Increased meat consumption has led to feedlot

This preview shows page 35 - 39 out of 91 pages.

Increased meat consumption has led to feedlot agriculture – huge warehouses deliver energy-rich food to animals living at extremely high population densities Concentrated Animal Feeding Operation (CAFO) A production process that concentrates large numbers of animals in relatively small, confined places. Structures and equipment (for feeding, temperature controls, and manure management) are substituted for land and labour. - Benefits Faster & greater production of food - uses less space - Drawbacks Major sources of water and air pollution Waste containment issues may cause human disease Antibiotics & hormones Unethical
Genetically modified organisms Transgenic organisms contain a gene inserted into its genome from a different organism to achieve a desired trait Recombinant DNA – DNA patched together from the DNA of multiple organisms Selective breeding – select phenotypes Splicing genes together Molecular markers help find genes of interest in the genome Enzymes are used to cut the gene The gene is amplified Incorporated into a plasmid Most GMOs are engineered for pest resistance, herbicide resistance, delayed rotting, better storage Higher yield, less waste, more nutritious Controversial topics Can genes escape into native populations? Can you patent an organism and control its distribution? Should GM food be labelled as such? Do they threaten natural species? Do they lead to biodiversity decline? Sustainable agriculture Does not focus solely on maximising productivity Recognising physical/hydrological limits to productivity Minimising negative impacts Involves: Conclusion
CHAPTER 9 Biodiversity provides goods and services o Provides food, shelter, fuel o Purifies air and water, detoxifies wastes o Generates and renews soil fertility o Pollinates plants, controls pests and disease o Maintains genetic resources o Provides cultural and aesthetic benefits o Allows us to adapt to change o Increases the stability and resilience of communities and ecosystems Organisms provide drugs and medicines Plants in response to herbivory, they produce a vast amount of medicinal drugs i.e. morphine Eco-tourism Acts as an incentive to preserve natural areas and reduce impacts on the landscape and on native species. It is particularly beneficial in developing countries. Deep ecology - Do other organisms have intrinsic value? Species diversity Definitions 1. Abundance – number of individuals 2. Richness – number of different species 3. Evenness – distribution of abundance over species Species richness There are three measures we can use to describe species richness: β –diversity – turnover in species from one local area to another = / β γ α α –diversity – number of species in a local area of homogeneous habitat γ –diversity – number of species in a large geographic area that comprises many habitats If the same species are found in different habitats over a wide area, then:
= and = 1 γ α β If different species are found in different habitats over a wide area, then: > 1 β Factors that drive species richness 1.

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture