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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Cloning | 6/9 | https://en.wikipedia.org/wiki/Cloning | reference | science, encyclopedia | 2026-05-05T14:17:46.685988+00:00 | kb-cron |
Human cloning is the creation of a genetically identical copy of a human. The term is generally used to refer to artificial human cloning, which is the reproduction of human cells and tissues. It does not refer to the natural conception and delivery of identical twins. The possibility of human cloning has raised controversies. These ethical concerns have prompted several nations to pass legislation regarding human cloning and its legality. As of right now, scientists have no intention of trying to clone people and they believe their results should spark a wider discussion about the laws and regulations the world needs to regulate cloning. Two commonly discussed types of theoretical human cloning are therapeutic cloning and reproductive cloning. Therapeutic cloning would involve cloning cells from a human for use in medicine and transplants, and is an active area of research, but is not in medical practice anywhere in the world, as of 2024. Two common methods of therapeutic cloning that are being researched are somatic-cell nuclear transfer and, more recently, pluripotent stem cell induction. Reproductive cloning would involve making an entire cloned human, instead of just specific cells or tissues.
==== Ethical issues of cloning ====
There are a variety of ethical positions regarding the possibilities of cloning, especially human cloning. While many of these views are religious in origin, the questions raised by cloning are faced by secular perspectives as well. Perspectives on human cloning are theoretical, as human therapeutic and reproductive cloning are not commercially used; animals are currently cloned in laboratories and in livestock production. Advocates support development of therapeutic cloning to generate tissues and whole organs to treat patients who otherwise cannot obtain transplants, to avoid the need for immunosuppressive drugs, and to stave off the effects of aging. Advocates for reproductive cloning believe that parents who cannot otherwise procreate should have access to the technology. Opponents of cloning have concerns that technology is not yet developed enough to be safe and that it could be prone to abuse (leading to the generation of humans from whom organs and tissues would be harvested), as well as concerns about how cloned individuals could integrate with families and with society at large. Cloning humans could lead to serious violations of human rights. Religious groups are divided, with some opposing the technology as usurping "God's place" and, to the extent embryos are used, destroying a human life; others support therapeutic cloning's potential life-saving benefits. There is at least one religion, Raëlism, in which cloning plays a major role. Contemporary work on this topic is concerned with the ethics, adequate regulation and issues of any cloning carried out by humans, not potentially by extraterrestrials (including in the future), and largely also not replication – also described as mind cloning – of potential whole brain emulations. Cloning of animals is opposed by animal-groups due to the number of cloned animals that suffer from malformations before they die, and while food from cloned animals has been approved as safe by the US FDA, its use is opposed by groups concerned about food safety. In practical terms, the inclusion of "licensing requirements for embryo research projects and fertility clinics, restrictions on the commodification of eggs and sperm, and measures to prevent proprietary interests from monopolizing access to stem cell lines" in international cloning regulations has been proposed, albeit e.g. effective oversight mechanisms or cloning requirements have not been described.
==== Cloning extinct and endangered species ====
Cloning, or more precisely, the reconstruction of functional DNA from extinct species has, for decades, been a dream. Possible implications of this were dramatized in the 1984 novel Carnosaur and the 1990 novel Jurassic Park. The best current cloning techniques have an average success rate of 9.4 percent (and as high as 25 percent) when working with familiar species such as mice, while cloning wild animals is usually less than 1 percent successful.
===== Conservation cloning ===== Several tissue banks have come into existence, including the "Frozen zoo" at the San Diego Zoo, to store frozen tissue from the world's rarest and most endangered species. This is also referred to as "Conservation cloning". Engineers have proposed a "lunar ark" in 2021 – storing millions of seed, spore, sperm and egg samples from Earth's contemporary species in a network of lava tubes on the Moon as a genetic backup. Similar proposals have been made since at least 2008. These also include sending human customer DNA, and a proposal for "a lunar backup record of humanity" that includes genetic information by Avi Loeb et al. In 2020, the San Diego Zoo began a number of projects in partnership with the conservation organization Revive & Restore and the ViaGen Pets and Equine Company to clone individuals of genetically-impoverished endangered species. A Przewalski's horse was cloned from preserved tissue of a stallion whose genes are absent in the surviving populations of the species, which descend from twenty individuals. The clone, named Kurt, had been born to a domestic surrogate mother, and was partnered with a natural-born Przewalski's mare in order to socialize him with the species' natural behavior before being introduced to the Zoo's breeding herd. In 2023, a second clone of the original stallion, named Ollie, was born; this marked the first instance of multiple living clones of a single individual of an endangered species being alive at the same time. Also in 2020, a clone named Elizabeth Ann was produced of a female black-footed ferret that had no living descendants. While Elizabeth Ann became sterile due to secondary health complications, a pair of additional clones of the same individual, named Antonia and Noreen, were born to distinct surrogate mothers, and Antonia successfully reproduced later in the year.