Question: Worker: Which animal which is white in winter and brown in summer lives throughout the Arctic and can trace its roots to an extinct animal that lived in the Himalayas?

Context articles: Charles Davies Sherborn
Haootia
Solza (animal)
Yorgia
Tree of Life (Disney)
Arctic fox
Journey to the Beginning of Time
Majorcan giant dormouse
Vulpes qiuzhudingi
Arctic ecology

Charles Davies Sherborn (30 June 1861 – 22 June 1942) was an English bibliographer, paleontologist and geologist.
 He wrote "Index Animalium", an 11-volume, 9,000-page work that catalogued the 444,000 names of every living and extinct animal discovered between 1758 and 1850.
 This work is considered the bibliographic foundation for zoological nomenclature.
 In addition, Sherborn authored almost 200 books, papers, and catalogs on a wide variety topics in natural history.
 He made important contributions to the study of microfossils and was a founding member and first president of the Society for the Bibliography of Natural History.
 In recognition of his endeavours he was awarded an Honorary Doctorate from Oxford University.
Haootia quadriformis is an extinct animal belonging to the Ediacaran biota.
 Estimated to be about 560 million years old, "H. quadriformis" is identified as a cnidarian polyp, and is regarded as the earliest animal possessing muscles. Discovered in 2008 from Newfoundland in eastern Canada, it was formally described in 2014.
 It is the first Ediacaran organism discovered to show fossil of muscle fibres.
 Structural comparison of the muscles and morphology indicate that the animal is a cnidarian, though, which class "H. quadriformis" belongs to is currently undetermined.
Solza margarita is an extinct animal of uncertain phylogeny which lived about 555 mya in the Ediacaran period.
Yorgia waggoneri is a discoid Ediacaran, and possibly represents a transition organism between "Dickinsonia" and "Spriggina".
 However, their growth form indicates that may not be the case.
 It has a low, segmented body consisting of a short wide "head", no appendages, and a long body region, reaching a maximum length of 25 cm .
 It is classified within the extinct animal phylum Proarticulata.
The Tree of Life is a 145 ft sculpture of a tree at Disney's Animal Kingdom, Walt Disney World Resort.
 It debuted when the attraction opened on April 22, 1998.
 Inspired by the mythical tree of the same name, the Tree of Life features 325 carvings of existing and extinct animal species on its trunk and surrounding roots.
The Arctic fox ("Vulpes lagopus"), also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome.
 It is well adapted to living in cold environments.
 It has a deep thick fur which is brown in summer and white in winter.
 Its body length ranges from 46 to , with a generally rounded body shape to minimize the escape of body heat.
Journey to the Beginning of Time (Czech: Cesta do pravěku , literally "Journey into prehistory") is a 1955 Czechoslovak children's science fiction feature film directed by Karel Zeman.
 Produced using a combination of 2-D and 3-D models, it was the first of Zeman's productions to include actors in conjunction with stop-motion and special effects, and won awards at the International Film Festivals of Venice and Mannheim.
 The documentary-type nature of the film showing extinct animal species behaving naturally in their own environments was most unusual for its era and foreshadowed many later TV productions that would depict prehistoric life for educational rather than purely entertainment purposes.
 "Cesta do pravěku" should not be confused with a dubbed and partly re-filmed US version of the film that was released in 1966 under the title "Journey to the Beginning of Time".
The Majorcan giant dormouse ("Hypnomys morpheus") is an extinct animal from Majorca, Spain in Europe.
 It is considered an example of island gigantism.
 The closest extant relative is considered to be the genus "Eliomys", which includes the garden dormouse.
 It is believed to have been omnivorous, and may have been terrestrial rather than arboreal.
 The arrival of humans on the island is believed to have been a major factor in its extinction.
 "H. morpheus" was described by the palaeontologist Dorothea Bate in 1919.
 A 2011 study estimated its body weight as between 173 and 284 g, with a head and body length of 179 mm and a total body length of 295 mm.
Vulpes qiuzhudingi is an extinct species of fox found in the Himalayas.
 It was primarily carnivorous.
 The fossils, dating from between 5.08 and 3.60 million years ago, were found in the Zanda Basin and Kunlun Mountains of Tibet.
 It was named after Qiu Zhuding, a paleontologist from the Chinese Academy of Sciences.
 The species is believed to be the ancestor of "Vulpes lagopus", the modern Arctic fox, which would support the "Out of Tibet" theory: namely, that a number of current arctic species trace their ancestry to species originally from the Tibetan Plateau.
Arctic ecology is the scientific study of the relationships between biotic and abiotic factors in the arctic, the region north of the Arctic Circle (66 33’).
 This is a region characterized by stressful conditions as a result of extreme cold, low precipitation, a limited growing season (50–90 days) and virtually no sunlight throughout the winter.
 The Arctic consists of taiga (or boreal forest) and tundra biomes, which also dominate very high elevations, even in the tropics.
 Sensitive ecosystems exist throughout the Arctic region, which are being impacted dramatically by global warming.
 The earliest inhabitants of the Arctic were the Neanderthals.
 Since then, many indigenous populations have inhabited the region, which continues to this day.
 Since the early 1900s, when Vilhjalmur Stefansson led the first major Canadian Arctic Expedition, the Arctic has been a valued area for ecological research.
 In 1946, The Arctic Research Laboratory was established in Point Barrow, Alaska under the contract of the Office of Naval Research.
 This launched an interest in exploring the Arctic examining animal cycles, permafrost and the interactions between indigenous peoples and the Arctic ecology.
 During the Cold War, the Arctic became a place where the United States, Canada, and the Soviet Union performed significant research that has been essential to the study of climate change in recent years.
 A major reason why research in the Arctic is essential for the study of climate change is because the effects of climate change will be felt more quickly and more drastically in higher latitudes of the world as above average temperatures are predicted for Northwest Canada and Alaska.
 From an anthropological point of view, researchers study the native Inuit peoples of Alaska as they have become extremely accustomed to adapting to ecological and climate variability.