Editing Common descent (section)

{{Short description|Characteristic of a group of organisms with a common ancestor}}
{{For|use of the term in linguistics and philology|Comparative method|Historical linguistics|Proto-language|Textual criticism}}
{{Redirect|Common ancestor|use of the term in graph theory|Lowest common ancestor}}

{{Evolutionary biology|Key topics}}

'''Common descent''' is a concept in [[evolutionary biology]] applicable when one species is the ancestor of two or more species later in time. According to modern evolutionary biology, all living beings could be descendants of a unique ancestor commonly referred to as the [[last universal common ancestor]] (LUCA) of all [[life]] on [[Earth]].<ref>{{Cite journal|last1=Weiss|first1=Madeline C.|last2=Sousa|first2=Filipa L.|last3=Mrnjavac|first3=Natalia|last4=Neukirchen|first4=Sinje|last5=Roettger|first5=Mayo|last6=Nelson-Sathi|first6=Shijulal|last7=Martin|first7=William F.|date=2016-07-25|title=The physiology and habitat of the last universal common ancestor|url=https://www.nature.com/articles/nmicrobiol2016116|journal=Nature Microbiology|language=en|volume=1|issue=9|page=16116|doi=10.1038/nmicrobiol.2016.116|pmid=27562259|s2cid=2997255|issn=2058-5276|url-access=subscription}}</ref><ref>{{Cite journal|last1=Forterre|first1=Patrick|last2=Gribaldo|first2=Simonetta|last3=Brochier|first3=Céline|date=October 2005|title=[Luca: the last universal common ancestor]|journal=Médecine/Sciences|volume=21|issue=10|pages=860–865|doi=10.1051/medsci/20052110860|issn=0767-0974|pmid=16197904|doi-access=free}}</ref><ref name="theobald">{{cite journal |last=Theobald |first=Douglas L. |date=13 May 2010 |title=A formal test of the theory of universal common ancestry |journal=[[Nature (journal)|Nature]] |volume=465 |issue=7295 |pages=219–222 |doi=10.1038/nature09014 |pmid=20463738|bibcode=2010Natur.465..219T |s2cid=4422345 }}</ref><ref name="steel">{{cite journal |last1=Steel |first1=Mike |author1-link=Mike Steel (mathematician) |last2=Penny |first2=David |date=13 May 2010 |title=Origins of life: Common ancestry put to the test |journal=Nature |volume=465 |issue=7295 |pages=168–169 |doi=10.1038/465168a |pmid=20463725|bibcode=2010Natur.465..168S |s2cid=205055573 |doi-access=free }}</ref>

Common descent is an effect of [[speciation]], in which multiple species derive from a single ancestral population. The more recent the ancestral population two species have in common, the more closely they are related. The most recent common ancestor of all currently living organisms is the last universal ancestor,<ref name="theobald" /> which lived about [[Timeline of the evolutionary history of life|3.9 billion years ago]].<ref>{{cite journal |last=Doolittle |first=W. Ford |author-link=Ford Doolittle |date=February 2000 |title=Uprooting the Tree of Life |url=http://shiva.msu.montana.edu/courses/mb437_537_2004_fall/docs/uprooting.pdf |journal=[[Scientific American]] |volume=282 |issue=2 |pages=90–95 |doi=10.1038/scientificamerican0200-90 |pmid=10710791 |archive-url=https://web.archive.org/web/20060907081933/http://shiva.msu.montana.edu/courses/mb437_537_2004_fall/docs/uprooting.pdf |archive-date=2006-09-07 |access-date=2015-11-22|bibcode=2000SciAm.282b..90D }}</ref><ref>{{cite journal |last1=Glansdorff |first1=Nicolas |author2=Ying Xu |last3=Labedan |first3=Bernard |date=9 July 2008 |title=The Last Universal Common Ancestor: emergence, constitution and genetic legacy of an elusive forerunner |journal=[[Biology Direct]]  |volume=3 |page=29 |doi=10.1186/1745-6150-3-29  |pmc=2478661 |pmid=18613974 |doi-access=free }}</ref> The two earliest pieces of evidence for life on Earth are [[graphite]] found to be [[Biogenic substance|biogenic]] in 3.7 billion-year-old [[metasedimentary rock]]s discovered in western [[Greenland]]<ref name="NG-20131208">{{cite journal |last1=Ohtomo |first1=Yoko |last2=Kakegawa |first2=Takeshi |last3=Ishida |first3=Akizumi |last4=Nagase |first4=Toshiro |last5=Rosing |first5=Minik T. |display-authors=3 |date=January 2014 |title=Evidence for biogenic graphite in early Archaean Isua metasedimentary rocks |journal=[[Nature Geoscience]] |volume=7 |issue=1 |pages=25–28 |bibcode=2014NatGe...7...25O |doi=10.1038/ngeo2025}}</ref> and [[microbial mat]] [[fossil]]s found in 3.48 billion-year-old [[sandstone]] discovered in [[Western Australia]].<ref name="AP-20131113">{{cite news |last=Borenstein |first=Seth |date=13 November 2013 |title=Oldest fossil found: Meet your microbial mom |url=https://www.yahoo.com/news/oldest-fossil-found-meet-microbial-mom-223338964.html |publisher=[[Yahoo News]] |agency=[[Associated Press]] |access-date=2015-11-22 |archive-date=2019-11-10 |archive-url=https://web.archive.org/web/20191110152138/https://www.yahoo.com/news/oldest-fossil-found-meet-microbial-mom-223338964.html |url-status=dead }}</ref><ref name="AST-20131108">{{cite journal |last1=Noffke |first1=Nora |author1-link=Nora Noffke |last2=Christian |first2=Daniel |last3=Wacey |first3=David |last4=Hazen |first4=Robert M. |author-link4=Robert Hazen |date=16 December 2013 |title=Microbially Induced Sedimentary Structures Recording an Ancient Ecosystem in the ''ca''. 3.48 Billion-Year-Old Dresser Formation, Pilbara, Western Australia |journal=[[Astrobiology (journal)|Astrobiology]] |volume=13 |issue=12 |pages=1103–1124 |doi=10.1089/ast.2013.1030 |pmc=3870916 |pmid=24205812|bibcode=2013AsBio..13.1103N }}</ref> All currently living organisms on Earth share a common [[Genetics|genetic]] heritage, though the suggestion of substantial [[horizontal gene transfer]] during early evolution has led to questions about the [[monophyly]] (single ancestry) of life.<ref name="theobald" /> 6,331 groups of [[gene]]s common to all living animals have been identified; these may have arisen from a single [[Animal#Phylogeny|common ancestor]] that lived [[Cryogenian|650 million years ago]] in the [[Precambrian]].<ref name="NYT-20180504" /><ref name="NC-20150430" />

Universal common descent through an [[evolution]]ary process was first proposed by the British [[Natural history|naturalist]] [[Charles Darwin]] in the concluding sentence of his 1859 book ''[[On the Origin of Species]]'':

{{Blockquote|There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.<ref name="origin_490">{{harvnb|Darwin|1859|p=490}}</ref>}}