210 likes | 458 Views
Artificial Selection. Exploring Biotechnology & GMOs. What is Artificial Selection?. What words come to mind when you think of Artificial Selection ?. What is Artificial Selection?. A process in which humans consciously select for or against particular features in organisms.
E N D
Artificial Selection Exploring Biotechnology & GMOs
What is Artificial Selection? • What words come to mind when you think of Artificial Selection?
What is Artificial Selection? • A process in which humans consciously select for or against particular features in organisms. • For example, humans may select only organisms with a desired feature to reproduce or provide more resources to the organisms with the desired feature. • This process causes evolutionary change in the organism and is similar to natural selection only with humans, not nature, doing the selecting.
AS Example: • Pigs are artificially selected by man to produce the largest amount of meat
AS Example: • Animal breeders • Peed in racehorses, milk production in cows, trail scenting in dogs.
Over the years, the plants with desirable characteristics are grown by man and their numbers increase. Meanwhile, plants without these characteristics are less likely to survive as they are not provided with the fertilizers and pesticides by man. • Eventually, the species of the plant will evolute. • What may be an example of this?
GMOs &Artificial Selection • GMOs: Genetically Modified Organisms • Crop plants created for human or animal consumption using the latest molecular biology techniques. • Biotechnology: Application of scientific and technical advances in life science to develop commercial products
How to create GMOs • Traditionally: breeding • time consuming • often not very accurate
How to create GMOs • Genetic engineering • Create plants with the exact desired trait very rapidly and with great accuracy. • For example: plant geneticists can isolate a gene responsible for drought tolerance and insert that gene into a different plant. The new genetically-modified plant will gain drought tolerance as well.
Did you know? • Genes can be transferred from one plant to another and from non-plant organisms. • The best known example is the use of B.t. genes in corn and other crops. • B.t., or Bacillus thuringiensis, natural bacterium that produces crystal proteins that are transferred into corn self produce pesticides
Let’s engineer our own crop • http://www.pbs.org/wgbh/harvest/engineer/transgen.html
How prevalent are GM crops? • Thirteen countries grew genetically-engineered crops commercially in over a decade, the U.S. produced the majority. • 68% of all GM crops were grown by U.S. farmers. In comparison, Argentina (23%), Canada (7%) and China produced (1%). • Other countries that grew commercial GM crops: Australia, Bulgaria, France, Germany, Mexico, Romania, South Africa, Spain, and Uruguay.
How prevalent are GM crops? • 40 plant varieties commercialized by the government including: tomatoes, cantalopes, soybeans • Not all these products are available in supermarkets yet the prevalence of GM foods in U.S. grocery stores is more widespread • Highly processed foods and its ingredients mixed with genetically modified ingredients
What are some advantages of GM Foods? • Pest resistance/Herbicide tolerance/ Disease resistance • Cold tolerance/Drought tolerance/salinity tolerance • Reduced Maturation time • Nutrition • Pharmaceuticals • Phytoremediation
What are some criticisms against GM foods? Environmental hazards • Unintended harm to other organisms • Reduced effectiveness of pesticides • Gene transfer to non target species Human health risks • Allergenicity • Unknown effects on human health Economic concerns
What’s your stance? • Selective breeding of agricultural crops can benefit populations in less-developed countries by producing hardier crops, increasing food supplies, and improving the nutritional content of food. However, opponents of artificial selection technology believe that it affects the natural ability of a species to reproduce, which negatively affects biodiversity.
What’s your stance • Brainstorm with your group key points for your argument • Support your points with facts and examples • Try this: Vote Online - Should we grow GM crops? • Debate next class!
Food for thought • Genetically-modified foods: Good or bad? • solve many of the world's hunger and malnutrition problems • help protect and preserve the environment • Proceed with caution to avoid causing unintended harm to human health and the environment.