SCOPE 44 - Introduction of Genetically Modified Organisms into the Environment

Joint SCOPE/COGENE Statement

INTRODUCTION

Genetic change is a fundamental biological phenomenon and is the basic process of evolution. It has been exploited by humans for their own purposes throughout history. Recent methodological developments, such as advances in the application of recombinant DNA (rDNA) techniques, have expanded these capabilities and provide the opportunity for addressing a wide variety of pressing human needs including solutions to environmental problems. Efforts to reduce pollution, to combat microbial infection, and to improve food production may require applications that involve the large-scale introduction of genetically modified organisms into the environment.

Any human intervention into the environment carries an element of risk. The natural response to this uncertainty is to proceed cautiously, but one must weigh any risks that might attend the implementation of the methodology against the benefits and against any risks that might be associated with delaying implementation.

The environmental introduction of any organisms, modified or unmodified, should be undertaken within a framework that maintains appropriate safeguards for the protection of the environment and human health while not discouraging innovation. This implies that an ecological perspective is essential to the assessment of risks associated with any introduction.

There is considerable experience in the introduction of organisms into the environment. Familiar examples include vaccines, agricultural varieties, and biological control. The positive and negative lessons learned from these experiences provide a basis for the rational development of safeguards. Nevertheless, these is much that still needs to be known about such topics as systematics; community structure; the factors governing the survival growth, and spread of populations of introduced organisms; and techniques for monitoring.

The development of new techniques also opens up new and exciting vistas for basic research, many of them involving close collaboration between molecular biologists, ecologists, and evolutionists. The new techniques will help us to understand the genetic structure of populations and to develop improved methods in applied ecology; ecological and epidemiological perspectives may serve to elucidate fundamental theoretical aspects of molecular biology, such as the population biology of plasmids and transposable elements.

RISKS

In view of the great potential of new technologies for addressing environmental and other problems, and because most introductions of modified organisms are likely to represent low or negligible ecological risk, generic arguments against the use of new genetic methodologies must be rejected. Indeed, the spectrum of available tools represents an evolving and expanding continuum, which includes conventional methods, rDNA techniques, and others. While much attention has been focused on the methods used to modify organisms, it is the products of these technologies and the uses to which they will be put that should be the objects of attention, rather than the particular techniques employed to achieve those ends.

Similarly, one must reject generic safety arguments based on the assertion that all introductions must have occurred some time during the course of evolution. Therefore, each introduction of an organism, whether modified or not, must be judged on its own merits, within the context of the scale of the application and the possible environmental costs and benefits.

Size, geographical scale, and frequency of introduction are among the factors that are important in determining whether a particular introduction will become established or spread. Therefore, small-scale field testing involves different considerations than does large-scale (e.g. commercial) application. This is not to suggest that small-scale testing should be exempt from examination for regulation, but simply that any risks are likely to be much smaller and more easily managed than those for large-scale applications. Nor does this suggest that all large-scale applications will be problematical, since we have many examples to the contrary, including vaccines, biological control methods, and the use of rhizobia in agriculture.

One must bear in mind that the greatest impact on the biosphere is through human activity. For example, deforestation, the widespread use of antibiotics, vaccines, herbicides, and pesticides, or the widespread introduction of a single type of organism in agriculture has led to a loss of genetic diversity. Such loss has had dramatic and unfortunate consequences for human survival because it has led to environmental degradation, loss of stability, and a depletion of biological resources that are valuable for food, fibre, medicines, and other purposes.

As the ability to manipulate our environment increases, so must an awareness of these problems and of the need to exercise our power wisely.

RISK ASSESSMENT

As already discussed, the risks of making a specific introduction must be weighed against the perceived benefits and the risks of not making the introduction. This balancing is part of risk management. This section addresses only the assessment of risks of introduction, but it is important that it be integrated into the management framework.

The properties of the introduced organism and its target environment are the key features in the assessment of risk. Such factors as the demographic characterization of the introduced organisms; genetic stability, including the potential for horizontal transfer or outcrossing with weedy species; and the fit of the species to the physical and biological environment. The scale and frequency of the introductions are important related factors. These considerations apply equally to both modified or unmodified organisms, and, in the case of modified organisms, they apply independently of the techniques used to achieve modification; that is it is the organism itself, and not how it was constructed, that is important.

Each proposed introduction must be treated on its own merits, but this  does not suggest that each needs to be considered de novo. As experience accumulates with particular kinds of introductions in particular environments, more generic approaches to these classes of introductions can be developed. The bases for classification should be refined continually, providing a set of criteria that will allow any proposed introductions judged to be innocuos to be carried out speedily and those judged to be problematical to be given the attention they deserve.

It is important to note that generalizations developed for particular groups of organisms (e.g. microorganisms) cannot be extended automatically to other groups (e.g. plants), which may have very different genetic and demographic characteristics, dispersal and reproductive mechanisms, and trophic positions.

In the development of assessment procedures, the potential for containment, monitoring, and mitigation must receive consideration. In this regard it should generally be assumed that the likelihood of being able to recall introduced organisms that have escaped containment is very small.

CODA

The new genetic methodologies add additional tools to the spectrum of techniques available to improve the human condition. These will lead to  rapid improvements in the development of ecologically sound approaches to agriculture and to environmental management, and in the acquisition of a better understanding of biological systems. These benefits in their various forms should be available to everyone, and know no national boundaries. It is therefore essential that the broadest possible international cooperation and datasharing be supported by all countries. Each improvement in our capacity to modify the environment carries with it responsibilities to use that capability wisely, with special attention given to the importance of maintaining biological diversity.