This argument, though initially appealing, loses its force in light of the fact that genes are continually being copied within every living organism. Since the new copies function in the same way as do the genes from which they were replicated, there is no essential difference between them. That is how the organism's integrity is maintained as new cells augment and replace the old. In an adult animal, every gene is a copy derived from one original set, and most are products of many generations of copies. Further, genes are important not in terms of the amount of matter they contain but in terms of the information they encode.
Genes comprise a minuscule fraction of an organism's matter.
They are sequences of information that direct the development of the organism's structure and bulk, but in themselves they contribute little to either. Gene replication is primarily the replication of an informational code, not the accumulation of bodily mass. As long as a laboratory copy fully replicates the structure of a particular gene, that copy can produce the same substances as its counterpart, whether implanted back within its native species or transplanted into a foreign one. Therefore, the key consideration regarding transplanted genes is not the extent to which they themselves constitute the substance of non-kosher animals, but the extent to which they create it. This will become more evident in the following discussion.