The field of biology has been constantly evolving in the 20th and 21st centuries. Genetics, for example, is a rather young science; many controversies and debates surround its principles and practices. Scientists have made a big step forward in studying genes in the last decades. Progress in the field of genetics and its contacts with molecular biology have allowed to come closer to answering one of the major questions – the mystery of the appearance of a man on Earth. Advances in the field of cloning have generated many questions. On the one hand, there are new opportunities such as to develop genetically modified foods, create fundamentally new drugs, transplant organs, solve the problem of infertility and save mankind from certain hereditary diseases. On the other hand, there is a moral issue related to the immorality of human cloning.
The term “clone” comes from the Greek word that means “a twig, shoot or stalk”. In the most general sense, it is the process of reproduction of any object. Objects obtained by cloning are called clones. Nowadays, the technology of human cloning is not perfect. It raises a number of technical, socio-ethical, legal and religious issues. However, one can confidently say that the issue of technology is resolved since scientists manage to clone animals. “It is interesting that some of this work is being done with farm animals including sheep, cows and pigs” (MacKinnon, 2001, p. 4).
In the book Human Cloning: Science, Ethics, and Public Policy, the author states that in the 50s, American embryologists Briggs and King made first steps in cloning. In their experiment, they managed to transfer the cell nuclei of the giant eggs of African frogs, from which tadpoles developed successfully. In 1962, an Oxford University zoologist John Gurdon significantly advanced these results. In his experiments with South African frogs, he started using not the germ cells, but the cells of the intestinal epithelium of adult tadpoles. Not more than two per cent of the cloned organisms survived, and the survivors had various defects. However, t was a big step forward on the path of cloning. At that time, scientists started talking about the cloning of mammals and possibly humans.
In 1996, the magazine Nature published the article of the scientific team (Wilmut and Campbell) about the birth of five lambs obtained without a ram. The next year, in the same journal, a photo of Dolly appeared. Until the mid-90s, biologists engaged mainly in the cloning of embryos of domestic animals. Moreover, experiments in this area were extremely difficult and had a high rate of failures. Therefore, the story of the famous cloned sheep became a sensation. The team of scientists led by Ian Wilmut demonstrated that they were able to use somatic (asexual) cells of an adult animal to get a clonal animal – a sheep named Dolly. When creating Dolly, they bypassed the sexual process. It allowed excluding genes accidentally acquired by crossing and opening a way to the pure genetic programming.
At first, the scientists took a cell from the mammary gland of an adult sheep and suppressed the activity of its genes by artificial methods. Then, they placed the cell in the fetal environment, oocyte, for the reorganization of the genetic program of the development of the embryo. Meanwhile, the experimenters took a nucleus from the ovule of another sheep. After cooling a cytoplasmic membrane under an electric field, they combined it with the core extracted from the cell of the mammary gland of the first sheep. They placed the fertilized ovule into the uterus of the third sheep – a surrogate mother. After the normal process of gestation, the sheep Dolly was born, which was a complete genetic copy of the donor of the mammary gland cell.
Cloning of plants, as opposed to animal cloning, is a usual process florists and gardeners face. They multiply plants with sprouts or cuttings, or by means of antennae. Such actions are examples of cloning. One can clone some animals naturally as well. Unfertilized eggs of different animals, such as frogs, worms, lizards and some species of fish, can grow into full-fledged adult animals under various environmental condiitions, often with the help of diverse methods of stimulation.
Experiments on human cloning have been going on for many years. In 1993, a scientist from South Korea created a clone of a person, raised it up to 4 cells and destroyed it. Due to technical difficulties, cloning of primates and humans is quite difficult to achieve and prove. This is because the core of the cloned cells misses two key bases of formation of proteins on the spindle, which is a key structure in the division of the cell. In ovules of female primates, these two spindles of protein are very close to the chromosomes. Therefore, the removal of the cell nucleus in order to make room for the somatic cell nucleus of the donor also removes the spindle of egg protein that interferes with cell division. Scientists believe that it may be the only reason why somatic cells are not suitable for cloning of primates. In contrast, in such animals as rabbits, mice or cats, two spindles of protein are distributed throughout the ovule; thus, the removal of the nucleus does not result in loss of cell proteins.
Certain researchers think human cloning is possible. However, the practice is absolutely unacceptable. Moral, ethical and legal issues related to the manipulation of the human embryos stand in the way. The reaction of the church to this new scientific discovery was clearly negative (Spriggs, 2003).
The modern development of cloning, the example of Dolly in particular, has opened the way to cloning of any species including humans. Human cloning has both advantages and shortcomings. The issue of human cloning causes controversy. On the one hand, cloning is potentially attractive both from scientific and practical points of view. However, from the ethical point of view, cloning of humans would have negative effects. Formation of a man as a person is based not only on biological inheritance; it is also defined by the family, social and cultural environment. When cloning an individual, it is impossible to recreate all conditions of education and training that have shaped the identity of its prototype.