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Human genetic engineering deals with the controlled modification of the human genome. The first clinical trial of human gene therapy began in 1990, but (as of 2006) gene therapy is still experimental. Other forms of human genetic engineering are still theoretical. Recombinant DNA research is usually performed to study gene expression and various human diseases. Some drastic demonstrations of gene modification have been made with mice and other animals, however: testing on humans is generally considered off-limits. In some instances changes are usually brought about by removing genetic material from one organism with similar gene architecture, and transferring them into another species. This method is known as recombinant genetics.
Applications
Curing medical conditions
When treating problems that arise from genetic disorder, one solution is gene therapy. A genetic disorder is a situation where some genes are missing or faulty. When this happens, genes may be expressed in unfavorable ways or not at all, and this generally leads to further complications.The idea of gene therapy is that a non-pathogenic virus or other delivery system can be used to insert a piece of DNA--a good copy of the gene--into cells of the living individual. The modified cells would divide as normal and each division would produce cells that express the desired trait. The result would be that he/she would then have the ability to express the trait that was previously absent at least partially. This form of genetic engineering could help alleviate many problems, such as diabetes, cystic fibrosis, or other genetic diseases.
Human Enhancement
The huge potential of genetic engineering to cure medical conditions opens the question of exactly what such a condition is. Many people, known as immortalists (ie the methuselah foundation), see aging and death as medical conditions and engineering problems to be solved. They see human genetic engineering as a key tool in this (see life extension). The difference between cure and enhancement is merely one of degree. Theoretically genetic engineering could be used to drastically change people's genomes which could enable people to regrow limbs, the spine, the brain. It could also be used to make people stronger, faster, smarter, or to increase the capacity of the lungs, among other things. If a gene exists in nature, it could be brought over to a human cell.Positive reasoning
It can be argued that genetic engineering could improve the human race. The human race would be able to adapt and survive in more environments and situations than are currently possible. For example, humans can't breathe the atmosphere on Mars, nor live in the sea. Genetically engineered people, theoretically, could. People could then comfortably live in an area currently difficult or impossible to live in.Chimeras
A chimera has at least two different populations of cells, which are genetically distinct and which originated in different zygotes (fertilized eggs). In the case of a human-animal chimera, an extensively chimeric person or creature could pose difficult legal problems concerning their classification.The Chimera in mythology is a three part creature, with the head of a lion, the body of a goat, and the tail of a dragon.
The creatures in the novel The Island of Dr. Moreau could be considered an example of human-animal chimeras in fiction (the actual method used is unclear).
The process
First, the ability that you want to carry over has to be isolated. If, for instance, you want to be able to regrow almost everything, you have to find a creature that can do this, such as the newt. Then, after isolating the genes that make this happen, you either find what changes you make to your body so that it can carry out this process, or you transfer that whole block of genes and isolate it.
Then, with whatever technique is available, insert those genes into some or all the cells of the human body. Later activate those genes at the appropriate time.
There are two techniques researchers are currently experimenting:
- Viruses are good at injecting their DNA payload into human cells and reproducing it. By adding the desired DNA to the DNA of non-pathogenic virus (a pathogen is something that harms you. A non pathogenic virus is still a virus by definition, but will not cause you to get sick), a small amount of virus will reproduce the desired DNA and spread it all over the body.
- Manufacture large quantities of DNA, and somehow package it to induce the target cells to accept it, either as an addition to one of the original 46 chromosomes, or as an independent 47th human artificial chromosome.
When to make changes
Changes at conception
Genetic engineering is most easily accomplished by making changes just after the egg and sperm have melded but before first division. In this way, the gene will be expressed throughout with few worries that it did not reach the whole body.Effects to the germline
There is some controversy about whether genetic changes should be allowed to affect the germline. Affecting the germline means that not only do you, or whoever the genetic engineering was done to, have the changes, but all children conceived after the engineering, and so on, as well.Changes after conception
Changes after conception, whether child or adult, is often a more desired form of genetic engineering. These changes would ideally take effect, and give the desired outcomes with no side effects. However, there is greater difficulty in reaching the correct parts of the body or the whole body as desired.Changes after birth
This is known as gene therapy. This is possibly the most desirable form as the engineered person can give consent. Each human cell contains a different set of genes, so different genes could be transferred to different parts of the body. Such changes will not be hereditary unless the sex cells are engineered.Considerations
Interference from laws and politics
Due to tough regulatory laws, research in this field have been stifled to a bare minimum. Experiments with approval were being carried out on people with a variety of diseases, and the experiments tried to insert genes and correct their diseases. However, one person treated died, and further research had been cancelled on most if not all projects.Ethical considerations
- We could choose to have changes made to us, but we might also be making the choice for our children if the changes are carried through to the germline. Do we have that right, and how far should we take our ability?
- Conversely, is it responsible and ethically acceptable to leave the potentials of our children to the chance effects of the "genetic lottery", if we obtain the technological capacity to make positive changes?
- If genetic engineering became the way of the future, would people whose parents could not afford to genetically 'modify' them while still in an embryo, have a chance of achieving with high standards compared to the people who were 'modified' to be perfect?
- Is it ethical to experiment on embryos that have yet to be born?
- How would genetic engineering be used to revolutionize warfare?
- Who decides which changes will be made?
Social considerations
- Would society treat genetic engineered people differently?
- Would they be left behind, would they be considered second class humans?
- What if this created a different species of human, would they still be able to interbreed, would they want to?
- What place would genetically engineered humans and regular humans have in society?
- Could unequal access to genetic engineering lock in or exaggerate current class divisions?
Metaphysical considerations
- The metaphysical (or "spiritual") implications of genetically engineered humans are vast in scope; e.g., were individual personality shown to be exclusively the result of genetic information acted upon by the environment, the concepts of the human soul and free will could be proven specious.
- However, could this be shown by the success of actual attempts at genetic engineering any more (or less) than it is shown by what is already known about the roles of genes and the environment in shaping the phenotypical characteristics (including behavior) of living things?
Examples
- Undercover genes slip into the brain article by Anil Ananthaswamy: William Pardridge and his team have developed a technique to put genes into the brain. The team inserted the gene for the luminescent protein luciferase into the brains of rhesus monkeys.
- Gene therapy may switch off Huntington's article by Bob Holmes: While the technique has not yet been tried in people, Beverly Davidson and Henry Paulson report some success in human cells.
Human Genetic engineering in fiction
main article: Genetic engineering in fiction
Examples in fiction of genetically engineered humans:
Movies
Resurrection: Ripley is cloned from a gene sample from her remains. The genes of the alien have accidentally been spliced into her.Blade Runner: Artificially created humans called "Replicants" are created by the Tyrell Corproration for off-world colonization.
Gattaca: In this movie, genetic engineering is appiled to humans, making them stronger and smarter. However it cause social changes, with the genetically engineered in power, and Naturally born humans relegated to second class status.
Apocalypse: A virus infects Alice. In Resident Evil 2, her body melds with the virus, accelerating her development, giving her super strength, speed, reaction time, and ability to heal, as well as the ability to recover from death.
The Island of Dr. Moreau: Dr. Moreau has been experimenting on animals and creating human like animals through vivisection. In most movie adaptations, this was achieved through altering DNA instead.
The Island: An Ewan McGregor film that explores the concept of an island where scientific clones of people in the real world live.
TV
Dark Angel:: The protagonist Max Guevara (X5-452), as well as several others, is genetically engineered to become supersoldiers.Gundam Seed: Set in a future society where human genetic enginneering has caused a violent social schism. One group, Coordinators, are genetically engineered humans who live in orbiting space colonies. The other group, Naturals, oppose genetic engineering on humans.
Star Trek: Has the perhaps most well known example of Human genetic engineering: Khan Noonien Singh and his fellow "supermen", the Augments. The Federation has banned human genetic engineering , save for correcting birth defects. However, some humans have been illegally modified, such as Doctor Julian Bashir. Despite the ban, the Federation did allow some legal human genetic modification experiments at Darwin Station. The research at the station produced superior human beings with telepathy, telekensis, and an aggressive immune system.
Books
The Seedling Stars (James Blish): James Blish's The Seedling Stars (1956) is the classic story of controlled mutation for adaptability. In this novel (originally a series of short stories) the Adapted Men are reshaped human beings, designed for life on a variety of other planets.
Lost Paradise: Due to accidental involvement with a client, an old man has to take a trip to another world. He enlists as a mercenary to fight for a Japanese colonization group alongside humans and engineered humans. In this sci-fi universe, a new breed of humans were created in South America that are smarter, faster, stronger, and more survivable in general. These people are looked down upon and treated worse than animals, with little or no protection given by most governments.
Beggars in Spain (Nancy Kress): This novel and its sequels are widely recognized by science fiction critics as among the most sophisticated fictional treatments of genetic engineering. They portray genetically-engineered characters whose abilities are far greater than those of ordinary humans (e.g. they are effectively immortal and they function without needing to sleep). At issue is what responsibility they have to use their abilities to help "normal" human beings. Kress explores libertarian and collectivist philosophies, attempting to define the extent of people's mutual responsibility for each other's welfare.
'''Warworld: Several stories in the series feature the Sauron Supermen, genetically enginnered humans bred to be the perfect soldiers.
When the Wind Blows (James Patterson, ISBN 0-316-69332-4) A veterinarian (Dr. Franny O'Neill) and an FBI agent (Kit Harrison) discover a place called the "School", where secret genetic experiments are carried out on children stolen as infants from clients of a local IVF clinic. They make this discovery after Dr. O'Neill finds a young girl named Max in the woods near her home. This girl amazes Franny and Kit by her high intelligence, physical strength and force of character, but most of all by her wings! With the help of the precocious Max, they uncover a well-funded plot to change the world through genetic modification and enhancement, at the expense of the young "experiments". Patterson makes an excellent plea to the value of human life, and demonstrates how easily greed can turn into cruelty.
See also
References
"Human genetic engineering"