The tarsus is a cluster of seven articulating bones in each foot situated between the lower end of tibia and fibula of the lower leg and the metatarsus. It is made up of the hindfoot; the tarsus articulates with the bones of the metatarsus, which in turn articulate with the proximal phalanges of the toes. The joint between the tibia and fibula above and the tarsus below is referred to as the ankle joint. In humans the largest bone in the tarsus is the calcaneus, the weight-bearing bone within the heel of the foot; the talus bone or ankle bone is connected superiorly to the two bones of the lower leg, the tibia and fibula, to form the ankle joint or talocrural joint. Together, the talus and calcaneus form the hindfoot; the five irregular bones of the midfoot—the cuboid and three cuneiform bones—form the arches of the foot which serves as a shock absorber. The midfoot is connected to the hind - and forefoot by the plantar fascia; the complex motion of the subtalar joint occurs in three planes and produces subtalar inversion and eversion.
Along with the transverse tarsal joint, the subtalar joint transforms tibial rotation into forefoot supination and pronation. The axis of rotation in the joint is directed upward 42 degrees from the horizontal plane and 16 degrees medially from the midline of the foot. However, the subtalar facets form a screw or Archimedean spiral, right-handed in the right foot, about which subtalar motion occurs. So, during subtalar inversion, the calcaneus rotates clockwise and translates forward along the axis of the screw. Average subtalar motion is 5-10 degrees eversion. Functional motion during the gait cycle is 10-15 degrees; the talonavicular and calcaneocuboid joints form the so-called transverse tarsal joint or Chopart's joint. It has two axes of motion. Inversion and eversion occur about a longitudinal axis oriented 15 degrees upward from the horizontal plane and 9 degrees medially from the longitudinal axis of the foot. Flexion and extension occur about an oblique axis oriented 52 degrees upward from the horizontal plane and 57 degrees anteromedially.
In vitro talonavicular motion is 17 degrees pronation-supination. The motions of the subtalar and transverse talar joints interact to make the foot either flexible or rigid. With the subtalar joint in eversion, the two joints of the transverse joint are parallel, which make movements in this joint possible. With the subtalar joint in inversion, the axes of the transverse joint are convergent, movements in this joint are thus locked and the midfoot rigid. In primitive tetrapods, such as Trematops, the tarsus consists of three rows of bones. There are three proximal tarsals, the tibiale and fibulare, named for their points of articulation with the bones of the lower limb; these are followed by a second row of four bones, referred to as the centralia, a row of five distal tarsals, each articulating with a single metatarsal. In the great majority of tetrapods, including all of those alive today, this simple pattern is modified by the loss and fusion of some of the bones. In reptiles and mammals, there are just two proximal tarsals, the calcaneus and the talus.
In mammals, including humans, the talus forms a hinge joint with the tibia, a feature well developed in the artiodactyls. The calcaneus is modified, forming a heel for the attachment of the Achilles tendon. Neither of these adaptations is found in reptiles, which have a simple structure to both bones; the fifth distal tarsal disappears early in evolution, with the remainder becoming the cuneiform and cuboid bones. Reptiles retain two centralia, while mammals have only one. In birds, the tarsus has disappeared, with the proximal tarsals having fused with the tibia, the centralia having disappeared, the distal bones having fused with the metatarsals to form a single tarsometatarsus bone giving the leg a third segment. Arches of the foot Carpus Cuboid syndrome Tarsal tunnel Tarsal tunnel syndrome Nordin, Margareta. Basic biomechanics of the musculoskeletal system. Lippincott Williams & Wilkins. ISBN 0-683-30247-7. "Anatomy of the foot and ankle". Podiatry Channel. Retrieved 30 August 2009. Romer, Alfred Sherwood.
The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. Pp. 205–208. ISBN 0-03-910284-X. Diagram, identifying bones xrayslowerlimb at The Anatomy Lesson by Wesley Norman
Calcariidae is a small family of passerine birds. It includes longspurs and snow buntings. There are six species in three genera worldwide, found in North America and Eurasia, they are migratory and can live in a variety of habitats including grasslands, tundra and beaches. Members of Calcariidae range in mass from around 20 grams to around 42 grams. Species have brown and white plumage, with dark brown or black irises; the legs of the snow bunting and McKay's bunting are dark gray or black, while legs of other species in the family range from dull pink to brown. The birds in Calcariidae were assigned to the family Emberizidae. A 2008 phylogenetic study by Alström and colleagues confirmed that the members of this family form a clade quite separated from the Emberizidae, with affinities instead with the New World warblers, cardinals or tanagers, though their exact relationships are unclear, they proposed to place them in the tribe Calcariini, but the International Ornithological Congress has placed them in a separate family in 2010.
Timing with the cytochrome b DNA suggests that the Calcariidae diverged from a common ancestor around 4.2–6.2 million years ago, around the beginning of the Pliocene soon after spread of grasslands in North America as the climate in the late Miocene became drier and cooler. Three genera—Calcarius and Rhynchophanes—are recognised. Genetic analysis with cytochrome b DNA showed that McCown's longspur was most related to the two snow bunting species, the three nested within the genus Calcarius. Smith's and the chestnut-collared longspur were each other's closest relatives; the Lapland longspur diverged from an ornatus/pictus ancestor near the beginning of the Pliocene and the snow and McKay's buntings diverged within the last 100,000–125,000 years. Though they differ in appearance, Smith's and the collared longspurs only diverged around 1.5–2 million years ago, around the start of the Pleistocene. McKay's bunting is sometimes considered a subspecies of the snow bunting, instances of the two species hybridizing have been reported.
However, a 2007 study by Maley and Winker found substantial differences in the juvenile plumage between the two groups, supporting a species-level division. Other members of Calcariidae known to hybridize with each other are McCown's longspur and the chestnut-collared longspur. CalcariusLapland longspur Smith's longspur Chestnut-collared longspur PlectrophenaxSnow bunting McKay's bunting RhynchophanesMcCown's longspur The range of the family is extensive. Of the six species within the family, the snow bunting and Lapland longspur are found both in both North America and Eurasia; the snow bunting breeds in northern latitudes in an extensive breeding range which consists of northern Alaska and Canada, the western and southern coasts of Greenland, northern Scandinavia and Russia. The snow bunting winters throughout southern Canada and the northern United States in North America, its Eurasian range includes the northern United Kingdom and a large band extending from Germany west through Poland and Ukraine to Mongolia and China.
Additionally, the snow bunting has been recorded as a vagrant to Algeria and Morocco in North Africa, the Balkans and Turkey, Malta. The Lapland longspur's range is similar to that of the snow bunting, breeding in northern Canada and Siberia, coastal Alaska and Greenland and wintering in the northern United States and Canada, in a band between 45° and 55° latitude across Russia, Kazakhstan and Mongolia to the Sea of Japan; the ranges of the other species in the family are less expansive than those of the snow bunting and the Lapland longspur. McKay's bunting breeds on several islands in the Bering Sea, winters on the western coast of Alaska. Additionally, it has been reported in the Aleutian Islands, has been a vagrant in British Columbia in Canada as well as Washington and Oregon in the United States. Smith's longspur breeds in Alaska and northern Canada, winters in the central southern United States; the chestnut-collared longspur's breeding range consists of prairie regions in the northern Great Plains and southern Canadian Prairies, while its winter range extends from the southern United States to central Mexico.
The breeding range of McCown's longspur is similar to that of the chestnut-collared longspur, but its winter range does not extend as far south, ending in northern Mexico. Members of Calcariidae inhabit open areas, including prairies, shores and beaches. Parts of the snow bunting's range include mountainous areas; the diet of species in this family consists of insects and grasses. Species are diurnal, forage by walking and picking up food from the ground. Yuri, T. and Mindell, D. "Molecular phylogenetic analysis of Fringillidae, “New World nine-primaried oscines", Molecular Phylogenetics and Evolution, vol. 23, pp. 229–243. Planet of Birds. Accessed 2 August 2009
St. Matthew Island
St. Matthew Island is a remote island in the Bering Sea in Alaska, 295 km west-northwest of Nunivak Island; the island has a land area of 137.857 sq mi, making it the 43rd largest island in the United States. Its most southerly point is Cape Upright. Similar heights are found at Glory of Russia Cape on the north, the highest point, 1,476 feet above sea level, lies south from the island center. There is a small island off its northwestern point called Hall Island; the 3.1 miles wide sound between both islands is called Sarichef Strait. A small rocky islet called; the entire island's natural scenery and wildlife is protected as it is part of the Bering Sea unit of the Alaska Maritime National Wildlife Refuge. The United States Coast Guard maintained a manned LORAN station on the island during the 1940s; the climatic conditions in the entire Bering Sea Area, according to National Climatic Data Center is reported as maritime with "considerable wind and cool and cloudy conditions" with mean annual temperature of 3.2 °C and annual precipitation of 389 mm, in the St Mathews Island.
The geological formation recorded in St. Mathew Island consists of calc-alkaline volcanic rocks of Late Cretaceous and earliest tertiary age with Pergelic Cryaquolls and Pergelic Cryoborolls soil types; the first recorded attempt at settlement occurred in 1809, when a Russian group led by Demid Ilyich Kulikalov, under the guise of the Russian-American Company, established an experimental outpost. A 2013 sailing expedition to the island showed that, in spite of the lack of human habitation, extensive areas of beach were contaminated with plastic marine debris from the fishing industry. Presently, Arctic foxes and insular voles are the only mammals resident on the island, though polar bears visit via pack ice. Notably, St. Matthew Island represents the southern limit of the range of polar bears in the Bering Sea. In 1944, 29 reindeer were introduced to the island by the United States Coast Guard to provide an emergency food source; the Coast Guard abandoned the island a few years leaving the reindeer.
Subsequently, the reindeer population rose to about 6,000 by 1963 and died off in the next two years to 42 animals. A scientific study attributed the population crash to the limited food supply in interaction with climatic factors. By the 1980s, the reindeer population had died out. Environmentalists see this as an issue of overpopulation. For example, ecologist Garrett Hardin cited the "natural experiment" of St. Matthew Island of the reindeer population explosion and collapse as a paradigmatic example of the consequences of overpopulation in his essay An Ecolate View of the Human Predicament. There are two major lakes on North Lake and Big Lake; the lakes contain a greater number of fish species than other nearby islands. Lichen studies were conducted on the island in the 1990s to prepare a list of lichens with their habitat and distribution pattern; these studies were considered important for characterizing the eating habits of caribou and air quality. The vegetation of the islands has been classified as wet and alpine tundra, based on landforms and drainage patterns.
The plant communities were attributed to five categories. In the area of rock rubble fields and high ridges the vegetation was crustacean lichens. Among the 148 lichen species of the islands, 125 showed the Arctic–alpine geographic distribution, 74 boreal, 18 were coastal, 9 amphi-Berengian and 41 widespread, with many species falling into more than one category; the lichen diversity was characterized by wide-ranging Arctic -- boreal species. St. Matthew Island: Block 1045, Census Tract 1, Bethel Census Area, Alaska United States Census Bureau
International Union for Conservation of Nature
The International Union for Conservation of Nature is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, field projects and education. IUCN's mission is to "influence and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. Unlike many other international environmental organisations, IUCN does not itself aim to mobilize the public in support of nature conservation, it tries to influence the actions of governments and other stakeholders by providing information and advice, through building partnerships. The organization is best known to the wider public for compiling and publishing the IUCN Red List of Threatened Species, which assesses the conservation status of species worldwide.
IUCN has a membership of over 1400 non-governmental organizations. Some 16,000 scientists and experts participate in the work of IUCN commissions on a voluntary basis, it employs 1000 full-time staff in more than 50 countries. Its headquarters are in Switzerland. IUCN has observer and consultative status at the United Nations, plays a role in the implementation of several international conventions on nature conservation and biodiversity, it was involved in establishing the World Wide Fund for Nature and the World Conservation Monitoring Centre. In the past, IUCN has been criticized for placing the interests of nature over those of indigenous peoples. In recent years, its closer relations with the business sector have caused controversy. IUCN was established in 1948, it was called the International Union for the Protection of Nature and the World Conservation Union. Establishment IUCN was established on 5 October 1948, in Fontainebleau, when representatives of governments and conservation organizations signed a formal act constituting the International Union for the Protection of Nature.
The initiative to set up the new organisation came from UNESCO and from its first Director General, the British biologist Julian Huxley. The objectives of the new Union were to encourage international cooperation in the protection of nature, to promote national and international action and to compile and distribute information. At the time of its founding IUPN was the only international organisation focusing on the entire spectrum of nature conservation Early years: 1948–1956 IUPN started out with 65 members, its secretariat was located in Brussels. Its first work program focused on saving species and habitats and applying knowledge, advancing education, promoting international agreements and promoting conservation. Providing a solid scientific base for conservation action was the heart of all activities. IUPN and UNESCO were associated, they jointly organized the 1949 Conference on Protection of Nature. In preparation for this conference a list of gravely endangered species was drawn up for the first time, a precursor of the IUCN Red List of Threatened Species.
In the early years of its existence IUCN depended entirely on UNESCO funding and was forced to temporarily scale down activities when this ended unexpectedly in 1954. IUPN was successful in engaging prominent scientists and identifying important issues such as the harmful effects of pesticides on wildlife but not many of the ideas it developed were turned into action; this was caused by unwillingness to act on the part of governments, uncertainty about the IUPN mandate and lack of resources. In 1956, IUPN changed its name to International Union for Conservation of Nature and Natural Resources. Increased profile and recognition: 1956–1965 In the 1950s and 1960s Europe entered a period of economic growth and formal colonies became independent. Both developments had impact on the work of IUCN. Through the voluntary involvement of experts in its Commissions IUCN was able to get a lot of work done while still operating on a low budget, it established links with the Council of Europe. In 1961, at the request of United Nations Economic and Social Council, the United Nations Economic and Social Council, IUCN published the first global list of national parks and protected areas which it has updated since.
IUCN's best known publication, the Red Data Book on the conservation status of species, was first published in 1964. IUCN began to play a part in the development of international treaties and conventions, starting with the African Convention on the Conservation of Nature and Natural Resources. Environmental law and policy making became a new area of expertise. Africa was the focus of many of the early IUCN conservation field projects. IUCN supported the ‘Yellowstone model’ of protected area management, which restricted human presence and activity in order to protect nature. IUCN and other conservation organisations were criticized for protecting nature against people rather than with people; this model was also applied in Africa and played a role in the decision to remove the Maasai people from Serengeti National Park and the Ngorongoro Conservation Area. To establish a stable financial basis for its work, IUCN participated in setting up the World Wildlife Fund
Wikispecies is a wiki-based online project supported by the Wikimedia Foundation. Its aim is to create a comprehensive free content catalogue of all species. Jimmy Wales stated that editors are not required to fax in their degrees, but that submissions will have to pass muster with a technical audience. Wikispecies is available under the GNU Free Documentation License and CC BY-SA 3.0. Started in September 2004, with biologists across the world invited to contribute, the project had grown a framework encompassing the Linnaean taxonomy with links to Wikipedia articles on individual species by April 2005. Benedikt Mandl co-ordinated the efforts of several people who are interested in getting involved with the project and contacted potential supporters in early summer 2004. Databases were evaluated and the administrators contacted, some of them have agreed on providing their data for Wikispecies. Mandl defined two major tasks: Figure out how the contents of the data base would need to be presented—by asking experts, potential non-professional users and comparing that with existing databases Figure out how to do the software, which hardware is required and how to cover the costs—by asking experts, looking for fellow volunteers and potential sponsorsAdvantages and disadvantages were discussed by the wikimedia-I mailing list.
The board of directors of the Wikimedia Foundation voted by 4 to 0 in favor of the establishment of a Wikispecies. The project is hosted at species.wikimedia.org. It was merged to a sister project of Wikimedia Foundation on September 14, 2004. On October 10, 2006, the project exceeded 75,000 articles. On May 20, 2007, the project exceeded 100,000 articles with a total of 5,495 registered users. On September 8, 2008, the project exceeded 150,000 articles with a total of 9,224 registered users. On October 23, 2011, the project reached 300,000 articles. On June 16, 2014, the project reached 400,000 articles. On January 7, 2017, the project reached 500,000 articles. On October 30, 2018, the project reached 600,000 articles, a total of 1.12 million pages. Wikispecies comprises taxon pages, additionally pages about synonyms, taxon authorities, taxonomical publications, institutions or repositories holding type specimen. Wikispecies asks users to use images from Wikimedia Commons. Wikispecies does not allow the use of content.
All Species Foundation Catalogue of Life Encyclopedia of Life Tree of Life Web Project List of online encyclopedias The Plant List Wikispecies, The free species directory that anyone can edit Species Community Portal The Wikispecies Charter, written by Wales
Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal refers only to non-human animals; the study of non-human animals is known as zoology. Most living animal species are in the Bilateria, a clade whose members have a bilaterally symmetric body plan; the Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes and molluscs—and the deuterostomes, containing the echinoderms and chordates.
Life forms interpreted. Many modern animal phyla became established in the fossil record as marine species during the Cambrian explosion which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified. Aristotle divided animals into those with those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between animal taxa. Humans make use of many other animal species for food, including meat and eggs. Dogs have been used in hunting, while many aquatic animals are hunted for sport.
Non-human animals have appeared in art from the earliest times and are featured in mythology and religion. The word "animal" comes from the Latin animalis, having soul or living being; the biological definition includes all members of the kingdom Animalia. In colloquial usage, as a consequence of anthropocentrism, the term animal is sometimes used nonscientifically to refer only to non-human animals. Animals have several characteristics. Animals are eukaryotic and multicellular, unlike bacteria, which are prokaryotic, unlike protists, which are eukaryotic but unicellular. Unlike plants and algae, which produce their own nutrients animals are heterotrophic, feeding on organic material and digesting it internally. With few exceptions, animals breathe oxygen and respire aerobically. All animals are motile during at least part of their life cycle, but some animals, such as sponges, corals and barnacles become sessile; the blastula is a stage in embryonic development, unique to most animals, allowing cells to be differentiated into specialised tissues and organs.
All animals are composed of cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. During development, the animal extracellular matrix forms a flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible; this may be calcified, forming structures such as shells and spicules. In contrast, the cells of other multicellular organisms are held in place by cell walls, so develop by progressive growth. Animal cells uniquely possess the cell junctions called tight junctions, gap junctions, desmosomes. With few exceptions—in particular, the sponges and placozoans—animal bodies are differentiated into tissues; these include muscles, which enable locomotion, nerve tissues, which transmit signals and coordinate the body. There is an internal digestive chamber with either one opening or two openings. Nearly all animals make use of some form of sexual reproduction, they produce haploid gametes by meiosis.
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement, it first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm develops between them; these germ layers differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. In some species, such as the splendid fairywren, females benefit by mating with multiple males, thus producing more offspring of higher genetic quality; some animals are capable of asexual reproduction, which results