Chicken or the egg
The chicken or the egg
Ancient legacy
The question represents an ancient folk paradox addressing the problem of origins and
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 enlightenment philosophers began to question this solution.[4] Carlo Dati in the mid 17th-century published an erudite satire on the subject.[5]
Scientific resolutions
Although the question is typically used metaphorically, evolutionary biology provides literal answers, made possible by the Darwinian principle that species evolve over time, and thus that chickens had ancestors that were not chickens,[4] similar to a view expressed by the Greek philosopher Anaximander when addressing the paradox.[3]
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.[6] In contrast, chickens are domesticated descendants of red junglefowl and probably arose little more than eight thousand years ago, at most.[7]
If the question refers to chicken eggs specifically, the answer is still the egg, but the explanation is more complicated.[8] 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 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.[9][4][10][11]
It has been suggested that the actions of a protein found in modern chicken eggs may make the answer different.[10][11] 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.[10][11] However, the presence of OC-17 or a homolog in other species, such as turkeys[12] and finches[13] suggests that such eggshell-reinforcing proteins are common to all birds,[14] and thus long predate the first chickens.
See also
- Bootstrapping (compilers), the solution to an analogous problem in computer science
- Catch-22
- Sorites paradox
References
- ^ "Essays and Miscellanies, by Plutarch". Project Gutenberg. Retrieved 2020-07-07.
- ISBN 978-1-107-07536-8.
- ^ ISBN 978-0-19-515903-5.
- ^ a b c d e Fabry, Merrill (2016-09-21). "Now You Know: Which Came First, the Chicken or the Egg?". Time. Retrieved 2017-07-11.
- ^ Cicalata sopra chi fosse prima o la gallina o l'ouovo, by Carlo Dati, Presse Settembre, Naples, 1840.
- PMID 17047029.
- PMID 23211792.
- .
- ^ Breyer, Melissa (2013-02-11). "Finally answered! Which came first, the chicken or the egg?". Mother Nature Network. Retrieved 2017-07-11.
- ^ a b c Zushi, Yo (27 February 2017). "Which came first: the chicken or the egg?". NewStatesman.com.
- ^ a b c "Which came first, the chicken or the egg? British scientists claim to have solved the mystery". NBCnews.com. 14 July 2010.
- PMID 23981693.
- PMID 26628892.
- .
Further reading
- Experts apply new technique to crack egg shell problem Archived 2023-03-28 at the PMID 20540126.