History of Cloning

Cloning of non-mammals was first accomplished in 1952, but mammals proved to be more difficult. Dolly was the first successful mammal clone in 1996. Mice and cows came shortly after in 1998 and pigs in 2000. The first cat was cloned in 2001. Rabbits were cloned in 2002, and the first cloned human embryos were not produced until 2001 by a private company (ADVANCED CELL TECNOLGY). But the first ever cloning of a human Blastocyst was not produced until 2004 by a group in Korea.

Applications and Examples of Cloning

Bio transplantation would be a very important application of cloning. For example, an animal with certain human genes could produce organs suitable for human use that would temporarily replace a deceased organ until a suitable human donor becomes available. Another application would be if you were testing different versions of a medicine on two cloned mice that were sick. You would know that the medicine in doing the job and not a genetic variation. We could even give an animal, a cow for instance, a gene that makes a very important, hard to get and expensive protein. Mass production would not hurt the animal because it would be excreted through the cow’s milk and make the protein cheaper and more accessible.

Introduction to Cloning

Cloning is the process of creating an exact replica of an organism. As you can see, no part of that definition mentions technology. In a sense, identical twins are clones! There are two ways that humans can utilize to create clones: artificial embryo twinning and somatic cell nuclear transfer (SCNT).
Artificial embryo twinning is relatively low-tech, mimicking natural twinning. In natural twinning, a zygote divides into two separate cells that are far enough apart to develop into two individuals. In artificial embryo twinning, a zygote is allowed to split into two cells, which are then manually separated to develop independently. The embryos are implanted in surrogate mothers and allowed to mature. The downside of this method of cloning is that an existing individual cannot be cloned. Let’s say you want a clone of yourself. Too bad. But if you want a clone for your child-to-be, who is just a few cells big, the cells can be utilized to make a twin. If the embryo is a complex structure with specialized cells, it cannot be cloned.
Somatic cell nuclear transfer is a more technological approach to cloning. A somatic cell is any cell other than a gamete. To clone using SCNT, an egg cell is devoid of genetic material. A somatic cell is then fused with the egg using electric pulses. This way, the new zygote will have genetic material from the donor of the somatic cell only. The zygote is allowed to grow a little before being implanted in a surrogate mother. Even though the process is complex and the survival rate of the clone is low, it has the advantage of producing clones of an existing organism. If you ever want a clone, this is how you would get it.
Unfortunately, your clone probably will not survive to do your homework for you, or will turn out to be defective. Dolly the sheep was created after 277 eggs, 29 of which yielded embryos, and only three of which survived to birth. Dolly was the only one to survive to adulthood, and even then died an early death, probably from a defect caused by the electric pulses used to fuse the somatic cell and egg.