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There are certain well-documented instances in which the DNAs 
of different living things become more or less permanently recombined 
in nature [see Section IV-A of this Environmental Impact Statement]. 
These instances involve recombination between the DNAs of nonchromo- 
somal genes, such as those of viruses or plasmids, or between the 
DNAs of viruses or plasmids and chromosomal genes. The former 
instance, for example, is the mechanism behind the rapid spread of 
resistance to antibiotics among different bacterial species (see Section 
IV-C-1 herein and references 11, 20). This spread accompanied the 
prevalent use of antibiotics in medicine and agriculture. Some viral 
DNAs recombine into and persist in the chromosomal DNA of cells 
of receptive organisms (12,13). And some viral DNAs acquire, in stable 
form, DNA sequences derived from their host cells (21). There is 
also strong evidence for recombination of the DNA form of RNA animal 
tumor virus genes with chromosomal genes (22). 
2. Expected Benefits of Recombinant DNA Research 
Benefits may be divided into two broad categories: an increased 
understanding of basic biological processes, and practical applications 
for medicine, agriculture, and industry. 
At this time the expected practical applications have not yet been 
realized and their success remains uncertain. But the ability of recom- 
binant DNA methods to increase understanding of basic biological 
processes has already been proved. It is important to stress that 
the most significant results of this work, as with any truly innovative 
endeavor, are likely to arise in unexpected ways and will almost certainly 
not follow a predictable path. 
a. Increased Understanding of Basic Biological Processes 
There are many important fundamental biomedical questions that 
can be answered or approached by DNA recombinant research (4). In 
order to advance against inheritable diseases or to understand how man's 
genetic makeup affects his response to the environment, we need to 
understand the structure of genes and how they work. The DNA recom- 
binant methodology provides a simple and inexpensive way to prepare 
large quantities of specific genetic information in pure form. This should 
permit elucidation of the organization and function of the genetic infor- 
mation in higher organisms. For example, current estimates of the 
fraction of this information that codes for proteins are simply educated 
guesses. There are almost no clues about the function of the portions 
of DNA that do not code for proteins, although these DNA sequences 
are suspected of being involved in the regulation of gene expression. 
