation does give guidance to students that chose the wrong answer to a multiple choice question, highlighted vocabulary words can be clicked-on for a definition of that word, it gives hints when a student chooses a wrong answer, and a glossary is included. The use of a bar graph to show how many of each type of rabbit is in the environment at any given time is helpful to visual learners. Educators and students may use this resource as a Guest without registration, but in order to save student work and 'photos', a student must register and log-in.

  • Monitoring Student Progress: The simulation has short answer questions and multiple choice questions embedded into the simulation, but they probably do not contain enough information for the teacher to evaluate comprehension of the standard since there is not a variable for the student to manipulate in this activity. The dam is either there or it is removed from the environment. To more fully check for student understanding, the teacher could have the students create their own population/change in environment situation and introduce it to the class.

  • Quality of Technological Interactivity: The resource offers a digital simulation where students may change variables in the environment and observe the results of those changes with the support of quantitative charted data. Some immediate feedback is provided by the resource to the student but log-ins are required for the saving of work and student data.