96 
I don't think it makes so much difference that E. coli K12 carries 
this material. The fact is that normal wild-type _E. coli K12, under op- 
timal laboratory conditions, is capable of exchanging plasmid DNA with 
strains from over 40 genera of bacteria, including Salmonella , Vibrio , 
Pseudomonas , many of which are pathogenic. 
The second point I would make is that I think we altogether place 
too much emphasis on the damage that these recombinants could do to 
humans. We don't happen to be an indispensable species in the biosphere. 
Plants and other microbes and things are, and we depend on them. I think 
we have to broaden our thinking of what organisms might be at risk. Al- 
though we like to protect ourselves, I think we have to consider the 
others . 
DR. FREDRICKSON: Dr. Callahan? 
DR. CALLAHAN: It seems to me the nature of this kind of discussion 
is rather confusing. I am not sure whether because there are potential 
benefits which can ensue from this research, the burden of proof is then 
on those who would like to point our harms, or vice versa, namely that 
the burden of proof is on people to suggest harms, and those who suggest 
benefits must then prove their case. 
I think this is rather important, because as I listen to particu- 
larly the last exchange between Drs. Berg and Petersdorf, I worry about 
the problem of any discussion on a risk benefit ratio. As I listened to 
the discussion this morning, I got a sense that we are totally ignorant 
about the possibilities of whether all the potentialities will in fact 
eventuate. We are also equally ignorant about all of the harms. 
Well, if we are really that ignorant in both directions, then it 
seems to me we have to perhaps work on the premise that the harms are 
as likely to eventuate as the benefits. Then if that is the case, I 
am very confused knowing how to listen to a discussion about safety 
features, because it seems to me that if the harms are as likely to 
eventuate, even if there is only a remote chance of things getting out 
of the lab, but should they get out we are going to have a disaster on 
our hands. That could be terribly influential in deciding whether the 
benefits are worth it or not. 
I am at least left with the conundrum on my hands, and I suppose 
the problem goes back to: "Are we in fact equally ignorant of benefits 
in this case as of harms, or vice versa?" Again, let me put it that way. 
DR. FREDRICKSON: Dr. Hogness? 
DR. HOGNESS: I think perhaps you have missed one point that I made, 
and that is that there are certain benefits that we are talking of at all. 
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