HS-LS2-6
The standard
Evaluate the claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem.
Next Generation Science Standards
What this standard means
Students need to judge scientific arguments about ecosystem stability and change. They should look at a claim, check the evidence, and decide whether the reasoning explains why populations often stay fairly steady under stable conditions, but may shift after disturbances.
Mastery looks like comparing two explanations using data from food webs, population graphs, or case studies. Students can explain feedback, competition, predation, resource limits, and disturbance size. Common trouble spots are treating ecosystems as balanced forever, ignoring time scale, or listing evidence without explaining how it supports the claim.
Ways to teach it
- Give groups food web cards and disturbance cards, then have them predict which populations change, stay stable, or cause ripple effects.
- Ask students to write which claim is stronger after reading two short ecosystem arguments with different evidence quality.
- Use a one-page exit ticket with a population graph, a claim, and the prompt, What evidence supports or weakens this claim?
- Connect to local deer, algae blooms, wildfires, or invasive species by having students match news data to possible ecosystem shifts.
Plan a lesson for HS-LS2-6
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Related standards
- MS-LS2-4
Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
- 3-LS4-4
Make a claim about the merit of a solution to a problem caused when the environment changes and the types of plants and animals that live there may change.
- HS-LS4-5
Evaluate the evidence supporting claims that changes in environmental conditions may result in: (1) increases in the number of individuals of some species, (2) ...
- MS-LS2-2
Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems.