The snow sheep (''Ovis nivicola''), or Siberian bighorn sheep, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

from the mountainous areas in the northeast of

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

. One

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

, the Putorana snow sheep ''(Ovis nivicola borealis)'', lives isolated from the other forms in the Putoran Mountains.

Subspecies

*Kolyma snow sheep, ''O. n. ssp'' *Koryak snow sheep, ''O. n. koriakorum'' *Okhotsk snow sheep, ''O. n. alleni'' *Yakutian snow sheep, ''O. n. lydekkeri'' *Kamchatkan snow sheep, ''O. n. nivicola'' *Putorana snow sheep, ''O. n. borealis'' *Chukotka snow sheep, ''O. n. tschuktschorum''

Taxonomy and genetics

''Ovis nivicola'' appeared about 600,000 years ago. A number of these wild sheep crossed the

Bering Land Bridge Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 72° north latitude in the Chukchi Sea; and on the south by the tip of the ...

(

Beringia Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 70th parallel north, 72° north latitude in the Chukchi Sea; and on the south ...

), from

into

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

, during the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

(about 750,000 years ago); new and extant lineages were created from this migration, notably the

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

n Dall sheep (or thin-horn sheep) and the

bighorn sheep The bighorn sheep (''Ovis canadensis'') is a species of Ovis, sheep native to North America. It is named for its large Horn (anatomy), horns. A pair of horns may weigh up to ; the sheep typically weigh up to . Recent genetic testing indicates th ...

, the two which ''O. nivicola'' is most closely related to. Currently the mitochondrial genome of ''Ovis nivicola'' has been completely mapped out. A first-draft genome assembly exists for ''Ovis nivicola''.Maulik Upadhyay, Andreas Hauser, Elisabeth Kunz, Stefan Krebs, Helmut Blum, Arsen Dotsev, Innokentiy Okhlopkov, Vugar Bagirov, Gottfried Brem, Natalia Zinovieva, Ivica Medugorac, The First Draft Genome Assembly of Snow Sheep (Ovis nivicola), Genome Biology and Evolution, Volume 12, Issue 8, August 2020, Pages 1330–1336, https://doi.org/10.1093/gbe/evaa124

References

External links

''Ovis nivicola'', Snow Sheep, on ultimateungulate.com
Ovis Mammals described in 1829 {{sheep-stub