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Introduction

In mathematics and abstract algebra, group theory studies the algebraic structures known as groups. The concept of a group is central to abstract algebra: other well-known algebraic structures, such as rings, fields, and vector spaces can all be seen as groups endowed with additional operations and axioms. Groups recur throughout mathematics, and the methods of group theory have strongly influenced many parts of algebra. Linear algebraic groups and Lie groups are two branches of group theory that have experienced tremendous advances and have become subject areas in their own right.

Various physical systems, such as crystals and the hydrogen atom, can be modelled by symmetry groups. Thus group theory and the closely related representation theory have many applications in physics and chemistry.

One of the most important mathematical achievements of the 20th century [1] was the collaborative effort, taking up more than 10,000 journal pages and mostly published between 1960 and 1980, that culminated in a complete classification of finite simple groups.

History

Group theory has three main historical sources: number theory, the theory of algebraic equations, and geometry. The number-theoretic strand was begun by Leonhard Euler, and developed by Gauss’s work on modular arithmetic and additive and multiplicative groups related to quadratic fields. Early results about permutation groups were obtained by Lagrange, Ruffini, and Abel in their quest for general solutions of polynomial equations of high degree. Évariste Galois coined the term “group” and established a connection, now known as Galois theory, between the nascent theory of groups and field theory. In geometry, groups first became important in projective geometry and, later, non-Euclidean geometry. Felix Klein’s Erlangen program proclaimed group theory to be the organizing principle of geometry.

Galois, in the 1830s, was the first to employ groups to determine the solvability of polynomial equations. Arthur Cayley and Augustin Louis Cauchy pushed these investigations further by creating the theory of permutation groups. The second historical source for groups stems from geometrical situations. In an attempt to come to grips with possible geometries (such as euclidean, hyperbolic or projective geometry) using group theory, Felix Klein initiated the Erlangen programme. Sophus Lie, in 1884, started using groups (now called Lie groups) attached to analytic problems. Thirdly, groups were (first implicitly and later explicitly) used in algebraic number theory.

The different scope of these early sources resulted in different notions of groups. The theory of groups was unified starting around 1880. Since then, the impact of group theory has been ever growing, giving rise to the birth of abstract algebra in the early 20th century, representation theory, and many more influential spin-off domains. The classification of finite simple groups is a vast body of work from the mid 20th century, classifying all the finite simple groups.

Main classes of groups

Main articles: Group (mathematics) and Glossary of group theory

The range of groups being considered has gradually expanded from finite permutation groups and special examples of matrix groups to abstract groups that may be specified through a presentation by generators and relations.

Permutation groups

The first class of groups to undergo a systematic study was permutation groups. Given any set X and a collection G of bijections of X into itself (known as permutations) that is closed under compositions and inverses, G is a group acting on X. If X consists of n elements and G consists of all permutations, G is the symmetric group Sn; in general, any permutation group G is a subgroup of the symmetric group of X. An early construction due to Cayley exhibited any group as a permutation group, acting on itself (X = G) by means of the left regular representation.

In many cases, the structure of a permutation group can be studied using the properties of its action on the corresponding set. For example, in this way one proves that for n ≥ 5, the alternating group An is simple, i.e. does not admit any proper normal subgroups. This fact plays a key role in the impossibility of solving a general algebraic equation of degree n ≥ 5 in radicals.

Matrix groups

The next important class of groups is given by matrix groups, or linear groups. Here G is a set consisting of invertible matrices of given order n over a field K that is closed under the products and inverses. Such a group acts on the n-dimensional vector space Kn by linear transformations. This action makes matrix groups conceptually similar to permutation groups, and the geometry of the action may be usefully exploited to establish properties of the group G.

Transformation groups

Permutation groups and matrix groups are special cases of transformation groups: groups that act on a certain space X preserving its inherent structure. In the case of permutation groups, X is a set; for matrix groups, X is a vector space. The concept of a transformation group is closely related with the concept of a symmetry group: transformation groups frequently consist of all transformations that preserve a certain structure.

The theory of transformation groups forms a bridge connecting group theory with differential geometry. A long line of research, originating with Lie and Klein, considers group actions on manifolds by homeomorphisms or diffeo-morphisms. The groups themselves may be discrete or continuous.

Abstract groups

Most groups considered in the first stage of the development of group theory were “concrete”, having been realized through numbers, permutations, or matrices. It was not until the late nineteenth century that the idea of an abstract group as a set with operations satisfying a certain system of axioms began to take hold. A typical way of specifying an abstract group is through a presentation by generators and relations,

G = langle S|Rrangle.

A significant source of abstract groups is given by the construction of a factor group, or quotient group, G/H, of a group G by a normal subgroup H. Class groups of algebraic number fields were among the earliest examples of factor groups, of much interest in number theory. If a group G is a permutation group on a set X, the factor group G/H is no longer acting on X; but the idea of an abstract group permits one not to worry about this discrepancy.

The change of perspective from concrete to abstract groups makes it natural to consider properties of groups that are independent of a particular realization, or in modern language, invariant under isomorphism, as well as the classes of group with a given such property: finite groups, periodic groups, simple groups, solvable groups, and so on. Rather than exploring properties of an individual group, one seeks to establish results that apply to a whole class of groups. The new paradigm was of paramount importance for the development of mathematics: it foreshadowed the creation of abstract algebra in the works of Hilbert, Emil Artin, Emmy Noether, and mathematicians of their school.

Topological and algebraic groups

An important elaboration of the concept of a group occurs if G is endowed with additional structure, notably, of a topological space, differentiable manifold, or algebraic variety. If the group operations m (multiplication) and i (inversion),

m: Gtimes Gto G, (g,h)mapsto gh, quad i:Gto G, gmapsto g^{-1},

are compatible with this structure, i.e. are continuous, smooth or regular (in the sense of algebraic geometry) maps then G becomes a topological group, a Lie group, or an algebraic group.[2]

The presence of extra structure relates these types of groups with other mathematical disciplines and means that more tools are available in their study. Topological groups form a natural domain for abstract harmonic analysis, whereas Lie groups (frequently realized as transformation groups) are the mainstays of differential geometry and unitary representation theory. Certain classification questions that cannot be solved in general can be approached and resolved for special subclasses of groups. Thus, compact connected Lie groups have been completely classified. There is a fruitful relation between infinite abstract groups and topological groups: whenever a group Γ can be realized as a lattice in a topological group G, the geometry and analysis pertaining to G yield important results about Γ. A comparatively recent trend in the theory of finite groups exploits their connections with compact topological groups (profinite groups): for example, a single p-adic analytic group G has a family of quotients which are finite p-groups of various orders, and properties of G translate into the properties of its finite quotients.

Combinatorial and geometric group theory

Groups can be described in different ways. Finite groups can be described by writing down the group table consisting of all possible multiplications g • h. A more compact way of defining a group is by generators and relations, also called the presentation of a group. Given any set F of generators {gi}i ∈ I, the free group generated by F surjects onto the group G. The kernel of this map is called subgroup of relations, generated by some subset D. The presentation is usually denoted by 〈F | D 〉. For example, the group Z = 〈a | 〉 can be generated by one element a (equal to +1 or −1) and no relations, because n·1 never equals 0 unless n is zero. A string consisting of generator symbols and their inverses is called a word.

Combinatorial group theory studies groups from the perspective of generators and relations.[3] It is particularly useful where finiteness assumptions are satisfied, for example finitely generated groups, or finitely presented groups (i.e. in addition the relations are finite). The area makes use of the connection of graphs via their fundamental groups. For example, one can show that every subgroup of a free group is free.

There are several natural questions arising from giving a group by its presentation. The word problem asks whether two words are effectively the same group element. By relating the problem to Turing machines, one can show that there is in general no algorithm solving this task. Another, generally harder, algorithmically insoluble problem is the group isomorphism problem, which asks whether two groups given by different presentations are actually isomorphic. For example the additive group Z of integers can also be presented by

〈x, y | xyxyx = e〉;

it may not be obvious that these groups are isomorphic.[4]

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The Cayley graph of 〈 x, y ∣ 〉, the free group of rank 2.

Geometric group theory attacks these problems from a geometric viewpoint, either by viewing groups as geometric objects, or by finding suitable geometric objects a group acts on.[5] The first idea is made precise by means of the Cayley graph, whose vertices correspond to group elements and edges correspond to right multiplication in the group. Given two elements, one constructs the word metric given by the length of the minimal path between the elements. A theorem of Milnor and Svarc then says that given a group G acting in a reasonable manner on a metric space X, for example a compact manifold, then G is quasi-isometric (i.e. looks similar from the far) to the space X.

Representation of groups

Saying that a group G acts on a set X means that every element defines a bijective map on a set in a way compatible with the group structure. When X has more structure, it is useful to restrict this notion further: a representation of G on a vector space V is a group homomorphism:

ρ : G → GL(V),

where GL(V) consists of the invertible linear transformations of V. In other words, to every group element g is assigned an automorphism ρ(g) such that ρ(g) ∘ ρ(h) = ρ(gh) for any h in G.

This definition can be understood in two directions, both of which give rise to whole new domains of mathematics.[6] On the one hand, it may yield new information about the group G: often, the group operation in G is abstractly given, but via ρ, it corresponds to the multiplication of matrices, which is very explicit.[7] On the other hand, given a well-understood group acting on a complicated object, this simplifies the study of the object in question. For example, if G is finite, it is known that V above decomposes into irreducible parts. These parts in turn are much more easily manageable than the whole V (via Schur’s lemma).

Given a group G, representation theory then asks what representations of G exist. There are several settings, and the employed methods and obtained results are rather different in every case: representation theory of finite groups and representations of Lie groups are two main sub domains of the theory. The totality of representations is governed by the group’s characters. For example, Fourier polynomials can be interpreted as the characters of U(1), the group of complex numbers of absolute value 1, acting on the L2-space of periodic functions.

Connection of groups and symmetry

Given a structured object X of any sort, a symmetry is a mapping of the object onto itself which preserves the structure. This occurs in many cases, for example

If X is a set with no additional structure, symmetry is a bijective map from the set to itself, giving rise to permutation groups.

If the object X is a set of points in the plane with its metric structure or any other metric space, a symmetry is a bijection of the set to itself which preserves the distance between each pair of points (an isometry). The corresponding group is called isometry group of X.

If instead angles are preserved, one speaks of conformal maps. Conformal maps give rise to Kleinian groups, for example.

Symmetries are not restricted to geometrical objects, but include algebraic objects as well. For instance, the equation

x^2-3=0

has the two solutions +sqrt{3}, and -sqrt{3}. In this case, the group that exchanges the two roots is the Galois group belonging to the equation. Every polynomial equation in one variable has a Galois group, that is a certain permutation group on its roots.

The axioms of a group formalize the essential aspects of symmetry. Symmetries form a group: they are closed because if you take symmetry of an object, and then apply symmetry, the result will still be a symmetry. The identity keeping the object fixed is always a symmetry of an object. Existence of inverses is guaranteed by undoing the symmetry and the associativity comes from the fact that symmetries are functions on a space, and compositions of functions are associative.

Frucht’s theorem says that every group is the symmetry group of some graph. So every abstract group is actually the symmetries of some explicit object.

The saying of “preserving the structure” of an object can be made precise by working in a category. Maps preserving the structure are then the morphisms, and the symmetry group is the automorphism group of the object in question.

Applications of group theory

Applications of group theory abound. Almost all structures in abstract algebra are special cases of groups. Rings, for example, can be viewed as abelian groups (corresponding to addition) together with a second operation (corresponding to multiplication). Therefore group theoretic arguments underlie large parts of the theory of those entities.

Galois theory uses groups to describe the symmetries of the roots of a polynomial (or more precisely the automorphism of the algebras generated by these roots). The fundamental theorem of Galois theory provides a link between algebraic field extensions and group theory. It gives an effective criterion for the solvability of polynomial equations in terms of the solvability of the corresponding Galois group. For example, S5, the symmetric group in 5 elements, is not solvable which implies that the general quintic equation cannot be solved by radicals in the way equations of lower degree can. The theory, being one of the historical roots of group theory, is still fruitfully applied to yield new results in areas such as class field theory.

Algebraic topology is another domain which prominently associates groups to the objects the theory is interested in. There, groups are used to describe certain invariants of topological spaces. They are called “invariants” because they are defined in such a way that they do not change if the space is subjected to some deformation. For example, the fundamental group “counts” how many paths in the space are essentially different. The Poincaré conjecture, proved in 2002/2003 by Grigori Perelman is a prominent application of this idea. The influence is not unidirectional, though. For example, algebraic topology makes use of Eilenberg-MacLane spaces which are spaces with prescribed homotopy groups. Similarly algebraic K-theory stakes in a crucial way on classifying spaces of groups. Finally, the name of the torsion subgroup of an infinite group shows the legacy of topology in group theory.

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A torus. Its abelian group structure is induced from the map C → C/Z+τZ, where τ is a parameter living in the upper half plane.

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The cyclic group Z26 underlies Caesar’s cipher.

Algebraic geometry and cryptography likewise uses group theory in many ways. Abelian varieties have been introduced above. The presence of the group operation yields additional information which makes these varieties particularly accessible. They also often serve as a test for new conjectures.[8] The one-dimensional case, namely elliptic curves is studied in particular detail. They are both theoretically and practically intriguing.[9] Very large groups of prime order constructed in Elliptic-Curve Cryptography serve for public key cryptography. Cryptographical methods of this kind benefit from the flexibility of the geometric objects, hence their group structures, together with the complicated structure of these groups, which make the discrete logarithm very hard to calculate. One of the earliest encryption protocols, Caesar’s cipher, may also be interpreted as a (very easy) group operation. In another direction, toric varieties are algebraic varieties acted on by a torus. Toroidal embeddings have recently led to advances in algebraic geometry, in particular resolution of singularities.[10]

Algebraic number theory is a special case of group theory, thereby following the rules of the latter. For example, Euler’s product formula

begin{align}

sum_{ngeq 1}frac{1}{n^s}& = prod_{p text{ prime}} frac{1}{1-p^{-s}}

end{align}

!

captures the fact that any integer decomposes in a unique way into primes. The failure of this statement for more general rings gives rise to class groups and regular primes, which feature in Kummer’s treatment of Fermat’s Last Theorem.

The concept of the Lie group (named after mathematician Sophus Lie) is important in the study of differential equations and manifolds; they describe the symmetries of continuous geometric and analytical structures. Analysis on these and other groups is called harmonic analysis. Haar measures, that is integrals invariant under the translation in a Lie group, are used for pattern recognition and other image processing techniques.[11]

In combinatorics, the notion of permutation group and the concept of group action are often used to simplify the counting of a set of objects; see in particular Burnside’s lemma.

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The circle of fifths may be endowed with a cyclic group structure

The presence of the 12-periodicity in the circle of fifths yields applications of elementary group theory in musical set theory.

In physics, groups are important because they describe the symmetries which the laws of physics seem to obey. According to Noether’s theorem, every symmetry of a physical system corresponds to a conservation law of the system. Physicists are very interested in group representations, especially of Lie groups, since these representations often point the way to the “possible” physical theories. Examples of the use of groups in physics include the Standard Model, gauge theory, the Lorentz group, and the Poincaré group.

In chemistry and materials science, groups are used to classify crystal structures, regular polyhedra, and the symmetries of molecules. The assigned point groups can then be used to determine physical properties (such as polarity and chirality), spectroscopic properties (particularly useful for Raman spectroscopy and infrared spectroscopy), and to construct molecular orbitals.

Cloning is the creation of an organism that is an exact genetic copy of another. This means that every single bit of DNA is the same between the two organisms. Cloning is at present illegal because of the devastating impacts it may have on humanity, cloning became popular when scientist Ian Wilmut first cloned Dolly by a process termed somatic cell nuclear transfer. Dolly was the only success out of 277 experiments and Cumulina, the first cloned mouse after Dolly, was among 15 live born mice from 942 tries; so this proves that cloning is yet not quite understandable for we have little knowledge about it. But even so humans won’t stop until it is a safe success. Cloning is bound to bring great benefits to human kind but it will also bring fort great chaos from ethical views and religion. The idea that a clone is an exact duplicate of another individual is not reliable, and so if the intent of cloning is to create such a copy, it simply will not work. To be clear, the tips of chromosomes, called telomeres, shorten with each cell division. A clone’s telomeres are as short as those from the donor nucleus, which means that they are “older” even at the start of the clone’s existence. DNA in the donor nucleus has also had time to mutate, that is to say, it has had time to undergo modification from its original sequence, thus distinguishing it genetically from other cells of the donor. A mutation that would have a negligible or delayed effect in one cell of a many-celled organism, such as a cancer-causing mutation, might be devastating if an entire organism develops under the direction of that nucleus. Finally, the clone’s mitochondria, the cell organelles that house the reactions of metabolism and contain some genes, are those of the recipient cell, not the donor, because they reside in the cytoplasm of the egg. Mitochondrial genes, therefore, are different in the clone than they are in the nucleus donor. The consequences of nuclear and mitochondrial genes from different individuals present in the same cell are not known, but there may be incompatibilities. Perhaps the most compelling reason why a clone is not really a duplicate is that the environment affects gene expression. Cloned calves have different colour patterns, because when the animals were embryos, the cells that were destined to produce pigment moved in different ways in each calf. For humans, consider identical twins. Nutrition, stress, exposure to infectious diseases, and other environmental factors greatly influence our characteristics. For these reasons, cloning a deceased child, the application that most would-be cloners give for pursuing the technology, would likely lead to disappointment.

Actual Process

In its most basic procedure, cloning encompasses three footsteps. In the first step, scientists obtain cells from an individual whose characteristics they want to copy for example they want to copy an ordinary dog’s colour, consider that I have a dog pot-licker but he has his two front legs white with black spots, like a dalmata. It’s this characteristic that they want to copy so they would take his cells for the process. They then place these cells, which are called donor cells, into a liquid culture. This culture contains nutrients that stop the cells from dividing. In the second footstep, an unfertilized egg is taken from a female. This unfertilized eggs nucleus is then removed, leaving an empty egg cell. The donor cell is then taken form the culture and is placed into the empty egg. This progression creates an embryo that is an exact copy of the donor, which would be the spotted leg dog and not the mother. In the final step, the embryo is put into the uterus of a female of the same species and the offspring arrives into the world by means of the natural birth process.

Plants

From a long time ago, people have been taking roots or stems of plants in order to make genetically identical copies. Usually, this is done by choosing the best plant, of course (for example, the most decorative or unusual), cutting a root or branch from it, and placing that cutting in water or soil. The cells will then divide and double in size every six weeks until the cutting develops roots. At this point, it is ready to be planted. It will then grow into an exact copy of the parent plant. This is normally done with flowers and vegetables and fruits.

Animals

Dolly, a Finn Dorset sheep, the first mammal cloned from an adult cell, was produced in Scotland at the Roslin Institute in Edinburgh, this happened in July 1997. Ian Wilmut and colleagues informed the birth of a lamb resulting from the transfer of a nucleus obtained from an adult ewe udder cell into an enucleated oocyte that was then implanted into a surrogate mother. Dolly was cloned through a process called nuclear transfer. The process that produced Dolly differs from ordinary reproduction in two major ways. First, body (or somatic) cells from an adult ewe’s udder (this is the donor) were placed in a culture dish and it was allowed to grow. The nutrients were then removed from the culture, which stopped the cells’ growth. One of these nongrowing cells was then fused by electric jolts with another ewe’s oocyte from which the nucleus had been previously removed. This procedure is known as ‘somatic cell nuclear transfer’. Within a day the fused cells began to divide in the culture dish. After several divisions, the early embryo was transferred to the uterus of a surrogate mother and allowed to develop. Second, unlike the sperm and the egg, each of which contributes half the number of chromosomes at fertilization, each body cell contains twice the number of chromosomes in each germ cell. So fusion of a sperm and an egg forms an individual whose full genetic composition is unique to that individual. On the other hand, the embryo cloned from somatic cell nuclear transfer begins development with the diploid (double) number of chromosomes, all derived from one somatic cell (adult udder) of a single individual. This embryo has the same nuclear genetic composition as the donor of the somatic cell. In the end, three sheep contributed to the production of a single lamb clone: a Finn Dorset sheep donated her udder cells for culture; a Scottish Blackface sheep donated the enucleated oocyte (with its nucleus removed, thus losing its own genetic identity in the process); and a Scottish Blackface sheep became the surrogate mother, carrying the embryo to birth.

There are 4 type of cloning: recombinant DNA technology or DNA cloning, reproductive cloning, therapeutic cloning and replacement cloning.

Therapeutic cloning, also called “embryo cloning,” is the production of human embryos for use in research. The goal of this process is not to create cloned human beings, but rather to harvest stem cells to be used to study human development and to treat disease.

Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal.

The terms “recombinant DNA technology,” “DNA cloning,” “molecular cloning,” and “gene cloning” all refer to the same process: the transfer of a DNA fragment of interest from one organism to a self-replicating genetic element such as a bacterial plasmid. The DNA of interest can then be propagated in a foreign host cell.

Replacement cloning, at present exists only in theory.

Concepts & Significance

Cloning is seen as the way to keep our species survival going, a way to better human life, a way to evolve, a way to relief, it is seen as the way out of many of our troubles. But cloning is also seen as the interference of nature; the meaning of cloning for people that see it as nature’s violation is great chaos and corruption of mankind by creating deformed beings which would then be living with the deformities. The concept of rejecting the idea of cloning is often based on emotions which stop humans from improving. Other concepts of cloning are that these clones would be treated as chemical ingredients this is considering the harvesting of organs for transplants and of course killing the clones. Clones might also be regarded as subjects rather than lives to their originals. Genetic cloning is very important. I don’t understand why people would not agree with it, maybe because they don’t know what it is. Genetic cloning is not cloning whole humans or any other animals, yet it most certainly could. Genetic cloning allows the experimentation and study of genetic disorders. By performing these experiments we learn about the different processes that occur within the cell thus the more we learn about these processes the more we can do to prevent disorders that occur due to malfunctions in these processes. Some people think that cloning is a “what the hell idea” I don’t believe so.

Benefits to Humanity

Cloning could be used to produce vital organs for transplant. The only way to do this, however, would be to clone the entire individual, including its organs. This practice would raise ethical questions and would require a long time to grow the organism. It would take a long time for a donor’s organs to be mature enough to be removed from the donor and used for transplant. In addition, scientists are unsure whether transplanted organs from cloning would be accepted or rejected by the recipient individual. Another benefit to humanity would be the salvation of endangered species. At that present time, the success was not likely to happen because it took 277 tries to clone Dolly the sheep. But if the success rate of cloning increases, it could be a way to increase the population of endangered species or animals that are difficult to breed for example the panda. Extinct species could also be revived using the cloning method although this would be more difficult. Cloning extinct animals has two problems. First, donor cells must be taken from living organisms; unless an extinct animal is found frozen (the woolly mammoth recently discovered in the Arctic), it would be impossible to find living cells. Because the fossil bones of dinosaurs contain no living cells, a dinosaur cannot be cloned. Second, current cloning technology requires a surrogate mother and an egg cell from a living female of the same species, which is something that we don’t have yet. Females normally cannot give birth to an animal from a different species. It is unlikely, for instance, that a female elephant could donate an egg cell and give birth to a woolly mammoth. Other benefits for us would be the obtaining of desired traits through cloning than through conventional breeding. For example, cloning could benefit crop engineering by creating foods that are more nutritious, disease free, and plentiful. Cloning could also help in the prevention and cure of diseases. In example, the same laboratory where Dolly was created is now working to create eggs that contain anticancer proteins to prevent various forms of cancer (such as fast growing forms of skin cancer). Dolly herself was cloned to produce a sheep whose milk had more proteins that are believed to help treat diseases such as emphysema, haemophilia, and cystic fibrosis. An interesting benefit is that aged cell nuclei can be rejuvenated. Studies using cell culture have shown that body cells grow and divide normally in culture for a while, but eventually stop dividing, become senescent, and die. An exception was seen in aged frog red blood cell nuclei (human red blood cells lack nuclei). After their transfer into enucleated oocytes, frog red blood cell nuclei were rejuvenated. They carried out the formation of tadpoles that survived almost a third of the way to metamorphosis. The oocyte cytoplasm contains an abundance of chemicals that promote DNA synthesis and cell division after normal fertilization. It’s believed that these substances also rejuvenate aged cell nuclei and turn non-cycling frog red blood cells into active ones. If they could isolate these substances, they might be able to alleviate or reverse senescence. Cloning will allow us to improve human life. It will allow more individuals to live more rewarding lives. And, it will actually have the potential to increase the quality of life of those who do not rank as high on the principal valued dimensions as the clones themselves. In addition, it will give us earlier knowledge of medical conditions of clones, so that these conditions can be addressed before they become life threatening. Longevity will also be increased by other means (chiefly gene therapy and anti-aging drugs). Thus, if the clones of a certain person have a normal life expectancy of 90 years, by the time they reach this life expectancy, in all probability, medical technology will have advanced to the point where another 30 or more years can be added to this. Hence, a clone’s foreknowledge that their proto died at a certain age from natural causes will not be an automatic death sentence for them. Clones can expect to add years to their lives through environmental influences and medical advances, so the age of their natural death will remain uncertain. There are many additional benefits from cloning to be considered. Cloning has great implications for the human species to the extent that candidates can be selected which are largely free from genetic defects. Correspondingly, the non-cloned offspring of clones will be more likely to be free from genetic defects themselves, thereby improving the quality of the human gene pool. The fears associated with establishing a qualitative distance between clones and the rest of humanity have already been discussed at some length. But summarily, the tendency of cloning will be to push the entire species in the direction of greater functionality and survivability. Inevitably, clones will marry and propagate with non-clones that are not their equals. In effect, some clones will marry to become weaker. Correspondingly, some non-clones will marry to become stronger, resulting in a genetic improvement and uplifting of the entire human race. In short, cloning will allow us to accelerate our evolution beyond what would normally occur merely by means of the choices people make in the mate selection process. Pet lovers would also have their pets for as long as they want by cloning and unfertile couples would have babies too.

Ethical Issues

The arrival of Dolly sparked widespread rumours about a human child being created using somatic cell nuclear transfer. Much of the superficial fear that met this announcement centred on the misunderstanding that a child or many children could be produced who would be identical to an existing person. This fear was based on the idea of “genetic determinism” genes alone determine all aspects of an individual and reflects the belief that a person’s genes bear a simple relationship to the physical and psychological traits that make him or her. Genes play an essential role in the formation of physical and behavioural characteristics; although each individual is, in fact, the result of an interaction between his or her genes and the environment within which he or she develops. Many of the concerns about cloning have focused on issues related to the idea of “playing God,” this is considered an interference with the natural order of life. Also there are those who believe that the embryo has the moral status of a person from the moment of conception, research or any other activity that would destroy it is wrong. Cloning ethics is structured in seven ways

The potential impact of cloning on individuals; its potential to create a genetic underclass; Clones would be considered better than others or even us humans.

The potential impact of cloning on the social structure and the division of labor. Some clones would be used for labour which would be wrong.

The implications of cloning for the composition of the gene pool and the future of human race

Who decides who is eligible to be cloned?

How will the decision to select and approve candidates for cloning be made, and what criteria will be used?

What will be the quality of life of the clones?

What are the implications of cloning for the survivability of the species; how will it enhance survivability?

Conclusion

Cloning has opened many doors and has lit many roads that could lead to significant medical advancements but, as with all new technologies, it will be accompanied by ethical and social standoffs. Today’s successes will shape the road to improving efficiencies and help add to the basic understanding of our cells. Even Dolly’s creator, Ian Wilmut, is focusing less on sheep and more on understanding the mechanism of reprogramming our genetic material. In conclusion, cloning is unsafe at this time because the complete list of defects cannot be accounted for. The sacrifice of countless children to death and physical abnormalities, as well as mental illness, cannot become real out for the sake of science. Experts say that cloning humans in the near future is not safe because: “It seems that a little knowledge is a dangerous thing and the authors (other scientists) have allowed themselves to over-interpret their findings,” said Ian Wilmut. This is a science that cannot be rushed into, because the consequence is paid with a lifetime of grief for a defective child.