Transcript Pests and Pollinators & Genetically Modified Food - science-b

AP Environmental
Science
Mr. Grant
Lesson 62
Pests and Pollinators
&
Genetically Modified Food
© 2011 Pearson Education, Inc.
Objectives:
• Define the term seed banks.
• Discuss the importance of pollination.
• Describe the science behind genetically modified food.
• Evaluate the debate over genetically modified food.
• TED - The varieties of wheat, corn and rice we grow today
may not thrive in a future threatened by climate change. Cary
Fowler takes us inside a vast global seed bank, buried within a
frozen mountain in Norway, that stores a diverse group of
food-crop for whatever tomorrow may bring.
© 2011 Pearson Education, Inc.
Define the term seed banks.
Seed Bank: Place where seeds are stored for
short-term use in farming or for long-term
preservation.
© 2011 Pearson Education, Inc.
Discuss the importance of pollination.
• Insects and other organisms are essential for the
reproduction of many crop plants.
• Conservation of pollinating insects is vitally important
to our food security.
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We depend on insects to pollinate crops
• Not all insects are pests; some are absolutely vital
- 800 crop species rely on insect pollinators
• Pollination = male plant sex cells fertilize female sex
cells
- By wind or animals
• Pollinators include:
- Hummingbirds
- Bats
- Insects (bees, wasps, etc.)
Flowers are evolutionary adaptations to attract pollinators
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Conservation of pollinators is vital
Bees pollinate over 100 crops
and contribute $15 billion in
services/year
• Populations of pollinators (e.g., bees) have plummeted
• Colony collapse disorder = entire beehives have
vanished
- Unknown causes—Insecticides? Parasites? Stress?
• Reducing or eliminating pesticide use and planting
flowering plants will help preserve bees
© 2011 Pearson Education, Inc.
Describe the science behind genetically
modified food.
• Genetic modification uses recombinant DNA
technology to move genes for desirable traits from one
type of organism to another.
• Genetic engineering is both like and unlike traditional
selective breeding.
• GM crops may have ecological impacts, including the
spread of transgenes, an increase in chemical pollution,
and indirect impacts on biodiversity.
© 2011 Pearson Education, Inc.
Genetically modified organisms
• Genetic engineering =
laboratory manipulation of
genetic material
- Add, delete, modify DNA
• Genetically modified (GM)
organisms = organisms that
have been genetically
engineered by …
• Recombinant DNA = DNA
created from multiple
organisms
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Biotechnology is impacting our lives
• Biotechnology = the application of biological science to
create products derived from organisms
• Transgenic organism = an organism that contains DNA
from another species
- Transgenes = the genes that have moved between
organisms
• Biotechnology has created medicines, cleaned up
pollution, and dissolved blood clots
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Some genetically modified foods
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Genetic engineering versus agricultural
breeding
• Traditional breeding = changes organisms through
selective breeding of the same or similar species
- Works with organisms in the field
- Genes come together on their own
- Uses the process of selection
• Genetic engineering = mixes genes of different species
- Works with genetic material in the lab
- Directly creates novel combinations of genes
- Resembles the process of mutation
© 2011 Pearson Education, Inc.
Biotechnology is changing our world
• GM foods are a big business
• Most GM crops are herbicide
and pesticide resistant
- Large-scale farmers grow
crops more efficiently
- Most U.S. corn, soybeans,
cotton, and canola are
genetically modified
Globally, 14 million farmers grew GM foods on 134
million ha
© 2011 Pearson Education, Inc.
What are the impacts of GM crops?
• As GM crops expanded, scientists, citizens, and
policymakers became concerned
- Impacts on human health
• Concerns over escaping transgenes
- They could harm nontarget organisms
- Pests could evolve resistance
- They could ruin the integrity of native ancestral
races and interbreed with closely related wild
plants
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Genetic engineering has benefits and risks
• Environmental benefits of genetic engineering:
- Reduced use of chemical insecticides
- Increased no-till farming
- Decreased irrigation, deforestation, land conversion
• Negatives of genetic engineering:
- Increased herbicide use affects health and habitats
- Some GM fields support less biodiversity
• Precautionary principle = don’t undertake a new
action until the effects of that action are understood
© 2011 Pearson Education, Inc.
Evaluate the debate over genetically modified
food.
• Many people have ethical qualms about altering food
through genetic engineering.
• Opponents of GM foods view multinational
biotechnology corporations as a threat to the
independence of small farmers.
• Nations have adopted differing stances on GM foods.
© 2011 Pearson Education, Inc.
The GM debate involves ethics
• People don’t like “tinkering” with the food supply
• With increasing use, people are forced to use GM
products, or go to special effort to avoid them
• Multinational corporations threaten the small farmer
• Research is funded by corporations that profit if GM
foods are approved for use
• GM crops have not eradicated hunger
- GM crops do not focus on increased nutrition,
drought tolerance, etc.
The GM industry is driven by market considerations
driven by financial interests of corporations
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GMO producers are suing farmers
Corporations go to great lengths to protect their GM
investments
• Monsanto has launched 112 lawsuits against 372
farmers, winning an average $385,000 per case
- Monsanto sued Percy Schmeiser of Canada for
using its GM seeds without paying for them
- Schmeiser said the seeds blew onto his field from
adjacent fields
- The courts sided with Monsanto, saying that
Schmeiser had violated Monsanto’s patent
© 2011 Pearson Education, Inc.
The future of GM foods
• Europeans demand that GM foods are labeled
• U.S. consumers have mostly accepted GM crops
- They don’t realize most food contains GM products
• The U.S. sued the European Union before the World
Trade Organization for hindering free trade
• The Cartagena Protocol on Biosafety lays out
guidelines for open information about exported crops
- The U.S. has not joined
• Brazil, India, and China approve GM crops
© 2011 Pearson Education, Inc.
TED Video
Biodiversity warrior Cary Fowler wants
to save the world from agricultural
collapse, one seed at a time.
"For individual crop varieties, doomsday does come every day. We want
to put an end to that."
Cary Fowler: One seed at a time, protecting the future of food
(17:06)
© 2011 Pearson Education, Inc.