Unit Plan 33 (Grade 7 Science): Artificial vs. Natural Selection
Compare natural and artificial selection—how environments vs. humans choose traits, how technologies guide selective breeding, and how both processes drive adaptation.
Focus: Compare natural selection and artificial selection (selective breeding), explaining mechanisms of change, the role of humans and technology, and how both processes can lead to adaptation.
Grade Level: 7
Subject Area: Science (Life Science — Biological Evolution, Technology & Society)
Total Unit Duration: 5 sessions (one week), 50–60 minutes per session
I. Introduction
In this unit, students contrast natural selection, where the environment “chooses” traits, with artificial selection, where humans intentionally select traits through selective breeding and modern technologies. They examine examples like dog breeds, crop plants, and livestock, and compare them to examples of wild adaptation such as camouflage or beak shape. Through readings, case studies, and a simple breeding/simulation activity, students map out mechanisms of change, identify similarities and differences, and consider trade-offs and ethical questions around human influence on other species. The unit culminates in an Artificial vs. Natural Selection Comparison Explanation aligned with MS-LS4-5 and spiraling MS-LS4-4.
Essential Questions
- How are natural selection and artificial selection similar, and how are they different?
- How do humans and technologies influence traits in organisms through selective breeding and related methods?
- In both natural and artificial selection, how do trait variations and selection lead to adaptations over generations?
- What are some benefits, risks, and ethical questions that come with using technology to influence traits in other species?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Describe natural selection as a process where environmental pressures influence which traits become more common in a population.
- Describe artificial selection as a process where humans intentionally select organisms with desirable traits for breeding.
- Gather and synthesize information about technologies that influence artificial selection (e.g., selective breeding, artificial pollination, basic genetic techniques).
- Use examples and simple models (e.g., trait cards, simulated breeding) to compare mechanisms of natural vs. artificial selection and the resulting adaptations.
- Construct a written or oral explanation that clearly compares natural and artificial selection, supported by evidence from readings, data, or models, aligned with MS-LS4-5 and MS-LS4-4.
Standards Alignment — 7th Grade (NGSS-based custom)
- MS-LS4-5 — Gather and synthesize information about the use of technologies that influence artificial selection and the traits of organisms.
- Example: Research how humans bred crops for higher yield or dogs for specific behaviors.
- MS-LS4-4 (spiral) — Construct an explanation based on evidence that natural selection leads to adaptation of populations.
- Example: Explain how beak shape in birds changes across generations in a certain environment.
Success Criteria — Student Language
- I can define and describe both natural selection and artificial selection.
- I can give examples of traits that changed through natural selection and traits that changed through human selective breeding.
- I can identify at least one technology (like selective breeding programs or controlled pollination) that humans use to change traits in organisms.
- I can clearly explain similarities and differences between natural and artificial selection using evidence.
- I can write or present an explanation that shows how both processes can lead to adaptations over many generations.