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Parashat Bo 5758-1998
Advances in Genetic Engineering -- New Halakhic Challenges
Dr. Uri Nir
Faculty of Life Sciences
The power which G-d gave to Moses and Aaron to change the natural order and bring ten plagues on Pharaoh and his people-- "Moses and Aaron had performed all these marvels" (Ex. 11:10)-- stemmed from the exceptional requirements of the moment and from the elevated status of Moses and Aaron. G-d did not confer such special powers on most human beings, but He did endow them with common sense, inquisitiveness and the ability to learn. These traits have motivated human beings throughout the ages to delve into the wonders of creation. In the last two decades biological research has made significant headway in the field of genetic engineering, opening new ways for changing (to some extent) the natural order of the universe.
Genetic engineering has developed new options for isolating genes (the genetic units responsible for defined traits), making it possible to characterize them and actively introduce them into tissues and organs of various organisms. The techniques that have been developed will make it possible to create human beings (and animals) with new genetic characteristics, and these traits will be transmitted hereditarily to subsequent generations. Introducing genes into specific human tissues and organs will advance medicine in the 21st century in terms of gene therapy, or curing diseases that stem from genetic defects. Here we discuss briefly two examples of organisms that could be created with new genetic properties and explore their halakhic consequences.
Today a gene coded with a specified trait can be introduced into a fertilized ovum of an animal or a human being. The ovum is then implanted in the host mother, who at the end of gestation gives birth to a creature that, in addition to all its basic traits, also has the newly acquired trait.
In the future this technique might enable us to create animals with new, acquired traits; for example, one might be able to introduce a gene for producing scales into the ovum of a fish which only had fins, as a result producing a fish which has both fins and scales. This new fish, not created in the six days of Creation and whose original characteristics defined it as non-kosher, would now have acquired the signs of a kosher fish: "These you may eat of all that live in water; anything in water, whether in the seas or in the streams, that has fins and scales--these you may eat" (Lev. 11:9). In the future it might even be possible to genetically engineer a kosher pig that chews its cud!
These two examples, which currently appear fantastic, one day might very well become a reality. Such developments will pose new challenges for those who rule on the halakhah. Will the new genetically engineered fish with fins and scales or the animal that chews its cud be considered kosher?
Ostensibly the answer would be affirmative, for they both have the requisite indications of purity; the fish, as cited above, and the pig, as follows: "Any animal that has true hoofs, with clefts through the hoofs, and that chews the cud--such you may eat" (Lev. 11:3). Since we believe the Torah and the halakhah derived from it to be eternal, we would expect that even such hypothetical questions could be clearly handled by the halakhah. The matter, however, is not that simple.
In the Mishnah, tractate Bekhorot 1.2, we read: "...that which issues from the impure is impure, and that which issues from the pure is pure." In other words, the decisive factor when dealing with animals is not necessarily the indications of purity; rather, the state of the mother that gives birth to the animal is the determining factor. Therefore, everything born of a pig is impure. This is supported by a talmudic ruling based on Lev.11:4: "The following, however, of those that either chew the cud or have true hoofs, you shall not eat..." One might have an animal that chews the cud and has true hoofs, yet is not to be eaten. And what might that be? A pure animal born of an impure one (Bekhorot 6a). Thus, it seems, with the means currently available to us, any genetically engineered pig parented by a fertilized ovum from an impure pig, reimplanted in a host pig, is not kosher and its offspring are not kosher.
However, the rule that "what issues from the impure is impure" is not mentioned in the Mishnah and Gemara with respect to fish. It appears, in my humble opinion, that only indications of cleanness, fins and scales, are operative with respect to fish. Thus a non-kosher fish that has been genetically engineered to have the requisite signs of cleanness would be kosher. Returning to the case of non-kosher animals, if it becomes possible to grow a fertilized egg in vitreo until it reaches maturity, then this will pose a more complicated halakhic question.
The distinction between animals and fish that follows from these sources invites deeper consideration of the origins of and possible reasons for this eternal distinction. It should be noted that this distinction is compounded with other differences between animals and fish: fish are not sacrificed on the altar, nor do the laws of ritual slaughter apply to fish, unlike certain animals.
Clearly what I have said above is not to be taken as a halakhic ruling. That will come in due time, and only by authorized experts who, after receiving the necessary scientific data, will surely know how to apply the relevant halakhic discussions to any new question that might arise.
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