104 
Concern over the potential for hazard in organisms containing 
recombined DNA develops from the central idea that such recombinants 
will be unique types of organisms, not normally arising in nature, 
and that their properties will therefore be unknown and unpredictable. 
Natural environments provide many opportunities for recombination 
of DNA between unrelated species, as for example, in the intestines 
of animals [see Section IV-C-l-b-(2) of this EIS]. Whether, or at 
what frequency, such recombinations occur is not known at present. 
They are probably rare, however, given the very low extent of shared 
base sequences that can be detected in DNAs derived from distantly 
related organisms. It would appear that naturally occurring interspecies 
recombinants, if they occur in nature, may have been selected against 
in evolution. However, tests for shared base sequences are of limited 
sensitivity. 
(3) Relative irreversibility of spread of organisms 
Should organisms containing recombined DNA be dispersed into the 
environment, they might, depending on their fitness relative to naturally 
occuring organisms, find a suitable ecological niche for their own 
reproduction. A potentially dangerous organism might then multiply 
and spread. Subsequent cessation of experiments would not stop the 
diffusion of the hazardous agent. 
As described earlier, however, it is likely that newly constructed 
organisms would be less fit than those occurring naturally and would 
therefore disappear over time. 
d. Views of the possible undesirable impact 
We quote in its entirety (following page) an article by Rene Dubos, 
Professor Emeritus at Rockefeller University, as it appeared in the 
New York Times on April 21, 1977 (22). 
Next, we quote from the article "Recombinant DNA: Fact and 
Fiction" by Stanley N. Cohen, Science, February 18, 1977 (2 3). 
Finally, we quote an editorial (p. 107) by Richard Goldstein from 
the New England Journal of Medicine and an article (Appendix Q) from 
the same issue, "When M"ay Research Be Stopped?" by Carl Cohen, 
dated May 26, 1977 (24). 
