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The biological definition of a clone is an organism that has the same genetic information as another organism or organisms. Thus, an elaboration on the history, techniques, ethics, and reasons for researching the technology of cloning is necessary. A clone is an organism derived asexually from a single individual by cuttings, bulbs, tubers, fission, or parthenogenesis reproduction. Parthenogenesis reproduction is the development of an organism from an unfertilized ovum, seed or spore. Hence, cloning, biologically speaking, is any process in which production of a clone is successful.
Thus, the biological term cloning is the production of a genetically identical duplicate of an organism. However, people can use the word cloning to intend other meanings. For instance, we generalize many older and new techniques as cloning. This is not a good practice because these techniques are different and impose concerns. In the world of scientific technology, cloning is the artificial production of organisms with the same genetic material. Scientists actually call the transferring of a nucleus from the cell of one organism to an enucleated egg cell nuclear transfer.
This will produce an organism that has the exact genetic material as that of the donor cell. Scientists are using current techniques exceedingly more, and with a variety of species. Surprisingly, there are many more clones in the world than one would think. In nature, and even in the lives of humans, clones are quite common. As stated earlier, a clone is an organism that has the same genetic information as another organism.
From this we can say that cloning occurs with all plants, some insects, algae, unicellular organisms that conduct mitosis or binary fissions, and occasionally by all multicellular organisms, including humans. Identical twins, are clones of each other. They have the same exact genetic information due to the division of an embryo early in development in which it produces two identical embryos. In unicellular organisms, a cell will produce two daughter cells that have the same genetic material. Today, the only cloning research is occurring in scientific model organisms.
These are organisms that research scientists from around the globe have collected copious amounts of data. All this data is necessary so that advancements in research can continue more efficiently. The most common scientific models are E. coli, mice, fruit flies, and frogs.
The first organisms that were cloned using nuclear transfer were frogs. This is because they have large egg cells and scientists can obtain up to two thousand of them from one ovulation. Successful cloning has occurred with livestock. The drive toward success is not because livestock like cows and sheep are model organisms.
Instead, the farming industry has made and continues to make a big effort toward finding a way to implement the technique of nuclear transfer for livestock. Research in cloning is also occurring in primates. The reason for studying primates is the similarities with humans. This leads us to the most talked about aspects of cloning, the use of the techniques with human cells and eggs. Throughout this century, conversation, novels, magazine articles, newspaper reports, and movies have focused on the implications of cloning humans. Part of this media creates thoughts of a utopian society, while some a horrific world; the majority of them being the latter.
Cloning of humans in a biological sense already has and is occurring. Scientists are researching by splitting embryos to execute experiments to find data relating to cell differentiation, the use of stem cells, and genetic screening. Amazingly, genetic screening is occurring in Britain quite often. Fertility clinics aim this service toward couples where the mother or father has a genetic disorder. A fertility clinic will clone an embryo, and then test it for genetic disorders. If the embryo is tested negative for genetic disorders, then the fertility clinic implants a clone of that embryo.
This should guarantee that the child will not have any genetic disorders. That is the current work with cloning. It is becoming a part of our society already. Cloning is currently a technology that many people could use.
I believe it will become more popular as prices for the technique decreases, and as the use of cloning becomes increasingly acceptable. That is if we humans consider cloning an acceptable technology, and that we would like to use for the twenty-first century. Cloning has progressed so quickly, few of us know if we should be even fooling with this technology. Some scientists say that we put technologies to use once the pros outweigh the cons. A good place for us to find that information is to look at the past and current research results with cloning and why scientists research it. Amazingly, the first attempts at artificial cloning were as early as the beginning of this century.
Adolph Eduard Driesch allowed the eggs of a sea urchin develop into the two-blastomere stage. Then he separated it by shaking it in a flask and allowing them to grow. The cells developed into dwarf sea urchins. Driesch could not explain his experiments and gave up embryology for philosophy. The first implantation of a nucleus into an egg cell occurred in 1952 by Robert Briggs and Thomas J. King in Philadelphia.
They had transferred the nuclei of Leopard Frogs eggs. The egg cells did not develop. Successful cloning of embryo cells was accomplished later in the 1970 s by Dr. John Gurdon. The frogs did not develop beyond tadpoles. In 1981, investigators announced they had transplanted nuclei from mouse embryos into mouse eggs.
However, other scientists tried to duplicate the experiments, but found that they fabricated the cloning results. During the late seventies and early eighties, there were few scientists still studying cloning. Many had predicted that it was impossible to clone embryonic mammal cells. Few continued with research. Many gave up and went into other fields. However, some persisted and were rewarded for their efforts.
In 1984, Dr. Seen Willadsen announced that he had successfully transferred nuclei from embryos of sheep to produce clones. He also was successful with cows and even monkeys. He advanced his methods, and began cloning embryos that were in the 64 - 128 cell-stage. This suggested that perhaps nuclear transfer was possible with differentiated cells. More exciting was when Dr.
Neal First produced cows by nuclear transfer from more developed embryos in 1994. Dr. First produced four calves. Two years later, Dr. Ian Wilmut and Dr.
Keith Campbell, of the Roslin Institute in Edinburgh, Scotland, produced for the world Megan and Morag, the first cloned sheep from embryo cells. Their new technique involved the starving of the donor embryo. This would put the cell in the right moment in the cell cycle, thus allowing the genetic material to integrate more successfully with the egg cell. This was the integral step of nuclear transfer. Dr.
First had executed the same step, but a laboratory staff member did it accidentally, and First did not realize the significance of his staff members mistake. Dr. Wilmut and Dr. Campbell became world famous. Their fame was not finished yet however. On July 5 at 4: 00 P.
M. lamb number 6 LL 3 or Dolly, was born in a shed down the road from the Institute. She weighed in at 14 pounds and was healthy. Scientists accomplished this by using frozen mammary cells taken from a six-year-old pregnant ewe and fusing them with an enucleated egg. The trick to fusing the cells is giving a small electric current to the petri dish on which the egg cell is.
This stimulates the egg much like a sperm would, and usually takes the genetic material from the cell and becomes a zygote. They let this zygote grow into an embryo, and then transplanted the embryo in a recipient ewe, acting as a surrogate mother. This procedure occurred late in January of 1996. This was the day of fusion date for Dolly, which is the natural equivalent to a conception date. After Dolly came other sheep, cows and even rhesus monkeys cloned using similar techniques but with slight variations.
These cloned animals came from Roslin and many universities from across America. The goals and purposes for researching cloning range from making copies of those that have deceased to better engineering the offspring in humans and animals. Cloning could also directly offer a means of curing diseases or a technique that could extend the means to acquiring new data for embryology and development of organisms as a whole. Currently, the agricultural industry demands nuclear transfer to produce better livestock. Cloning could massively improve the agricultural industry as the technique of nuclear transfer improves. Scientists also ponder the idea of cloning endangered species to increase their population.
The possibilities are endless. However, we are actually doing much of this research for the improvement of life for humans. Scientists foresee the cloning of pigs to produce organs that humans will not reject. Also livestock can produce biological proteins helping people who have diseases including diabetes, Parkinsons, and Cystic Fibrosis. Cloning also provides better research capabilities for finding cures to many diseases. There are also possibilities that nuclear transfer could provide benefits to those who would like children.
For instance, couples who are infertile, or have genetic disorders, could use cloning to produce a child. Equally important, women who are single could have a child using cloning instead of in-vitro fertilization. Nuclear transfer could also provide children who need organ transplants to have a clone born to donate organs. Cloning could also provide a copy of a child for a couple whose child had died. Cloning does offer some negative affects it could have to life. The biggest problem with asexual reproduction is that genetic diversity becomes limited.
If a population of organisms has the same genetic information, then the disease would wipe out the population. This is because not one organism has an advantage of fighting the disease over the other. The technique of nuclear transfer is also early in its developmental stages. Thus, errors are occurring when scientists carry out the procedure. For instance, it took 277 tries to produce Dolly, and Roslin scientists produced many lambs with abnormalities. This is the main reason science is holding out on cloning humans.
Other arguments for cloning include if we are taking nature into our own hands by cloning. Religious organizations consider nuclear transfer to cause men to be reproductively obsolete. Religious groups claim that cloning defies the rule or their belief that humans have souls. They also consider cloning unnatural, and say we are taking the work of God into our own hands. People question when we will draw the line for getting involved in natural events. There is also a debate as to the moral rights of clones.
Some say this will occur because there is no birth of newness, as well as uniqueness. We would not receive clones with such excitement as a child of a couple who conceived naturally. If natural reproduction were to occur, genetic variation would occur. They say cloning would deprive someone to have any perception of uniqueness. They argue that identical twins are not unique from each other. However, they are new in genetic variation and unique from anything that came before them.
People also wonder what mental and emotional problems would result if a clone were to find out that he or she was cloned. Although nuclear transfer produces clones, scientists confess that they are not exact clones because the recipient egg does not receive all the genetic information from the donor cell. The genetic material that does not make it to the egg cell is found in ribosomes, which are present in the cytoplasm. In addition, mutations can occur and genomic imprinting could cause other differences. Scientists even say identical twins, are not as identical as we thought. Scientists also predict that fraternal twins, would maintain more similarities than clones.
The reason seems that fraternal twins grow a bond during their first nine months. This is an example that genetics does not fully contribute to the personality of a person. Time spent intrauterine for nine months has a greater effect than genetics. Cloning does not artificially produce copies of adult humans. Nuclear transfer is the artificial making of an embryo that will develop into an identical twin. No machine that can produce carbon-copy humans when performing nuclear transfer is involved.
At this point, I believe we should not use cloning. I do not believe enough research has been taken on the consequences of cloning and until that point I don t believe it is an acceptable risk.
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