Transcript Genetically modified foods by Tim Harding B.Sc

Genetically modified foods
by Tim Harding B.Sc.
1. What are they?
2. Are they safe to eat?
3. Are public concerns rational?
Brief history of DNA research
 1850s: natural selection and sexual selection (Darwin)
 1860s-90s: basic rules of genetics (Mendel)
 1910-13: genes arranged linearly on the chromosome
(Morgan and Sturtevant)
 1944: DNA identified as gene carrier
 1953: discovery of the chemical structure of DNA (Watson
and Crick)
DNA structure
Genetic code
Genetic modification
 evolution: natural selection and sexual selection
 human intervention: artificial selection
Artificial selection
 plant and animal breeding (long-term)
 mutagenesis (hit or miss)
 genetic engineering (short-term)
End result is the same = modification of genetic code
All DNA is safe to eat
 DNA is DNA – no ‘natural’ vs ‘artificial’ DNA
 biochemically and nutritionally the same
 only difference is in the genetic code i.e. sequence of the
bases G, C, T and A.
Current food regulations in Australia
 Australia has one of the most rigorous food safety testing
regimes in the world
 GE foods are tested even more rigorously than non‐GE foods
 principle of ‘substantial equivalence’
 foods certified as organic or biodynamic should not contain
any GE ingredients (according to voluntary organic food
industry guidelines)
GM foods
 all farmed foods
 all meats except for wild game and kangaroo
 farmed fish e.g. salmon
 all plant foods except bush tucker
 all cultivated mushrooms
GE foods
 cisgenesis (within the same species) or
 transgenesis (from different species)
 early 1990s: transgenic plant products (soybean, corn,
canola, and cotton seed oil)
 no GE whole foods available in Australia – why?
Objections to GE foods
 the appeal to nature fallacy
 alleged but unproven safety issues
 ideological concerns
 ecological concerns
Benefits of GE foods
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sturdy plants able to withstand weather extremes
better quality food crops
higher nutritional yields in crops
inexpensive and nutritious food
foods with a greater shelf life
food with medicinal (nutraceutical) benefits
crops resistant to disease and insects
produce that requires less chemical application