Lesson at a Glance | He Tirohanga Whakamua
Ngā Whāinga Ako | Learning Intentions
Students will know
- The Ecological Benefits of gene drive pest eradication: rapid recovery of endangered native birds (kiwi, kākāpō), forest canopy rejuvenation, and eliminating chemical 1080 poison drops.
- The Ecological Risks:
• Trophic Cascades: Unexpected food web shifts (e.g. stoat eradication causing mouse or feral cat population spikes).
• Transgene Escape: Accidental transport of gene-drive possums to Australia.
• Daisy-Chain Containment: Synthetic self-limiting drives that run out of fuel after fixed generations.
Students will demonstrate
- By constructing an ecosystem food web model showing pre- and post-gene drive predator release dynamics.
- By completing Section 5 of their Level 3 Biology Socio-Scientific Report Portfolio.
Do Now | Tīmatanga Whakaaro (10 min)
Food Web Ripple Effect Prompt:
"If we use a gene drive to eliminate 100% of ship rats from a forest ecosystem, will native birds immediately thrive, or could another predator step into the void?"
Unpack: In ecology, removing one species triggers a trophic cascade. Ship rats prey on native bird eggs, but they also compete with mice and provide food for feral cats. Removing rats might cause feral cats to switch to preying on native kiwi chicks, creating unintended ecological harm!
Ecological Benefits vs Risk Matrix (15 min)
- Prevents extinction of 25M native birds per year.
- Restores forest canopy species (rātā, kāmahi).
- Replaces chemical poisons (1080, brodifacoum).
- Trophic cascade predator switching.
- Cross-border accidental dispersal to native ranges.
- Daisy-chain drives & molecular kill switches.
📁 Socio-Scientific Report Portfolio — Section 5: Ecological Risk & Ecosystem Dynamics
Students open their Level 3 Biology Portfolio and complete Section 5:
Section 5 Requirements:
1. Food Web Impact Diagram: Draw an Aotearoa forest food web (native birds, lizards, insects, possums, stoats, rats, 1080 poison) showing ecological energy flows.
2. Trophic Cascade Analysis: Write a 2-paragraph analysis evaluating potential secondary ecological impacts of predator removal.
3. Excellence Containment Rationale: 1-paragraph explanation of Daisy-Chain Gene Drives (split drive components across loci) to enforce geographically self-limiting containment.
Exit Verification | Ka Mutu Hoki (5 min)
Exit Check:
"My Section 5 models food web cascades and evaluates Daisy-Chain gene drives as a biological risk mitigation strategy."
Teacher Planning & NCEA Alignment
NCEA Level 3 Biology Alignment (3 Credits Internal):
- Environmental Impacts: Evaluate ecological benefits, risks, food web interactions, and mitigation strategies.
- Ecosystem Modelling: Analyse population dynamics and trophic cascades.
Vocabulary: Ecosystem dynamics, trophic cascade, food web, invasive predator, Pest Free 2050, 1080 poison, daisy-chain gene drive, cross-border dispersal.