Writer: Jacqueline Goh
Editor: Isabella Io
Have you ever wondered what it would be like to have a person who is made of the exact genetic composition as you? Unless you are an identical twin, you have probably never encountered a genetic duplicate of yourself.
The concept of cloning is ethically immoral to many, but for others, it presents a new approach to regenerative medicine, curing diseases, and allowing infertile couples the opportunity to have children genetically related to them.
Types of Cloning
Cloning can be defined simply as producing a genetically identical (having the same DNA) copy of a biological entity [2]. It can either be done naturally or artificially.
In nature, cloning happens when plants and single-celled organisms asexually produce offspring. A new, genetically identical individual is generated from a copy of a single cell from the parent organism. However, in the case of mammals, they produce natural clones (identical twins) if a fertilized egg splits, creating two or more embryos that carry almost identical DNA. Therefore, identical twins have almost the same genetic makeup as each other, since they have the same genes in their nuclei [2].
There are 3 main types of artificial cloning:
Medical Applications
One of the most common applications of cloning is the disease model. Disease models, such as mice, must be used to understand how a technology or drug affects a biological entity. Usually, animal models are genetically engineered to carry a specific faulty mutation in their genes that causes the disease being studied; these are called transgenic animals. However, producing enough transgenic animal models for study becomes too time-consuming—it is a process that requires many generations of breeding, as well as trial and error. This is where cloning comes into play, allowing scientists to have a population of transgenic animal models that are genetically identical [3].
Transgenic animals have another important use, which is xenotransplantation [2]. Seventeen people die everyday waiting for an organ transplant. As of February 2021, there are over 107,000 people on the American national transplant waiting list [5]. In this case, transgenic animals like pigs have become a potential solution by transferring organs genetically modified with human genes from animals to people [2]. This way, patients no longer have to wait for organ availability from a donor, saving many potential lives.
Another important medical purpose of cloning is regenerative medicine. Stem cells are cells that can build, maintain and repair the body throughout our lives. These cells are special because of their ability to differentiate into more specialized cells such as heart or liver cells. Stem cells can be manipulated to repair damaged or diseased organs and tissues. As of now, researchers are creating stem cells genetically identical to the individual to understand the disease for treatment and drug development purposes [3].
Reviving Endangered or Extinct Species
Cloning has been proposed by many as a solution to revive endangered or extinct species. First, scientists can collect a DNA sample from a preserved specimen of the species, then insert it into an egg cell of a closely related species to create a clone. However, cloning can be aimless because it does not address the reasons behind why many animals become endangered in the first place, which is often hunting and habitat destruction. Secondly, scientists do not have a large database of preserved genetic profiles. Unfortunately, this means that clones will be more susceptible to a single genetic mutation or disease due to an inbred population. However, it would work if researchers have access to preserved DNA from many individuals [4].
Lastly, to accomplish a successful cloning, DNA from the extinct/endangered animal, an egg, and a surrogate mother is required. Unfortunately, injecting the DNA of one species into the egg of another creates a hybrid embryo that results in poor development. In most cases, hundreds of embryos and pregnancies are needed just to produce a few clones. To put that into perspective, less than 5% of domestic animal species and less than 1% of wild animal species are successfully cloned using current cloning techniques [4].
Despite many challenges in cloning, researchers have managed to clone endangered and extinct mammals, including a mouflon sheep in 2001; a banteng in 2003; a Pyrenean ibex in 2009; and wild coyotes in 2012 [4].
Medical and Ethical Perspective on Human Cloning
After many successful attempts at cloning mammals, people have started envisioning cloning for reproductive purposes. Can we clone humans? The answer to that is yes. However, there is currently no scientific evidence that suggests that a human embryo has been cloned despite many claims in the last few decades [2]. Similar to cloning endangered or extinct animals, human cloning is the asexual production of a human being whose genetic makeup is copied from an existing individual [6]. If infertile couples aren’t able to reproduce, why not make a copy of themselves? Why not make a copy of famous artists, athletes, and musicians, so that their legacies can live on forever?
The concept of human cloning has raised many societal fears and concerns regarding eugenics and the sanctity of life. With terrifying speculative dystopian movies and science fiction concerning genetic engineering rising to flame, their concerns are completely valid. The majority of researchers, scientists, healthcare professionals, policy makers, bioethicists, theologians, and the general public have opposed the practice [6].
Firstly, there is a low success rate of cloning and a high chance of medical implications [7]. 95-97% of animal cloning attempts fail, and the first mammal was cloned after 276 trials [8]. Furthermore, clones suffer from an increased risk of genetic malformation, cancer, and a shortened lifespan, in addition to pregnancy losses and abnormal births [7].
Secondly, there are many dangerous misconceptions around human cloning. Many people assume that if you clone Albert Einstein, for example, the clone would be exactly like him, with the same personality and mannerisms. However, we must remember that clones are first babies. This means that there are various environmental and cultural factors that could shape their personalities. No matter the outcome, the clone would be a separate human being with autonomy. It is unreasonable to expect them to live up to someone else's legacy, violating their rights to individuality [7].
Lastly, cloning can lead to eugenic selections: if we allow humans to clone whoever they admire, we will start placing a “value” or “worth” on specific characteristics and face the urge to only make desirable human beings. This can lead to serious violations of human rights and human dignity [7]. Furthermore, wealthier people may be more inclined towards cloning since they have the money to “design” a perfect version of themselves without a specific disease, or even an add-on of a desirable trait such as intelligence. This in turn creates a larger gap in natural characteristics and an unfair disadvantage to less privileged people. Most importantly, research into cloning will lead to the exploitation of women, because scientists need to obtain large quantities of eggs in order to manufacture enough cloned embryos to create stem cell lines, which are cultures of stem cells that can be grown and manipulated in a lab [8].
Ongoing Research in Cloning
Medically, research on embryonic stem cells from cloning has not led to any beneficial therapeutic treatment methods. On the other hand, however, adult stem cell therapy has allowed for the treatment of cartilage defects, vision restorations, systemic lupus, multiple sclerosis, rheumatoid arthritis, and severe combined immunodeficiency [8]. Adult stem cell research is evidently more advantageous than embryonic stem cell research, both morally and clinically.
Conclusions
Before we move on with this technology, we must first understand the consequences of cloning. Once a human clone is made, there is no going back. From treating a medical disease to finding a solution for infertility, human beings will crave more and more–even to the point of removing their “imperfections” through genetic engineering. Undoubtedly, there will be places where cloning is taken too far. But how far are we willing to go for perfection?
Sources & Works Cited
[1] Frontline Genomics. “Evolution of cloning: A Dolly good show!”, https://frontlinegenomics.com/evolution-of-cloning-a-dolly-good-show
[2] National Human Genome Research Institute. “Cloning Fact Sheet.”, August 15, 2020. https://www.genome.gov/about-genomics/fact-sheets/Cloning-Fact-Sheet
[3] Genetic Science Learning Center. "Why Clone?." Learn.Genetics. July 10, 2014. Accessed July 10, 2024. https://learn.genetics.utah.edu/content/cloning/whyclone/
[4] Ferris Jabr, “Will Cloning Ever Save Endangered Animals?”, Scientific American. March 11, 2013. https://www.scientificamerican.com/article/cloning-endangered-animals/
[5] “Organ Donation Statistics” https://www.organdonor.gov/learn/organ-donation-statistics
[6] Mayo Clinic Proceedings. “Stem Cell Research: Why Medicine Should Reject Human Cloning - Mayo Clinic Proceedings”, August 2003 https://www.mayoclinicproceedings.org/article/S0025-6196(11)63148-0/fulltext#secd12624194e430
[7] Satomi Angelika Murayama, “Op-ed: The dangers of cloning.”, Fung Institute for Engineering Leadership, May 11, 2020. https://funginstitute.berkeley.edu/news/op-ed-the-dangers-of-cloning/
[8] Dave Weldon, "Why Human Cloning Must Be Banned Now,” Dignity 8, no. 1 (2002): 1, 4. https://cbhd.org/content/why-human-%20cloning-must-be-banned-now
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