Editing Human–animal hybrid (section)

==Scientific research and related issues==
===Background and technological analyses===
{{see also|History of genetic engineering}}

[[File:Bluetomato.jpg|thumb|right|upright|These [[Blue tomato|blue-colored tomatoes]] are an example of a [[genetically modified food]].]]

Broadly speaking, a [[Hybrid (biology)|hybrid]] being has one cell line throughout its entire body and came originally from a mix of entities, with different species involved to make a new genetic combination. For instance, a [[liger]] has a lion father and a [[tigress]] mother, such a creature only existing in [[Captivity (animal)|captivity]]. Such hybridization has frequently caused difficult health problems that caregivers for the captive animals struggle with.<ref name=zonkey>{{cite web|last=Palmer|first=Roxanne|date=July 25, 2013|title=Zonkey, Wholphin, Liger, Tigon: Fascinating Animal Hybrids|url=http://www.ibtimes.com/zonkey-wholphin-liger-tigon-fascinating-animal-hybrids-photos-1359907|website=[[International Business Times]]|accessdate=August 8, 2015}}</ref>

A [[chimera (biology)|chimera]] is not the same thing as a hybrid because it is a being composed of two or more genetically distinct cell lines in one entity. The entity does not exist as a member of a separate species but has differing elements inside of it. An animal that has experienced an [[organ transplant]] or related surgery involving tissues from a different species is an example.<ref name=Mott/>

Throughout past [[human evolution]], hybridization occurred in many different instances, such as cross-breeding between [[Neanderthal]]s and ancient versions of what are now modern humans. Some scientists have believed that particular genes of the Neanderthal may have been key to ancient humans' adapting to the harsh [[climate]]s they faced [[Recent African origin of modern humans|when they left Africa]]. However, mixing between species in the wild both now and through natural history have generally resulted in [[Infertility|sterile offspring]], thus being a kind of dead end in reproductive terms.<ref name=zonkey/>

For much of modern history, the creation of [[genetically modified organism]]s in general was a topic rooted in fiction rather than practical research. This has changed significantly over the past few decades such that a number of plants and animals are commonly subject to [[genetic engineering]] for commercial purposes. For example, as of 2013 about 85% of the corn grown in the US as well as about 90% of its [[canola]] crops have been genetically modified.<ref name=foods/> As well, many Americans that have had cardiovascular surgery have had heart valves initially from pigs used in their procedures.<ref name=Weiss>{{cite news|url=https://www.washingtonpost.com/wp-dyn/articles/A19781-2005Feb12.html|last=Weiss|first=Rick|date=February 13, 2005|title=U.S. Denies Patent for a Too-Human Hybrid|newspaper=[[The Washington Post]]|accessdate=August 8, 2015}}</ref>

Issues relating to possible human-animal hybrids outside of a fictional, historical, or mythic context but as real, engineered beings received major international attention in 2003, after some Chinese scientists at the [[Shanghai Jiao Tong University School of Medicine|Shanghai Second Medical University]] managed to successfully fuse human cells with rabbit eggs. The embryos formed reportedly were the first stable human-animal chimeras in existence. Research in similar areas continued into 2004 and 2005, with the topic picking up coverage from publications such as ''[[National Geographic News]]''. The [[National Academy of Sciences]] soon began to look into the ethical questions involved.<ref name=Mott/> The [[U.S. Patent and Trademark Office]] additionally stirred interest into the topic by granting a patent request for a genetically modified mouse with a human [[immune system]].<ref name=Weiss/> Scientists announced in 2017 that they successfully created the first human-pig chimeric embryo. The embryo consisted mostly pig cells and some human cells. Scientists stated that they hope to use this technology to address the shortage of donor organs.<ref>{{Cite news|url=http://news.nationalgeographic.com/2017/01/human-pig-hybrid-embryo-chimera-organs-health-science/|title=Human-Pig Hybrid Created in the Lab—Here Are the Facts|date=2017-01-26|access-date=2017-01-27}}</ref><ref>{{Cite journal|last=Wu|first=Jun|last2=Platero-Luengo|first2=Aida|last3=Sakurai|first3=Masahiro|last4=Sugawara|first4=Atsushi|last5=Gil|first5=Maria Antonia|last6=Yamauchi|first6=Takayoshi|last7=Suzuki|first7=Keiichiro|last8=Bogliotti|first8=Yanina Soledad|last9=Cuello|first9=Cristina|last10=Valencia|first10=Mariana Morales|last11=Okumura|first11=Daiji|date=2017-01-26|title=Interspecies Chimerism with Mammalian Pluripotent Stem Cells|url=https://www.cell.com/cell/abstract/S0092-8674(16)31752-4|journal=Cell|language=English|volume=168|issue=3|pages=473–486.e15|doi=10.1016/j.cell.2016.12.036|issn=0092-8674|pmc=5679265|pmid=28129541}}</ref> In July 2019, Japanese scientist [[Hiromitsu Nakauchi]] got the approval of the Japanese government to experiment with inserting human [[stem cell]]s into animal (particularly [[rodent]]) embryos.<ref>{{Cite journal|last=Cyranoski|first=David|date=2019-07-26|title=Japan approves first human-animal embryo experiments|url=http://www.nature.com/articles/d41586-019-02275-3|journal=Nature|language=EN|doi=10.1038/d41586-019-02275-3}}</ref> Although its main use will be to make organ transplantation easier, this can be considered the first more effective step of making animal-human hybrids real.

===Legal and moral discussions===
[[File:20080618 Bush Kempthorne oil exploration speech.jpg|thumb|right|[[POTUS|President]] [[George W. Bush]], pictured here in 2008 with then [[U.S. Interior Secretary|Interior Secretary]] [[Dirk Kempthorne]] to his side, has advocated for increased [[regulation of genetic engineering]], including on research mixing animal and human elements.]]

{{see also|Bioethics|Regulation of genetic engineering}}

Advances in [[genetic engineering]] have generally caused a large amount of debates and discussion in the fields related to [[bioethics]], and research relating to the hypothetical creation of human-animal hybrids in the future has been no exception. The technical analyses of intermingling human-based and animal-based genetic material are ongoing; the ethical, moral, and legal issues arising from actual research using chimeras (rather than hybrids per se) at the moment also touch more speculative concerns as well. While laws against the creation of hybrid beings have been proposed in U.S. states and in the [[United States Congress|U.S. Congress]], several scientists have argued that legal barriers might go too far and prohibit medically beneficial studies into human modification.<ref name=Columbus/><ref name=Mott/><ref name=Weiss/> Although the two topics are not strictly related, the debates involving the creation of human-animal hybrids have paralleled that of the debates around the stem-cell research controversy.<ref name=Columbus/>

The question of what line exists between a 'human' being and a 'non-human' being has been a difficult one for many researchers to answer. While animals having one percent or less of their cells originally coming from humans may clearly appear to be in the same boat as other animals, no consensus exists on how to think about beings in a genetic middle ground that have something like an even mix. "I don't think anyone knows in terms of crude percentages how to differentiate between humans and nonhumans," [[United States Patent and Trademark Office|U.S. patent office]] official John Doll has stated.<ref name=Weiss/> Critics of increased government restrictions include scientists such as Dr. Douglas Kniss, head of the Laboratory of PeriNatal Research at [[Ohio State University]], who has remarked that formal laws aren't the best option since the "notion of animal–human hybrids is very complex." He's also argued that their creation is inherently "not the kind of thing we support" in his kind of research since scientists should "want to respect human life".<ref name=Columbus/> "There are chimeras out there that serve very valuable purposes in medical research, such as mice that make human antibodies," Michael Werner, the chief of policy for the [[Biotechnology Industry Organization]], has commented.<ref name=Weiss/>

In contrast, notable socio-economic theorist [[Jeremy Rifkin]] has expressed opposition to research that creates beings crossing species boundaries, arguing that it interferes with the fundamental 'right to exist' possessed by each animal species. "One doesn't have to be religious or into animal rights to think this doesn't make sense," he has argued when expressing support for anti-chimera and anti-hybrid legislation. As well, William Cheshire, associate professor of neurology at the [[Mayo Clinic]]'s Florida branch, has called the issue "unexplored biologic territory" and advocated for a "moral threshold of human neural development" to restrict the destroying a human embryo to obtain cell material and/or the creation of an organism that's partly human and partly animal." He has said, "We must be cautious not to violate the integrity of humanity or of animal life over which we have a stewardship responsibility".<ref name=Mott/>

In the U.S., efforts into creating a hybrid entity appeared to be legal when the topic first came up. The developmental biologist [[Stuart Newman]], a professor at [[New York Medical College]] in [[Valhalla, N.Y.]], applied for a patent on a human-animal chimera in 1997 as a challenge to the U.S. Patent and Trademark Office and the [[United States Congress|U.S. Congress]], motivated by his moral and scientific opposition to the notion that living things can be patented at all. Prior legal precedent had established that genetically engineered entities in general could be patented, even if they were based on beings occurring in nature.<ref name=Weiss/>

After a seven-year process, Newman's patent finally received a flat rejection. The legal process had created a paper trail of arguments, giving Newman what he considered a victory. ''[[The Washington Post]]'' ran an article on the controversy that stated that it had raised "profound questions about the differences-- and similarities-- between humans and other animals, and the limits of treating animals as property."<ref name=Weiss/> President [[George W. Bush]] brought up the topic in his [[2006 State of the Union Address]], in which he called for the prohibition of "human cloning in all its forms", "creating or implanting embryos for experiments", "creating ''human-animal hybrids''", and also "buying, selling, or patenting human embryos". He argued, "A hopeful society has institutions of science and medicine that do not cut ethical corners and that recognize the matchless value of every life." He also stated that humanity "should never be discarded, devalued or put up for sale."<ref name=Bush>{{cite news|url=https://www.washingtonpost.com/wp-dyn/content/article/2006/01/31/AR2006013101468.html|title=President Bush's State of the Union Address – CQ Transcripts Wire|newspaper=[[The Washington Post]]|accessdate=August 8, 2015|date=January 31, 2006}}</ref>

A 2005 appropriations bill passed by the U.S. Congress and signed into law by President Bush contained specific wording forbidding any patents on humans or human embryos.<ref name=Weiss/> In terms of outright bans on hybrid research in the first place, a measure came up in the [[110th Congress]] entitled the ''Human-Animal Hybrid Prohibition Act of 2008''. Congressman [[Chris Smith (New Jersey politician)|Chris Smith]] ([[Republican Party (United States)|R]], [[New Jersey's 4th congressional district|NJ-4]]) introduced it on April 24, 2008. The text of the proposed act stated that "human dignity and the integrity of the human species are compromised" if such hybrids exist and set up a punishment of imprisonment for up to ten years as well as a fine of over one million dollars. Though attracting support from many co-sponsors such as then [[United States House of Representatives|Representatives]] [[Mary Fallin]], [[Duncan L. Hunter|Duncan Hunter]], [[Joseph R. Pitts]], and [[Rick Renzi]] among others, the Act failed to get through Congress.<ref>{{cite web|title=H.R. 5910 (110th): Human-Animal Hybrid Prohibition Act of 2008|publisher=[[GovTrack]]|accessdate=August 8, 2015|url=https://www.govtrack.us/congress/bills/110/hr5910}}</ref>

A related proposal had come up in the [[United States Senate|U.S. Senate]] the prior year, the ''Human–Animal Hybrid Prohibition Act of 2007'', and it also had failed. That effort was proposed by then Senator [[Sam Brownback]] ([[Republican Party (United States)|R]], [[Kansas|KS]]) on November 15, 2007. Featuring the same language as the later measure in the House, its bipartisan group of cosponsors included then Senators [[Tom Coburn]], [[Jim DeMint]], and [[Mary Landrieu]].<ref>{{cite web|title=S. 2358 (110th): Human–Animal Hybrid Prohibition Act of 2007|publisher=[[GovTrack]]|accessdate=August 8, 2015|url=https://www.govtrack.us/congress/bills/110/s2358}}</ref>

A localized measure designed to ban the creation of hybrid entities came up in the state of [[Arizona]] in 2010. The proposal was signed into law by then [[List of Governors of Arizona|Governor]] [[Jan Brewer]]. Its sponsor stated that it was needed to clarify important "ethical boundaries" in research.<ref name=Columbus/>