Compare industrial and sustainable agriculture, evaluate the environmental trade-offs of the Green Revolution and pesticide use through biomagnification, and state the current science on genetically modified crops plainly.
The Green Revolution of the mid-20th century -- high-yield crop varieties, synthetic fertilizer, irrigation, and pesticides, closely associated with agricultural scientist Norman Borlaug -- dramatically increased global grain yields starting in the 1940s through the 1960s and is widely credited with preventing mass famine as world population grew. It came with real trade-offs: heavy reliance on fertilizer and pesticides, water-intensive irrigation, reduced crop genetic diversity from widespread monocultures (connecting back to Week 10), and dependence on fossil fuels for both machinery and fertilizer production (connecting back to Week 9's Haber-Bosch process).
Persistent pesticides introduce a pattern that runs opposite to the energy flow you learned in Week 3 and Week 5: biomagnification. While energy is LOST at roughly 90% per trophic level, a persistent toxin like DDT instead CONCENTRATES at each step, because predators eat many contaminated prey and store the toxin in their tissue rather than losing it as waste. On genetically modified (GM) crops, the current science is worth stating plainly: major scientific bodies, including the National Academies of Sciences, have found approved GM foods on the market are not more risky to eat than their conventional counterparts. Separate from that food-safety finding, genuine and ongoing debates exist about herbicide-resistant weeds evolving in GM cropping systems, seed patenting and cost, and other economic and ecological questions -- real, open issues distinct from the safety-to-eat question.
Mastery looks like: They can calculate biomagnification through several trophic steps, correctly contrast it with the trophic energy pyramid, and state the GM food safety science and a separate non-safety concern accurately and distinctly.
Common stumbles: Mixing up which direction concentration increases (persistent toxins up, energy down); conflating the food-safety question about GM crops with separate economic or ecological questions.