Editing Brown bear (section)

===Taxonomy and subspecies===
{{main|Subspecies of brown bear}}
[[File:Eurasian brown bear (Ursus arctos arctos) female 1.jpg|thumb|Adult female [[Eurasian brown bear]], the [[nominate subspecies]]|alt=A bear in a wooded area|left]]

[[Carl Linnaeus]] scientifically described the species under the name ''Ursus arctos'' in the 1758 edition of ''[[Systema Naturae]]''.<ref>{{Cite book |last=Linnaeus |first=Carl |chapter-url=https://gdz.sub.uni-goettingen.de/id/PPN362053006?tify=%7B%22pages%22:%5B51%5D,%22pan%22:%7B%22x%22:0.524,%22y%22:0.878%7D,%22view%22:%22scan%22,%22zoom%22:0.831%7D |title=Caroli Linnæi ó. Systema naturæ per regna tria naturæ, secundum classses, ordines, genera, species, cum characteribus, differentiis, synonymis, locis |year=1758 |page=47|location=Stockholm|publisher=Lars Salvius|language=la|chapter=''Ursus arctos''}}</ref> Brown bear taxonomy and subspecies classification has been described as "formidable and confusing", with few authorities listing the same set of subspecies.<ref>{{citation |last1=Wilson |first1=D. E. |last2=Ruff |first2=S. |year=1999 |title=The Smithsonian Book of North American Mammals |publisher=[[Smithsonian Institution Press]] |location=Washington, D.C.|pages=160–201}}</ref> There are hundreds of obsolete brown-bear subspecies. As many as 90 subspecies have been proposed.<ref name=Harris>{{cite news|last1=Harris|first1=Arthur H.|url=https://www.researchgate.net/publication/236842872|title=Pleistocene Vertebrates of Arizona, New Mexico, and Trans-Pecos Texas|date=2013|publisher=UTEP Biodiversity Collections, University of Texas at El Paso}}</ref><ref name=Storer1955>{{cite book |last1=Storer |first1=T. I. |last2=Tevis |first2=L. P. |title=California Grizzly |url=https://books.google.com/books?id=1QVZFQu01KcC&pg=PA149 |url-access=registration |year=1996 |publisher=[[University of California Press]] |location=[[Berkeley, California|Berkeley, CA]] |isbn=978-0-520-20520-8 |pages=[https://archive.org/details/californiagrizzl00stor/page/335 335], 42–187 |access-date=18 November 2019 |archive-date=2 February 2024 |archive-url=https://web.archive.org/web/20240202162031/https://books.google.com/books?id=1QVZFQu01KcC&pg=PA149#v=onepage&q&f=false |url-status=live }} [https://archive.org/details/californiagrizzl00stor Alt URL]</ref> A 2008 [[DNA analysis]] identified as few as five main [[clade]]s, which comprise all extant brown bear species, while a 2017 [[Phylogenetics|phylogenetic]] study revealed nine clades, including one representing polar bears.<ref name="ReferenceA">{{cite journal |author1=Calvignac, S. |author2=Hughes, S. |author3=Tougard, C. |author4=Michaux, J. |author5=Thevenot, M. |author6=Philippe, M. |author7=Hamdine, W.|author8=Hanni, C.|title=Ancient DNA evidence for the loss of a highly divergent brown bear clade during historical times |journal=[[Molecular Ecology]] |year=2008 |volume=17 |issue=8 |pages=1962–1970 |doi=10.1111/j.1365-294x.2008.03631.x |pmid=18363668|bibcode=2008MolEc..17.1962C |s2cid=23361337 |url=https://hal.archives-ouvertes.fr/hal-00287307/file/calvignac2008.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://hal.archives-ouvertes.fr/hal-00287307/file/calvignac2008.pdf |archive-date=2022-10-09 |url-status=live }}</ref><ref name="lan">{{cite journal |author1=Lan, T. |author2=Gill, S. |author3=Bellemain, E. |author4=Bischof, R. |author5=Zawaz, M. A. |author6=Lindqvist, C. |year=2017 |title=Evolutionary history of enigmatic bears in the Tibetan Plateau–Himalaya region and the identity of the yeti |journal=Proceedings of the Royal Society B: Biological Sciences |volume=284 |issue=1,868 |pages=20,171,804 |doi=10.1098/rspb.2017.1804 |pmid=29187630 |pmc=5740279}}</ref> {{as of|2005}}, 15 extant, or recently extinct, subspecies were recognized by the general scientific community.<ref name=MSW3>{{MSW3 Wozencraft | id =14000970 | pages = 588–589|heading = ''Ursus arctos''}}</ref>

DNA analysis shows that, apart from recent, human-caused [[population fragmentation]],<ref>{{Cite journal |last1=Proctor |first1=Michael F. |last2=Paetkau |first2=David |last3=Mclellan |first3=Bruce N. |last4=Stenhouse |first4=Gordon B. |last5=Kendall |first5=Katherine C. |last6=Mace |first6=Richard D. |last7=Kasworm |first7=Wayne F. |last8=Servheen |first8=Christopher |last9=Lausen |first9=Cori L. |year=2012 |title=Population fragmentation and inter-ecosystem movements of grizzly bears in western Canada and the northern United States |journal=[[Wildlife Monographs]] |volume=180 |issue=1 |pages=1–46 |doi=10.1002/wmon.6 |bibcode=2012WildM.180....1P |s2cid=16790669 |issn=1938-5455}}</ref> brown bears in North America are generally part of a single interconnected population system, with the exception of the population (or subspecies) in the [[Kodiak Archipelago]], which has probably been isolated since the end of the [[Last Glacial Period|last Ice Age]].<ref>{{Cite journal |last1=Strobeck |first1=Curtis |last2=Craighead |first2=Lance |last3=Clarkson |first3=Peter L. |last4=Waits |first4=Lisette P. |last5=Paetkau |first5=David |date=1 December 1997 |title=An Empirical Evaluation of Genetic Distance Statistics Using Microsatellite Data From Bear (Ursidae) Populations |url=http://www.genetics.org/content/147/4/1943 |journal=[[Genetics (journal)|Genetics]] |volume=147 |issue=4 |pages=1943–1957 |doi=10.1093/genetics/147.4.1943 |issn=0016-6731 |pmid=9409849 |pmc=1208359 |access-date=29 January 2019 |archive-date=29 January 2019 |archive-url=https://web.archive.org/web/20190129235849/http://www.genetics.org/content/147/4/1943 |url-status=live }}</ref><ref name="Waits">{{cite journal |author=Waits, L. P. |year=1998 |title=Mitochondrial DNA Phylogeography of the North American Brown Bear and Implications for Conservation |journal=[[Conservation Biology (journal)|Conservation]] |volume=12 |issue=2 |pages=408–417 |doi=10.1111/j.1523-1739.1998.96351.x |bibcode=1998ConBi..12..408W |s2cid=86172292 |display-authors=etal}}</ref> These data demonstrate that ''U. a. gyas'', ''U. a. horribilis'', ''U. a. sitkensis'', and ''U. a. stikeenensis'' are not distinct or cohesive groups, and would more accurately be described as [[Ecotype|ecotypes]]. For example, brown bears in any particular region of the Alaska coast are more closely related to adjacent grizzly bears than to distant populations of brown bears.<ref>{{Cite journal|last1=Paetkau|first1=D.|last2=Shields|first2=G. F.|last3=Strobeck|first3=C.|date=1998|title=Gene flow between insular, coastal and interior populations of brown bears in Alaska|journal=Molecular Ecology|volume=7|issue=#10|pages=1283–1292|issn=0962-1083|pmid=9787441|doi=10.1046/j.1365-294x.1998.00440.x|bibcode=1998MolEc...7.1283P |s2cid=21848010}}</ref>

The history of the bears of the [[Alexander Archipelago]] is unusual in that these island populations carry polar bear DNA, presumably originating from a population of polar bears that was left behind at the end of the [[Pleistocene]], but have since been connected with adjacent mainland populations through the movement of males, to the point where their nuclear genomes indicate more than 90% brown bear ancestry.<ref name="Shapiro_al.2013">{{Cite journal |last1=Shapiro |first1=Beth |last2=Slatkin |first2=Montgomery |last3=Stirling |first3=Ian |last4=John |first4=John St. |last5=Salamzade |first5=Rauf |last6=Ovsyanikov |first6=Nikita |last7=Jay |first7=Flora |last8=Stiller |first8=Mathias |last9=Fulton |first9=Tara L. |date=14 March 2013 |title=Genomic Evidence for Island Population Conversion Resolves Conflicting Theories of Polar Bear Evolution |journal=[[PLOS Genetics]] |volume=9 |issue=3 |page=e1003345 |doi=10.1371/journal.pgen.1003345 |issn=1553-7404 |pmc=3597504 |pmid=23516372 |doi-access=free |bibcode=2013PLOSG...9.3345C }}</ref> [[MtDNA]] analysis revealed that brown bears are apparently divided into five different clades, some of which coexist or co-occur in different regions.<ref name="Servheen" />