Somatic cell nuclear transfer is the technical name for the process most frequently associated with the word cloning. In this process, a cell, usually an unfertilized egg, is readied in several ways, the most important of which involves removing the cell’s DNA. DNA – deoxyribonucleic acid – contains the genetic code, the instructions that guide the replication and differentiation of cells as they develop into an animal.
Cloning is initiated by inserting the DNA from the animal to be cloned into the prepared cell. This process frequently fails, generally requiring two hundred plus attempts before a prepared cell with its new DNA will multiply and differentiate, producing a clone. A significant number of the failures produce animals with abnormalities, perhaps acceptable with animals but a frightening prospect with humans. Although a human has yet to be cloned, the technology that now exists would seem to pose no barrier to human cloning. The Internet even has a one-page recipe for human cloning posted at http://www.biofact.com/cloning/human.html.
Science fiction depictions of cloning full-grown animals or humans as in the movie Multiplicity are just that – science fiction. Cloning by any method cannot even yield an egg much less a child that will grow into an exact replica of its DNA donor. Identical twins have identical DNA, are alike in many ways, yet are distinct and unique individuals. This is because humans, and the same is true of other animals, are determined by factors in addition to heredity. Environmental factors – diet, climate, illness, parenting – all influence the maturation process. Humans also have some measure of free will that also affects their development.
So even if a human were cloned, the resulting individual would not exactly duplicate the DNA donor. Presuming that DNA was available from Michealangelo, Lincoln, Hitler, Einstein, or Schweitzer there is no assurance that a clone would have the same abilities or values and every likelihood that the clone would be significantly different than the original.
The value of cloning animals derives from their contribution to human welfare, that is, although animals are God's creatures and therefore intrinsically valuable God also intended them as instrumental goods, i.e., a means to an end. We eat fish, meat, eggs, and other animal products; we wear skins and wool; animals in dozens of other ways enrich human life. Humans have animal pets; animals do not have human pets.
Genetic modification of animals can enhance their value, e.g., as cows are bred to produce more milk, chickens bred to lay eggs with less cholesterol, etc. Cloning animals has the potential to produce large numbers of animals that share the same beneficial traits.
The dangers of cloning animals are: first, as the genetic similarity of a breed increases the susceptibility to disease wiping out large numbers of that breed also increases; second, the consequences of humans and other life forms consuming genetically modified animal products is largely unknown.
The morality of cloning animals largely hinges on one’s view of the intrinsic value of animals and on the answer to a utilitarian question: which is greater, the benefit to human well being from cloning animals or the dangers to human well-being? Further research will probably provide an answer to that question.
The second part of this three part post explores arguments in favor of cloning humans; the third part delineates reasons against human cloning.