Unit Plan 32 (Grade 7 Science): Adaptations & Survival
Use math—fractions, ratios, percentages, and graphs—to show how trait variations influence survival rates, shaping population adaptation over generations.
Focus: Use mathematical representations (tables, ratios, percentages, graphs) to support explanations of how trait variations affect population survival and long-term adaptation.
Grade Level: 7
Subject Area: Science (Life Science — Biological Evolution & Adaptation • Quantitative Reasoning)
Total Unit Duration: 5 sessions (one week), 50–60 minutes per session
I. Introduction
In this unit, students build on their understanding of natural selection and adaptation by adding a strong mathematical lens. Instead of only describing which traits seem helpful, they collect and analyze numerical data about survival and reproduction in model populations. Using ratios, fractions, percentages, and graphs, they quantify how different traits change the survival chances of individuals and the trait frequencies in a population. By the end, students use these mathematical representations as evidence to support explanations aligned with MS-LS4-6.
Essential Questions
- How can numbers and graphs help us see how trait variations affect survival in a population?
- Why does a small difference in survival rate for a trait matter when you look across many generations?
- How can we use fractions, ratios, and percentages to compare how different traits influence population survival?
- In what ways do mathematical representations make explanations about adaptations and survival clearer and more convincing?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Describe trait variation in a model population and identify which traits may influence survival in a given environment.
- Collect or analyze numerical data (counts of survivors, offspring, trait frequencies) from a natural selection or survival simulation.
- Calculate fractions, ratios, and/or percentages to compare survival rates of different traits within a population.
- Create and interpret graphs (bar graphs or line graphs) that show how trait frequencies or survival rates change over time.
- Construct a clear Adaptations & Survival Math Explanation that uses mathematical representations to support claims about how trait variations affect population survival.
Standards Alignment — 7th Grade (NGSS-based custom)
- MS-LS4-6 — Use mathematical representations to support explanations of how trait variations affect the probability of survival and reproduction of individuals and population survival.
- Example: Compare survival percentages for different colored organisms in contrasting environments and explain which population is more likely to persist.
Success Criteria — Student Language
- I can record data about how individuals with different traits survive or do not survive in a given environment.
- I can use fractions, ratios, or percentages to compare survival rates between traits.
- I can make and read graphs that show how traits change in a population over several “generations.”
- I can use numbers and graphs as evidence in my explanation of how trait variations affect population survival.
- I can clearly explain how a small advantage in survival can lead to a big difference in which traits are common over time.