Explain a feedback between life and Earth

How can organisms change the environment that later shapes life?

Submit: An evidence record, explanation and revision.

Related lesson: Climate and Earth Systems

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

Life responds to environmental conditions and also changes them. Oxygen-producing photosynthesis altered Earth’s atmosphere over geological time, while oxygen reacted with reduced materials and did not accumulate instantly. Later oxygen availability changed opportunities and constraints for organisms. A feedback account needs both directions and an ordered evidence-based history.

Evidence and model inputs

Source reading task: NASA’s early-oxygen research account describes evidence from ancient shale and changes in ocean oxygen. Build an evidence chain for photosynthetic organisms → oxygen production → reactions and eventual atmospheric accumulation → altered conditions for organisms. Distinguish the biological origin of oxygen from the timing and complexity of its accumulation.

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

One well-supported coevolution example; a comprehensive account of all Earth–biosphere mechanisms is not required.

Do the work

1. Read the source and record an observation or geological evidence example supporting a stage in the history.
2. Draw a timeline with broad sequence rather than unsupported exact dates.
3. Create two arrows: biosphere changes atmosphere/geosphere; changed environment affects the biosphere.
4. Explain why an oxygen source does not imply immediate high atmospheric oxygen when sinks also exist.
5. Evaluate a one-way claim that Earth shapes life but life never changes Earth, using the evidence chain and a limitation.

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. What does coevolution mean in this context?
2. Why might oxygen fail to accumulate immediately?
3. Is a feedback merely two unrelated events?
4. Does this one example explain every Earth–life interaction?

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. Uses source evidence in a sequenced history.
2. Explains biological effects on an Earth system.
3. Explains environmental effects on life.
4. Includes sinks, timescales and limits in a feedback argument.

Sources and standard reference

• Official NGSS HS-ESS2-7 performance expectation — inspect the practice, core idea, crosscutting concept and assessment boundary.
• NASA: evidence of early oxygen

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.