Editing Chicken or the egg

{{Short description|Philosophical paradox}}
{{pp-vandalism|small=yes}}
[[Image:10-alimenti,uova,Taccuino Sanitatis, Casanatense 4182..jpg|thumb|upright=1.35|Illustration of a woman collecting hens' eggs from ''[[Tacuinum Sanitatis|Tacuina sanitatis]]'', 14th century]]
The '''chicken or the egg''' [[causality]] [[dilemma]] is commonly stated as the question, "which came first: the [[chicken]] or the [[egg (biology)|egg]]?" The dilemma stems from the observation that all chickens hatch from eggs and all chicken eggs are laid by chickens. "Chicken-and-egg" is a metaphoric adjective describing situations where it is not clear which of two events should be considered the ''cause'' and which should be considered the ''effect'', to express a scenario of [[infinite regress]], or to express the difficulty of sequencing actions where each seems to depend on others being done first. [[Plutarch]] posed the question as a philosophical matter in his essay "[[Moralia|The Symposiacs]]", written in the 1st century CE.<ref>{{Cite web|title=Essays and Miscellanies, by Plutarch|url=https://www.gutenberg.org/files/3052/3052-h/3052-h.htm|access-date=2020-07-07|website=[[Project Gutenberg]]}}</ref><ref name="O'Brien">{{cite book|url=https://books.google.com/books?id=KQNEBgAAQBAJ&q=chicken+and+the+egg+problem+Plutarch&pg=PA106|title=The Demiurge in Ancient Thought|last=O'Brien|first=Carl Séan|date=2015|publisher=Cambridge University Press|isbn=978-1-107-07536-8|location=Cambridge, England|page=106}}</ref>

==Ancient legacy==
The question represents an ancient folk paradox addressing the problem of origins and [[first cause]].<ref name="paradox">{{cite book|last=Sorensen|first=Roy|title=A Brief History of the Paradox: Philosophy and the Labyrinths of the Mind|url=https://archive.org/details/strategicinnovat00afua_285|url-access=limited|publisher=Oxford University Press|place=Oxford|year=2003|pages=[https://archive.org/details/strategicinnovat00afua_285/page/n24 4]–11|isbn=978-0-19-515903-5}}</ref> [[Aristotle]], writing in the fourth century BCE, concluded that this was an infinite sequence, with no true origin.<ref name="paradox" /> Plutarch, writing four centuries later, specifically highlighted this question as bearing on a "great and weighty problem (whether the world had a beginning)".<ref name="Fabry">{{cite magazine
| title=Now You Know: Which Came First, the Chicken or the Egg?
| url=https://time.com/4475048/which-came-first-chicken-egg/
| first=Merrill
| last=Fabry
| date=2016-09-21
| magazine=[[Time (magazine)|Time]]
| access-date=2017-07-11}}</ref> In the fifth century CE, [[Macrobius]] wrote that while the question seemed trivial, it "should be regarded as one of importance".<ref name="Fabry" />

By the end of the 16th century, the well-known question seemed to have been regarded as settled in the Christian world, based on the origin story of the [[Bible]]. In describing the creation of animals, it allows for a first chicken that did not come from an egg. However, later [[Age of Enlightenment|Enlightenment]] philosophers began to question this solution.<ref name="Fabry" /> [[Carlo Roberto Dati|Carlo Dati]] in the mid 17th-century published an erudite satire on the subject.<ref>[https://books.google.com/books?id=IhmFYITiwGYC Cicalata sopra chi fosse prima o la gallina o l'ouovo], by Carlo Dati, Presse Settembre, Naples, 1840.</ref>

==Scientific resolutions==
Although the question is typically used metaphorically, [[evolutionary biology]] provides literal answers, made possible by the Darwinian principle that species [[Evolution|evolve]] over time, and thus that chickens had ancestors that were not chickens,<ref name="Fabry" /> similar to a view expressed by the Greek philosopher [[Anaximander]] when addressing the paradox.<ref name="paradox" /> 

If the question refers to eggs in general, the egg came first. The first [[amniote]] egg – that is, a hard-shelled egg that could be laid on land, rather than remaining in water like the eggs of fish or amphibians – appeared around 312 million years ago.<ref>{{Cite journal|last1=Benton|first1=Michael J.|last2=Donoghue|first2=Philip C. J.|date=2007-01-01|title=Paleontological Evidence to Date the Tree of Life|url=https://academic.oup.com/mbe/article/24/1/26/1070944|journal=[[Molecular Biology and Evolution]]|volume=24|issue=1|pages=26–53|doi=10.1093/molbev/msl150|issn=0737-4038|pmid=17047029|doi-access=free}}</ref> In contrast, chickens are domesticated descendants of [[red junglefowl]] and probably arose little more than eight thousand years ago, at most.<ref>{{Cite journal|last1=Miao|first1=Y-W|last2=Peng|first2=M-S|last3=Wu|first3=G-S|last4=Ouyang|first4=Y-N|last5=Yang|first5=Z-Y|last6=Yu|first6=N|last7=Liang|first7=J-P|last8=Pianchou|first8=G|last9=Beja-Pereira|first9=A|date=2012-12-05|title=Chicken domestication: an updated perspective based on mitochondrial genomes|journal=[[Heredity (journal)|Heredity]]|language=en|volume=110|issue=3|pages=277–282|doi=10.1038/hdy.2012.83|issn=1365-2540|pmc=3668654|pmid=23211792}}</ref>

If the question refers to ''chicken'' eggs specifically, the answer is still the egg, but the explanation is more complicated.<ref name=SOR>{{cite journal|first= Roy A. |last=Sorensen|title=The Egg came before the chicken|journal=Mind|volume=101|number=403|pages=541–542|year=1992|url=https://academic.oup.com/mind/article-abstract/101/403/541/947797?redirectedFrom=fulltext|doi=10.1093/mind/101.403.541}}</ref> The process by which the chicken arose through the interbreeding and domestication of multiple species of wild jungle fowl is poorly understood, and the point at which this evolving organism became a chicken is a somewhat arbitrary distinction. Whatever criteria one chooses, an animal nearly identical to the modern chicken (i.e., a [[wiktionary:proto-|proto]]-chicken) laid a fertilized egg that had DNA making it a modern chicken due to mutations in the mother's ovum, the father's sperm, or the fertilised [[zygote]].<ref>{{cite web
| title=Finally answered! Which came first, the chicken or the egg?
| url=https://www.mnn.com/earth-matters/animals/stories/finally-answered-which-came-first-the-chicken-or-the-egg
| first=Melissa
| last=Breyer
| date=2013-02-11
| website=[[Mother Nature Network]]
| access-date=2017-07-11}}</ref><ref name="Fabry" /><ref name="Zushi">{{cite news|last=Zushi |first=Yo |publisher=NewStatesman.com |date=27 February 2017|title=Which came first: the chicken or the egg? |url=https://www.newstatesman.com/2017/which-came-first-chicken-or-egg}}</ref><ref name="NBCnews.com">{{cite news|publisher=NBCnews.com |date=14 July 2010|title=Which came first, the chicken or the egg? British scientists claim to have solved the mystery|url=https://www.nbcnews.com/id/wbna38238685}}</ref>

It has been suggested that the actions of a [[protein]] found in modern chicken eggs may make the answer different.<ref name="Zushi" /><ref name="NBCnews.com"/> In the uterus, chickens produce ovocleidin-17 (OC-17), which causes the formation of the thickened [[calcium carbonate]] shell around their eggs. Because OC-17 is expressed by the hen and not the egg, the bird in which the protein first arose, though having hatched from a non-reinforced egg, would then have laid the first egg having such a reinforced shell: the chicken would have preceded this first 'modern' chicken egg.<ref name="Zushi" /><ref name="NBCnews.com"/> However, the presence of OC-17 or a homolog in other species, such as turkeys<ref>{{cite journal|last1=Mann|first1=Karlheinz|last2=Mann|first2=Matthias|title=The proteome of the calcified layer organic matrix of turkey (Meleagris gallopavo) eggshell|journal=Proteome Sci.|year=2013|volume=11|issue=1|page=40|doi=10.1186/1477-5956-11-40|pmid=23981693|pmc=3766105 |doi-access=free }}</ref> and finches<ref>{{cite journal|last=Mann|first=Karlheinz|title=The calcified eggshell matrix proteome of a songbird, the zebra finch (Taeniopygia guttata)|journal=Proteome Sci.|year=2015|volume=13|page=29|doi=10.1186/s12953-015-0086-1|pmc=4666066|pmid=26628892 |doi-access=free }}</ref> suggests that such eggshell-reinforcing proteins are common to all birds,<ref>{{cite journal|last1=Hincke|first1=Maxwell T.|last2=Nys|first2=Yves|last3=Gautron|first3=Joel|title=The Role of Matrix Proteins in Eggshell Formation|journal=The Journal of Poultry Science|year=2010|volume=47|issue=3|pages=208–219|doi=10.2141/jpsa.009122|doi-access=free}}</ref> and thus long predate the first chickens.

==Disputations==
On 24 July 2024, two men began a chicken-or-egg debate at a party with alcohol in Indonesia. One man became so emotionally enraged he left and returned with a knife, stabbing the other 15 times and killing him. It is uncertain what side of the argument — chicken or egg — the killer took.<ref>{{cite web |last=Sharma |first=Shweta |title=Indonesian man stabs friend to death over chicken or egg debate |work=The Independent |date=30 July 2024 |access-date=2024-08-01 |url=https://www.independent.co.uk/asia/southeast-asia/indonesia-chicken-egg-question-murder-sulawesi-b2588159.html }}</ref><ref>{{cite web |last=Beschizza |first=Rob |title=Man stabbed to death in debate over whether chicken or egg came first |work=[[BoingBoing]] |date=1 August 2024 |access-date=2024-04-01 |url=https://boingboing.net/2024/08/01/man-stabbed-to-death-in-debate-over-whether-chicken-or-egg-came-first.html }}</ref><ref>{{cite web |last= |first= |title=Perkara Teka-teki Ayam atau Telur Duluan, Pria di Sultra Bunuh Temannya |date=27 July 2024 |work=Kumparan |access-date=2024-04-01 |url=https://kumparan.com/kumparannews/perkara-teka-teki-ayam-atau-telur-duluan-pria-di-sultra-bunuh-temannya-23D1L0YXc97 |language=id}}</ref>

==See also==
* [[Bootstrapping (compilers)]], the solution to an analogous problem in computer science
* [[Catch-22 (logic)|Catch-22]]
* [[Sorites paradox]]

==References==
{{Reflist}}

==Further reading==
{{Wiktionary|chicken-or-egg question}}
* [https://www.sheffield.ac.uk/news/nr/1706-1.174049 Experts apply new technique to crack egg shell problem] {{Webarchive|url=https://web.archive.org/web/20230328152932/https://www.sheffield.ac.uk/news/nr/1706-1.174049 |date=2023-03-28 }} 12 July 2010 {{cite journal|doi=10.1002/anie.201000679|pmid=20540126|volume=49|title=Structural Control of Crystal Nuclei by an Eggshell Protein|year=2010|journal=Angewandte Chemie International Edition|pages=5135–5137|last1=Freeman|first1=Colin L.|last2=Harding|first2=John H.|last3=Quigley|first3=David|last4=Rodger|first4=P. Mark|issue=30}}

{{DEFAULTSORT:Chicken Or Egg}}
[[Category:Chickens]]
[[Category:Eggs in culture]]
[[Category:Metaphors referring to birds]]
[[Category:Paradoxes]]
[[Category:Philosophical phrases]]
[[Category:Ancient Greek logic]]
[[Category:Recursion]]
[[Category:Articles titled with a question]]