THE JOHNS HOPKINS UNIVERSITY 
SCHOOL OF MEDICINE 
DEPARTMENT OF 
MOLECULAR BIOLOGY AND GENETICS 
September 28, 1984 
i 
i 
725 N. WOLFE STREET 
BALTIMORE, MARYLAND 21205 
Dr. William J. Gartland, Jr. 
Executive Secretary 
Recombinant DNA Advisory Committee 
National Institutes of Health 
Building 31, Room 3B10 
Bethesda, MD 20205 
Dear Dr. Gartland: 
I am responding to Mr. Jeremy Rifkin’s proposed addition of prohibited 
experiments to the Guidelines as stated in the Federal Register, Vol. 49, No. 
184. He proposes that NIH prohibit experimentation involving the transfer of a 
genetic trait from a human being into the germ line of another mammalian species 
and vise versa. This proposal, if approved, would in my opinion, severely 
hinder many potentially important and useful experiments. Furthermore, it might 
constitute a "foot in the door" to future prohibitions involving other species, 
including plants. 
At this time, we as biological scientists, simply do not know all the 
answers as to what constitutes a risky or dangerous experiment. It would be a 
mistake, and I believe it has been perceived as a mistake by the RAC committee 
in the past, to simply ban experiments because of our ignorance of their 
possible consequences. Potential risk must be weighed against the reality of 
gain in our knowledge from such experiments. 
No genome in nature is completely isolated and protected from 
"contamination" with external or foreign DNA sequences. Many animal viruses 
infect man and are capable of carrying DNA from the animal into the human 
genome. This presumably occurs frequently in nature on an evolutionary time 
scale and is perhaps beneficial to our evolution. In addition, 
cross-hybridization of plant species is common, and crossing of closely related 
animal species has been done without dangerous outcomes. The implantation of 
small known DNA sequences from one species to another is probably much less 
risky than the above examples. 
Many thousands of recombinant DNA experiments have now been carried out 
freely by laboratories all over the world with enormous advancement in our 
knowledge, and with no dangerous consequences. Let us not roll back the clock 
to the prohibitive environment of ten years ago. 
Hamilton 0. Smith 
Professor of Molecular Biology 
and Genetics 
HOSrmk 
