Dr. Ahmed Rebai from CBS, Tunisia. Ahmed.Rebai@cbs.rnrt.tn

I would like first to comment an email by Lorna Salzman sent a month ago [Mar 30: subject: 'Re: pest res to Bt/GM and human health'] about GMOs, incest and crossing the species barriers. The Parallell between these three things does not make sense for a scientist. Crossing the species barriers is a natural phenomenon in the plant kingdom since thousands of year. What do you think bread wheat (Triticum aestivum) is ? It is a (allopolyploid) hybrid between three species: Triticum monococcum, Aegilops speltoides and Aegilops Squarrosa. Do you really think that wheat was disadvantaged by natural selection ?

Interspecific crosses are also possible by controlled sexual hybridization, as plant breeders used to do since many years for example in backcross breeding of tomato (e.g. crossing the cultivated tomato cultivars from species Lycopersicon esculentum with donor wild related species L. Pervianum to transfer resistance genes) or in creating new interspecific hybrid such as Triticale (between Wheat and Rye) which has been used in agriculture since many years. The equivalent of incest in plants is inbreeding which does not have anything to do with species barriers. Cross-fertilizing species generally show an inbreeding depression when selfed whereas autogamous species do not suffer from self-crossing.

Let's now go back to GMOs; in fact GMOs are made by a process which crosses the species barriers and even more: the genera and kingdom barriers (from animal or bacteria to plants). Sure, this makes a difference and that's why scientists themselves and since the beginning of the genetic engineering era (say 1975) have questioned and started to develop appropriate tools for studying the risks linked to the use of such 'transgenic' organisms. Now we have many tools to study the many different potential risks (on human health, environment, on agricultural practice and so on) of GMOs and we are able to carry out a risk assessment study for any GMO submitted for field release, based on the most recent scientific findings. Of course no body can garantie the zero risk (anyway it does not exist) but one can say that the risk is very minor, minor, medium or strong. Remember the thousands of poeple who were exposed to DDT (and other chemicals or drugs) before we find that it is can cause a big harm to the organism and environment. GMOs is the first thing in the history of human beings where the risk assessment is done prior to the commercial realease. Let us think about these and try to have an as-objective-as-possible point of view.

I will now end by going back a question: "Are GMOs more or less risky than radiation induced mutation?". There seems to be no public debate about the use of radiation to generate new mutated genes whereas we have much less control and knowledge of the genetic modifications induced by radiation (which can affect a large proportion of the genome) than on those induced by transferring a single gene (as we do in GMOs)! Any answer?

I am not defending anyhow the use of GMOs and as I've said before the final decision as to whether to use them or not should be based on a case-by-case risk/benefit assessment, taking into account scientific, socio-economic and cultural considerations. To me, there are other more easily accessible biotechnologies for the developing countries which can substantially improve crop production with minor financial inputs; among these are in vitro culture (mainly to produce disease-safe plants of vegetatively propagated species), molecular marker technologies (to improve efficiency and time-saving in breeding programs)... but we do not have to miss the GMO train and try to keep a 'kernel' research on genetic transformation of local major crops.

[To contribute to this conference, send your message to biotech-room1@mailserv.fao.org For further information on the Electronic Forum on Biotechnology in Food and Agriculture see http://www.fao.org/biotech/forum.asp ]

-----Original Message-----
From: Biotech-Mod1
Sent: Friday, April 28, 2000 4:59 PM
To: 'biotech-room1@mailserv.fao.org'
Subject: Re: interspecific hybrids, induced mutation and GMOs

Thanks for the measured and serious response. If you review my original posting [30 March], you will find that I did acknowledge successful hybrids, i.e. those derived from closely related species (usually in the same genus, sometimes in the same family). Dr. Rebai himself acknowledges that recombining genes of species very distantly related presents an entirely new paradigm, one that is routinely rejected by evolution. It is the uncertainties of this new situation that concern not just activists but many biologists.

Dr. Rebai is incorrect, however, in stating that such uncertainties and potential risks have resulted in required GMO testing before commercial release. Rebai is completely wrong in assuming there have been no untested releases. We have genetically modified ingredients in many many food products, almost too many to list. These ingredients are sometimes the main ingredient (corn) and sometimes a lesser one or a process ingredient (canola oil, soya lecithin).

Moreover, test plantings here and abroad mean that we have ENVIRONMENTAL release, which is obviously far riskier than "commercial" release because these releases cannot be recalled, whereas foods not purchased can be recalled. It is this fact of environmental experimental plantings - which release pollen and GE exudates such as that from Bt corn - that are of grave concern to biologists and environmentalists. The fact is that, because the US refused to conduct proper environmental impact statements and assessments before allowing recombinant-DNA experiments to move ahead in the 1970s, we now have totally uncontrolled environmental releases of genetically engineered seeds and crops (as well as GM products within foods).

It is broad-scale commercialization, by routine incorporation in foodstuffs and selling of GM fruits, vegetables, etc., that has not yet taken hold, but withholding these is no hardship except to corporations and agribusiness. Consumers are not going to be deprived of healthy food if GMO commercialization is stopped. They seem to have managed without it for a long time.

But the ecological, health and social implications of global broadcasting of GE seeds and crops are only just now beginning to manifest themselves. Until Arpad Pusztai conducted his rat experiments using GM potatoes, the claims of "safety" of GM foods rested on a single, corporate-sponsored study (Monsanto) relating to Roundup Ready soybeans, which are used for animal feed mainly, not human food. Nonetheless, corporations, agribusiness, Big Science (National Academy of Sciences (NAS)) and their government allies are unrelenting in their insistence that no harm to public health has been demonstrated yet. (Critics of the NAS report point out that the NAS study did NOT deal with GE foodstuffs or potential health problems but ONLY with the issue of genetically modifying a genome to incorporate pesticide resistance. This is hardly a wholesale demonstration of safety).

As some scientists admit, lack of evidence of harm is no evidence of safety. And the problem is that pro-GE scientists and corporations are intent on using the global environment and human beings as their experimental arena. We used to have an illustration of this: a man falls off the top of the Empire State Building, and as he passes the 80th floor, he announces "So far, so good".

In our case it is alien and novel genomically-distorted organisms that could in some circumstances (especially if modified for pesticide resistance) be selected for and successfully compete with established biotic communities, not just weedy relations or crop land races, and become dominant, irreversibly changing ecosystems and undermining their established processes and functions. This is not sci fi; this is evolution and natural selection, purportedly the hypothetical infrastructure for scientific experimentation. If scientists themselves choose to ignore these facts, they will continue to provide the general public with good reason for distrusting all their claims, including the benign.

Lorna Salzman, USA
718-522-0253; 631-653-3387
lsalzman@aba.org

[To contribute to this conference, send your message to biotech-room1@mailserv.fao.org For further information on the Electronic Forum on Biotechnology in Food and Agriculture see http://www.fao.org/biotech/forum.asp ]