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IMPACT OF MODERN BIOTECHNOLOGY ON BIODIVERSITY
C Kameswara Rao Foundation for Biotechnology Awareness and Education, Bangalore, India
Modern Biotechnology Modern Biotechnology provides novel goods and services using organisms or their products, applying innovative scientific and engineering principles. Modern biotechnology found several new applications in agriculture, medicine, industrial production and environmental management, using one or more of the following procedures:
a) recombinant DNA (rDNA) technology to incorporate new genes from an organism into the genome of another organism cutting across genetic relationships, resulting in transgenic organisms (with transgenes from the bacterium Bacillus thuringiensis into crop plants, or human insulin genes into bacteria and yeasts),
b) the control of gene expression through several different means (coffee seeds without caffeine through gene silencing or enhanced production of hepatitis B antigens through somatic hybridization).
Cloning of cells, tissues, organs and organisms through culture techniques is a very important tool in biotechnological procedures, but do not constitute biotechnology per se.
Medical biotechnology aims at a) safe, effective and inexpensive medicine, b) the rapid and low cost synthesis of purer industrial products, c) restoring damaged environmental components such as soil and water, d) better crops in terms of crop health, yield, quality and reduced labor and financial inputs, to help the farmer whose focus is lower cultivation inputs, higher quality and yield. Ingenious techniques have led to innovative crops that produce nutritionally important compounds (Golden Rice with β-carotene) or therapeutically active agents (vaccines, antibodies).
Biodiversity Biodiversity, the short form of Biological Diversity, refers to the variety of life in all its forms, levels and combinations and includes the diversity of ecosystems, species and genes, focussing on bioresources and gene pools.
The composition of biodiversity is not static and it has changed and will continue to change gradually, responding to numerous factors inherent in the organisms or the environment, and their interactions.
Biodiversity Loss Some component or the other of biodiversity was always lost as a natural process, and was replaced by new diversity components over time.
Sudden and catastrophic changes in the habitat due to natural causes (fires, earth quakes, cyclones and floods) or human intervention (excessive use of forest resources like timber, development projects such as townships, roads, dams) cause often irreplaceable loss of biodiversity.
Agriculture has been the single largest cause of habitat destruction and biodiversity loss. Nevertheless, agriculture has also created new and different kinds of diversity in the same environment.
Impact of Genetically Engineered Products on Biodiversity The impact of medical and environmental biotech products on biodiversity and environment is largely confined to the management of effluents and pollutants from the production sites. Environmental biotechnology actually restores degraded environmental components like soil and water.
Agricultural biotechnology caused very contentious arguments regarding its ‘impact’ on biodiversity and the environment. A particular Bt gene (like Cry 1 Ac) and its product have no impact if the target pest (like cotton bollworm) of the gene is not present on a plant. Herbicide tolerance genes have no impact if an appropriate herbicide is not sprayed. Drought, flood and salinity tolerance genes have no impact in the absence of the respective stress factors.
Activists persistently projected GE technology as a serious threat to biodiversity and the environment. Three issues are commonly raised in this context: a) Bt corn pollen are harmful to Monarch butterflies, b) corn transgenes have introgressed into native corn varieties in Mexico and c) Bt pollen are responsible for bee Colony Collapse Disaster (CCD) in North America and Europe. All these claims have been challenged and disproved by the scientific community. A February 2008 publication indicates that Cry 1Ab Bt proteins do not affect the performance of bumble bees in any manner.
Crop Variety Diversity and Genetically Engineered crops The dimensions of crop diversity are reflected in the vast numbers of varieties of globally important crops such as rice (about 1,00,000 varieties), wheat (70,000), corn (45,000), and many others. As crops are bred to improve over the existing varieties, the new varieties of a crop, preferred by the farmers and the consumers, displaced the older ones, resulting in a continuous reduction in the number of older varieties under cultivation. The present day farmers prefer genetically engineered (GE) varieties of crops, which replace the conventional varieties.
Anti-tech activists argue that GE crops will destroy the existing gene pools of crops, since discontinued cultivation results in the disappearance of genetic traits that may prove to be valuable in future. There are hundreds of thousands of crop seed collections in different institutions which may contain genes for some valuable traits. Even though these seeds may not germinate now to produce plants needed for research, modern techniques of molecular biology could be used to rescue any useful genes from them.
A comprehensive report on the impact of agricultural biotechnology on biodiversity from the Bern University’s Botanic Garden (2004) reiterated that the introduction of GE crop varieties does not represent any greater risk to crop genetic diversity than the varieties of conventional agriculture. GE actually increases crop diversity by adding new varieties.
Crop Field Diversity Another aspect related to crop diversity is crop field diversity, constituted by a) the insects colonizing on the crop plants, b) other insects, birds and small animals that feed on the former, c) the pathogens of the crop and d) the weeds in the crop fields.
Pest or pathogen tolerant GE crops affect only the target pest or pathogen. They reduce application of chemical pesticides that harm non-target organisms and enhance populations of beneficial insects, facilitating visits by birds preying on insects, thus restoring crop field biodiversity that was restrained by excessive inputs of agricultural chemicals. Reduced handling of chemical pesticides reduces the risk farm workers face from exposure to them.
The composition of weeds in a given crop field depends upon the crop and agricultural practices, as for example the weeds in a rice field are not necessarily the same as those in sugarcane or corn or pulse crop fields in the same area. Weeds cause over 30 per cent crop yield losses and so need to be removed effectively and scientifically.
Activists insist that the weeds in crop fields are valuable components of diverse diets and that they are important as medicinal plants and so herbicides should not be used. The crop field weeds are common species that are found easily in the same area and there is no special merit in them to be protected at the expense of crop productivity.
Anti-tech activists have also contended that the genes from GE crops would get incorporated into the wild and weedy varieties of the crops, through ‘gene flow’ and result in ‘super weeds’. Nothing, in centuries of agricultural experience, or about 15 years’ of research and regulatory processing of several GE crops in different countries, has indicated such a possibility. A ten year long experiment in the UK has shown that pest tolerant and herbicide tolerant GE crops have actually perished earlier than their non-GE counter parts. None escaped into the environment to become a super weed. Crops are heavily pampered with inputs and care, which are unavailable outside a crop field.
A peer reviewed report of March 2007 stated that no aspect of credible science based on ten years of field research and commercial cultivation has indicated that GE crops have harmed biodiversity or the environment.
February 22, 2008
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