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Learning Interchange
National Writing Institute

Sunday, July 21, 2024

1.  Unit Title/Grade Level

Natural Selection
9th/10th Grade

2.  What do you want students to understand?

What are the fundamental understandings?

Life on Earth today is very unlike life on Earth in the distant past because environmental pressures have "selected" population members most fit to the changing environment.

What are the essential questions?

  • Why is life on Earth so different now than when dinosaurs lived?
  • If the environment changes dramatically, what might assure human survival?
  • As we create human survival advantages, how does this impact the survival advantage of other species?

What should students know?

  1. Tremendous variety exists among species members.
  2. Species have unlimited capacities to reproduce, but resources in a habitat are limited.
  3. Some members of a species are more able to compete for limited resources, therefore have a greater chance of survival and reproduction.
  4. Those species members who survive to reproduce pass on genes for favorable traits in that environment.
  5. As the environment changes, different genetic traits may be more favorable for survival.

What should students be able to do?

  1. Ask questions
  2. Develop models
  3. Conduct experiments
  4. Communicate understandings/results
  5. Analyze/interpret data
  6. Design solutions to problems
  7. Use technology and mathematics to investigate
3.  With which national content standards do the understandings align?
  • Life Science: Biological Evolution
  • Unifying Concepts and Processes: Evolution and Equilibrium
  • Science as Inquiry: Abilities necessary to do Scientific Inquiry
  • Information Literacy/Technology Standards: Access information; evaluate information; use information accurately & creatively; participate effectively as groups to generate information.

4.  What are the relevance and significance of these fundamental understandings?

  • Evolution is a major theory that accounts for the relatedness of organisms, the diversity of life on Earth, and the role that life has in terms of impacting the planet's physical environment. These are central concepts in biological science.
  • Since evolution is such a controversial subject it is an ongoing part of the lay person's dialogue. It is therefore important that students understand evolution as a theory.
  • While students often understand that there is genetic diversity among members of a species, they struggle more to understand selection. Many people interpret evolutionary selection as Lamarkian rather than selection among species members for inherent genetic traits that favor survival. This requires thorough investigation of the concepts and opportunity for students to dialogue to unearth their misconceptions.

5.  What is the context for this learning? (Prior and future understandings as well as developmental appropriateness)

Prior to this unit, students should have an understanding of the genetic basis of diversity (through mutation and recombination). This lays the foundation for the exploration of diversity among members of a species. After this unit, the teacher could choose to explore the evidence of evolution. If this is the theory, how do we know it is valid?

6.  Assessment - How will you know that the students have learned?

What summative performance assessment will be used to determine understanding?

Given a scenario, students will apply their understandings of natural selection to determine whether natural selection has occurred in the description. Students will be given the option of a variety of verbal or written performances.

What formative assessments will be used during the unit of study to assure that students develop the knowledge and skills required to reach understanding?

  • Other performances:
  • Written, oral or visual products in response to prompts:

Given pictures of various environments in which segments of a population are placed (isolated), students will identify which members (with given variations) will have selective advantage and describe what might happen given enough time in isolation.

  • Formal observations or interviews:
  • Teacher observation using a skill checklist during experimental work

  • Student exhibits or models:

Student models of population dynamics will be assessed against a rubric

  • Quizzes or tests:
  • Student self-assessments, logs, and peer reviews:

Learning logs to record information and internalize concepts related to natural selection

7.  What are the components (lessons/modules) of your unit and how will each component contribute to the learning of all students?

Consider the appropriate sequence to provide inquiry-based learning opportunities.

  • Variation Everywhere: In this activity cooperative groups select a human trait and measure that trait across the classroom. They will determine a way in which to represent their data graphically, and, based on that graphic representation, derive a statement about the trait to share with the class. As each cooperative group shares their findings, class members will use double entry journals to record findings (note taking) and to look at similarities among the groups' findings (note making). Finally, a whole-class discussion will focus on 1) variation among a variety of species and 2) advantages/disadvantages of variation among members of a species.
  • Population Pressure: Students are asked to briefly put their understandings of variation within a species "on the back burner" as they explore population growth. They are presented with a variety of population curves from various species. Their task is to develop a model that explains the population cycles. They then test their model by designing and conducting an experiment with selected species. Students share their models with two other teams and select the model (or merger of models) they think best explains population dynamics and submits to the teacher (assessment). Whole class discussion of submitted models consolidates classroom understandings of population dynamics.
  • Expanding the Model: Students are asked to add the concept of variation among members of a species to this model. They are asked to predict how variety impacts survivorship in this model. They then test the model through a series of traditional classroom activities on adaptive advantage. They use these activities to test the feasibility of their model. The "labels" of competitive advantage and natural selection are layered into the models.
  • Question of the Future: Students develop a product that describes how their model would predict future generations of this species. How would "competitive advantage" and "natural selection" influence the gene pool? They are given a choice of product: poem, mind map, skit or video commercial. In addition, students will complete a reading assignment that overviews these concepts and discuss their reading in small groups. In these small groups, they will summarize what they know and questions they still have. As a whole class, their knowledge and questions will be discussed.
  • Problem of Environment: Students will be posed with a problem. They will create a creature designed to best survive and reproduce in a given environment. Each group will be given a different environment. Students record in their double entry journals the reasons for their creature design (note taking). Then groups will switch environments and check survival advantage. As they move their creature from environment to environment, they record their findings in their double entry journals (note taking). Students will then be asked to individually make sense of their findings (note making) and submit their journal responses to the teacher. As a group, they expand their model to include their understandings from the entire unit, and they resubmit their model to the teacher.

Adapted from work by Grant Wiggins and Jay McTighe

Copyright 1997-2003
Career Connection to Teaching with Technology
USDOE Technology Innovation Challenge Grant
Marshall Ransom, Project Manager
All rights reserved.

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