Presentation on theme: "Agriculture PART 2: Resistance & GMOs. Evolution and Chemicals Resistance (Bacteria) If an antibiotic is very effective it may kill 99.99% of all the."— Presentation transcript:
Agriculture PART 2: Resistance & GMOs
Evolution and Chemicals Resistance (Bacteria) If an antibiotic is very effective it may kill 99.99% of all the bacteria causing an infection. The weakest bacteria are killed first. The strongest bacteria are killed last. Out of 10,000 bacteria, only one will survive.
Evolution and Chemicals Resistance (Bacteria) If any bacteria survive and replicate, they will be the strongest ones. Over time genes for strength against the antibiotic spread in the population. Bacteria EVOLVE to be resistant to the antibiotic.
Evolution and Chemicals Resistance (Plants) Other organisms can go through the same process –The strongest insects survive pesticides –The strongest “weeds” survive herbicides
Evolution and Chemicals Resistance (Plants) The genes in a population change over time. Change in the genes in a population is called “Evolution.”
Evolution and Chemicals Ecological Impact of Resistance As chemicals become less effective, more are used to kill pests Harsher chemicals are needed for the same impact on pests Pests are evolving to be stronger separately from the rest of ecology Native species can be delicate in comparison
Pesticide application has the highest illness and death rate of any occupation.
What are GMOs “Genetically Modified Organisms” Scientists have spliced the DNA of these organisms in some way
GMO vs. Breeding Humans have modified plant genes through selective breeding –Best crop plants –We’ve done this for thousands of years Genetic Engineering involves inserting genes rather than waiting for variation or mutation to cause them We are inserting genes from sometimes unrelated organisms
Examples: (You do not have to copy these)
GMO Example 1 Decreasing Herbivory & Disease Bt Corn – has a gene to protect against a fungus that destroys the crop
GMO Example 2 Round-Up Ready Many crops (Soybeans) Easier to apply herbicides (Round-Up doesn’t harm the crop plant at all)
GMO Example 3 Improving the Product Including genes for vitamins to make a more nutritious crop Edible vaccines (still being developed)
GMO Example 4 Stronger Plant Insert a gene from a drought-tolerant plant Use less water or survive in saltier soil More potential crop land
Benefits/Costs of GMOs
Benefits of GMOs Increase efficiency & convenience Improves productivity while reducing the chemicals sprayed into the environment More food produced with fewer resources
Subjective Concerns “Not natural” Ethics: Are we over-stepping our bounds and playing God? What is the impact on human health by eating foods with these genes?
–Lectin producing potatoes Toxic to insects and nematodes May be allegedly toxic to mammals (rats had depressed immune system) –Corn strain Differences in kidney size and blood composition in rats –Allergy transfer Gene from Brazil nut was transferred to soybeans
Objective Concerns If GMOs grow wild, they may out-compete the native plants (extinction or changing the food web) Patented GMOs – Farmers cannot keep seed and replant Patented GMOs – If a GMO cross-breeds with a regular plant in a different field, the seeds cannot be kept!
What’s the best course? –Feeding/clothing a huge population –Keeping costs low enough for the poor –Sustainable agriculture (reduce harm to planet) You vote every time you eat something!!!
Enough food “Abundance, not scarcity, best describes the world's food supply. Enough wheat, rice and other grains are produced to provide every human being with 3,500 calories a day. That doesn't even count many other commonly eaten foods - vegetables, beans, nuts, root crops, fruits, grass-fed meats, and fish. Enough food is available to provide at least 4.3 pounds of food per person a day worldwide: two and half pounds of grain, beans and nuts, about a pound of fruits and vegetables, and nearly another pound of meat, milk and eggs- enough to make most people fat! The problem is that many people are too poor to buy readily available food. Even most ‘hungry countries’ have enough food for all their people right now. Many are net exporters of food and other agricultural products.”