d work in any other animal, and without adverse effects. But assuming it could be applied more widely, what are the potential applications in animals? PPL (PPL Thearaputics Ltd, 1997) gives the example that it might be used, say, to clone 5-10 animals from a single genetically modifiedanimal. These would be bred naturally, thus becoming the "founders" of a set of lines of genetically modified animals from whose milk they would extract and purify the relevant protein.But these medical applications tend to be small-scale affairs. The amount of animals and the amount of milk is very small compared with conventional meat or bulk milk production. Imagine you are a commercial breeder of cows or hogs, and over many generations you have bred some fine and valuable animals with highly desirable characteristics. One possible application of Roslin's work could be to clone such animals from the cells of one of them, and sell the cloned animals to "finishers" - those farmers who simply feed up the animals for slaughter, rather than breed them to produce more stock. Again, the breeder might want to clone a series of fast growing, highly productive animals in a breeding program, in order to test how the same "genotype" responded to different environmental changes. ANALYSISWould cloning narrow genetic diversity too far? Before we look at the ethics, there are some practical problems to consider. One of the fundamental rules of selective breeding is that you must maintain a high enough level of genetic variation. The more you narrow down the genetic "pool" to a limited number, the more you run two risks. One is that you could also have accidentally selected for some other not-so-desirable characteristic along with the one you wanted. (Klug, 1996) The selected lines could have certain disadvantages in some other genetic trait. These would be evened out in normal genetic diversity of selective breeding, but if animals were cloned, there would be no select...
