Cloning in biology is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects orplants reproduce asexually. Cloning inbiotechnology refers to processes used to create copies of DNA fragments (molecular cloning), cells (cell cloning), or organisms. The term also refers to the production of multiple copies of a product such as digital media or software.
The term clone is derived from κλῶνος, the Greek word for "trunk, branch", referring to the process whereby a new plant can be created from a twig. In horticulture, the spelling clon was used until the twentieth century; the final e came into use to indicate the vowel is a "long o" instead of a "short o". Since the term entered the popular lexicon in a more general context, the spelling clone has been used exclusively.
• 1 Molecular cloning
• 2 Cellular cloning
o 2.1 Unicellular organisms
o 2.2 Cloning in stem cell research
• 3 Organism cloning
o 3.1 Horticultural
o 3.2 Parthenogenesis
o 3.3 Artificial cloning of organisms
Main article: Molecular cloning
Molecular cloning refers to the process of making multiple molecules. Cloning is commonly used to amplify DNA fragments containing whole genes, but it can also be used to amplify any DNA sequence such as promoters, non-coding sequences and randomly fragmented DNA. It is used in a wide array of biological experiments and practical applications ranging from genetic fingerprinting to large scale protein production. Occasionally, the term cloning is misleadingly used to refer to the identification of the chromosomal location of a gene associated with a particular phenotype of interest, such as inpositional cloning. In practice, localization of the gene to a chromosome or genomic region does not necessarily enable one to isolate or amplify the relevant genomic sequence. To amplify any DNA sequence in a living organism, that sequence must be linked to an origin of replication, which is a sequence of DNA capable of directing the propagation of itself and any linked sequence. However, a number of other features are needed and a variety of specialised cloning vectors (small piece of DNA into which a foreign DNA fragment can be inserted) exist that allow protein expression, tagging, single stranded RNA and DNA production and a host of other manipulations.
Cloning of any DNA fragment essentially involves four steps
1. fragmentation - breaking apart a strand of DNA
2. ligation - gluing together pieces of DNA in a desired sequence
3. transfection - inserting the newly formed pieces of DNA into cells
4. screening/selection - selecting out the cells that were successfully transfected with the new DNA
Although these steps are invariable among cloning procedures a number of alternative routes can be selected, these are summarized as a 'cloning strategy'.
Initially, the DNA of interest needs to be isolated to provide a DNA segment of suitable size. Subsequently, a ligation procedure is used where the amplified fragment is inserted into a vector (piece of DNA). The vector (which is frequently circular) is linearised using restriction enzymes, and incubated with the fragment of interest under appropriate conditions with an enzyme called DNA ligase. Following ligation the vector with the insert of interest is transfected into cells. A number of alternative techniques are available, such as chemical sensitivation of cells, electroporation, optical injection and biolistics. Finally, the transfected cells are cultured. As the aforementioned procedures are of particularly low efficiency, there is a need to identify the cells that have been successfully transfected with the vector construct containing the desired insertion sequence in the required orientation. Modern cloning vectors include selectable antibiotic resistance markers, which allow only cells in which the vector has been transfected, to grow. Additionally, the cloning vectors may contain colour selection markers, which provide blue/white screening (??-factor complementation) on X-gal medium. Nevertheless, these selection steps do not absolutely guarantee that the DNA insert is present in the cells obtained. Further investigation of the resulting colonies must be required to confirm that cloning was successful. This may be accomplished by means of PCR, restriction fragment analysis and/or DNA sequencing.
Cloning cell-line colonies using cloning rings
Cloning a cell means to derive a population of cells from a single cell. In the case of unicellular organisms such as bacteria and yeast, this process is remarkably simple and essentially only requires the inoculation of the appropriate medium. However, in the case of cell cultures from multi-cellular organisms, cell cloning is an arduous task as these cells will not readily grow in standard media.
A useful tissue culture technique used to clone distinct lineages of cell lines involves the use of cloning rings(cylinders). According to this technique, a single-cell suspension of cells that have been exposed to a mutagenic agent or drug used to drive selection is plated at high dilution to create isolated colonies; each arising from a single and potentially clonal distinct cell. At an early growth stage when colonies consist of only a few of cells, sterile polystyrene rings (cloning rings), which have been dipped in grease are placed over an individual colony and a small amount oftrypsin is added. Cloned cells are collected from inside the ring and transferred to a new vessel for further growth.
Cloning in stem cell research
Main article: Somatic cell nuclear transfer
Somatic cell nuclear transfer, known as SCNT, can also be used to create embryos for research or therapeutic purposes. The most likely purpose for this is to produce embryos for use in stem cell research. This process is also called "research cloning" or "therapeutic cloning." The goal is not to create cloned human beings (called "reproductive cloning"), but rather to harvest stem cells that can be used to study human development and to potentially treat disease. While a clonal human blastocyst has been created, stem cell lines are yet to be isolated from a clonal source.
Further information: Asexual reproduction
Organism cloning (also called reproductive cloning) refers to the procedure of creating a new multicellular organism, genetically identical to another. In essence this form of cloning is an asexual method of reproduction, where fertilization or inter-gamete contact does not take place. Asexual reproduction is a naturally occurring phenomenon in many species, including most plants (seevegetative reproduction) and some insects. Scientists have made some major achievements with cloning, including the asexual reproduction of sheep and cows. There is a lot of ethical debate over whether or not cloning should be used. However, cloning, or asexual propagation, has been common practice in the horticultural world for hundreds of years.
The term clone is used in horticulture to mean all descendants of a single plant, produced byvegetative reproduction or apomixis. Many horticultural plant cultivars are clones, having been derived from a single individual, multiplied by some process other than sexual reproduction. As an example, some European cultivars of grapes represent clones that have been propagated for over two millennia. Other examples are potato and banana. Grafting can be regarded as cloning, since all the shoots and branches coming from the graft are genetically a clone of a single individual, but this particular kind of cloning has not come under ethical scrutiny and is generally treated as an entirely different kind of operation.
Many trees, shrubs, vines, ferns and other herbaceous perennials form clonal colonies. Parts of a large clonal colony often become detached from the parent, termed fragmentation, to form separate individuals. Some plants also form seeds is asexually, termed apomixis, e.g. dandelion.
Clonal derivation exists in nature in some animal species and is referred to as parthenogenesis(reproduction of an organism by itself without a mate). This is an asexual form of reproduction that is only found in females of some insects, crustaceans and lizards. The growth and development occurs without fertilization by a male. In plants, parthenogenesis means the development of an embryo from an unfertilized egg cell, and is a component process of apomixis. In species that use the XY sex-determination system, the offspring will always be female. An example is the "Little Fire Ant" (Wasmannia auropunctata), which is native to Central and South America but has spread throughout many tropical environments.
Artificial cloning of organisms
Artificial cloning of organisms may also be called reproductive cloning.
Reproductive cloning generally uses "somatic cell nuclear transfer" (SCNT) to create animals that are genetically identical. This process entails the transfer of a nucleus from a donor adult cell (somatic cell) to an egg that has no nucleus. If the egg begins to divide normally it is transferred into the uterus of the surrogate mother. Such clones are not strictly identical since the somatic cells may contain mutations in their nuclear DNA. Additionally, the mitochondria in the cytoplasm also contains DNA and during SCNT this DNA is wholly from the donor egg, thus the mitochondrial genome is not the same as that of the nucleus donor cell from which it was produced. This may have important implications for cross-species nuclear transfer in which nuclear-mitochondrial incompatibilities may lead to death.
Artificial embryo splitting or embryo twinning may also be used as a method of cloning, where anembryo is split in the maturation before embryo transfer. It is optimally performed at the 6- to 8-cell stage, where it can be used as an expansion of IVF to increase the number of available embryos. If both embryos are successful, it gives rise to monozygotic (identical) twins.
Dolly the Sheep
Dolly, a Finn-Dorset ewe, was the first mammal to have been successfully cloned from an adult cell. She was cloned at the Roslin Institute in Scotland and lived there from her birth in 1996 until her death in 2003 when she was six. Her stuffed remains were placed at Edinburgh's Royal Museum, part of the National Museums of Scotland.
Dolly was publicly significant because the effort showed that the genetic material from a specific adult cell, programmed to express only a distinct subset of its genes, can be reprogrammed to grow an entirely new organism. Before this demonstration, it had been shown by John Gurdon that nuclei from differentiated cells could give rise to an entire organism after transplantation into an enucleated egg. However, this concept was not yet demonstrated in a mamallian system.
Cloning Dolly the sheep had a low success rate per fertilized egg; she was born after 237 eggs were used to create 29 embryos, which only produced three lambs at birth, only one of which lived. Seventy calves have been created and one third of them died young; Prometea took 277 attempts. Notably, although the first clones were frogs, no adult cloned frog has yet been produced from a somatic adult nucleus donor cell.
There were early claims that Dolly the Sheep had pathologies resembling accelerated aging. Scientists speculated that Dolly's death in 2003 was related to the shortening of telomeres, DNA-protein complexes that protect the end of linear chromosomes. However, other researchers, includingIan Wilmut who led the team that successfully cloned Dolly, argue that Dolly's early death due to respiratory infection was unrelated to deficiencies with the cloning process.
On September 15, 2007, the Philippines announced its development of Southeast Asia’s first clonedwater buffalo. The Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD), under the Department of Science and Technology in Los Baños, Lagunaapproved this project. 
Further information: List of animals that have been cloned
The modern cloning techniques involving nuclear transfer have been successfully performed on several species. Landmark experiments[clarification needed] in chronological order:
Tadpole: (1952) Many scientists questioned whether cloning had actually occurred and unpublished experiments by other labs were not able to reproduce the reported results.
Carp: (1963) In China, embryologist Tong Dizhou produced the world's first cloned fish by inserting the DNA from a cell of a male carp into an egg from a female carp. He published the findings in a Chinese science journal.
Mice: (1986) A mouse was the first mammal successfully cloned from an early embryonic cell.Soviet scientists Chaylakhyan, Veprencev, Sviridova, and Nikitin had the mouse "Masha" cloned. Research was published in the magazine "Biofizika" volume ХХХII, issue 5 of 1987.[clarification needed]
Sheep: (1996) From early embryonic cells by Steen Willadsen. Megan and Morag cloned from differentiated embryonic cells in June 1995 and Dolly the sheep from a somatic cell in 1997.
Rhesus Monkey: Tetra (January 2000) from embryo splitting[clarification needed]
Gaur: (2001) was the first endangered species cloned.
Cattle: Alpha and Beta (males, 2001) and (2005) Brazil
Cat: CopyCat "CC" (female, late 2001), Little Nicky, 2004, was the first cat cloned for commercial reasons
Dog: Snuppy, a male Afghan hound was the first cloned dog (2005).
Rat: Ralph, the first cloned rat (2003)
Mule: Idaho Gem, a john mule born 4 May 2003, was the first horse-family clone.
Horse: Prometea, a Haflinger female born 28 May 2003, was the first horse clone.
Water Buffalo: Samrupa was the first cloned water buffalo. It was born on February 6, 2009, atIndia's Karnal National Diary Research Institute but died five days later due to lung infection.
Camel: (2009) Injaz, is the first cloned camel.
Main article: Human cloning
Human cloning is the creation of a genetically identical copy of an existing or previously existinghuman. The term is generally used to refer to artificial human cloning; human clones in the form ofidentical twins are commonplace, with their cloning occurring during the natural process of reproduction. There are two commonly discussed types of human cloning: therapeutic cloning and reproductive cloning. Therapeutic cloning involves cloning adult cells for use in medicine and is an active area of research. Reproductive cloning would involve making cloned humans. A third type of cloning called replacement cloning is a theoretical possibility, and would be a combination of therapeutic and reproductive cloning. Replacement cloning would entail the replacement of an extensively damaged, failed, or failing body through cloning followed by whole or partial brain transplant.
The various forms of human cloning are controversial. There have been numerous demands for all progress in the human cloning field to be halted. Most scientific, governmental and religious organizations oppose reproductive cloning. The American Association for the Advancement of Science(AAAS) and other scientific organizations have made public statements suggesting that human reproductive cloning be banned until safety issues are resolved. Serious ethical concerns have been raised by the future possibility of harvesting organs from clones. Some people have considered the idea of growing organs separately from a human organism - in doing this, a new organ supply could be established without the moral implications of harvesting them from humans. Research is also being done on the idea of growing organs that are biologically acceptable to the human body inside of other organisms, such as pigs or cows, then transplanting them to humans, a form ofxenotransplantation.
The first hybrid human clone was created in November 1998, by American Cell Technologies. It was created from a man's leg cell, and a cow's egg whose DNA was removed. It was destroyed after 12 days. Since a normal embryo implants at 14 days, Dr Robert Lanza, ACT's director of tissue engineering, told the Daily Mail newspaper that the embryo could not be seen as a person before 14 days. While making an embryo, which may have resulted in a complete human had it been allowed to come to term, according to ACT: "[ACT's] aim was 'therapeutic cloning' not 'reproductive cloning'"
On January, 2008, Wood and Andrew French, Stemagen's chief scientific officer in California, announced that they successfully created the first 5 mature human embryos using DNA from adult skin cells, aiming to provide a source of viable embryonic stem cells. Dr. Samuel Wood and a colleague donated skin cells, and DNA from those cells was transferred to human eggs. It is not clear if the embryos produced would have been capable of further development, but Dr. Wood stated that if that were possible, using the technology for reproductive cloning would be both unethical and illegal. The 5 cloned embryos, created in Stemagen Corporation lab, in La Jolla, were destroyed.
Ethical issues of cloning
Main article: Ethics of cloning
Because of recent technological advancements, the cloning of animals (and potentially humans) has been an issue. The Catholic Church and many religious organizations oppose all forms of cloning, on the grounds that life begins at conception. Judaism does not equate life with conception and, though some question the wisdom of cloning, Orthodox rabbis generally find no firm reason in Jewish law and ethics to object to cloning. From the standpoint of classical liberalism, concerns also exist regarding the protection of the identity of the individual and the right to protect one's genetic identity.
Gregory Stock is a scientist and outspoken critic against restrictions on cloning research.Bioethicist Gregory Pence also attacks the idea of criminalizing attempts to clone humans.
The social implications of an artificial human production scheme were famously explored in Aldous Huxley's novel Brave New World.
On December 28, 2006, the U.S. Food and Drug Administration (FDA) approved the consumption of meat and other products from cloned animals. Cloned-animal products were said to be virtually indistinguishable from the non-cloned animals. Furthermore, companies would not be required to provide labels informing the consumer that the meat comes from a cloned animal.
Critics have raised objections to the FDA's approval of cloned-animal products for human consumption, arguing that the FDA's research was inadequate, inappropriately limited, and of questionable scientific validity. Several consumer-advocate groups are working to encourage a tracking program that would allow consumers to become more aware of cloned-animal products within their food.
Joseph Mendelson, legal director of the Center for Food Safety, said that cloned food still should be labeled since safety and ethical issues about it remain questionable.
Carol Tucker Foreman, director of food policy at the Consumer Federation of America, stated that FDA does not consider the fact that the results of some studies revealed that cloned animals have increased rates of mortality and deformity at birth.
Cloning extinct and endangered species
Cloning, or more precisely, the reconstruction of functional DNA from extinct species has, for decades, been a dream of some scientists. The possible implications of this were dramatized in the best-selling novel by Michael Crichton and high budget Hollywood thriller Jurassic Park. In real life, one of the most anticipated targets for cloning was once the Woolly Mammoth, but attempts to extract DNA from frozen mammoths have been unsuccessful, though a joint Russo-Japanese team is currently working toward this goal.
In 2001, a cow named Bessie gave birth to a cloned Asian gaur, an endangered species, but the calf died after two days. In 2003, a banteng was successfully cloned, followed by three African wildcats from a thawed frozen embryo. These successes provided hope that similar techniques (using surrogate mothers of another species) might be used to clone extinct species. Anticipating this possibility, tissue samples from the last bucardo (Pyrenean Ibex) were frozen in liquid nitrogen immediately after it died in 2000. Researchers are also considering cloning endangered species such as the giant panda, ocelot, and cheetah. The "Frozen Zoo" at the San Diego Zoo now stores frozen tissue from the world's rarest and most endangered species.
In 2002, geneticists at the Australian Museum announced that they had replicated DNA of theThylacine (Tasmanian Tiger), extinct about 65 years previous, using polymerase chain reaction.However, on February 15, 2005 the museum announced that it was stopping the project after tests showed the specimens' DNA had been too badly degraded by the (ethanol) preservative. On 15 May 2005 it was announced that the Thylacine project would be revived, with new participation from researchers in New South Wales and Victoria.
In January 2009, for the first time, an extinct animal, the Pyrenean ibex mentioned above was cloned, at the Centre of Food Technology and Research of Aragon, using the preserved DNA of the skin samples from 2001 and domestic goat egg-cells. (The ibex died shortly after birth due to physical defects in its lungs.)  One of the continuing obstacles in the attempt to clone extinct species is the need for nearly perfect DNA. Cloning from a single specimen could not create a viable breeding population in sexually reproducing animals. Furthermore, even if males and females were to be cloned, the question would remain open whether they would be viable at all in the absence of parents that could teach or show them their natural behavior.
Cloning endangered species is a highly ideological issue. Many conservation biologists andenvironmentalists vehemently oppose cloning endangered species — mainly because they think it may deter donations to help preserve natural habitat and wild animal populations. The "rule-of-thumb" in animal conservation is that, if it is still feasible to conserve habitat and viable wild populations, breeding in captivity should not be undertaken in isolation.
In a 2006 review, David Ehrenfeld concluded that cloning in animal conservation is an experimental technology that, at its state in 2006, could not be expected to work except by pure chance and utterly failed a cost-benefit analysis. Furthermore, he said, it is likely to siphon funds from established and working projects and does not address any of the issues underlying animal extinction (such as habitat destruction, hunting or other overexploitation, and an impoverished gene pool). While cloning technologies are well-established and used on a regular basis in plant conservation, care must be taken to ensure genetic diversity. He concluded:
Vertebrate cloning poses little risk to the environment, but it can consume scarce conservation resources, and its chances of success in preserving species seem poor. To date, the conservation benefits of transgenics and vertebrate cloning remain entirely theoretical, but many of the risks are known and documented. Conservation biologists should devote their research and energies to the established methods of conservation, none of which require transgenics or vertebrate cloning.
Cloning: The process of making a clone, a genetically identical copy. Cloning can refer to the technique of producing a genetically identical copy of an organism by replacing the nucleus of an unfertilized ovum with the nucleus of a body cell from the organism.
The first adult mammal cloned was Dolly the Sheep in 1997.
1. A cell, group of cells, or organism that is descended from and genetically identical to a single common ancestor, such as a bacterial colony whose members arose from a single original cell.
2. An organism descended asexually from a single ancestor, such as a plant produced by layering or a polyp produced by budding.
3. A DNA sequence, such as a gene, that is transferred from one organism to another and replicated by genetic engineering techniques.
4. One that copies or closely resembles another, as in appearance or function: "filled with business-school clones in gray and blue suits" (Michael M. Thomas).
v. cloned, clon•ing, clones
1. To make multiple identical copies of (a DNA sequence). 2. To create or propagate (an organism) from a clone cell: clone a sheep. 3. To reproduce or propagate asexually: clone a plant variety.
4. To produce a copy of; imitate closely: "The look has been cloned into cliché"(Cathleen McGuigan).
clon al (kl n l) adj. clon al•ly adv. clon er n.
Cloning is the process of creating an identical copy of an original. A clone in the biological sense, therefore, is a multi-cellular organismthat is genetically identical to another living organism. Sometimes this can refer to "natural" clones made either when an organismreproduces asexually or when two genetically identical individuals are produced by accident (as with identical twins), but in common parlance the clone is an identical copy by some conscious design. Also see clone (genetics).
The term clone is derived from κλων, the Greek word for "twig". In horticulture, the spelling clon was used until the twentieth century; the final e came into use to indicate the vowel is a "long o" instead of a "short o". Since the term entered the popular lexicon in a more general context, the spelling clone has been used exclusively.
In biology, cloning is used in two contexts: cloning a gene, or cloning an organism. Cloning a gene means to extract a gene from one organism (for example by PCR) and insert it into a second organism (usually via a vector), where it can be used and studied. Cloning a gene sometimes can refer to success in identifying a gene associated with some phenotype. For example, when biologists say that the gene for disease X has been cloned, they mean that the gene's location and DNA sequence has been identified, although the ability to specifically copy the physical DNA is a side-effect of its identification.
Cloning an organism means to create a new organism with the same genetic information as an existing one. In a modern context, this can involve somatic cell nuclear transfer in which the nucleus is removed from an egg cell and replaced with a nucleus extracted from a cell of the organism to be cloned (currently, both the egg cell and its transplanted nucleus must be from the same species). As the nucleus contains (almost) all of the genetic information of a lifeform, the "host" egg cell will develop into an organism genetically identical to the nucleus "donor". Mitochondrial DNA, which is not transferred by this process, is generally ignored as its effects on organisms are thought to be relatively minor.
The term clone is used in horticulture to mean all descendants of a single plant, produced by vegetative reproduction. Many horticultural varieties of plants are clones, having been derived from a single individual, multiplied by some process other than sexual reproduction. As an example, some European varieties of grapes represent clones that have been propagated for over two millennia. This is a genuine example of cloning in the broader biological sense, as it creates genetically identical organisms by biological means, but this particular kind of cloning has not come under ethical scrutiny and is generally treated as an entirely different kind of operation.
Therapeutic cloning is the procedure for creating stem cells genetically compatible with the patient.
The modern cloning techniques involving nuclear transfers have been successfully performed on several species: (in chronological order) frogs: (1962) Unsuccessful
carp: (1963) ** Successfully cloned ** sheep: (1996) Dolly
rhesus monkey: Tetra (female, January 2000) pig: 5 Scottish PPL piglets (March 2000), Xena (female, August 2000) gaur: Noah (male, January 2001)
cattle: Alpha and Beta (males, 2001) cat: CopyCat "CC" (female, late 2001), Little Nicky, 2004, was the first cat cloned for commercial reasons mice: over a dozen as of 2002
rabbit: (March-April, 2003) in France and North Korea independently. Human-rabbit hybrid in China (August, 2003)
mule: Idaho Gem (male, May 2003) and Utah Pioneer (male, June 2003)
deer: Dewey (2003) horse: Prometea (female, 2003)
rat: Ralph (male, 2003) fruit flies (2004)
Surprisingly, an Asian scientist, embryologist Tong Dizhou, cloned a fish in 1963, 33 years before Dolly the sheep. Apparently, he published the findings in an obscure Chinese science journal, which was never translated into English. 
However, the success rate has been very low: Dolly was born after 276 failed attempts; 70 calves have been created from 9,000 attempts and one third of them died young; Prometea took 328 attempts. With certain species such as dogs no successful clones have been created at all.
A surprising development to do with aging resulted from finds that Dolly was apparently born old; she developed arthritis at age six. Aging of this type is thought to be due to telomeres, regions at the tips of chromosomes which prevent genetic threads fraying every time a cell divides. Over time telomeres get worn down until cell-division is no longer possible - this is thought to be a cause of aging. However, when researchers cloned cows they appeared to be younger than they should be. Analysis of the cow's telomeres showed they had not only been 'reset' to birth-length, but they were actually longer - suggesting these clones would live longer life spans than normal cows (but many have died young after excessive growth). Researchers think that this could eventually be developed to reverse aging in humans.
Main article: Human cloning
Human cloning is a subject of great controversy regarding its ethical and practical consequences. Many people believe that attempts to perform human reproductive cloning would be unethical, but some scientists have publicly announced their intention to do so. A number of groups have made claims that they are working on or have already produced human clones. None of these claims has been independently confirmed. Meanwhile therapeutic cloning appears to be a promising technology for combating many deadly diseases. It should be noted that natural clones occur - identical twins.
Cloning extinct species
Cloning , or more precisely, the reconstruction of functional DNA from extinct species has, for decades, been a dream of some scientists. The possible implications of this were dramatized in the novel by Michael Creighton and high budget Hollywood thriller, called "Jurassic Park". In real life, one of the most anticipated targets for cloning was once the Woolly mammoth, but attempts to extract DNA from frozen mammoths have been unsuccessful.
In 2000, a cow named Bessie gave birth to a cloned Asian guar, an endangered species; this provided hope that similar techniques (using surrogate mothers of another species) might be used to clone extinct species; in anticipation of this possibility, the last bucardo, a Spanish mountain goat, was frozen immediately after it died (from illness after birth). Researchers are also considering cloning endangered species such as the giant panda, ocelot, and cheetah.In 2002, geneticists at the Australian Museum announced that they had replicated DNA of the Thylacine (Tasmanian Tiger), extinct about 65 years previous, using polymerase chain reaction (PCR).
One of the continuing obstacles in the attempt to clone extinct species is the need for nearly perfect DNA. Furthermore, if animals were cloned from one individual, the significant problem of lack of genetic diversity would still remain in the attempt to establish a breeding population.
While the promise cloning extinct species is an old justification for developing cloning, there are a lot of other applications. One is cloningcattle, horses and other domestic animals. This appears to be a much faster and more efficient way to propagate good genes (as chosen by humans) than traditional breeding.
Another application that has recently became feasible is cloning pets. Little Nicky was the first pet cloned (by the Genetic Savings and Clone company) after the death of the original. The procedure is still very expensive and the demand is in its infancy, though. But there is potential demand in many unexpected areas. For example, some Hollywood movies studios stored genetic samples of some of their "animal actors" to have the possibility of growing a clone that could replace then dead animal in a future sequel .
To those against it, cloning presents as much a moral problem as a technical problem. For them, cloning is an affront to religious sensibilities; it seems like "playing God," and interfering with the natural process. There are, of course, more logical objections, regarding susceptibility to disease, expense, and diversity. Others are worried about the abuses of cloning. Cloning appears to be a powerful force that can be exploited to produce horrendous results. Their basic objections to cloning research are outlined here.
Cloning may reduce genetic variability, Producing many clones runs the risk of creating a population that is entirely the same. This population would be susceptible to the same diseases, and one disease could devastate the entire population. One can easily picture humans being wiped out be a single virus, however, less drastic, but more probable events could occur from a lack of genetic diversity. For example, if a large percentage of an nation's cattle are identical clones, a virus, such as a particular strain of mad cow disease, could effect the entire population. The result could be catastrophic food shortages in that nation.
Cloning may cause people to settle for the best existing animals, not allowing for improvement of the species. In this way, cloning could potentially interfere with natural evolution.
Cloning is currently an expensive process. Cloning requires large amounts of money and biological expertise. Ian Wilmut and his associates required 277 tries before producing Dolly. A new cloning technique has recently been developed which is far more reliable. However, even this technique has 2-3% success rate.
There is a risk of disease transfer between transgenic animals and the animal from which the transgenes were derived. If an animal producing drugs in its milk becomes infected by a virus, the animal may transmit the virus to a patient using the drug.
Any research into human cloning would eventually need to be tested on human. The ability to clone humans may lead to the genetic tailoring of offspring. The heart of the cloning debate is concerned with the genetic manipulation of a human embryo before it begins development. It is conceivable that scientists could alter a baby's genetic code to give the individual a certain color of eyes or genetic resistance to certain diseases. This is viewed as inappropriate tampering with "Mother Nature" by many ethicists.
Because clones are derived from an existing adult cell, it has older genes. Will the clone's life expectancy be shorter because of this? Despite this concern, so far, all clones have appeared to be perfectly normal creatures.
A "genetic screening test" could be used to eliminate zygotes of a particular gender, without requiring a later abortion.
Cloning might be used to create a "perfect human," or one with above normal strength and sub-normal intelligence, a genetic underclass. Also, if cloning is perfected in humans, there would be no genetic need for men.
Cloning might have a detrimental effect on familial relationships. A child born from an adult DNA cloning of his father could be considered a delayed identical twin of one of his parents. It is unknown as to how a human might react if he or she knew he or she was an exact duplicate of an older individual.
Supporters of cloning feel that with the careful continuation of research, the technological benefits of cloning clearly outweigh the possible social consequences. In their minds, final products of cloning, like farm animals, and laboratory mice will not be the most important achievement. The applications of cloning they envision are not nightmarish and inhumane, but will improve the overall quality of science and life. Cloning will help to produce discoveries that will effect the study of genetics, cell development, human growth, and obstetrics. Human cloning is not the issue, it is merely a threat to the continuation of cloning research. Their arguments for such research are displayed here.
Cloning might produce a greater understanding of the cause of miscarriages, which might lead to a treatment to prevent spontaneous abortions. This would help women who can't bring a fetus to term. It might lead to an understanding of the way a morula (mass of cells developed from a blastula) attaches itself to the uterine wall. This might generate new and successful contraceptives.
Cloning experiments may add to the understanding of genetics and lead to the creation of animal organs that an be easily accepted by humans. This would supply limitless organs to those in need. The growth of the human morula is similar to the growth at which cancer cells propagate. If information derived from cloning research allows scientists to stop the division of the human ovum, a technique for terminating cancer may be found.
Cloning could also be used for parents who risk passing a defect to a child. A fertilized ovum could be cloned, and the duplicate tested for disease and disorder. If the clone was free from defects, then other would be as well. The latter could be implanted in the womb.
Damage to the nervous system could treated through cloning. Damaged adult nerve tissue does not regenerate on its own. However, stem cells might be able to repair the damaged tissue. Because of the large number of cells required, human embryo cloning would be required.
In in-vitro fertilization, a doctor often implants many fertilized ova into a woman's uterus and counts on one resulting in pregnancy. However, some women can only supply one egg. Through cloning, that egg could be divided into eight zygotes for implanting. The chances of pregnancy would be much greater.
Cloning would allow a women to have one set of identical twins instead of going through two pregnancies. The women may not want to disrupt her career, or would prefer to only have one pregnancy. With cloning it would be assured that they would be identical.
Cloning could provide spare parts. Fertilized ova could be cloned into several zygotes, one would be implanted and the others would be frozen for future use. In the event the child required a transplant, another zygote could be implanted, matured, and eventually contribute to the transplant. Some believe that if a parent wanted to produce talents in a child similar to his own, cloning using DNA from the cell of the adult may produce a child with the same traits. Many are skeptical about this possibility. In the debate over cloning, there are those that feel that the benefits and advances gained from cloning outweigh any social dilemmas, and there are those feel that cloning is wrong on a fundamental moral level and would produce scientific and social problems. In weighing in on these views, major organizations draw on numerous sources including religious law, party philosophy and scientific concern. Some object to cloning on a purely ethical level, while others favor cloning solely for the scientific advances it will produce. These are the stances of some prominent religious, scientific, and ethical groups.
The Catholic Church: John Paul II released a statement condemning the cloning of all life forms. The
Vatican also issued a statement that only condemned human cloning, but did not address other forms.
Sunni Islam: Abdelmo’ti Bayyumi, theologian from Al-Azhar University declared it is forbidden to clone animals under Islamic law. However, some Muslims have testified to the National Bioethics Advisory Committee that they feel cloning might be allowable if it produced ways to counteract infertility.
Judaism: The Chief Rabbi of Israel, Meir Law, stated that the cloning of any creature is against Jewish law. However, some believe cloning in order to produce better food and medication would be allowable in Jewish tradition.
Biotechnology Industry Organization: Carl Felbaum, president- "One of the prospects should not be, perhaps should never be, the extension of this technique to human beings... Now that it may be possible we would say it should be prohibited if necessary by law."
Libertarian Party: Steve Dasch, chairman- "Politicians should not have veto power over the creation of new life - especially human life...That’s why the Libertarian Party supports reproductive freedom of choice for Americans-whether they choose to reproduce using the traditional method, or artificial insemination, or in-vitro fertilization, or cloning... if cloning research is banned, millions of people could suffer."
Foundation of Economic Trends: Jeremy Rifkin, president- Proposing a world-wide ban on cloning, he says it should carry a penalty "on par with rape, child abuse, and murder."
World Council of Churches: Martin Robra, executive secretary- the council would prefer a moratorium until all ethical questions can be resolved.
Church of England Board of Social Responsibility: Mary Seller- "The antics of a few cranks and Hitler types" should not impede cloning research. "Cloning. like all science, must be used responsibly. Cloning humans is not desirable. But cloning sheep has its uses."
Clones Rights United Front: Randolfe Wicker, founder- "We’re fighting for research, and we’re defending people’s reproductive rights... I realize my clone would be my identical twin, and my identical twin has a right to be born."
Stephen Grebe: professor of biology, American University- "We’re going to be facing this issue with humans... With that possibility open, I’m concerned without safeguards that this will become a reality. It may very well already be."
Terça, 03 Fevereiro 2009 08:58 |Class Forum: Cloning
Ana Bastos, 16: One of the issues that have caused more division in today’s society is cloning. There are various views but none is completely correct or perfect.
In my opinion, cloning has two faces, each with completely different characteristics.
For example, in some cases it is stated by the scientific community that cloning will help cure cancer. So… why not open the doors to cloning? It would be very important for medical science advances.
However, look at cloning from an ethical and moral viewpoint: the cloning of human embryos is truly against ethics and nobody knows what its results would be! Moreover, we humans, haven’t the right to clone a baby for the simple reason that it’s necessary for the advance of science and to find affective medical treatments.
Finally, I would say that cloning can be used for terrorist purposes and if it can help discover the cure for diseases, it can also create new diseases!
Because of these last devastating factors, I’m against human cloning.
João Ferreira, 17: I think cloning expresses the scientific revolution we are living nowadays. Times ago, who would say that it would be possible to create a copy of a potato or of a sheep with exactly the same characteristics?
It’s, no doubt, an authentic new engineering “play” that we can manipulate genetically organisms, turning them into what we want.
Cloning, like every recently discovery, must be very carefully studied before its use becomes unsafe. It wouldn’t be nice to see all world with all the people looking the same; the same haircuts, the same face expressions, etc. Cloning can bring us many good things as bad results. On the one hand there are many diseases that could be cured with the replacement ill organs and cloning would be the answer. Almost-extinct species could be replaced through cloning in their natural habitat. On the other hand clones could become smarter than men and start a new social revolution. They could even control us, if they got to know how to do it. There are many bad people who could use cloning to create armies, assassins, etc.
To conclude, I just think that cloning is fascinating. However, this should be a technique to be only on the hands of those who really know its risks and know how to control it.
Tânia Nogueira,16: I do not agree with cloning. Firstly because nature does not allow that, then it goes against the law of nature. Secondly because the cloned person or even the clone itself may have consequences with this action.
Miriam Garrett,17 , If cloning would be well succeed, it could help in the advance of science and, as a consequence, it would help children with serious diseases.
However, I am against cloning because clones would not be treated as human beings, but as scientific projects. Besides, from the religious point of view, if God wanted us to live forever, he would made us immortal.
Ricardo Dias,16, Nowadays cloning is a subject that is well accepted by some people, but at the same time is much questionable by the majority f people in the world.
However in my opinion cloning has good and bad things.
Firstly cloned cells can be used to increase the production of food plants and to increase livestock and thus reduce famine. More cloned cells can be used to help infertile people have babies as well as for transplants.
On the other hand cloning has been a subject of great controversy for several reasons: so far, the majority of clones have been born with deformities, have died before birth or younger than normal animals, clones could be used to fight in wars, for slave labour or slave trade.
In short, I think that cloning would bring advantages, but it would also bring several serious problems to the world.
Tiago Matos,17: I don’t know very well but I think that it would be such a big problem to have one or two more of me. I know that if I had a clone and people didn’t know about it, he could make my friends mad about me and some other wrong things and that would bring me big troubles.
I may understand people who like the idea of having a clone, but individuality is an amazing thing. I like being unique and if I had a clone that wouldn’t be possible.
Márcia Costa,16: I think that cloning will be very useful in our life because we will be able to clone organs and use them for transplant or clone cells to cure some diseases that today still with no cure. So we will improve the life quality of patients.
Don't I also understand that this theme have also problems principally ethical problems but when I talk about cloning and don't mean to cloning completely an human, but just some organs if that person really need. People cannot think to clone a person to replace her; people must have the idea that a clone is some other life just genetically identical to his cells-donor. I think just the idea of somebody have a person exactly like her is ridiculous because normally everyone want to be recognize by the society.
For me is this: we just need clone for medical questions but there are always people who have others crazies' ideas and this people could be very dangerous.
Diogo Baig,16: have always been for the advance of technology, and I have never been afraid of it – that’s why I have chosen this school area.
But in this case, I have a different opinion. I believe that cloning human beings is an area that we shouldn’t explore, because we are talking about human life which it’s not something to play with.
We don’t know the risks and the consequences of cloning human beings, because it’s something that has was never been experienced before. Besides, it is anti-nature – and I am not talking from the religious point. It's just my opinion as a human being.
About the cloning of organs, I think that’s a try to avoid and change the natural law of life, which is born to live and die.We should be careful about it, this is serious - just because we can do something, that doesn't mean that we should.Sara Tavares,16: Genetic engineering and genetic modification are the process of handling the genes in an organism, generally out of the normal reproductive process.
Many opponents to genetic engineering believe that the growing use of GMO in great plantations can led biotechnical companies to gain excessive power on the production of food, and on the farmers.
Genetic modification alters the genes and, consequently, the characteristics of the individual. It is possible, for example, to modify genetically strawberries so that they can remain fresh during more time.
When a plant is modified genetically, a strange gene is introduced in the genes of the plant itself. It can be, for example, a gene of a resistant bacterium to the pesticide. As result, the genetically modified plant inherits the characteristics contained in the genetic code transplanted, becoming also able to support the pesticides.
In traditional agriculture genes are transferred from a plant to another one. This is also the case in the genetic modification - but the way of doing it is very different. Genetic modification is a more precise technique, in which it is possible to transfer exactly the wanted characteristics. In the traditional process, it is not possible to avoid the eventuality of transferring other characteristics and the characteristics can be exchanged only between identical or very similar sorts of plants. In the genetic modification, the characteristics can be transferred from any sort of organism to a very different one.
Science has come along way since the dawn of our era. The break through s and discoveries in the modern medical and technical fields are amazing. Computers are another advance in modern science and technology. People use computers to type papers, play games, and use the internet among many other things. Computers can also be used for science. Formulas that may fail or be very expensive if tried physically, can easily be tested using a computer. After successfully cloning a sheep, man now feels the possibilities for genetic engineering are endless. After creating a living, breathing creature, what is to prevent scientists from creating a human? Greed, religion, and power are the biggest negatives against man playing god.
Money is said to be the root of all evil, a statement that could very well be proven correct if the genetic cloning of a human being were allowed. The first company to develop the correct technology to properly clone and grow a human would have exclusive rights to it. The price of making a clone would be determined solely by that company. The balance of power would be entirely in the favor of the company that made human cloning possible, and that spells chaos for the rest of the world. Consumers wishing to use or purchase the technology would have to abide by every rule and restriction made by the parent company. Too much power in one individual s hands is never a good thing, and that scenario seems very apparent in this situation. Power corrupts people in a way that is inexplicable, a good example would be an Olympian winning a gold metal in his or her respective sport. They suddenly realize that they are better than all the other competition and that they are indeed the best in the world. Then of course they will want to show of their achievements by gloating and bragging about what they ve done and trying to show people that they could very well and easily do it again. The problem with this is that when they try to accomplish their feat again, they are unable to, and the world is disappointed and in trouble at the same time. All the money that was invested in the software and technology will be lost and wasted. Human cloning could be a one hit wonder .
Many religions believe that god put mankind on the earth. Genetic engineering challenges the beliefs of much of the world, in that man is playing the role of god by creating living, breathing organisms. A sheep has already been created by using the dna of a living sheep. One of the only things standing in science s way from cloning a human is religion. Most religions believe that god made things the way they were meant to be according to that particular religion, but no matter what the belief of that religion says, human cloning would go against it. Judaism believes that god created everything, and that god is everything, no where does it state that man has the power to take the genetic reigns and build a carbon based form of life. Scientists however, feel that the world is relatively up for grabs, and the person able to unlock the code, holds the key to being a god.
Human cloning could easily become the next big thing since computers. The person or people that come up with the technology that makes human cloning possible own and have all the rights to the technology; the power belongs solely to that person or group of people. Power corrupts the mind. The corruption that is waiting to take place in the underworld of human cloning is huge. Regulations need to be made well before the software goes public. The government needs to know what kind of regulatory actions need to be taken against the field of human cloning so monopolies will not form and power will not ruin the industry. The field of human cloning is already volatile, as many companies and research laboratories are working furiously to develop a way to clone a human being. The company that cracks the code first is the obvious winner, getting all the copyright s and trademark s, along with all the money and corporate power. The power awarded to the winner of the genetic race is near godly, with profit s that would most likely exceed the account of Bill Gates. The scientists attributed with making human cloning possible would become the most powerful person in the world.
Greed, religion, and power are three negative points against human genetic engineering. The possibilities for problems are far too large for the government to allow this research to go on. The room for error is oversized and if something bad were to happen, chaos would likely soon follow. Human cloning should not be allowed.