Editing Kingdom (biology) (section)

=== Three domains of life ===
{{main|Three-domain system|Domain (biology)}}

{{PhylomapB||caption=A [[phylogenetic tree]] based on [[rRNA]] data showing Woese's [[three-domain system]]. All smaller branches can be considered kingdoms.|size = 440px}}
Based on RNA studies, [[Carl Woese]] thought life could be divided into three large divisions and referred to them as the "three primary kingdom" model or "urkingdom" model.<ref name="Balch_Magrum_Fox_Wolfe_Woese">{{cite journal|last1=Balch |first1=W.E. |last2=Magrum |first2=L.J. |last3=Fox |first3=G.E. |last4=Wolfe |first4=C.R. |last5=Woese |first5=C.R. |name-list-style=amp |date=August 1977|title=An ancient divergence among the bacteria|journal=[[Journal of Molecular Evolution]] |volume=9|issue=4 |pages=305–311 |doi=10.1007/BF01796092 |pmid=408502 |bibcode=1977JMolE...9..305B |s2cid=27788891}}</ref>

In 1990, the name "domain" was proposed for the highest rank.<ref name="Woese"/> This term represents a synonym for the category of dominion (lat. dominium), introduced by Moore in 1974.<ref name=Moore1974>{{cite journal|last=Moore |first=R.T. |year=1974|title=Proposal for the recognition of super ranks |journal=Taxon |volume=23|issue=4 |pages=650–652 |doi=10.2307/1218807 |jstor=1218807 |url=http://www.iapt-taxon.org/historic/Congress/IBC_1975/Prop034bis-037.pdf}}</ref> Unlike Moore, Woese et al. (1990) did not suggest a Latin term for this category, which represents a further argument supporting the accurately introduced term dominion.<ref name=Luketa2012>{{cite journal |last=Luketa |first=S. |year=2012|title=New views on the megaclassification of life |journal=[[Protistology]] |volume=7|issue=4 |pages=218–237 |url=http://protistology.ifmo.ru/num7_4/luketa_protistology_7-4.pdf}}</ref>

Woese divided the prokaryotes (previously classified as the Kingdom Monera) into two groups, called [[bacteria|Eubacteria]] and [[Archaea|Archaebacteria]], stressing that there was as much genetic difference between these two groups as between either of them and all eukaryotes.

{{clade
   |label1=[[Life]]
   |1={{clade
      |1=Domain [[Bacteria]] ([[Eubacteria]])
      |2=Domain [[Archaea]] ([[Archaebacteria]])
      |3=Domain [[Eukaryote|Eukarya]] ([[Eukaryota]])
   }}
}}

According to genetic data, although eukaryote groups such as plants, fungi, and animals may look different, they are more closely related to each other than they are to either the Eubacteria or Archaea. It was also found that the eukaryotes are more closely related to the Archaea than they are to the Eubacteria. Although the primacy of the Eubacteria-Archaea divide has been questioned, it has been upheld by subsequent research.<ref name="DagenEtAl2010">{{cite journal |last1=Dagan |first1=T. |last2=Roettger |first2=M. |last3=Bryant |last4=Martin |first4=W. |year=2010|title=Genome Networks Root the Tree of Life between Prokaryotic Domains|journal=[[Genome Biology and Evolution]] |volume=2|pages=379–92 |doi=10.1093/gbe/evq025 |pmid=20624742 |pmc=2997548 |name-list-style=amp}}</ref> There is no consensus on how many kingdoms exist in the classification scheme proposed by Woese.