An arthropod is an invertebrate animal having an exoskeleton, a segmented body, paired jointed appendages. Arthropods form the phylum Euarthropoda, which includes insects, arachnids and crustaceans; the term Arthropoda as proposed refers to a proposed grouping of Euarthropods and the phylum Onychophora. Arthropods are characterized by their jointed limbs and cuticle made of chitin mineralised with calcium carbonate; the arthropod body plan consists of each with a pair of appendages. The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting. Arthopods are bilaterally symmetrical and their body possesses an external skeleton; some species have wings. Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments, they have over a million described species, making up more than 80 per cent of all described living animal species, some of which, unlike most other animals, are successful in dry environments. Arthropods range in size from the microscopic crustacean Stygotantulus up to the Japanese spider crab.
Arthropods' primary internal cavity is a haemocoel, which accommodates their internal organs, through which their haemolymph – analogue of blood – circulates. Like their exteriors, the internal organs of arthropods are built of repeated segments, their nervous system is "ladder-like", with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, their brains are formed by fusion of the ganglia of these segments and encircle the esophagus; the respiratory and excretory systems of arthropods vary, depending as much on their environment as on the subphylum to which they belong. Their vision relies on various combinations of compound eyes and pigment-pit ocelli: in most species the ocelli can only detect the direction from which light is coming, the compound eyes are the main source of information, but the main eyes of spiders are ocelli that can form images and, in a few cases, can swivel to track prey.
Arthropods have a wide range of chemical and mechanical sensors based on modifications of the many setae that project through their cuticles. Arthropods' methods of reproduction and development are diverse; the evolutionary ancestry of arthropods dates back to the Cambrian period. The group is regarded as monophyletic, many analyses support the placement of arthropods with cycloneuralians in a superphylum Ecdysozoa. Overall, the basal relationships of Metazoa are not yet well resolved; the relationships between various arthropod groups are still debated. Aquatic species use either external fertilization. All arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. Arthropod hatchlings vary from miniature adults to grubs and caterpillars that lack jointed limbs and undergo a total metamorphosis to produce the adult form; the level of maternal care for hatchlings varies from nonexistent to the prolonged care provided by scorpions. Arthropods contribute to the human food supply both directly as food, more indirectly as pollinators of crops.
Some species are known to spread severe disease to humans and crops. The word arthropod comes from the Greek ἄρθρον árthron, "joint", πούς pous, i.e. "foot" or "leg", which together mean "jointed leg". Arthropods are invertebrates with jointed limbs; the exoskeleton or cuticles consists of a polymer of glucosamine. The cuticle of many crustaceans, beetle mites, millipedes is biomineralized with calcium carbonate. Calcification of the endosternite, an internal structure used for muscle attachments occur in some opiliones. Estimates of the number of arthropod species vary between 1,170,000 and 5 to 10 million and account for over 80 per cent of all known living animal species; the number of species remains difficult to determine. This is due to the census modeling assumptions projected onto other regions in order to scale up from counts at specific locations applied to the whole world. A study in 1992 estimated that there were 500,000 species of animals and plants in Costa Rica alone, of which 365,000 were arthropods.
They are important members of marine, freshwater and air ecosystems, are one of only two major animal groups that have adapted to life in dry environments. One arthropod sub-group, insects, is the most species-rich member of all ecological guilds in land and freshwater environments; the lightest insects weigh less than 25 micrograms. Some living crustaceans are much larger; the embryos of all arthropods are segmented, built from a series of repeated modules. The last common ancestor of living arthropods consisted of a series of undifferentiated segments, each with a pair of appendages that functioned as limbs. However, all known living and fossil arthropods have grouped segments into tagmata in which segments and their limbs are specialized in various ways; the three-
The Richardson Mountains are a mountain range located west of the mouth of the Mackenzie River in northern Yukon, Canada. They parallel the northernmost part of the boundary between Northwest Territories. Although some sources consider the Richardson Mountains to be part of the Canadian Rockies, the common northern limit of the Canadian Rockies is the Liard River, a long way south; the Richardson Mountains are a sub-range of the Brooks Range which lies in Alaska. List of mountain ranges Albert Johnson
Siberia is an extensive geographical region spanning much of Eurasia and North Asia. Siberia has been a part of modern Russia since the 17th century; the territory of Siberia extends eastwards from the Ural Mountains to the watershed between the Pacific and Arctic drainage basins. The Yenisei River conditionally divides Siberia into two parts and Eastern. Siberia stretches southwards from the Arctic Ocean to the hills of north-central Kazakhstan and to the national borders of Mongolia and China. With an area of 13.1 million square kilometres, Siberia accounts for 77% of Russia's land area, but it is home to 36 million people—27% of the country's population. This is equivalent to an average population density of about 3 inhabitants per square kilometre, making Siberia one of the most sparsely populated regions on Earth. If it were a country by itself, it would still be the largest country in area, but in population it would be the world's 35th-largest and Asia's 14th-largest. Worldwide, Siberia is well known for its long, harsh winters, with a January average of −25 °C, as well as its extensive history of use by Russian and Soviet administrations as a place for prisons, labor camps, exile.
The origin of the name is unknown. Some sources say that "Siberia" originates from the Siberian Tatar word for "sleeping land". Another account sees the name as the ancient tribal ethnonym of the Sirtya, an ethnic group which spoke a Paleosiberian language; the Sirtya people were assimilated into the Siberian Tatars. The modern usage of the name was recorded in the Russian language after the Empire's conquest of the Siberian Khanate. A further variant claims; the Polish historian Chyliczkowski has proposed that the name derives from the proto-Slavic word for "north", but Anatole Baikaloff has dismissed this explanation. He said that the neighbouring Chinese and Mongolians, who have similar names for the region, would not have known Russian, he suggests that the name might be a combination of two words with Turkic origin, "su" and "bir". The region has paleontological significance, as it contains bodies of prehistoric animals from the Pleistocene Epoch, preserved in ice or in permafrost. Specimens of Goldfuss cave lion cubs and another woolly mammoth from Oymyakon, a woolly rhinoceros from the Kolyma River, bison and horses from Yukagir have been found.
The Siberian Traps were formed by one of the largest-known volcanic events of the last 500 million years of Earth's geological history. Their activity continued for a million years and some scientists consider it a possible cause of the "Great Dying" about 250 million years ago, – estimated to have killed 90% of species existing at the time. At least three species of human lived in Southern Siberia around 40,000 years ago: H. sapiens, H. neanderthalensis, the Denisovans. In 2010 DNA evidence identified the last as a separate species. Siberia was inhabited by different groups of nomads such as the Enets, the Nenets, the Huns, the Scythians and the Uyghurs; the Khan of Sibir in the vicinity of modern Tobolsk was known as a prominent figure who endorsed Kubrat as Khagan of Old Great Bulgaria in 630. The Mongols conquered a large part of this area early in the 13th century. With the breakup of the Golden Horde, the autonomous Khanate of Sibir was established in the late 15th century. Turkic-speaking Yakut migrated north from the Lake Baikal region under pressure from the Mongol tribes during the 13th to 15th century.
Siberia remained a sparsely populated area. Historian John F. Richards wrote: "... it is doubtful that the total early modern Siberian population exceeded 300,000 persons."The growing power of Russia in the West began to undermine the Siberian Khanate in the 16th century. First, groups of traders and Cossacks began to enter the area; the Russian Army was directed to establish forts farther and farther east to protect new settlers from European Russia. Towns such as Mangazeya, Tara and Tobolsk were developed, the last being declared the capital of Siberia. At this time, Sibir was the name of a fortress at Qashlik, near Tobolsk. Gerardus Mercator, in a map published in 1595, marks Sibier both as the name of a settlement and of the surrounding territory along a left tributary of the Ob. Other sources contend that the Xibe, an indigenous Tungusic people, offered fierce resistance to Russian expansion beyond the Urals; some suggest. By the mid-17th century, Russia had established areas of control; some 230,000 Russians had settled in Siberia by 1709.
Siberia was a destination for sending exiles. The first great modern change in Siberia was the Trans-Siberian Railway, constructed during 1891–1916, it linked Siberia more to the industrialising Russia of Nicholas II. Around seven million people moved to Siberia from European Russia between 1801 and 1914. From 1859 to 1917, more than half a million people migrated to the Russian Far East. Siberia has extensive natural resources. During the 20th century, large-scale exploitation of these was developed, industrial towns cropped up throughout the region. At 7:15 a.m. on 30 June 1908, millions of trees were felled near the Podkamennaya Tunguska River in central Siberia in the Tunguska Event. Most scientists believe this resulted from the air burst of a comet. Though no crater has been found, the landscape in the area still bears the scars of this event. In the early decades of the Soviet Union (
Yukon is the smallest and westernmost of Canada's three federal territories. It has the smallest population of any province or territory in Canada, with 35,874 people, although it has the largest city in any of the three territories. Whitehorse is Yukon's only city. Yukon was split from the Northwest Territories in 1898 and was named the Yukon Territory; the federal government's Yukon Act, which received royal assent on March 27, 2002, established Yukon as the territory's official name, though Yukon Territory is still popular in usage and Canada Post continues to use the territory's internationally approved postal abbreviation of YT. Though bilingual, the Yukon government recognizes First Nations languages. At 5,959 m, Yukon's Mount Logan, in Kluane National Park and Reserve, is the highest mountain in Canada and the second-highest on the North American continent. Most of Yukon has a subarctic climate, characterized by brief warm summers; the Arctic Ocean coast has a tundra climate. Notable rivers include the Yukon River, as well as the Pelly, Peel and Tatshenshini rivers.
The territory is named after the longest river in Yukon. The name itself is from a contraction of the words in the Gwich'in phrase chųų gąįį han, which means white water river and refers to "the pale colour" of glacial runoff in the Yukon River. Long before the arrival of Europeans and southern Yukon was populated by First Nations people, the area escaped glaciation. Sites of archeological significance in Yukon hold some of the earliest evidence of the presence of human habitation in North America; the sites safeguard the earliest First Nations of the Yukon. The volcanic eruption of Mount Churchill in 800 AD in what is now the U. S. state of Alaska blanketed southern Yukon with a layer of ash which can still be seen along the Klondike Highway, which forms part of the oral tradition of First Nations peoples in Yukon and further south in Canada. Coastal and inland First Nations had extensive trading networks. European incursions into the area began early in the 19th century with the fur trade, followed by missionaries.
By the 1870s and 1880s gold miners began to arrive. This drove a population increase that justified the establishment of a police force, just in time for the start of the Klondike Gold Rush in 1897; the increased population coming with the gold rush led to the separation of the Yukon district from the Northwest Territories and the formation of the separate Yukon Territory in 1898. The territory is the approximate shape of a right triangle, bordering the U. S. state of Alaska to the west and northwest for 1,210 km along longitude 141° W, the Northwest Territories to the east and British Columbia to the south. Its northern coast is on the Beaufort Sea, its ragged eastern boundary follows the divide between the Yukon Basin and the Mackenzie River drainage basin to the east in the Mackenzie mountains. Most of the territory is in the watershed of the Yukon River; the southern Yukon is dotted with a large number of large and narrow glacier-fed alpine lakes, most of which flow into the Yukon River system.
The larger lakes include Teslin Lake, Atlin Lake, Tagish Lake, Marsh Lake, Lake Laberge, Kusawa Lake and Kluane Lake. Bennett Lake on the Klondike Gold Rush trail is a lake flowing into Nares Lake, with the greater part of its area within Yukon. Canada's highest point, Mount Logan, is in the territory's southwest. Mount Logan and a large part of Yukon's southwest are in Kluane National Park and Reserve, a UNESCO World Heritage Site. Other national parks include Ivvavik National Vuntut National Park in the north. Other watersheds include the Mackenzie River, the Peel Watershed and the Alsek–Tatshenshini, a number of rivers flowing directly into the Beaufort Sea; the two main Yukon rivers flowing into the Mackenzie in the Northwest Territories are the Liard River in the southeast and the Peel River and its tributaries in the northeast. Notable widespread tree species within Yukon are white spruce. Many trees are stunted because of severe climate; the capital, Whitehorse, is the largest city, with about three-quarters of the population.
British Columbia Northwest Territories Alaska, United States While the average winter temperature in Yukon is mild by Canadian arctic standards, no other place in North America gets as cold as Yukon during extreme cold snaps. The temperature has dropped down to −60 °C three times, 1947, 1954, 1968; the most extreme cold snap occurred in February 1947 when the abandoned town of Snag dropped down to −63.0 °C. Unlike most of Canada where the most extreme heat waves occur in July and September, Yukon's extreme heat tends to occur in June and May. Yukon has recorded 36 °C three times; the first time was in June 1969 when Mayo recorded a temperature of 36.1 °C. 14 years this record was beaten when Forty Mile recorded 36 °C in May 1983. The old record was broken 21 years in June 2004 when the Mayo Road weather station, located just northwest of Whitehorse, recorded a temperature of 36.5 °C. The 2016 census reported a Yukon population of 35,874, an increase of 5.8% from 2011. With a land area of 474,712.64 km2, it had a population de
Binomial nomenclature called binominal nomenclature or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomen, binominal name or a scientific name; the first part of the name – the generic name – identifies the genus to which the species belongs, while the second part – the specific name or specific epithet – identifies the species within the genus. For example, humans belong within this genus to the species Homo sapiens. Tyrannosaurus rex is the most known binomial; the formal introduction of this system of naming species is credited to Carl Linnaeus beginning with his work Species Plantarum in 1753. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus; the application of binomial nomenclature is now governed by various internationally agreed codes of rules, of which the two most important are the International Code of Zoological Nomenclature for animals and the International Code of Nomenclature for algae and plants.
Although the general principles underlying binomial nomenclature are common to these two codes, there are some differences, both in the terminology they use and in their precise rules. In modern usage, the first letter of the first part of the name, the genus, is always capitalized in writing, while that of the second part is not when derived from a proper noun such as the name of a person or place. Both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a binomial name is given, at least when it is first mentioned, the date of publication may be specified. In zoology "Patella vulgata Linnaeus, 1758"; the name "Linnaeus" tells the reader who it was that first published a description and name for this species of limpet. "Passer domesticus". The original name given by Linnaeus was Fringilla domestica; the ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, although nomenclatorial catalogs include such information.
In botany "Amaranthus retroflexus L." – "L." is the standard abbreviation used in botany for "Linnaeus". "Hyacinthoides italica Rothm. – Linnaeus first named this bluebell species Scilla italica. The name is composed of two word-forming elements: "bi", a Latin prefix for two, "-nomial", relating to a term or terms; the word "binomium" was used in Medieval Latin to mean a two-term expression in mathematics. Prior to the adoption of the modern binomial system of naming species, a scientific name consisted of a generic name combined with a specific name, from one to several words long. Together they formed a system of polynomial nomenclature; these names had two separate functions. First, to designate or label the species, second, to be a diagnosis or description. In a simple genus, containing only two species, it was easy to tell them apart with a one-word genus and a one-word specific name; such "polynomial names" may sometimes look like binomials, but are different. For example, Gerard's herbal describes various kinds of spiderwort: "The first is called Phalangium ramosum, Branched Spiderwort.
The other... is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia". The Latin phrases are short descriptions, rather than identifying labels; the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné, more known by his Latinized name Carl Linnaeus, it was in his 1753 Species Plantarum that he first began using a one-word "trivial name" together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as specific name; the Bauhins' genus names were retained in many of these, but the descriptive part was reduced to a single word. Linnaeus's trivial names introduced an important new idea, namely that the function of a name could be to give a species a unique label; this meant. Thus Gerard's Phalangium ephemerum virginianum became Tradescantia virgi
Alaska is a U. S. state in the northwest extremity of North America, just across the Bering Strait from Asia. The Canadian province of British Columbia and territory of Yukon border the state to the east and southeast, its most extreme western part is Attu Island, it has a maritime border with Russia to the west across the Bering Strait. To the north are the Chukchi and Beaufort seas—southern parts of the Arctic Ocean; the Pacific Ocean lies to southwest. It is the largest U. S. state by the seventh largest subnational division in the world. In addition, it is the most sparsely populated of the 50 United States. Half of Alaska's residents live within the Anchorage metropolitan area. Alaska's economy is dominated by the fishing, natural gas, oil industries, resources which it has in abundance. Military bases and tourism are a significant part of the economy; the United States purchased Alaska from the Russian Empire on March 30, 1867, for 7.2 million U. S. dollars at two cents per acre. The area went through several administrative changes before becoming organized as a territory on May 11, 1912.
It was admitted as the 49th state of the U. S. on January 3, 1959. The name "Alaska" was introduced in the Russian colonial period when it was used to refer to the Alaska Peninsula, it was derived from an Aleut-language idiom. It means object to which the action of the sea is directed. Alaska is the northernmost and westernmost state in the United States and has the most easterly longitude in the United States because the Aleutian Islands extend into the Eastern Hemisphere. Alaska is the only non-contiguous U. S. state on continental North America. It is technically part of the continental U. S. but is sometimes not included in colloquial use. S. called "the Lower 48". The capital city, Juneau, is situated on the mainland of the North American continent but is not connected by road to the rest of the North American highway system; the state is bordered by Yukon and British Columbia in Canada, to the east, the Gulf of Alaska and the Pacific Ocean to the south and southwest, the Bering Sea, Bering Strait, Chukchi Sea to the west and the Arctic Ocean to the north.
Alaska's territorial waters touch Russia's territorial waters in the Bering Strait, as the Russian Big Diomede Island and Alaskan Little Diomede Island are only 3 miles apart. Alaska has a longer coastline than all the other U. S. states combined. Alaska is the largest state in the United States by total area at 663,268 square miles, over twice the size of Texas, the next largest state. Alaska is larger than all but 18 sovereign countries. Counting territorial waters, Alaska is larger than the combined area of the next three largest states: Texas and Montana, it is larger than the combined area of the 22 smallest U. S. states. There are no defined borders demarcating the various regions of Alaska, but there are six accepted regions: The most populous region of Alaska, containing Anchorage, the Matanuska-Susitna Valley and the Kenai Peninsula. Rural unpopulated areas south of the Alaska Range and west of the Wrangell Mountains fall within the definition of South Central, as do the Prince William Sound area and the communities of Cordova and Valdez.
Referred to as the Panhandle or Inside Passage, this is the region of Alaska closest to the rest of the United States. As such, this was where most of the initial non-indigenous settlement occurred in the years following the Alaska Purchase; the region is dominated by the Alexander Archipelago as well as the Tongass National Forest, the largest national forest in the United States. It contains the state capital Juneau, the former capital Sitka, Ketchikan, at one time Alaska's largest city; the Alaska Marine Highway provides a vital surface transportation link throughout the area, as only three communities enjoy direct connections to the contiguous North American road system. Designated in 1963; the Interior is the largest region of Alaska. Fairbanks is the only large city in the region. Denali National Park and Preserve is located here. Denali is the highest mountain in North America. Southwest Alaska is a sparsely inhabited region stretching some 500 miles inland from the Bering Sea. Most of the population lives along the coast.
Kodiak Island is located in Southwest. The massive Yukon–Kuskokwim Delta, one of the largest river deltas in the world, is here. Portions of the Alaska Peninsula are considered part of Southwest, with the remaining portions included with the Aleutian Islands; the North Slope is tundra peppered with small villages. The area is known for its massive reserves of crude oil, contains both the National Petroleum Reserve–Alaska and the Prudhoe Bay Oil Field; the city of Utqiagvik known as Barrow, is the northernmost city in the United States and is located here. The Northwest Arctic area, anchored by Kotzebue and containing the Kobuk River valley, is regarded as being part of this region. However, the respective Inupiat of the No
The Satyrinae, the satyrines or satyrids known as the browns, are a subfamily of the Nymphalidae. They were considered a distinct family, Satyridae; this group contains nearly half of the known diversity of brush-footed butterflies. The true number of the Satyrinae species is estimated to exceed 2400, they are weak fliers and shun bright sunlight, preferring moist and semishaded habitats. The caterpillars feed chiefly on monocotyledonous plants such as palms and bamboos; the Morphinae are sometimes united with this group. The taxonomy and systematics of the subfamily are under heavy revision. Much of the early pioneering work of L. D. Miller has helped by creating some sort of order. Dyndirus is a satyrid incertae sedis. Other than this genus, according to the latest studies on the classification of Nymphalidae, all satyrines have been assigned to one of the tribes, at least preliminarily. For detailed lists, see the tribe pages. Glassberg, Jeffrey Butterflies through Binoculars, The West Guppy, Crispin S. and Shepard, Jon H.
Butterflies of British Columbia James, David G. and Nunnallee, David Life Histories of Cascadia Butterflies Pelham, Jonathan Catalogue of the Butterflies of the United States and Canada Pyle, Robert Michael The Butterflies of Cascadia Satyrinae of the Western Palearctic Tree of Life: Satyrinae Insect Life Forms - Satyridae Butterflies and Moths of North America Butterflies of America