Genetically-Engineered Simanim
‘A Bird With One Siman’
(Chullin 62a)
Genetic engineering is developing so fast that the following question isn’t science fiction: If an animal that is usually considered not kosher is born with two kashrus symbols, is it kosher? In other words, suppose scientists could genetically engineer a lion so that it is born with split hooves and chews its cud, would it be kosher to eat?
Do Simanim Identifying or Render a Kosher Species?
The question hinges on another: Do kashrus signs make an animal kosher or simply indicate that it is? If they make it kosher, then a lion with split hooves that chews its cud would be kosher. If they merely indicate that it’s kosher (kind of like a sign on one’s house informing people of the identities of the residents within), then in this particular instance, the signs would be misleading (just like the sign on a house can be misleading) and the lion would remain not kosher since a lion born from another lion is, by definition, not kosher.
That Which Comes from the Impure Is Impure…
The Mishnah (Bechoros 5:2) lays down an iron rule: “That which comes from the impure is impure; that which comes from the pure is pure.” Therefore, theoretically, if a cow gave birth to a camel, the camel may be eaten as it came from a kosher animal. But if a camel gave birth to a calf, the calf is forbidden to eat it because it came from a non-kosher animal.
This mishnah is seemingly proof that the kashrus signs merely indicate that an animal is kosher or not kosher for if they actually made them kosher or not kosher, a camel that looks like a camel would remain not kosher even if a cow gave birth to it.
Animals Hatched from Eggs
The question, however, still remains open for animals hatched from eggs. They are not considered to “come” directly from their parents in the sense that the mishnah means. The mother lays an egg, which becomes like dust not fit to be eaten, after which life in it starts to truly develop (see Temurah 31a). So these animals come from eggs, not pure or impure animals, and the question remains open about the nature of their kashrus signs.
What’s Good For The Goose Not Good For The Gander
Rabbi Elchanan Wasserman, zt”l, discusses this question in his Kovetz Beiurim (Chullin 27) and says it is the subject of a machlokes Rishonim. Our sugya states that a male chicken can be kosher while the female chicken not kosher. Tosafos (s.v. “Tarnegulta”) argues that the Gemara must be talking about chickens from two different species. Elsewhere, however, Tosafos (at Nidah 50b, s.v. “Tarnegultai”) notes an opinion that a female can have kosher signs while the male does not.
What is the basis of these two views? Rabbi Wasserman maintains that our question is at its basis. If kashrus signs merely indicate that an animal is kosher, then it makes little sense for a male to be kosher and a female not to be. But if the kashrus signs make an animal kosher, then we can imagine a situation where the female has the signs, and is kosher, while the male for some reason doesn’t have the signs and isn’t kosher.
Signs As A Testament
The Maharit (Responsa 1:51) asserts that the signs are just signs, nothing else – just like the signs of maturity in a human being merely indicate that the human being is mature. They don’t make him or her mature.
Natural Signs of Purity
Rabbi Shlomo Zalman Auerbach, zt”l (Minchas Shlomo, II, end) argues that even if kashrus signs do make an animal kosher, they only do so if they are natural to that kind of animal, not if they are unnatural to it. Thus, a lion with split hooves that chews its cud would not be kosher even if kashrus signs did make animals kosher (see Chidushei Rabeinu Chayim HaLevi, Hilchos Maachalos Asuros, 3:11).
We should mention that Tosafos (on our sugya and in Nidah 50b, s.v. “Tarnegulta”) concludes that kashrus signs are merely signs, nothing else. They indicate that an animal is kosher; they don’t make it kosher.