Chapter 8

• Biological diversity or biodiversity is the variety of life, and refers collectively to variation at all levels of biological organization.
• The term biodiversity refers to the full abundance or variety of life – plant, animal and microbial. This variety of life occurs at all levels of ecological organization, but biodiversity generally refers to genetic, species and ecosystem diversity.
• Biodiversity is the foundation of human health.
• Threats to biodiversity: Habitat loss, overharvesting. invasive species, climate change
• Overharvesting Overhunting, overfishing and over-harvesting contribute greatly to the loss of biodiversity, killing off numerous species over the past several hundred years
• Exotic species are species that have been intentionally or unintentionally introduced by humans into an ecosystem in which they did not evolve
• These exotic species often undergo dramatic population increases in their new habitat and reset the ecological conditions in the new environment, threatening the species that exist there. When this happens, the exotic species also becomes an invasive species. Invasive species can threaten other species through competition for resources, predation, or disease
• Climate change, and specifically the anthropogenic warming trend presently underway, is recognized as a major extinction threat, particularly when combined with other threats such as habitat loss.
• Anthropogenic warming of the planet has been observed and is due to past and continuing emission of greenhouse gases, primarily carbon dioxide and methane, into the atmosphere caused by the burning of fossil fuels and deforestation.
• Biotechnology is a set of techniques that involves the use of biological processes and living organisms for industry, agricultural or other activities.
• biotechnology has four major industrial processes based on biological systems, namely cell and tissue culture, fermentation, enzyme technology, and genetic engineering – also referred to as modern technology.
• Genetic engineering or recombinant DNA (deoxyribonucleic acid) technology differs from other forms of biotechnology as it allows the isolation and transfer of genes coding specific characteristics between living organisms to produce a new living organism that expresses the desired characteristics of both organisms
• intended uses of GMOs: biomedical, farm/food animals, agriculture
• “GMO” (genetically modified organism) has become the common term consumers and popular media use to describe foods that have been created through genetic engineering
• Some Genetically Modified Organisms developed in the Philippines: Longer-lasting papayas, Protein enriched copra meal (PECM), Tomato Leaf Curve Virus (ToLCV)- resistant Variety, Bt corn
• Longer-lasting papayas Institute of Plant Breeding in UPLB developed delayed-ripening papaya that is resistant to ring-spot virus (PRSV). The initial project assisted by the Australian government developed a papaya variety with a 14-day shelf life, or double the usual 6 days.
• The Institute of Plant Breeding (IPB) of the University of the Philippines Los Banos (UPLB) has developed tomato breeding line resistant to tomato leaf curl virus (ToLCV) in the hope of reviving tomato’s robust production in the country.
• Tomato was the leading vegetable crop in the country in terms of area planted until 1990. The peak of decline in the area of production in 1997 was primarily due to pests and diseases as well as unfavorable climatic conditions especially during off-season months
• Bt corn in the Philippines was engineered to be specifically resistant to the Asian corn borer (ACB), Ostrinia furnacalis (Guenee), the most devastating corn pests in the industry. It was introduced as a “practical and ecologically sustainable solution” for poor corn farmers, a major bullet to combat poverty and improve livelihood.
• Genetic Contamination/Interbreeding. Introduced GMOs may interbreed with the wildtype or sexually compatible relatives. The novel trait may disappear in wild types unless it confers a selective advantage to the recipient. However, tolerance abilities of wild types may also develop, thus altering the native species’ ecological relationship and behavior.
• Competition with Natural Species. Faster growth of GMOs can enable them to have a competitive advantage over the native organisms. This may allow them become invasive, to spread into new habitats, and cause ecological and economic damage
• increased Selection Pressure on Target and Non-target Organisms. Pressure may increase on target and non-target species to adapt to the introduced changes as if to a geological change or a natural selection pressure causing them to evolve distinct resistant populations
• Ecosystem Impacts. The effects of changes in a single species may extend well beyond to the ecosystem. Single impacts are always joined by the risk of ecosystem damage and destruction.
• Impossibility of Follow-up. Once the GMOs have been introduced into the environment and some problems arise, it is impossible to eliminate them. Many of these risks are identical to those incurred with regards to the introduction of naturally or conventionally bred species. But still this does not suggest that GMOs are safe or beneficial, nor that they should be less scrutinized
• One risk of particular concern relating to GMOs is the risk of horizontal gene transfer (HGT). HGT is the acquisition of foreign genes (via transformation, transduction, and conjugation) by organisms in a variety of environmental situations. It occurs especially in response to changing environments and provides organisms, especially prokaryotes, with access to genes other than those that can be inherited.
• Loss of Management Control Measures. Regulatory approvals for field trials of GMOs often require measures to limit and control the release in space and time. With the spread of the introduced gene(s) to another species by HGT, a new GMO is created. This new GMO may give rise to adverse effects which are not controlled by management measures imposed by the original license or permit
• Long-term Effects. Sometimes the impact of HGT may be more severe in the long term. Even under relatively strong selection pressure, it may take thousands of generations for a recipient organism to become the dominant form in the population. In addition, other factors such as timing of appropriate biotic or abiotic environmental conditions and additional changes in the recipient organism could delay adverse effects.
• Antibiotic Resistance and Horizontal Gene Transfer. Most of the first generation of GM crops have antibiotic resistance gene as selectable marker. It has been hypothesized that such antibiotic resistance genes could lead to the innovation of oral doses of the antibiotic, or that these genes could be transferred to pathogenic microorganism in the gut or the soil which will render them resistant to such antibiotics.
• Pro-GMO researchers maintain that if crops are genetically modified for pest resistance, farmers can reduce their reliance on insecticides, so that local fauna, such as birds, rodents, and insects, can flourish in the area.
• e, GMO skeptics have argued that up to 75% of plant genetic diversity has been lost since farmers switched to uniform GM crop varieties. In this view, less popular, non-GM seed varieties are being neglected
• Studies of wildlife anatomy, physiology and biochemistry can lead to important developments in human medicine. Examples of species of interest to medical science include bears (for insights into osteoporosis, cardio-vascular disorders, renal disease and diabetes), sharks (osmoregulation and immunology), cetaceans (respiration and treatments for divers suffering from decompression sickness) and horse-shoe crabs (optometry/ophthalmology and molecular biology).
• Genetic engineering is a process that involves: 1. Identifying the genetic information or “gene” that gives an organism (plant, animal or microorganism) a desired trait. 2. Copying the information from the organism that has the trait 3. Inserting that information into the DNA of another organism