Cloning is the process of creating an exact replica of something or, in the case of human cloning, somebody. There are many ethical concerns about the cloning of humans, and there have been laws passed in several countries declaring it illegal. In addition, the United Nations issued a Global Declaration on Human Cloning in 2005, which prohibits any form of human cloning. These restrictions have been placed on cloning to protect human dignity and life.
Some of the possible complications that could arise from human cloning are:
- Cloning of an individual without their consent.
- Covering up a murder by using a clone, or replacing an individual in a position of power with a clone.
- The use of biometrics, fingerprints and other biological factors used to identify an individual, would become obsolete in criminal investigations.
In theory, there are two possible types of human cloning:
Therapeutic – The cloning of human cells for use in medical procedures.
Reproductive – The process of duplicating an entire human.
The methods by which either type of cloning would be accomplished include:
Somatic Cell Nuclear Transfer (SCNT)
A somatic cell is any biological cell that forms the body of an organism. The process of SCNT transplants the nucleus from a donor’s somatic cell into a host egg cell, which has had its own genetic material removed. After the donor’s somatic material is transferred, it is fused with this enucleated egg using an electric current. Once the cells have fused, the new one can be successfully grown by artificially methods, or in a surrogate.
In 2008, this process was used to create the first five mature human embryos. These cells were allowed to develop and be observed for a brief period, before being destroyed. This experiment yielded great insight into the development of human embryos, which scientists were previously unable to observe.
Induced Pluripotent Stem Cells (iPSCs)
This cloning process takes more time than SCNT, and is also less efficient. The method consists of introducing a special set of genes into a specific adult cell type. These genes are called reprogramming factors, and emit signals which turn the host cell into a pluripotent stem cell – one which can potentially become any of the three germ layers. The iPSCs process is believed to pose several dangers, including the possible replication of cancer and other harmful cells.
Even though these processes cannot be currently used to replicate a human, both have been useful in research into the causes of disease and the systems used in drug discovery. They have also been applied to stem cell therapy, and the creation of organs which may be used for transplants.