[To contribute to this conference, send your message to
For further information on the Electronic Forum on Biotechnology in Food and
Agriculture see Forum website.
NB - participants are assumed to be speaking on their own behalf, unless they state otherwise.]
Sent: 18 June 2002 08:56
Subject: 53: Risk to biodiversity of gene transfer versus conventional breeding
This is from Dr. Irvin Mettler, Director of Biotechnology for Seminis Vegetable Seed in Woodland, California, USA.
I would like to add to the comments of Dr. Knibb (message 51, June 17) regarding the differences between the risk of transgenes to biodiversity and the risk of natural mutations or conventional breeding.
Dr. Knibb asks whether natural processes can also generate risks? If so, then how do these risks compare? I think that this is an important point that those who are against the "unknown risks" associated with transgenes fail to consider. A transgene represents, after all, a single genetic allele with a relatively well understood phenotypic effect. The background genetics of the host organism contains tens of thousands of genes - many of which are altered, rearranged, or mutated with each generation in ways that are completely unknown. Typical new varieties that are developed by conventional breeding for many crops include genomic regions that have been introgressed from wild relatives, recombined with the domestic variety through many generational selections, and finally released with essentially no information or testing for safety or potential impact on biodiversity. One only has to look at any catalogue or description of available varieties and new releases to see that all sorts of new traits are being developed and released currently from conventional breeding programs with essentially no regulatory oversight for safety or potential impact on biodiversity.
Dr. Knibb's question is logical and straightforward: if we hypothesize that use of transgenes is risky because we have incomplete knowledge and may miss some unintended hazard, then how much more dangerous should we consider conventional breeding which changes more genes but has essentially no information on the nature or even number of unknown changes? Fortunately, we already know much of the answer for conventional breeding and it is based on centuries of real observations -not speculation or "what ifs". Major problems have resulted from the introduction of new, invasive species into new environments, but specific genes in agricultural crops have not been, and are not likely to be, a threat to biodiversity. By far, the real threat to biodiversity is the extent of land that is devoted to agriculture and the simple displacement of existing ecosystems by farms. The identification of one gene as being a transgene (for example for disease resistance) is no more of a threat than the already common use of conventionally developed traits for disease resistance.
Increases in yield and quality by genetic improvements are, likely, the most effective and efficient way to improve food security and safety and at the same time reduce the potential for negative environmental impacts of agriculture. I submit that whether new genetic traits are identified by conventional breeding or developed through gene transfer is biologically unimportant. If one were to take a purely objective view, the increased molecular detail, knowledge, and understanding required to use transgenes means that the generally accepted low risk associated with the introduction of new traits by conventional breeding could be logically argued to be even lower in the case of regulated transgenes.
Irvin J. Mettler
Seminis Vegetable Seeds, Inc.
37437 State Highway 16
Woodland, CA 95695
irvin.mettler (at) seminis.com
Sent: 18 June 2002 14:17
Subject: 54: Re: Risk to biodiversity of gene transfer versus
This is Javier M. Claparols, Director of the Ecological Society of the Philippines.
Drs. Mettler (message 53, June 18) and Knibb (message 51, June 17) have put forward a most important point of who is monitoring conventional breeding and it's impact on biodiversity. Invasive alien species (IAS) have been documented to have costed billions of US dollars in economic losses (estimated approximately at $400 billion annually in agriculture and livestock). It has been confirmed that IAS are responsible for the extinction of 39% of the species disappearing in the planet since 1600, with habitat destruction ranking second at 36%. Information comes from the World Conservation Union (IUCN).
Knowing this, it may be proper to be more prudent in venturing into areas where the science, as this debate shows, has no conclusive answer to the risks of gene transfer. The Convention on Biological Diversity runs on the precautionary principle, though others look at it on a precautionary approach. Where do we stand?
Javier M. Claparols
Ecological Society of the Philippines
jmc1 (at) mozcom.com
Sent: 18 June 2002 17:21
Subject: 55: Evolutionary risks of transgenes
In response to Wayne Knibb's questions (message 51, June 17) regarding his response to Bill Muir (message 34, June 10) and further related correspondence:
It is unclear whether he is being serious or facetious but the difference between introduced, "for profit", genetic traits and altered traits through natural selection, through whatever form of spontaneous mutation, should be self-evident. The (externally) human-driven process of transgene insertion (genetic engineering (GE)) runs independently to the evolutionary process, in that a construct that can never naturally occur, has been introduced to the gene pool. To presume that there is little difference between a transgene mutation and a natural mutation is clearly flawed from an evolutionary perspective. Further, the nature of these mutations is intentionally advantageous for survival while they concurrently lack the natural checks and balances that naturally exist to correct evolutionary mistakes.
This dichotomy is the central reason for conflict between "hard" scientists who perform technical procedures because they can, and those who feel that genetic engineering is an ill-conceived act of biological barbarism in "soft", evolutionary terms. It is also the primary reason for the polarity in the debate around gene flow.
All species will naturally mutate to a greater or lesser extent. It is only when such natural mutations benefit the species as a whole that they are taken up. Contrastingly, GE traits operate against a completely different background of artificial stability. However, there may be hope as recent reports from China about Bt tolerance confirm that the effect of inserted transgenes may diminish over time. It is unclear whether this reduction is genetic or is manifested solely by other evolutionary biological feedback mechanisms. For it is when we interfere in the latter by forced transgenic transfer, that we are working outside the bounds of natural selection. The feedback loop is broken.
To suggest that "if we view genetic engineering as a little risky", that we should then "view natural evolution and spontaneous mutation as positively dangerous", is mischievous and misleading. It is correct and scientific to ask this question, but it can be refuted by examining the danger posed by externally imposed genetic alteration undertaken only for profit. We cannot in good conscience interfere in the evolutionary process for profit. Beside ethical and moral considerations, it is plain irresponsible in that incalculable risk is introduced. When risk is naturally introduced the changes are also incalculable in number but these risks are at least responsive to direct environmental factors that limit the changes to within sustainable parameters. In contrast, by allowing one "super fish" into the wild, we may initiate a fatally disruptive series of events with many potentially negative, and few potentially positive, outcomes, with no extant evolutionary controls. The risk exists at so many levels that such acts of GE should not allowed.
Real, transparent controls on GE have failed since Asilomar 1. [Asilomar-1 refers to the Conference on Biohazards in Biological Research held in Asilomar, California, United States in January 1973...Moderator]. Every act of GE incalculably increases the risks to naturally controlled environmental sustainability (ecological feedback loops). It took us hundreds of years to recognise the risks and costs of inter-continental transfer of invasive "alien" organisms. How long must it take us to realise the dangers in continuing with GE against a background of immeasurable ignorance as to what we are actually doing?
Gene flow should be a priority issue, yet it is so low on the agenda that it has not yet been meaningfully and openly discussed, as proposed at Asilomar and elsewhere. We have to ask ourselves honestly whether the corporate capitalist system can be trusted to redesign evolutionary biology, right down to genetic level. The only sane response to such an obscene suggestion can be strongly in the negative.
ekogaia (at) iafrica.com
Sent: 18 June 2002 17:38
Subject: 56: Re: Fundamental considerations in hazard identification of GMOs
In response to Suzanne Wuerthele (message 1, 31 May) "Because GMOs are fundamentally different from conventionally-bred organisms, they raise novel concerns about their effects on ecosystems at the genetic level and about their behavior in ecosystems at the agricultural level.", Prof. Derek Burke (message 17, June 6) replies "I want to know what is the evidence for this broad statement?"
In reply to Prof. Burke's question, the evidence is clear and unequivocal. All of the transgenic plants now commercialised or being tested, originated from genetic transformation based on illegitimate (non-homologous) recombination, while all of the traits selected and manipulated in traditional breeding originated from homologous (legitimate) recombination. Plant genetic engineering has not yet achieved a genetic transformation that is based on homologous recombination. In a sense it is correct to say that transgenic plants are genetic "bastards". The publication below reviews the elementary concepts related to genetic engineering and the lack of a system for legitimate recombination.
Trends In Plant Sciences. Volume 6, Issue 4, 1 April 2001, Pages 155-159. Sandeep Kumar and Matthias Fladung. Controlling transgene integration in plants.
Professor Joe Cummins,
University of Western Ontario.
jcummins (at) uwo.ca