Breeding programs to create animals or plants with specific characteristics, involve selection of parents with the characteristics, or that they believe may have genes for the characteristic even tho the characteristic is not evident, mating them, then checking the offspring for presence or absence of the characteristic. If the F1 generation (filial 1 generation) have the characteristic, or genes for it, they are bred, to produce an F2 generation. If not, well, us plant breeders, we gnerally eat them, even tho they aren't exactly what we want. Animal breeders must get rid of them somehow. That usually means killing them while they are small.
Modern breeding involves additonal technologies beyond simply obseriving the full organism. It is simply taking cells from developing organisms, and actually determining if they have the correct chromosome (with the correct gene sequence). But it still involves killing animals that don't meet the specifications you are shooting for. There are just too many of them, and no-one knows what to do with them.
The more unusual or a characteristic is, the more animals will have to be bred, and the more failures will be produced, and have to be killed, before you can produce a line of animals that reliably produces the desired characteristic. Producing hypo-allergenic cats undoubtedly involved producing lots and lots of cats that failed to meet the desired qualifications. They did not find an occasional cat that was hypoallergenic, rather, they found an occasional cat that was just slightly less allergenic. After many many trials they gradually reduced the allergenic capacity of the animals. Most likely all their cats that were not hypoallergenic enough, were simply killed.
Modern breeding involves additonal technologies beyond simply obseriving the full organism. It is simply taking cells from developing organisms, and actually determining if they have the correct chromosome (with the correct gene sequence). But it still involves killing animals that don't meet the specifications you are shooting for. There are just too many of them, and no-one knows what to do with them.
The more unusual or a characteristic is, the more animals will have to be bred, and the more failures will be produced, and have to be killed, before you can produce a line of animals that reliably produces the desired characteristic. Producing hypo-allergenic cats undoubtedly involved producing lots and lots of cats that failed to meet the desired qualifications. They did not find an occasional cat that was hypoallergenic, rather, they found an occasional cat that was just slightly less allergenic. After many many trials they gradually reduced the allergenic capacity of the animals. Most likely all their cats that were not hypoallergenic enough, were simply killed.
