Cloning

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DNA: The Code of Life

Summary

Not that long ago, the thought of creating a living copy of a higher form of life was considered science fiction. Now, science fiction has become science fact. In the Stargate SG-1 universe, members of SG-1 have encountered many advanced cultures and alien races that have mastered the art of creating copies of higher life forms, such as those of a human being. Although some of the methods imagined are still way out in the realm of science fiction, there are some elements of fact hidden behind the stories brought forth.

What Is Cloning?

The word "clone" is derived from the Greek for a twig (klon), and horticulturists have been taking cuttings and growing new plants from them for centuries. The word came into current usage when the renowned British biologist J.B.S. Haldane suggested in 1963 that it would soon be possible to create genetic duplicates of plants, animals, and even humans.

The word "cloning" can be applied to the many levels of duplicating living cells, tissues, organs, and organisms. In nature, cloning is accomplished through asexual reproduction. Sexual reproduction involves the merging of two sets of DNA (one from the father's sperm and one from the mother's egg) to produce a new offspring that is genetically different from either parent. Asexual reproduction (without sex) produces offspring that are genetically identical to the single parent organism.

In today's terms, the word "clone" itself can be defined as "a group of replicas of all or part of a large biological molecule" (such as DNA). The key to this definition of cloning is that it is biological.

Cloning on Earth

Scientists created the most famous clone of a higher life form in 1997 with the birth of Dolly, the sheep clone. Dolly lived for six years, dying by lethal injection in 2003. Her lifespan was about half the usual for a sheep of her kind. She suffered from lung cancer and crippling arthritis. Scientists claim, however, that other than the cancer and arthritis, Dolly was normal. She was even the mother of six lambs, reproducing the "old-fashioned way."

Dolly was produced by a method of cloning called "reproductive cloning." In this method, scientists transfer genetic material from the nucleus of a donor adult cell to an egg whose nucleus, and thus its genetic material, has been removed (this method is also called "somatic cell nuclear transfer"). The reconstructed egg is treated with chemicals or electric current in order to stimulate cell division and once the cloned embryo reaches a suitable stage, it is transferred to the uterus of a female host where it continues to develop until birth.

This method of cloning does not produce an identical clone of the donor animal. Only the clone's chromosomal or nuclear DNA is the same as the donor while some of the clone's genetic materials come from the mitochondria in the cytoplasm of the enucleated egg. The source of Dolly's donor cell was an udder cell that was reprogrammed to generate an entire new organism, rather than just more udder cells. Scientists believe that errors or incompleteness in the reprogramming process cause the high rates of death, deformity, and disability observed among animal clones.

There are other forms of cloning practiced by our scientists today. One form of cloning is called "embryo cloning." Embryo cloning is achieved in two different ways, but both ways start out with a fertilized egg known as a zygote. How far scientists allow the embryo to develop defines the type of cloning technique used. If the embryo is allowed to divide into four cells and then those four cells are separated and allowed to grow individually in a culture, the method is called "blastomere separation" (a blastomere is one of the individual cells derived after the embryo is separated). If the embryo is allowed to grow into a mass of about 32 to 150 cells, known as a blastocyst, and then the embryo is divided into two, the method is called "blastocyst division." The resulting cells from either of these two methods can be implanted into the uterus of a surrogate mother and the resulting children would be clones of each other. When blastocyst division happens naturally, for example, identical twins are created. In either case, the resulting children are clones of each other because they possess identical genes.

The goal of "therapeutic cloning," a form of "embryo cloning," is not to create cloned human beings, but rather to harvest stem cells, those cells that can form any cell type, which can be used to study human development and to treat disease. To this end, scientists have been working on a way to clone embryo cells that are the product of somatic cell nuclear transfer rather than of a zygote (fertilized egg). As recent as 1998, South Korean scientists announced that they had cloned a human embryo through somatic cell nuclear transfer and then extracted the stem cells from one of the embryos. In 2001, researchers at Advanced Cell Technology were able to get a human embryo to divide into six cells before dying. In 2004, South Korean researchers claimed they had cloned human embryos to the blastocyst stage and succeeded at extracting stem cells from one of the embryos. Techniques for prompting an unfertilized egg to produce stem cells have not been effectively developed and researchers admit that it will be many more years before these methods of producing human stem cells can be used in therapies to treat diseases such as Parkinson or heart disease.

Another form of "therapeutic cloning," is the production of human embryos by means of parthenogenesis (unfertilized egg; "parthenogenesis" is Greek for "virgin birth"). If scientists are able to extract a ovum before it gets to a certain stage of maturity, that egg cell will actually have all of the genetic code instead of half of it (the other half expected to come from the sperm cell in sexual reproduction). Embryos that develop from parthenogenesis would not be clones of the individual from which the egg is extracted because of the genetic diversity that goes into the creation of the egg initially. However, if the embryos developed by parthenogenesis develop such that they are successfully implanted into a surrogate mother, they'd be clones of each other. Researchers of the therapeutic cloning technology stress, however, that the goal of this type of stem cell generation is not to produce a living human being, but only the stem cells. The ovum can be used to create compatible cardiac muscle cells, for example, for the woman from whom the ovum is originally extracted. For men, the process would involve taking the nuclei from two sperm cells and transferring them into a contributed egg that has been stripped of its nucleus. This process is similar to the process of somatic cell nuclear transfer, but is called androgenesis (literally, "man birth").

The form of cloning called "recombinant DNA technology," "DNA cloning," "molecular cloning," or "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 (bacteria are the most often used host cells, but yeast and mammalian cells are also used). The DNA of interest propagates in the foreign host cell. This technology has been around since the 1970s and is a common practice in molecular biology labs today. Recombinant DNA technology is important for learning about other related technologies, such as gene therapy, genetic engineering of organisms, and sequencing genomes.

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Stargate References

1.14 "Hathor": DNA Cloning to Prevent Transplant Rejection

Hathor rapes Daniel for his DNA
Hathor's Goa'uld larvae
Hathor's larvae perish

The Goa'uld queen named Hathor, living in a female human host, extracted DNA, what she referred to as "the code of life," from Daniel Jackson in order to produce Goa'uld larvae that would be compatible with their future human hosts. She obtained Daniel's DNA through forced sexual intercourse and thus gained access to the genetic information encoded in his sperm cells.

Sperm cells were used by the Human Genome Project (HGP) to sequence human DNA. According to the documentation from this project, it is much easier technically to prepare DNA cleanly from sperm than from other cell types because of the much higher ratio of DNA to protein in sperm and the much smaller volume in which purifications can be done. Using sperm provides all of the chromosomes for study, including equal numbers of sperm with the X (female) or Y (male) sex chromosomes. However, HGP scientists also used white cells from the blood of female donors so as to include female-originated samples.

In her reproductive process, Hathor combined portions of Daniel's DNA into her offspring. The exact method is not known, but could be considered a form of gene splicing. She may have used one sequence of his DNA and duplicated, or cloned, it to produce her treated offspring, similar to the process of recombinant DNA technology of today, also called gene or DNA cloning. The larvae, however, had mostly Goa'uld genetic materials. Daniel's sperm did not fertilize eggs, such as is the case in the human reproductive process, to produce half of the genetic make-up of the offspring. According to the Tok'ra named Malek, in the episode, 6.10 "Cure", Goa'uld reproduction is asexual (without the production or union of two kinds of germ cells). He said that a Goa'uld queen is able to fertilize her own eggs and she does not need a "man friend." This method of fertilization most likely was Hathor's means of incorporating some of Daniel's DNA sequence into her offspring. Daniel had drawn the analogy that Hathor was like a queen bee in her method of reproduction. Honey bee queens are able to determine the genetic make-up of their offspring similar to the Tok'ra's description of the Goa'uld queen's asexual reproduction by fertilizing her own eggs. Unfertilized eggs in a honey bee actually develop into male honey bees, or drones (parthenogenesis). Since this is science fiction and the Goa'uld are alien beings, we cannot say for sure exactly how the queen Goa'uld creates her young or if she even requires a male counterpart at any time to produce those young. We are told, however, in the episode, 6.10 "Cure", that the queen symbiote has the ability to manipulate the genes that she passes on to her offspring.

Hathor's goal to create larvae that would not be rejected by a human host is similar to that of therapeutic cloning of today. The creation of genetically-modified pigs from which organs suitable for human transplants could be harvested is a potential of this form of cloning. The transplant of organs from animals to human is called xenotransplantation. Pigs have been cloned more successfully than primates, even though primates are closer to humans genetically. Scientists create something called a "knock-out" pig wherein they inactivate the genes that cause the human immune system to reject an implanted pig organ. The genes are knocked out in individual cells, which are then used to create clones from which organs can be harvested. In 2002, a British biotechnology company reported that it was the first to produce "double knock-out" pigs that have been genetically engineered to lack both copies of a gene involved in transplant rejection. The research is still ongoing.

All of the larvae that Hathor produced at the SGC base were destroyed by fire. Dr. Fraiser attempted to get DNA samples of their remains. Daniel informed her that some of the DNA would be his. This clue to the larval Goa'uld's genetic make-up was very important. If she was able to obtain a complete sample of the larval DNA, Dr. Fraiser might have been able to isolate the section of the DNA that was Daniel's and thus found which sequence was responsible for symbiote rejection and then a gene therapy could have been devised that could have enabled a human host to reject a symbiote from his body or created genetic changes in a human so that a symbiote could not blend with him (such as those of Aris Boch's people, in the episode, 3.07 "Deadman Switch"). Scientists of today have conducted research in using gene therapy to rewrite a subject's DNA in order to treat a problem, such as Alzheimer's.

Even though Hathor's larvae produced using Daniel's DNA all perished, it might have been possible for Hathor to have stored the necessary DNA fragments from Daniel's sperm in order to produce more larvae later. We are not made aware if she produced more larvae with Daniel's "code of life" after she escaped to Chulak or before she died in the episode, 3.01 "Into the Fire."

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1.19 "Tin Man": A Clone by Another Name

Daniel and his android clone
Teal'c's android clone being created
Jack's injured android clone

Totally within the realm of science fiction, the creation of SG-1's android doubles, or clones, was executed quite easily by Harlan of the planet Altair (P3X-989). These clones were produced by copying the likeness of each team members' physical form into a mechanical body and then copying their consciousness—memories, behavior patterns, and feelings—in the android body much like artificial intelligence. Harlan also augmented each clone with the knowledge of the underground power station that sustained them and with the ability to compute and think faster. Their bodies were also stronger and able to endure stress, such as jumping down over twenty feet without injury. The androids were also capable of existing for thousands of years if they maintained their power source, their only form of nourishment.

These androids are not clones by the classical definition because they are not biological replicas. However, to the androids themselves, their bodies felt to them as if they were still human, but "better." Their type of clone comes down low in the list of definitions of clone, but is there, nonetheless: "one that appears to be a copy of an original form" (from Merriam-Webster's Reference Library).

Because these clones did not bleed when their skin was injured, it is probably reasonable to assume that there were no biological aspects of their bodies whatsoever, and that their skin was artificial. Harlan said that they were synthetic and never distinguished that any part of the android bodies were not.

In today's cloning technology, scientists have taken skin cells and grown tissue, and even small forms of organs for cows. The same therapeutic cloning can be done for humans through the use of stem cells. Research is still ongoing, but scientists hope that this leads to treating often fatal diseases by growing replacement tissue and organs without the side effect of rejection.

When the android clones went home to the SGC, Dr. Fraiser was not able to tell that they were mechanical until she listened to Jack's android's chest and found no heartbeat. Up until that moment, she might have already tested his pupils with her light pen, an instrument she has been seen using first during physical examinations, and seen nothing that would have indicated that he wasn't human. Still, it is highly doubtful that these androids had any biological aspects to them because of the thousand-year lifespan, unless Harlan's machine was somehow able to stop the aging process.

The android clones of SG-1 all perished in the episode, 4.21 "Double Jeopardy."

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2.10 "Bane": Cloning and Biological Warfare

Large Insect-like Organism
Dr. Harlow extracts venom
Teal'c undergoes a transformation

Meeting up with alien lifeforms is an expectation everytime SG-1 goes through the Stargate. The lifeform they encountered on BP6-3Q1 changed everyone's opinion about harmless insects, however, when Teal'c was stung by one of these large "bugs." The venom injected into his body began to rewrite his DNA and replace it with the organism's with the aid of a retrovirus, because, in the geneticist Dr. Timothy Harlow's words, "DNA does not alter DNA."

A retrovirus is characterized by a unique mode of replication within the cells of their hosts. Like some other viral groups, retroviruses contain a core of the nucleic acid RNA instead of the usual DNA. Unlike other RNA viruses, retroviruses replicate as DNA rather than RNA genomes inside their hosts by means of an enzyme they carry, called reverse transcriptase. The retroviruses cause various infections in birds and mammals, including humans. Some genera also cause cancers in animals, such as feline leukemia and bovine sarcoma. Research in the mid-1980s indicated that some retroviruses may cause cancers in humans. The disease known as AIDS (acquired immune deficiency syndrome) has been linked with a retrovirus as well (MSN Encarta Encyclopedia).

Dr. Harlow observed also that not only was Teal'c going to become one of these organisms by the eventual replication of the organism's DNA, but several of them, because of "equal matter conversion." Teal'c's mass would determine how many of these fully-developed insect-like organisms he would become. Based on this method of replication, the organisms were all genetically identical—they were all clones.

The potential for this organism's venom to become a biological weapon in the war against the Goa'uld was tempting to the people at the NID. According to Col. Harry Maybourne of the NID, the SGC's mandate is search and retrieval while the NID's is research and development. Both programs work to protect Earth from the alien threats, but each does that from different points of view. After learning that Teal'c was undergoing some form of metamorphosis, Col. Maybourne was willing to have Teal'c change completely in order to study the effects of this organism's venom.

Biological weapons that are viruses are nothing new. Routine vaccination for smallpox (variola virus) ended in 1972 and the smallpox infection was eliminated from the world in 1977. However, strains of the smallpox virus still exist and could be used by a group of terrorists to wipe out a population because it is not certain if those who got the vaccines before 1972 are no longer susceptible. Additional viral warfare agents include viral hemorrhagic fevers (VHF), Venezuelan equine encephalitis virus, and the yellow fever virus. The mortality rate of these viral diseases varies from very low to 35% (usually in un-vaccinated populations).

When Col. Maybourne saw that the larval Goa'uld that Teal'c carried was not able to prevent Teal'c from being affected by the organism's retrovirus, he was eager to let Teal'c continue in his transformation. He saw the potential of a 100% mortality rate among those who were subjected to the retrovirus contained in the organism's venom, even among the Goa'uld. According to Carter's worse-case scenerio simulation, estimating that each person produced ten "bugs," there would be millions of these organisms in six to eight weeks. The population of BP6-3Q1 was totally wiped out and the potential for Earth's population to be wiped out by the bugs that Teal'c would become was extremely high if they were not able to come up with a reversal of the replication process.

Dr. Harlow developed a drug that slowed down the transformation enough to enable Teal'c's larval Goa'uld symbiote to do the remainder of the healing. This drug would not work on humans because they would need the Goa'uld symbiote's natural healing abilities to totally cure them. Dr. Harlow intended to keep the specimen from falling into the NID's hands by reporting a lab accident, but it is not certain if he actually destroyed the organism or his research.

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2.20 "Show and Tell": The Value of a Life Created Through Cloning

Genetically engineered Charlie
Charlie and his Reetou "Mother"
Charlie joins the Tok'ra

Cloning was most likely involved in the production of the genetically-engineered human boy named Charlie, created by a member of the alien race called the Reetou. The Reetou are basically a bug-like intelligent life form and far from being human. They also live 180 degrees out of phase with humans, thus existing invisible to humans. They were advanced enough, however, to create a human being in the laboratory. This technology is so far beyond our current abilities that it is hard to imagine how a human boy could have grown and developed outside the uterus of a living genetically-compatible surrogate mother, such as was the case in the creation of Dolly through reproductive cloning.

The Reetou genetic engineer that created Charlie, affectionately called "Mother" by him, had to not only know the exact DNA sequence of human beings, but also other factors which scientists refer to as the building blocks of life, such as amino acids and proteins, hormones, and the nurturing environment of the womb. We are so far from that aspect of creating life solely from DNA that Mother's method of cloning is still science fiction. In other words, Mother could not have created Charlie solely from a single strand of human DNA, even though Dr. Fraiser said that was all that Mother needed to construct him in a lab (by today's technological capabilities). There have been claims made by scientists all over the world that they have successfully cloned human beings and that these clones' surrogate mothers have delivered them after a normal pregnancy. These scientists have not, however, revealed the identities of these alleged clones, so it is still debatable as to the truth of their statements. These clones, if they exist, however, could have only been produced through reproductive cloning that started with an egg that had been enucleated or fertilized.

Even though we are not capable of giving life to a full-grown human outside the womb, we can make certain assumptions about how Mother created Charlie. She might have used a technique similar to our "embryo cloning" in which a fertilized egg is stimulated to divide, thus making the single cell into a two-cell embryo, and then she would have taken that process further by allowing the embryo to develop into a human. She would have needed something beyond the DNA itself to start the process, such as having an actual zygote. We're not given any information as to how Mother created Charlie, so it is possible that she had more materials with which to start than just a strand of human DNA.

According to Dr. Fraiser, Charlie was not put together accurately because his organs were beginning to fail. Charlie said that he was created quickly, indicating that his rate of cell division must have been increased substantially. Mother had to do this in order for him to fulfill his mission of warning the people of Earth of a full-scale attack sooner than she had originally anticipated. If Charlie had been allowed to develop at a slower pace, his health may have been vastly improved. Mother also modified his genetic material so that he would be able to see and communicate with her in her phase as well.

Although we may currently have the technology to create a human being through cloning, the actual ethics of doing so is still of major debate. Frozen embryos, originally intended by their parents to become living beings, have been used for stem cell research and this use has been the subject of concern of many nations all over the globe. How far does science take the development of an embryo and still not call it life?

Charlie was created to save a world. His potential and right to live seemed to not have been considered beyond that. To SG-1, however, Charlie was an individual, nonetheless, who had life and the right to live it. SG-1 did not feel that it was right for Mother to have created such a life as if it were only for communication purposes and then allow it to die so horribly. The Tok'ra Jacob/Selmak offered an alternative: Charlie could become a Tok'ra host and the symbiote would heal and correct his failing body. Charlie went with the Tok'ra, but further information about his life has not been revealed.

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3.10 "Forever In A Day": Cloning and Genetic Memory

Egyptian Scribe/Goa'uld Apophis
Sha're/Goa'uld Amaunet
Harsesis Shifu

According to the Stargate SG-1 universe, the Goa'uld record their memories, or knowledge, in their DNA so that these memories are passed on genetically to the offspring (1.03 "The Enemy Within"). Each symbiote gains the knowledge of not only its parent, but of its parent's parent, and so on. The memories recorded by these symbiotes in their DNA most likely include those they have chosen to retain of their hosts as well.

When two "Goa'ulded" human hosts produce a human offspring, the child inherits the Goa'uld genetic memory and is called "harsesis." The human host of the Goa'uld Apophis, a scribe from the temple of Amon of Ancient Egypt (2.17 "Serpent's Song"), and the human host of the Goa'uld Amaunet, Sha're of Abydos and Daniel Jackson's wife, were used by the Goa'uld symbiotes to conceive a boy through sexual intercourse. Upon conception, however, the Goa'uld Amaunet hibernated in order to prevent Sha're from miscarrying the baby (2.09 "Secrets").

The boy conceived as harsesis came to be known as Shifu (4.17 "Absolute Power"). He was human, but he inherited the Goa'uld genetic memory from the symbiotes hosted by his human parents. So, not only did he inherit the genetic memory of Amaunet, but possibly that of Apophis as well. Because of this additional advantage, the Goa'uld System Lords hunted down such offspring and killed them because their positions of power would be greatly threatened by one who possessed this abundant knowledge. Basically, they saw that the more knowledge one possessed, the more power one could obtain. It was Apophis' goal to take this child as his next host and thus ensure his supremacy amongst the System Lords (2.09 "Secrets").

For Shifu to have this Goa'uld genetic memory, his DNA was most likely modified by the symbiotes themselves. Their method is a complete mystery, as was Hathor's ability to splice Daniel's DNA from his sperm cells into her offspring. We could assume that some form of DNA duplication, or cloning, most likely took place to incorporate these memories into Shifu's DNA so that he would genetically inherit them.

According to Teal'c, it is the genetic memory of the Goa'uld that makes them evil. Shifu said that Oma Desala, his Ascended Being step-mother (3.20 "Maternal Instinct"), buried his Goa'uld genetic memories deep into his subconscious mind because the evil would have been too hard to resist. Shifu taught Daniel through a dream that gaining access to the genetic memories of the Goa'uld would not be the means of defeating them, but of destroying himself and possibly others whom he loved. Shifu chose to continue his path as an Ascended Being rather than access his buried memories and he asked Daniel to choose another path as well. (4.17 "Absolute Power")

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5.22 "Revelations": Cloning and Degredation Due to Mutation and Lack of Genetic Diversity

Asgard of 30,000 years ago
Heimdall, Asgard Geneticist
Research facility in the Adara System

The Asgard geneticist, Heimdall, revealed to SG-1 that the Asgard reproduced exclusively through a process of enhanced cellular mitosis, or cloning. In fact, for nearly a thousand years, the Asgard had been physically incapable of achieving cell division through meiosis, or sexual reproduction. Through cloning, they had achieved a measure of immortality. As each Asgard's body failed, his consciousness was transferred into a newer, younger version of himself. Unfortunately the lack of genetic diversity became a problem. It's like making a copy of a copy of a copy — eventually, there's deterioration.

Mutation is a change in DNA that alters a gene and thus the gene's product, leading in some cases to deformity or disease. Mutations can occur spontaneously during cell division or can be triggered by environmental stresses, such as sunlight, radiation, and chemicals. According to the Council for Responsible Genetics, there is a dangerous loss of diversity when a population, be it plant, livestock, human, or even Asgard, is built solely through cloning: "The robustness of natural populations, including their flexible response to new conditions and hence resistance to disease, lies to a great extent in their genetic variability. This characteristic would be entirely eliminated in a population of clones. The near total loss of the entire U.S. corn crop in the 1970's as a result of monoculture — overuse of too narrow a genetic base — is a harbinger of what could happen with cloned livestock."

Heimdall said that the Asgard had created a process of controlled mutation that had helped them avoid complete genetic breakdown, but they had reached the limits of their technical capabilities, and, at that point, the Asgard were a dying race. But, the Asgard found some hope in the 30,000-year-old body of an Asgard ancestor found in stasis only six months prior to SG-1's meeting Heimdall in an underground facility in the Adara System. This perfectly-preserved body represented the Asgard from the time before their cloning program became irreversible. The mutation of the Asgard through cloning was visually evident when comparing the appearances of this ancestor and any Asgard of today: the ancestor was taller and more human-like. The Asgard hoped that his physiology could give them clues to overcome the Asgard race's genetic degredation.

Two years later, however, the Asgard had not made progress in this area of research and continued to clone bodies into which their consciousnesses were transferred. It appeared that they decided to upload nearly the entire population's consciousnesses into storage banks in order to transport them and then create clone bodies for them once they arrived at their new homeworld, Orilla. (8.01 "New Order Part 1", 8.02 "New Order Part 2")

Finally, after realizing that they had mistakenly doomed their entire race with a fatal genetic disease, the Asgard took the last year of their existence to gather their knowledge and technology into the Asgard Core and gift this, their legacy, to the SGC, the representatives of humans on Earth. When Thor presented this Legacy, he stated that humanity had become "The Fifth Race", alluding to the Alliance of the Four Great Races (Ancients, Asgard, Nox, Furlings) that had represented the most knowledgeable and powerful races in the galaxy eons ago (1.11 "The Torment of Tantalus", 2.16 "The Fifth Race"). The Asgard committed mass suicide as they blew Orilla into smithereens. (10.20 "Unending")

Daniel grieved for the Asgard, stating that they had been no different than humanity in their bid for a better quality of life: "I mean, all they wanted to do was live a little longer. We're no different. Sequence DNA. Cure diseases. One fatal mistake, and they doom their entire race." With their Legacy, the Asgard hoped that humanity could learn from their mistakes. (10.20 "Unending")

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6.05 "Nightwalkers": Cloning and Disease Resistance

The Original Goa'uld Symbiote
Symbiote Clones
Clone-Killing Serum

They called each other "brother" and they were clones produced from one Goa'uld symbiote. Their creation by a Earth geneticist, Dr. Richard Flemming, can only be considered science fiction, since, at this point in our current cloning capabilities, we cannot create a living organism of this complexity without the use of reproductive cloning (use of a surrogate mother).

The Goa'uld symbiotes are still somewhat of a mystery to us, however, and, since they reproduce asexually to start, there might have been a way for Dr. Flemming to clone them with relative ease. We are not given the information on how he accomplished this, however. Dr. Flemming was famous for developing hybrid strains of disease-resistant corn and cotton, and he applied his genetic expertise in creating these clones with genetic kill switches. If they were exposed to a common antibiotic, they would die.

Dr. Flemming worked for a company called Immunotech Research that was a wholly-owned subsidiary of Zetatron Industries, the companies created by billionaire Adrian Conrad. Conrad gained access to a Goa'uld symbiote (5.11 "Desperate Measures") and started to conduct research on it to take advantage of its healing capabilities. He wanted to implant himself with the symbiote in order for it to cure him of a fatal disease and then remove the symbiote once the healing was completed. He grew desperate and impatient and had himself implanted with the symbiote before the research was complete. As a result, Adrian Conrad lost his identity, and eventually, his life, to the Goa'uld (6.11 "Prometheus").

In order for Dr. Flemming to create clones of the Conrad Goa'uld symbiote with this kill switch programmed into their DNA, he would have to have known the exact segment in the DNA sequence of a Goa'uld symbiote pertaining to disease and resistance. If Dr. Fraiser had been successful in gathering complete DNA samples of Hathor's larvae created in the episode, 1.14 "Hathor", then Dr. Flemming would have had the benefit of a map of the Goa'uld genetic sequence already having been started, if not completed, after about five years. If, however, he did not obtain this knowledge until after his employer's acquisition of the symbiote, then he had about a year of research to map the genome. In reality, it took the Human Genome Project (HGP) thirteen years to complete the human genome sequence. It is possible that Dr. Flemming used some of the information gathered through previous genome sequencing done on Earth to help him locate the proper genes in the clones to reprogram them with the kill switch. This is assuming, of course, that the Goa'uld symbiotes are anything like the lifeforms found on Earth.

The serum created by Dr. Flemming was a simple antibiotic, basically harmless to humans. The people of Steveston, Oregon, who were implanted with the symbiotes were cured by receiving an injection of this antibiotic, having never been aware that they had been implanted because the symbiotes were immature and could only take control while their hosts slept. The NID knew of the symbiotes and allowed them to continue to function because they were building a space ship that the NID wanted. The clones, however, became aware of the NID's surveillance and decided to infiltrate the NID and SGC. These Goa'uld, it appeared, inherited the Goa'uld genetic memory of evil-doing.

Dr. Flemming is presumed dead after an automobile accident, but his body was never recovered. His research notes were obtained by the SGC and, most probably, the NID. As far as we know, all of the symbiote clones were killed after their discovery.

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6.10 "Cure": Cloning and the Price of Perfect Health

Tok'ra Queen Egeria
Jonas among Egeria's offspring
Tretonin

The ultimate goal of cloning technology and genetic engineering of today is the improvement of the human condition. If we can turn this gene on or that gene off, then our ability to reverse diseases and aging comes into focus. The use of cloning techniques help scientists control their experiments so that they can observe the results of their manipulations.

It wasn't that easy for the Pangarans. They had the means of producing a drug that gave their people perfect health. They discovered that Goa'uld symbiotes have a natural healing ability and they used that genetic design in formulating the miracle drug, tretonin. They were given access to Goa'uld symbiotes through the use of the queen, Egeria. She had been banished by Ra for opposing him and starting the Tok'ra resistance (Tok'ra means "against Ra"). Her descendents are those symbiotes who call themselves the Tok'ra who wage war against the Goa'uld and attempt to live in a truly symbiotic relationship with their human hosts.

Egeria was held captive by the Pangarans and she was forced to spawn a seemingly endless supply of symbiotes so that the Pangarans could produce tretonin. What the Pangarans didn't know was that Egeria was capable of altering the genetic make-up of her offspring. She deliberately reprogrammed her larvae in two ways: she gave them no intelligence by withholding the Goa'uld genetic memory, and she gave them a defective gene that gave the tretonin derived from them a negative side effect. The Pangarans who were taking tretonin needed more and more of the drug to keep them healthy because the drug completely suppressed the human's immune system, requiring that they continue to take the drug or die. Egeria had hoped that they would stop manufacturing tretonin from her offspring because of this negative side effect, but the Pangarans continued to make and use the drug, hoping that they'd eventually discover a way to refine it.

Egeria's goal of genetically engineering her offspring to gain her freedom and terminate the use of her young was not met. She lived in captivity until her death. Before she died, however, she gave the Tok'ra a formula to reverse the side effects of the tretonin so that the Pangarans would live without the drug. The Pangarans learned that in some cases, the cure is no better than the disease.

Tretonin proved to be of no use for humans, but the Tok'ra refined the drug into a version that allows a Jaffa to live without carrying a symbiote (Jaffa are genetically-engineered humans who have no immune system other than what is provided to them through the larval Goa'uld they carry in their pouches). Teal'c and Bra'tac were the first Jaffa to successfully take this new form of the drug and survive without a symbiote (6.19 "Changeling") and they have been able to free many Jaffa through its introduction (7.10 "Birthright"). However, as with the Pangarans, those Jaffa who take tretonin depend upon it for their very lives and have, in effect, traded one dependence for another (8.09 "Sacrifices").

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7.03 "Fragile Balance": A Clone Does Not a Duplicate Make

Jack O'Neill
Asgard geneticist Loki
Jack's teenaged clone

After a much younger version of Col. Jack O'Neill attempted to use SG-1's commanding officer's identification badge at the check-in station at the SGC, a shocking series of events unfolded. Gen. George Hammond, Dr. Daniel Jackson, Maj. Samantha Carter, Teal'c, Dr. Janet Fraiser, and Jacob Carter/Selmak engaged in an investigation and determined that this 15-year-old boy was actually a clone of Jack created by a renegade Asgard geneticist named Loki.

Loki's modus operandi was to create a clone of an Earthling he wished to study for a week. The clone would take the place of the "original" while Loki did his genetic studies to determine if that person held the key to saving the Asgard race from extinction due to the deminishing returns of their cloning technology—the only method available to them to continue their race (see the section above on 5.22 "Revelations"). The clone would be physically aged and given a copy of the subject's consciousness so that no one could tell the difference. After the week of study was completed, Loki would exchange the original and the clone. The clone was not genetically programmed to live much beyond that week-long use and eventually died.

Before everyone discovered that Jack's clone was indeed a clone, his behavior and memories were up-to-date with the 50-something man they knew. Even the clone thought himself to be "real." Jacob Carter/Selmak was able to determine that the teenager was actually a clone by examining his DNA, which had a "tiny abnormality" from what Dr. Fraiser had on record as being Jack's DNA sequence. This small difference was a genetically-engineered marker placed in Jack's DNA to prevent further tampering when the Asgard removed the knowledge of the Ancients from his mind after he looked into one of their Repository of Knowledge machines (2.16 "The Fifth Race"). Because Jack was able to utilize the knowledge in order to successfully seek help to have the knowledge removed, Loki believed that his brain was advanced enough to harbor the advanced intellect of the Asgard. When Thor was called to help, it was revealed that Loki had been prevented from doing his experiments because they were not sanctioned. He had been out of action for about 19 years, but was able to return to Earth while the rest of the Asgard were preoccupied with the war with the Replicators and relocating their population.

The Asgard have had thousands of years to perfect their cloning techniques, even those which pertain to cloning human beings. Loki's methods were abhorrent to the other Asgard and Earthlings alike, but his goal was a noble one: he wished to save his people from the certain extinction they were facing unless something could be done to reverse the negative side effects of their cloning program. In his efforts, however, he preserved the lives of the originals, but sacrificed those of the clones. Loki did not consider the clones to be individuals worthy of living their lives.

Jack's young clone was dying because of Loki's genetic programming. Jack asked Thor to help the clone live and Thor was successful in manipulating his DNA in order for him to grow up at a normal human rate.

There has been much controversy concerning cloning human beings. The means of creating clones of humans from zygotes (embryo cloning) exists today through the use of a technique similar to in vitro fertilization that gives thousands of couples the opportunity to have children they could not have otherwise. However, the means of cloning a person in the manner of Dolly, somatic cell nuclear transfer, has not yet been perfected.

There are people out there, however, who wish to clone their fathers, or a dead child, or even themselves, thinking that this will give them a measure of immortality. We know this is not the case as it was with Jack's clone, since Jack's clone was given a copy of Jack's consciousness (purely science fiction). The clone may look like the original (eventually), but he will have experienced many differences in his life before and after his birth. These differences can change the person's health and personality. These very differences can be observed today in the lives of identical twins, especially those who were separated at birth or at a very young age who have grown up in different environments and have related with different people along the way.

Jack's clone may have looked like him, but a clone does not a duplicate make. The clone decided that he wanted to go back to high school, something Jack originally disliked, and live a different life than what he had before, knowing what he knew now. He said to Jack as he was dropped off at school, "Well, from here on in, you and me are different."

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7.11-7.12 "Evolution": Cloning and Eugenics

Kull Warrior in action
Kull Warrior's face
Kull Warrior army

Eugenics is the science of the improvement of hereditary qualities and can be applied to all life forms, but has been applied specially to the genetic improvement of human beings. Before cloning, the improvement was accomplished via selective breeding. Extremes in creating the perfect human have taken the form of sterilization of certain "undesirables" (such as criminals, the mentally challenged, or the insane) to all-out extermination of a certain group (genocide). SG-1 saw both cases of eugenics and genocide in the mission to Euronda in the episode, 4.02 "The Other Side."

Anubis had an idea to create the perfect footsoldier through cloning and genetic engineering. When SG-1 was able to conduct an autopsy of one of Anubus' Kull Warriors, they found that it had been grown in a laboratory to be the perfect athlete with enlarged heart and lungs to supply enough blood and oxygen to its muscles. It was also implanted with a Goa'uld symbiote that had natural healing capabilities. There was little consideration, according to Jacob/Selmak, however, to produce these warriors with longevity in mind.

In our society today, the debate continues on the ethical aspects of cloning and genetically engineering children with desirable traits. Some have referred to the children born of this form of eugenics as "designer babies." By using the current technologies of blastocyst division and therapeutic cloning, couples can create for themselves twins who are genetically engineered to have "improved" traits. Couples with enough money can have this done privately, without the fear of government regulation. In effect, this form of eugenics could create a society of those who have and those who have not in the genetic "superiority" department. Basically, if the technology exists and it can be done, it will be done no matter what.

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7.19 "Resurrection": Cloning Failures

Geneticist Dr. Keffler
Mutated Fetuses
Human-Goa'uld Hybrid Anna

Not everyone had learned of the inadvisability of seeking the knowledge of the Goa'uld through accessing their genetic memory as Daniel had. A rogue NID cell operating in California had tried to create a human-Goa'uld hybrid who'd be physically human, but possess the Goa'uld genetic knowledge without the implantation of a symbiote. Dr. Keffler was the geneticist who was successful in creating such a hybrid, whom he named Anna, through the use of both current cloning technology and alien technology. He spliced a human ovum with Goa'uld DNA from a symbiote discovered in a canopic jar and accelerated its growth with the use of Goa'uld nanite technology stolen from Area 51 (the nanite technology was probably that of the Goa'uld Pelops who used it to rapidly age his human slaves on the planet Argos in the episode, 1.09 "Brief Candle").

Evidence of his failed attempts was in the form of three semi-human mutated fetuses stored in jars in Keffler's laboratory. The fetuses had umbilitical cords, suggesting that there was a surrogate mother involved with the development of these hybrids. According to Keffler's records, there were 45 failed attempts before Anna was born. Each one of these attempts endangered not only the woman carrying them, but the actual hybrids themselves, especially if they lived to be born. Because of the possibility that each hybrid would grow incorrectly and have a painful existence, Dr. Keffler implanted a biotoxin at the base of their brains so that he could trigger their deaths via a remote control before they suffered. At first, this seemed to be a very humane thing for him to do, but he used this biotoxin as a threat to manipulate Anna into accessing the Goa'uld genetic memories.

Anna had developed further than her predecessors, but she was still an experimental failure because Dr. Keffler had not spliced the correct DNA sequence into her DNA. Not only did Anna possess the Goa'uld genetic memory of the symbiote, named Sekhmet, but she also possessed that symbiote's personality. The Goa'uld personality was stronger than the human's and soon it would overtake her completely. In addition, Anna's physical condition was failing and there was nothing that could be done for her. She realized this and committed suicide by pressing the remote button to activate the biotoxin.

There were 277 failures before Dolly the cloned sheep was born. Scientists who studied her found that she lived shorter than expected because she was born already aged. She lived about half the lifespan of sheep of her kind. With each failure, came the knowledge of making it right, but there were some sheep born who lived for a while outside of the womb and suffered. Even Dolly did not die naturally, but by means of lethal injection.

Ethicists debate the same issues if human cloning were to come into common practice. According to some researchers who are cloning mammals, there are fewer than 5% successful results. There will be failures before there are successes because the technology has not been perfected. What, then, is to be done for all of those children who are born with defects such as Anna had been?

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8.08 "Covenant": Cloning Capabilities of Today

Alec Colson
Colson's Asgard Clone
Thor of the Asgard

When SG-1 found out about the Asgard's cloning problems, Major Carter offered the help of Earth's scientists. A biotech company called Biovail won the contract to sequence the Asgard DNA, but they went further than their contract specified and cloned the DNA into a full-grown Asgard body.

Given our current level of cloning technology, the feasibility of the Biovail's success in cloning a full-grown Asgard from a strand of DNA seems highly unlikely. But because the Asgard's method of cloning is advanced and we are not made aware of how it is done, the writers of "Covenant" would have us believe that this feat could be accomplished by scientists of Earth today.

The Asgard have programmed the DNA to produce a full-grown body in three months. The body is created without a "soul" so that when the consciousness of the Asgard is transferred into it, no knowledge or life is lost. The body is basically an empty, yet biologically functional, shell. Thor of the Asgard was able to save the clone that Biovail made by giving it to an Asgard whose current body was failing.

How did the researchers know how to clone the DNA they were given? We'll probably never know. However, the lack of ethics on the part of Alec Colson, the man who built the Biovail corporation, is quite evident, even when ignoring the fact that he used this Asgard clone as blackmail against the governments of the world to reveal the existence of alien life. The government had already investigated this man and determined that he was a security risk. Why on Earth would they have awarded his company this contract is beyond comprehension. And, because of the very nature of the DNA itself, it is highly doubtful that the government would have given any one company access to the full strand of DNA for sequencing, but would have instead given fragments of the DNA to different companies and then had their own security-cleared scientists put the final sequencing together.

This story, therefore, can only be classified as science fiction. The only capabilities portrayed in this story that are in evidence today are those of the unethical behavioral kind of Alec Colson and his researchers at Biovail.

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9.07 "Ex Deus Machina": Cloning and Expendible Replacements

Ba'al's clone is executed on Dakara
Ba'al's clone is killed by Teal'c
A group of Ba'al's clones perished when their ha'tak exploded

Normally, the Goa'uld are very self-centered beings, thinking of themselves as gods and having centuries-long lives. They use the most attractive of hosts as vessels, maintaining the human body with the sophisticated technology of the sarcophagus. But, even with this technology, Goa'ulds cannot live forever, as the late System Lord Yu demonstrated with his growing senility and inability to take a new host after thousands of years of existence. Even the Asgard attempted a measure of immortality with their cloning program, transferring their computer-stored consciencenesses into new bodies when the old one is damaged beyond repair or dying.

What if a Goa'uld obtained access to the Asgard cloning technology? Would he seek immortality through its use, or use it to advance his status in the galaxy?

After Anubis obtained knowledge of all of the Asgard's technology within Thor's mind (5.22 "Revelations"), it was only a matter of time before he used their cloning technology to realize his goal of galactic domination. It is possible he used Asgard cloning techniques in order to create his Kull Warriors (see above). Eventually, Anubis's technology was acquired by Ba'al, so he not only gained access to the Asgard beaming technology, but to the cloning technology as well.

Ba'al decided to clone himself. He successfully cloned both the host and the symbiote into viable beings. But, something was surprisingly different about these clones. Instead of seeing one another as enemies, they worked together to advance Ba'al's place in the galaxy after the defeat of the System Lords in the battle over Dakara. The five clones that Ba'al had on Earth lived together and coordinated their whereabouts. One of these clones was captured by the Free Jaffa and executed on Dakara. His attitude about his approaching demise was almost casual, but he did show his contempt for the Jaffa who were about to kill him. (9.07 "Ex Deus Machina")

Another one of Ba'al's clones captured Teal'c and other Free Jaffa council members in order to brainwash them to support him as their new leader against the Ori. This clone readily admitted that the Goa'uld were not gods and even spoke with his host's natural voice. But, when he noticed that he was about to be overtaken, his natural reflex of attempting to escape through the beaming technology (such as how Ba'al escaped after his defeat over Dakara) failed and he was killed by Teal'c with a staff weapon. He had touched the beaming trigger on his ribbon device, but nothing happened. It is possible that Ba'al gave all of his clones no means of self-preservation even if they had some measure of that instinct still inside of them. (9.14 "Stronghold")

Still another group of Ba'al's clones perished when their ha'tak was destroyed in a firefight with three Lucian Alliance ha'tak. These clones might have been destined to rule over the worlds that Ba'al was locating in order to set up a private network of Stargates. This private network would, theoretically, be outside the galactic-wide network and inaccessible to the Priors of the Ori. (9.16 "Off The Grid")

In order to gain access to the SGC's database of Ancient Stargate addresses, Ba'al's clones allowed themselves to be captured and brought to the SGC for interrogation. One of the Ba'als, presumably the "real" one, told the SGC how to capture these clones using their transmitter tags, similar to the SGC's locator implants used in conjunction with the Asgard beaming technology onboard Earth's starships. The group of clones executed an escape plan and coerced Carter to give them the Stargate address database by threatening to kill hostages. Some of the Ba'al clones were killed in the firefight with SGC personnel as they gathered for their escape by concentrating their implant signals so that they could be beamed out as a group. It appeared that the surviving clones were not bothered by their fellow clones' deaths. (10.04 "Insiders")

The clones showed some of the typical behavior of their original, but there appeared to be some differences in their behavior when it came to self-worth. It's obvious they that were aware that they were clones and that Ba'al could create, and destroy, as many as he desired. What was amazing about these clones was that they appeared to be resolved to the fact that their own lives were expendible and took approaching death with some measure of indifference.

Ba'al appeared to have subjugated his clones and denied them their own individual identities. He used them as a group to obtain the Stargate address database from the SGC (10.04 "Insiders"), and killed them en masse when he felt they threatened his bid for galactic dominance (10.19 "Dominion").

The creating of expendible replacements remains strongly in the realm of science fiction, but raises many ethical questions, including placing a value on the lives created through cloning.

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9.09 "Prototype": Cloning and Immortality

Daniel studies Anubis's research stored in a DNA manipulation device
Khalek in his stasis chamber on P3X-584
Daniel and Mitchell kill Khalek

Even the Asgard admitted that they obtained a measure of immortality through their cloning programming, but immortality for them was not successful because they failed to perfect their cloning techniques. Finding the ultimate solution to the cloning problem would mean taking on a form outside that which was originally cloned, such as through ascension, the shedding of the physical form to become a being of energy (Ascended Being). (3.20 "Maternal Instinct", 5.22 "Revelations", 10.20 "Unending")

What is rather ironic is that one who appeared to achieve immortality through ascension would want to create a corporeal clone of himself. Anubis, a Goa'uld who ascended, created Khalek, a clone of Anubis's host prior to his ascension who was also programmed with the Goa'uld genetic memory and some of Anubis's ascended memories. Anubis modified Khalek's DNA with an Ancient DNA manipulation device that made Khalek physically advanced with all of Anubis's memories and knowledge. Khalek was both a hok'taur and a Harsesis rolled into one.

It was Anubis's goal to modify Khalek's DNA so that he could use over 80% of his brain's capabilities to wilfully ascend just like the advanced human race of Ancients had. Anubis had achieved ascension through the help of the Ascended Being Oma Desala; Khalek, after an eight-step treatment in the DNA manipulation device, would achieve ascension on his own. Anubis's goals in creating Khalek were not revealed in the research notes he left behind on P3X-584 where Khalek was discovered. Was it possible that Khalek was to become one of many who could ascend and take over the ascended planes of existence? Since Anubis himself was limited in what he could do by The Others (a collective of Ascended Beings who watch over their plane of existence and combine their powers to maintain cosmic balance), perhaps he believed that Khalek and others like him would reach a higher plane of existence and raise him up from his limited existence, since Khalek considered Anubis to be his father rather than being Anubis re-incarnate.

What was disturbing about Khalek's discovery was the debate as to what to do with him. Daniel proposed destroying Khalek immediately, feeling that there was no hope to ever prevent Khalek from being who he was and from his plan to destroy the galaxy to be remade in his own design, just like Anubis himself (9.18 "Threads"). The SGC compromised and decided to return him to his stasis chamber on P3X-584. Richard Woolsey, the International Oversight Committee's (IOC's) liaison, proposed studying Khalek's advanced human capabilities in order to understand the Priors of the Ori who had similar physiology and to explore humanity's evolution toward ascension. Woolsey's proposal won out because the IOC that was financing the majority of the SGC's efforts believed that much could be learned by studying Khalek. Daniel warned Woolsey of the incredible risks, and true-to-form, Khalek used his advanced human powers and killed several SGC personnel before he was destroyed by Daniel and Lt. Col. Cameron Mitchell.

Anubis's ability to duplicate his memories in Khalek was similar to how the Asgard achieved their level of immortality by transferring their consciousnesses into clone bodies. But with Khalek, this immortality would reach beyond the physical form and into a higher plane of existence. Humanity's desire to learn more about himself and where he is going, including the possibility of immortality in an energy form, came at a high price in this particular instance.

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Conclusion

Cloning technology of today is still in its early developments. If we were to consider the tremendous leaps in scientific knowledge we have made and the very vivid imaginations we use to create the stories of which science fiction is made, it is very well possible that one day someone from Earth will write an article such as this, but call it science fact.

Episodes

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Related Characters

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Related Articles

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Further Reading

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--DeeKayP 19:51, 14 Oct 2004 (PDT)