Editing Reindeer (section)

== Evolution ==
The "glacial-interglacial cycles of the [[Late Pleistocene|upper Pleistocene]] had a major influence on the evolution" of ''Rangifer'' species and other Arctic and sub-Arctic species. Isolation of tundra-adapted species ''Rangifer'' in [[Last Glacial Maximum refugia]] during the last glacial – the [[Wisconsin glaciation]] in North America and the [[Weichselian glaciation]] in Eurasia – shaped "intraspecific [[genetic variability]]" particularly between the North American and Eurasian parts of the [[Arctic]].<ref name="Flagstad">{{cite journal |last1=Flagstad |first1=Oystein |last2=Roed |first2=Knut H. |year=2003 |title=Refugial origins of reindeer (''Rangifer tarandus'' L) inferred from mitochondrial DNA sequences |url=http://genome-lab.ucdavis.edu/LabMeeting/Lab_Meeting_Papers/temporary/Flagstad2003Evol.pdf |url-status=dead |journal=Evolution |volume=57 |pages=658–670 |doi=10.1554/0014-3820(2003)057[0658:roorrt]2.0.co;2 |pmid=12703955 |archive-url=https://web.archive.org/web/20060904024954/http://genome-lab.ucdavis.edu/LabMeeting/Lab_Meeting_Papers/temporary/Flagstad2003Evol.pdf |archive-date=4 September 2006 |access-date=4 January 2013 |number=3}}</ref>

Reindeer / caribou (''Rangifer'') are in the subfamily [[Capreolinae|Odocoileinae]], along with [[roe deer]] (''[[Capreolus]]''), [[Moose|Eurasian elk / moose]] (''Alces''), and [[water deer]] (''Hydropotes''). These antlered cervids split from the horned ruminants ''[[Bos]]'' (cattle and yaks), ''[[Ovis]]'' (sheep) and ''[[Capra (genus)|Capra]]'' (goats) about 36 million years ago.<ref name="Weldenegodguad-2020">{{Cite journal |last1=Weldenegodguad |first1=Melak |last2=Pokharel |first2=Kisun |last3=Ming |first3=Yao |last4=Honkatukia |first4=Mervi |last5=Peippo |first5=Jaana |last6=Reilas |first6=Tiina |last7=Røed |first7=Knut H. |last8=Kantanen |first8=Juha |date=December 2020 |title=Genome sequence and comparative analysis of reindeer (''Rangifer tarandus'') in northern Eurasia |journal=[[Scientific Reports]] |language=en |volume=10 |issue=1 |pages=8980 |doi=10.1038/s41598-020-65487-y |pmid=32488117 |pmc=7265531 |bibcode=2020NatSR..10.8980W |issn=2045-2322}}</ref> The Eurasian [[clade]] of Odocoileinae (Capreolini, Hydropotini and Alcini) split from the New World tribes of Capreolinae ([[Odocoileini]] and Rangiferini) in the [[Late Miocene]], 8.7–9.6 million years ago.<ref>{{Cite book |last=Croitor |first=Roman |title=Plio-Pleistocene deer of Western Palearctic: taxonomy, systematics, phylogeny |publisher=Institute of Zoology of the Academy of Sciences of Moldova |year=2018 |location=Chișinău, Moldova |pages=1–142}}</ref> ''Rangifer'' "evolved as a mountain deer, ...exploiting the subalpine and alpine meadows...".<ref name="Geist1998" /> ''Rangifer'' originated in the [[Piacenzian|Late Pliocene]] and diversified in the [[Early Pleistocene]], a 2+ million-year period of multiple glacier advances and retreats. Several named ''Rangifer'' fossils in [[Eurasia]] and North America predate the evolution of modern tundra reindeer.

Archaeologists distinguish "modern" tundra reindeer and barren-ground caribou from primitive forms – living and extinct – that did not have adaptations to extreme cold and to long-distance migration. They include a broad, high muzzle to increase the volume of the nasal cavity to warm and moisten the air before it enters the throat and lungs, bez tines set close to the brow tines, distinctive coat patterns, short legs and other adaptations for running long distances, and multiple behaviors suited to tundra, but not to forest (such as synchronized calving and aggregation during rutting and post-calving).<ref>{{Cite book |last=Croitor |first=Roman |title=Plio-Pleistocene deer of Western Palearctic: taxonomy, systematics, phylogeny |publisher=Institute of Zoology of the Academy of Sciences of Moldova |year=2018 |location=Chișinău}}</ref> As well, many genes, including those for [[vitamin D]] metabolism, [[Lipid metabolism|fat metabolism]], retinal development, [[circadian rhythm]], and tolerance to cold temperatures, are found in tundra caribou that are lacking or rudimentary in forest types.<ref>{{Cite journal |last1=Cavedon |first1=Maria |last2=Gubili |first2=Chrysoula |last3=Heppenheimer |first3=Elizabeth |last4=vonHoldt |first4=Bridgett |last5=Mariani |first5=Stefano |last6=Hebblewhite |first6=Mark |last7=Hegel |first7=Troy |last8=Hervieux |first8=Dave |last9=Serrouya |first9=Robert |last10=Steenweg |first10=Robin |last11=Weckworth |first11=Byron V. |last12=Musiani |first12=Marco |date=April 2019 |title=Genomics, environment and balancing selection in behaviourally bimodal populations: The caribou case |url=https://onlinelibrary.wiley.com/doi/10.1111/mec.15039 |journal=Molecular Ecology |language=en |volume=28 |issue=8 |pages=1946–1963 |doi=10.1111/mec.15039 |pmid=30714247 |bibcode=2019MolEc..28.1946C |s2cid=73423576 |issn=0962-1083|hdl=20.500.11820/82fe4f52-d3f2-4970-ab52-8dbb97b997c1 |hdl-access=free }}</ref><ref>{{Cite bioRxiv |last1=Prunier |first1=Julien |last2=Carrier |first2=Alexandra |last3=Gilbert |first3=Isabelle |last4=Poisson |first4=William |last5=Albert |first5=Vicky |last6=Taillon |first6=Joëlle |last7=Bourret |first7=Vincent |last8=Côté |first8=Steeve D. |last9=Droit |first9=Arnaud |last10=Robert |first10=Claude |date=2021-07-23 |title=Copy number variations with adaptive potential in caribou (''Rangifer tarandus''): genome architecture and new annotated genome assembly |biorxiv=10.1101/2021.07.22.453386}} {{s2cid|236436985}}</ref> For this reason, forest-adapted reindeer and caribou could not survive in [[tundra]] or [[polar desert]]s. The oldest undoubted ''Rangifer'' fossil is from [[Omsk]], Russia, dated to 2.1-1.8 Ma.<ref>Bondarev, A.A.; Tesakov, A.S.; Simakova, A.N.; Dorogov, A.L. (2017) Reindeer (''Rangifer'') from Early Pleistocene of the south of Western Siberia (in Russian). In: Bogdanov, A.A.; others (eds.) Integrative palaeontology: development prospects for geological objectives, material of the LXIII session of the Palaeontological Society, April, 3-7, 2017. Sankt-Peterburg, 173-175.</ref> The oldest North American ''Rangifer'' fossil is from the [[Yukon]], 1.6 million years before present (BP).<ref>{{Cite journal |last=Harington |first=C.R. |date=August 2011 |title=Pleistocene vertebrates of the Yukon Territory |journal=Quaternary Science Reviews |volume=30 |issue=17–18 |pages=2341–2354 |doi=10.1016/j.quascirev.2011.05.020 |bibcode=2011QSRv...30.2341H |issn=0277-3791}}</ref> A fossil skull fragment from Süßenborn, Germany, ''R. arcticus stadelmanni'',<ref>{{Cite journal |last=Kahlke |first=H-D |title=Die Cerviden-Reste aus den Kiesen von Süßenborn bei Weimar. Palaeontologische Abhandlungen Abteilung A |journal=Palaozoologie |volume=1969 |pages=367–788}}</ref> (which is probably misnamed) with "rather thin and cylinder-shaped" antlers, dates to the [[Chibanian|Middle Pleistocene]] (Günz) Period, 680,000-620,000 BP.<ref name="Croitor-2010">{{Cite journal |last=Croitor |first=Roman |date=2010 |title=Preliminary data on reindeer fossils from the Palaeolithic site Rascov-8 (eastern Moldova) with remarks on systematics and evolution of Upper Pleistocene reindeer |journal=Ştiinţele Naturii |volume=1 |pages=323–330}}</ref> ''Rangifer'' fossils become increasingly frequent in circumpolar deposits beginning with the [[Riss glaciation]]s, the second youngest of the [[Pleistocene]] Epoch, roughly 300,000–130,000 BP. By the [[Würm glaciation|4-Würm period]] (110,000–70,000 to 12,000–10,000 BP), its European range was extensive, supplying a major food source for prehistoric Europeans.<ref>{{Cite book |last=Kurtén |first=B. |title=Pleistocene mammals in Europe |publisher=Weidenfeld and Nicolson |year=1968 |issn=0345-0074 |location=London, U.K.}}</ref> North American fossils outside of [[Beringia]] that predate the [[Last Glacial Maximum]] (LGM) are of [[Rancholabrean]] age (240,000–11,000 years BP) and occur along the fringes of the Rocky Mountain and [[Laurentide ice sheet]]s as far south as northern [[Alabama]]; and in [[Sangamonian]] deposits (~100,000 years BP) from western Canada.<ref name="Geist-2007">{{Cite journal |last=Geist |first=Valerius |date=2007-04-01 |title=Defining subspecies, invalid taxonomic tools, and the fate of the woodland caribou |journal=[[Rangifer (journal)|Rangifer]] |volume=27 |issue=4 |pages=25 |doi=10.7557/2.27.4.315 |issn=1890-6729|doi-access=free }}</ref>

A ''R. t. pearyi''-sized caribou occupied Greenland before and after the LGM and persisted in a relict enclave in northeastern Greenland until it went extinct about 1900 (see discussion of ''R. t. eogroenlandicus'' below). Archaeological excavations showed that larger barren-ground-sized caribou appeared in western Greenland about 4,000 years ago.<ref name="HighArctic2">{{cite journal |author1=Peter Gravlund |author2=Morten Meldgaard |author3=Svante Pääbo |author4=Peter Arctander |name-list-style=amp |year=1998 |title=Polyphyletic Origin of the Small-Bodied, High-Arctic Subspecies of Tundra Reindeer (''Rangifer tarandus'') |journal=Molecular Phylogenetics and Evolution |volume=10 |issue=2 |pages=151–159 |doi=10.1006/mpev.1998.0525 |pmid=9878226|bibcode=1998MolPE..10..151G }}</ref>

The late [[Valerius Geist]] (1998)<ref name="Geist1998" /> dates the Eurasian reindeer radiation dates to the large Riss glaciation (347,000 to 128,000 years ago), based on the Norwegian-Svalbard split 225,000 years ago.<ref>Røed, K.H. (1985) Comparison of the genetic variation in Svalbard and Norwegian reindeer. Canadian Journal of Zoology 63: 2038-2042. {{doi|10.1139/z85-300}}</ref> Finnish forest reindeer (''R. t. fennicus'') likely evolved from ''Cervus [Rangifer] geuttardi'' Desmarest, 1822, a reindeer that adapted to forest habitats in Eastern Europe as forests expanded during an interglacial period before the LGM (the Würmian or [[Weichsel glaciation]]);.<ref name="Croitor-2010" /> The fossil species ''geuttardi'' was later replaced by ''R. constantini'', which was adapted for grasslands,<ref>{{Cite journal |last1=Baranova |first1=A. I. |last2=Panchenko |first2=D. V. |last3=Kholodova |first3=M. V. |last4=Tirronen |first4=K. F. |last5=Danilov |first5=P. I. |date=November 2016 |title=Genetic diversity of wild reindeer ''Rangifer tarandus'' L. from the eastern part of the Kola Peninsula: Polymorphism of the mtDNA control region |journal=Biology Bulletin |volume=43 |issue=6 |pages=567–572 |doi=10.1134/s1062359016060029 |bibcode=2016BioBu..43..567B |s2cid=15672189 |issn=1062-3590}}</ref> in a second immigration 19,000–20,000 years ago when the LGM turned its forest habitats into tundra, while ''fennicus'' survived in isolation in southwestern Europe.<ref name="Croitor-2010" /> ''R. constantini'' was then replaced by modern tundra / barren-ground caribou adapted to extreme cold, probably in Beringia, before dispersing west (''R. t. tarandus'' in the [[Scandinavia]]n mountains and ''R. t. sibiricus'' across Siberia) and east (''R. t. arcticus'' in the North American Barrenlands) when rising seas isolated them. Likewise in North America, [[Genetic testing|DNA analysis]] shows that woodland caribou (''R. caribou'') diverged from primitive ancestors of tundra / barren-ground caribou not during the LGM, 26,000–19,000 years ago, as previously assumed, but in the Middle Pleistocene around 357,000 years ago.<ref name="Horn-2018">{{Cite journal |last1=Horn |first1=Rebekah L. |last2=Marques |first2=Adam J. D. |last3=Manseau |first3=Micheline |last4=Golding |first4=Brian |last5=Klütsch |first5=Cornelya F. C. |last6=Abraham |first6=Ken |last7=Wilson |first7=Paul J. |date=June 2018 |title=Parallel evolution of site-specific changes in divergent caribou lineages |journal=Ecology and Evolution |language=en |volume=8 |issue=12 |pages=6053–6064 |doi=10.1002/ece3.4154 |pmid=29988428 |pmc=6024114|bibcode=2018EcoEv...8.6053H }}</ref><ref name="Yannic-2018">{{Cite journal |last1=Yannic |first1=Glenn |last2=Ortego |first2=Joaquín |last3=Pellissier |first3=Loïc |last4=Lecomte |first4=Nicolas |last5=Bernatchez |first5=Louis |last6=Côté |first6=Steeve D. |date=2018 |title=Linking genetic and ecological differentiation in an ungulate with a circumpolar distribution |journal=Ecography |volume=41 |issue=6 |pages=922–937 |doi=10.1111/ecog.02995 |bibcode=2018Ecogr..41..922Y |issn=0906-7590 |s2cid=4518424|doi-access=free }}</ref> At that time, modern tundra caribou had not even evolved. Woodland caribou are likely more related to extinct North American forest caribou than to barren-ground caribou. For example, the extinct caribou ''Torontoceros [Rangifer] hypogaeus'', had features (robust and short pedicles, smooth antler surface, and high position of second tine) that relate it to forest caribou.<ref>{{Cite journal |last=Croitor |first=Roman |date=2022 |title=Paleobiogeography of Crown Deer |journal=Earth |volume=3 |issue=4 |pages=1138–1160|doi=10.3390/earth3040066 |bibcode=2022Earth...3.1138C |doi-access=free }}</ref>

Humans started hunting reindeer in both the [[Mesolithic]] and [[Neolithic]] Periods, and humans are today the main predator in many areas. [[Norway]] and [[Greenland]] have unbroken traditions of hunting wild reindeer from the [[Last Glacial Period]] until the present day. In the non-forested mountains of central Norway, such as [[Jotunheimen]], it is still possible to find remains of stone-built [[trapping pit]]s, guiding fences and bow rests, built especially for hunting reindeer. These can, with some certainty, be dated to the [[Migration Period]], although it is not unlikely that they have been in use since the [[Stone Age]].

[[Cave painting]]s by ancient Europeans include both tundra and forest types of reindeer.<ref name="Geist1998" />

A 2022 study of ancient [[environmental DNA]] from the [[Early Pleistocene]] (2 million years ago) [[Kap Kobenhavn Formation]] of northern Greenland identified preserved DNA fragments of ''Rangifer'', identified as basal but potentially ancestral to modern reindeer. This suggests that reindeer have inhabited Greenland since at least the Early Pleistocene. Around this time, northern Greenland was {{cvt|11|–|19|C-change}} warmer than the [[Holocene]], with a [[Taiga|boreal forest]] hosting a species assemblage with no modern analogue. These are among the oldest DNA fragments ever sequenced.<ref>{{Cite journal |last1=Kjær |first1=Kurt H. |last2=Winther Pedersen |first2=Mikkel |last3=De Sanctis |first3=Bianca |last4=De Cahsan |first4=Binia |last5=Korneliussen |first5=Thorfinn S. |last6=Michelsen |first6=Christian S. |last7=Sand |first7=Karina K. |last8=Jelavić |first8=Stanislav |last9=Ruter |first9=Anthony H. |last10=Schmidt |first10=Astrid M. A. |last11=Kjeldsen |first11=Kristian K. |last12=Tesakov |first12=Alexey S. |last13=Snowball |first13=Ian |last14=Gosse |first14=John C. |last15=Alsos |first15=Inger G. |date=December 2022 |title=A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA |journal=Nature |language=en |volume=612 |issue=7939 |pages=283–291 |doi=10.1038/s41586-022-05453-y |issn=1476-4687 |pmc=9729109 |pmid=36477129|bibcode=2022Natur.612..283K }}</ref><ref>{{Cite web |last=Pappas |first=Stephanie |title=World's Oldest DNA Discovered, Revealing Ancient Arctic Forest Full of Mastodons |url=https://www.scientificamerican.com/article/worlds-oldest-dna-discovered-revealing-ancient-arctic-forest-full-of-mastodons/ |access-date=2022-12-08 |website=Scientific American |language=en}}</ref>