22 
Secondly, I believe that the novelty of the proposed organisms has been 
very much exaggerated. There is no doubt that DNA can enter bacteria, some 
much more readily than others. It is extremely unlikely, from what we know 
of cell biology, that there are going to be very sharp lines that will 
restrict this to very few bacteria, and we can expect rare integration of 
the entered material, which in fact was demonstrated by Chang and Cohen in 
PNAS [ Proceedings of the National Academy of Sciences ] this month. It 
seems impossible, then, that a million DNAs have not entered bacteria many 
times in the past. 
I believe that the concern arose also from an underestimate of the 
spread of DNA in the microbial world, in which we now increasingly see 
that plasmids and restriction enzymes have evolved as devices for promo- 
ting spread of a great variety of DNAs in evolutionary experiments. 
The most serious reason, I think, for the great anxiety that arose 
was that the epidemiological aspects of these novel organisms were treated 
as though they were a black box. Now, it is true that for precise quantita- 
tion of precise hazards of any specific organism, one needs data on that 
organism, but for general assessment of a class of organisms, our knowledge 
of that class from the past is sufficient, and E. coli with one-tenth percent 
foreign DNA inserted in it will still certainly have the modes of spread, 
the normal habitat of E. coli and of other enteric pathogens which we know 
are contained well by modern sanitation. 
Now, let me close with several specific recommendations. First, I 
would recommend strengthening the introduction by interjecting the question 
of the novelty of the proposed recombinants compared with what has happened 
in nature. Secondly, by putting in some references to the work of Chang 
and Cohen and Roy Curtiss in the introduction rather than simply later. 
And thirdly, the phrase, "the intent of erring on the side of caution." I 
appreciate the intent of that statement, but I think it is perhaps too 
strong, and would suggest something like, "because of the persistence of 
the widespread public anxiety that arose before these principles and these 
findings had been considered, the revised Guidelines represent only a modest 
relaxation of the restrictions." 
Thank you. 
DR. FREDRICKSON: Questions or comments from members of the Committee? 
Mr. Hutt. 
MR. HUTT: I would just like to make sure, Dr. Davis, you are not sug- 
gesting that we should not err on the side of caution, or are you? 
DR. DAVIS: The aim I agree with. I think the phrase "err on the side 
of caution" isn't an ideal aim. The ideal aim is to be as reasonable as 
possible, and not to err. I don't like to have a document put out by a 
group of scientists saying we are deliberately erring. I would rather use 
another phrase, as I suggested, that gets at much the same point. 
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