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Gloger's Rule
Gloger's rule is an ecogeographical rule which states that within a species of endotherms, more heavily pigmented forms tend to be found in more humid environments, e.g. near the equator. It was named after the zoologist Constantin Wilhelm Lambert Gloger, who first remarked upon this phenomenon in 1833 in a review of covariation of climate and avian plumage color. Erwin Stresemann later noted that the idea had been expressed even earlier by Peter Simon Pallas in ''Zoographia Rosso-Asiatica'' (1811). Gloger found that birds in more humid habitats tended to be darker than their relatives from regions with higher aridity. Over 90% of 52 North American bird species studies conform to this rule. One explanation of Gloger's rule in the case of birds appears to be the increased resistance of dark feathers to feather- or hair-degrading bacteria such as ''Bacillus licheniformis''. Feathers in humid environments have a greater bacterial load, and humid environments are more suitable for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three Evolution of mammalian auditory ossicles, middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors Genetic divergence, diverged in the Carboniferous Period over 300 million years ago. Around 6,640 Neontology#Extant taxon, extant species of mammals have been described and divided into 27 Order (biology), orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, Mole (animal), moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the Artiodactyl, even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including Felidae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
August Schulz
August is the eighth month of the year in the Julian and Gregorian calendars. Its length is 31 days. In the Southern Hemisphere, August is the seasonal equivalent of February in the Northern Hemisphere. In the Northern Hemisphere, August falls in summer. In the Southern Hemisphere, the month falls during winter. In many European countries, August is the holiday month for most workers. Numerous religious holidays occurred during August in ancient Rome. Certain meteor showers take place in August. The Kappa Cygnids occur in August, with yearly dates varying. The Alpha Capricornids meteor shower occurs as early as July 10 and ends around August 10. The Southern Delta Aquariids occur from mid-July to mid-August, with the peak usually around July 28–29. The Perseids, a major meteor shower, typically takes place between July 17 and August 24, with the peak days varying yearly. The star cluster of Messier 30 is best observed around August. Among the aborigines of the Canary I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prentice Hall
Prentice Hall was a major American publishing#Textbook_publishing, educational publisher. It published print and digital content for the 6–12 and higher-education market. It was an independent company throughout the bulk of the twentieth century. In its last few years it was owned by, then absorbed into, Savvas Learning Company. In the Web era, it distributed its technical titles through the Safari Books Online e-reference service for some years. History On October 13, 1913, law professor Charles Gerstenberg and his student Richard Ettinger founded Prentice Hall. Gerstenberg and Ettinger took their mothers' maiden names, Prentice and Hall, to name their new company. At the time the name was usually styled as Prentice-Hall (as seen for example on many title pages), per an orthographic norm for Dash#Relationships and connections, coordinate elements within such compounds (compare also ''McGraw-Hill'' with later styling as ''McGraw Hill''). Prentice-Hall became known as a publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Condor (journal)
''Ornithological Applications'', formerly ''The Condor'' and ''The Condor: Ornithological Applications'', is a peer-reviewed quarterly scientific journal covering ornithology. It is an official journal of the American Ornithological Society. History The journal was first published in 1899 as the ''Bulletin of the Cooper Ornithological Club'' by the Cooper Ornithological Club (later Cooper Ornithological Society), a California-based ornithological society. In 1900, the journal was renamed as ''The Condor''. It published ornithological research, and through the 1950s, its scope was regional, focusing on the western United States. An editorial board was established in 1951 to address increasing submissions to the journal. James R. King, editor-in-chief following 1965, instituted an external peer review system. Moreover, King broadened the journal's geographic scope. By 1966, at least 40% of papers published in ''The Condor'' were written by scientists outside the United States. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bergmann's Rule
Bergmann's rule is an ecogeographical rule that states that, within a broadly distributed taxonomic clade, populations and species of larger size are found in colder environments, while populations and species of smaller size are found in warmer regions. The rule derives from the relationship between size in linear dimensions meaning that both height and volume will increase in colder environments. Bergmann's rule only describes the overall size of the animals, but does not include body proportions like Allen's rule does. Although originally formulated in relation to species within a genus, it has often been recast in relation to populations within a species. It is also often cast in relation to latitude. It is possible that the rule also applies to some plants, such as '' Rapicactus''. The rule is named after nineteenth century German biologist Carl Bergmann, who described the pattern in 1847, although he was not the first to notice it. Bergmann's rule is most often applied t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allen's Rule
Allen's rule is an ecogeographical rule formulated by Joel Asaph Allen in 1877, broadly stating that animals adapted to cold climates have shorter and thicker limbs and bodily Appendage, appendages than animals adapted to warm climates. More specifically, it states that the body surface-area-to-volume ratio for Homeothermy, homeothermic animals varies with the average temperature of the habitat to which they are adapted (i.e. the ratio is low in cold climates and high in hot climates). Explanation Allen's rule predicts that endotherm, endothermic animals with the same body volume should have different surface areas that will either aid or impede their heat dissipation. Because animals living in cold climates need to conserve as much heat as possible, Allen's rule predicts that they should have evolved comparatively low surface area-to-volume ratios to minimize the surface area by which they dissipate heat, allowing them to retain more heat. For animals living in warm climates, Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibetan Plateau
The Tibetan Plateau, also known as the Qinghai–Tibet Plateau or Qingzang Plateau, is a vast elevated plateau located at the intersection of Central Asia, Central, South Asia, South, and East Asia. Geographically, it is located to the north of Himalayas and the Indian subcontinent, and to the south of Tarim Basin and Mongolian Plateau. Geopolitically, it covers most of the Tibet Autonomous Region, most of Qinghai, western half of Sichuan, Southern Gansu provinces, southern Xinjiang province in Western China, Bhutan, the Administrative divisions of India, Indian regions of Ladakh and Lahaul and Spiti district, Lahaul and Spiti (Himachal Pradesh) as well as Gilgit-Baltistan in Pakistan, northwestern Nepal, eastern Tajikistan and southern Kyrgyzstan. It stretches approximately north to south and east to west. It is the world's highest and largest plateau above sea level, with an area of . With an average elevation exceeding and being surrounded by imposing mountain ranges that har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inuit
Inuit (singular: Inuk) are a group of culturally and historically similar Indigenous peoples traditionally inhabiting the Arctic and Subarctic regions of North America and Russia, including Greenland, Labrador, Quebec, Nunavut, the Northwest Territories, Yukon (traditionally), Alaska, and the Chukotsky District of Chukotka Autonomous Okrug. The Inuit languages are part of the Eskaleut languages, also known as Inuit-Yupik-Unangan, and also as Eskimo–Aleut. Canadian Inuit live throughout most of Northern Canada in the territory of Nunavut, Nunavik in the northern third of Quebec, the Nunatsiavut in Labrador, and in various parts of the Northwest Territories and Yukon (traditionally), particularly around the Arctic Ocean, in the Inuvialuit Settlement Region. These areas are known, by Inuit Tapiriit Kanatami and the Government of Canada, as Inuit Nunangat. In Canada, sections 25 and 35 of the Constitution Act of 1982 classify Inuit as a distinctive group of Abo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibetan People
Tibetans () are an East Asian people, East Asian ethnic group Indigenous peoples, native to Tibet. Their current population is estimated to be around 7.7 million. In addition to the majority living in the Tibet Autonomous Region of China, significant numbers of Tibetans live in the provinces of China, Chinese provinces of Gansu, Qinghai, Sichuan, and Yunnan, as well as in Bhutan, Tibetan refugees in India, India, and Nepal. The Tibetic languages belong to the Tibeto-Burman languages, Tibeto-Burman language group. The traditional or mythological explanation of the Tibetan people's origin is that they are the descendants of the human Pha Trelgen Changchup Sempa and rock ogress Ma Drag Sinmo. It is thought that most of the Tibeto-Burman speakers in southwest China, including Tibetans, are direct descendants from the Qiang (historical people), ancient Qiang people. Most Tibetans practice Tibetan Buddhism, although a significant minority observe the Indigenous Bon religion. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteomalacia
Osteomalacia is a disease characterized by the softening of the bones caused by impaired bone metabolism primarily due to inadequate levels of available phosphate, calcium, and vitamin D, or because of resorption of calcium. The impairment of bone metabolism causes inadequate bone mineralization. Osteomalacia in children is known as rickets, and because of this, use of the term "osteomalacia" is often restricted to the milder, adult form of the disease. Signs and symptoms can include diffuse body pains, muscle weakness, and fragility of the bones. In addition to low systemic levels of circulating mineral ions (for example, caused by vitamin D deficiency or renal phosphate wasting) that result in decreased bone and tooth mineralization, accumulation of mineralization-inhibiting proteins and peptides (such as osteopontin and ASARM peptides), and small inhibitory molecules (such as pyrophosphate), can occur in the extracellular matrix of bones and teeth, contributing locally to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin D
Vitamin D is a group of structurally related, fat-soluble compounds responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, along with numerous other biological functions. In humans, the most important compounds within this group are vitamin D3 ( cholecalciferol) and vitamin D2 ( ergocalciferol). Unlike the other twelve vitamins, vitamin D is only conditionally essential, as with adequate skin exposure to the ultraviolet B (UVB) radiation component of sunlight there is synthesis of cholecalciferol in the lower layers of the skin's epidermis. For most people, skin synthesis contributes more than diet sources. Vitamin D can also be obtained through diet, food fortification and dietary supplements. In the U.S., cow's milk and plant-based milk substitutes are fortified with vitamin D3, as are many breakfast cereals. Government dietary recommendations typically assume that all of a person's vitamin D is taken by mouth, given the potential for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
