Ĭoastal grizzlies, often referred to by the popular but geographically redundant synonym of "brown bear" or "Alaskan brown bear" are larger and darker than inland grizzlies, which is why they, too, were considered a different species from grizzlies. įurther testing of Y-chromosomes is required to yield an accurate new taxonomy with different subspecies. In 1963, Rausch reduced the number of North American subspecies to one, Ursus arctos middendorffi. Therefore, everywhere it is the "brown bear" in North America, it is the "grizzly", but these are all the same species, Ursus arctos. Rausch found that North America has but one species of grizzly. However, modern genetic testing reveals the grizzly to be a subspecies of the brown bear ( Ursus arctos). However, by 1928 only seven grizzly species remained, and by 1953, only one species remained globally. In the 19th century, the grizzly was classified as 86 distinct species. The genome of the grizzly bear was sequenced in 2018 and found to be 2,328.64Mb (mega-basepairs) in length, and contain 30,387 genes. Ursus arctosīrown bears originated in Eurasia and traveled to North America approximately 50,000 years ago, spreading into the contiguous United States about 13,000 years ago. There are two morphological forms of Ursus arctos: the grizzly and the coastal brown bears, but these morphological forms do not have distinct mtDNA lineages. Evolution and genetics PhylogeneticsĬlassification has been revised along genetic lines. The modern spelling supposes the former meaning even so, naturalist George Ord formally classified it in 1815 as U. Meriwether Lewis and William Clark first described it as grisley, which could be interpreted as either " grizzly" (i.e., "grizzled"-that is, with grey-tipped hair) or " grisly" ("fear-inspiring", now usually "gruesome"). lasiotus), inhabiting Russia, Northern China, Japan, and Korea, is sometimes referred to as the "black grizzly", although it is no more closely related to North American brown bears than other subspecies of the brown bear around the world. On average, grizzly bears near the coast tend to be larger while inland grizzlies tend to be smaller. nelsoni†), and Ungava-Labrador grizzly (formerly U. californicus†), Mexican grizzly (formerly U. gyas)-as well as the extinct California grizzly ( U. beringianus), and the peninsular grizzly ( U. These include three living populations-the Kodiak bear ( U. In addition to the mainland grizzly ( Ursus arctos horribilis), other morphological forms of brown bear in North America are sometimes identified as grizzly bears. The grizzly bear ( Ursus arctos horribilis), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
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