Evaluate three possible responses to environmental change

Why can the same environmental change have different biological outcomes?

Submit: An evidence record, explanation and revision.

Related lesson: Biodiversity and Conservation

This is a teacher-led extension beyond the short lesson. The task supplies a performance opportunity; completion alone does not certify mastery, full NGSS coverage or state alignment.

Build the idea

Environmental change can favor some populations, reduce others, or contribute to extinction. If populations become isolated and diverge over many generations, reproductive isolation can arise and new species may form. A short-term abundance increase is not speciation, and local disappearance is not automatically global extinction.

Evidence and model inputs

Original scenario cards: A, a drought favors an already drought-tolerant plant while competing plants decline; B, a new barrier separates a population, and later observations show accumulated inherited differences and failure to interbreed under appropriate conditions; C, all populations of a range-restricted species lose suitable habitat and repeated broad surveys find no survivors. These are hypothetical evidence chains, not documented extinction announcements.

Keep actual observations, published findings and invented model cases labeled separately. If a source or required equipment is unavailable, pause that part with a teacher; do not invent results.

Materials and preparation

Paper, graph paper or spreadsheet, and the linked readings.

Grade-level scope

Use supported causal arguments, not claims that a single short observation proves speciation or extinction.

Do the work

1. Map each card to abundance change, possible speciation or possible extinction.
2. Build an evidence–mechanism explanation including variation, reproduction, isolation or habitat dependence as appropriate.
3. List evidence missing before claiming a new species or global extinction.
4. Compare alternative explanations such as seasonal absence or temporary separation.
5. Revise a deterministic claim that every environmental change creates a new species.

Learner worksheet

Write on paper or type here and print. Entries stay in this page’s memory and are lost when you leave or reload; they are not saved or submitted.

Check your reasoning

1. Does A demonstrate speciation?
2. Is a barrier alone proof of speciation?
3. Is one empty survey proof of extinction?
4. Must all species respond in the same way?

Teacher review guide

Review the actual deliverable and discuss the reasoning. For each criterion, use 0 when evidence is absent or fundamentally incorrect, 1 when partly supported with a material error or omission, and 2 when accurate, supported and complete for the stated task. Maximum 8 points is a task score, not a proficiency certification. Give feedback and allow revision.

1. Distinguishes all three possible outcomes.
2. Uses evidence and evolutionary mechanisms.
3. Evaluates alternative explanations and missing data.
4. Avoids intentional or inevitable-change narratives.

Sources and standard reference

• Official NGSS HS-LS4-5 performance expectation — inspect the practice, core idea, crosscutting concept and assessment boundary.

Instructional text and hypothetical cases are original. Linked source readings supply published evidence where specified. Teachers should judge fit with their course and state requirements.