|
Greenback Cutthroat Trout
The greenback cutthroat trout (''Oncorhynchus clarkii stomias'') is the easternmost subspecies of cutthroat trout. The greenback cutthroat, once widespread in the Arkansas and South Platte River drainages of Eastern Colorado and Southeast Wyoming, today occupies less than 1% of its historical range. It is currently listed as threatened under the Endangered Species Act. It was adopted as the state fish of Colorado on March 15, 1994 replacing the unofficial rainbow trout. Description The greenback cutthroat's maximum size is . It has the largest spots of all cutthroats and is reported to have the most brilliant spawning coloration. Like all cutthroats, it has red coloration in the area of the lower jaw and throat. Historically, it has been reported to grow as large as . Natural history The cutthroat trout is thought to have evolved over the past two million years from other Oncorhynchus species which migrated up the Columbia and Snake river basins to the Green and Yellowstone ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Drinker Cope
Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontologist, comparative anatomist, herpetologist, and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of 19. Though his father tried to raise Cope as a gentleman farmer, he eventually acquiesced to his son's scientific aspirations. Cope married his cousin and had one child; the family moved from Philadelphia to Haddonfield, New Jersey, although Cope would maintain a residence and museum in Philadelphia in his later years. Cope had little formal scientific training, and he eschewed a teaching position for field work. He made regular trips to the American West, prospecting in the 1870s and 1880s, often as a member of United States Geological Survey teams. A personal feud between Cope and paleontologist Othniel Charles Marsh led to a period of intense fossil-finding competiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet. Earth is currently in the Quaternary glaciation. Individual pulses of cold climate within an ice age are termed '' glacial periods'' (or, alternatively, ''glacials, glaciations, glacial stages, stadials, stades'', or colloquially, ''ice ages''), and intermittent warm periods within an ice age are called '' interglacials'' or ''interstadials''. In glaciology, ''ice age'' implies the presence of extensive ice sheets in both northern and southern hemispheres. By this definition, Earth is currently in an interglacial period—the Holocene. The amount of anthropogenic greenhouse gases emitted into Earth's oceans and atmosphere is predicted to prevent the next glacial period for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drexel University
Drexel University is a private research university with its main campus in Philadelphia, Pennsylvania. Drexel's undergraduate school was founded in 1891 by Anthony J. Drexel, a financier and philanthropist. Founded as Drexel Institute of Art, Science and Industry, it was renamed Drexel Institute of Technology in 1936, before assuming its current name in 1970. , more than 24,000 students were enrolled in over 70 undergraduate programs and more than 100 master's, doctoral, and professional programs at the university. Drexel's cooperative education program (co-op) is a prominent aspect of the school's degree programs, offering students the opportunity to gain up to 18 months of paid, full-time work experience in a field relevant to their undergraduate major or graduate degree program prior to graduation. History Drexel University was founded in 1891 as the Drexel Institute of Art, Science and Industry, by Philadelphia financier and philanthropist Anthony J. Drexel. The or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academy Of Natural Sciences Of Drexel University
The Academy of Natural Sciences of Drexel University, formerly the Academy of Natural Sciences of Philadelphia, is the oldest natural science research institution and museum in the Americas. It was founded in 1812, by many of the leading naturalists of the young American republic with an expressed mission of "the encouragement and cultivation of the sciences". It has sponsored expeditions, conducted original environmental and systematics research, and amassed natural history collections containing more than 17 million specimens. The Academy also organizes public exhibits and educational programs for both schools and the general public. History During the first decades of the United States, Philadelphia was the cultural capital and one of the country's commercial centers. Two of the city's institutions, the Library Company and the American Philosophical Society, were centers of enlightened thought and scientific inquiry. The increasing sophistication of the earth and life scie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Wars
The American Indian Wars, also known as the American Frontier Wars, and the Indian Wars, were fought by European governments and colonists in North America, and later by the United States and Canadian governments and American and Canadian settlers, against various American Indian and First Nation tribes. These conflicts occurred in North America from the time of the earliest colonial settlements in the 17th century until the early 20th century. The various wars resulted from a wide variety of factors, the most common being the desire of settlers and governments for lands that the Indian tribes considered their own. The European powers and their colonies also enlisted allied Indian tribes to help them conduct warfare against each other's colonial settlements. After the American Revolution, many conflicts were local to specific states or regions and frequently involved disputes over land use; some entailed cycles of violent reprisal. As settlers spread westward across North America ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William A
William is a male given name of Germanic origin.Hanks, Hardcastle and Hodges, ''Oxford Dictionary of First Names'', Oxford University Press, 2nd edition, , p. 276. It became very popular in the English language after the Norman conquest of England in 1066,All Things William"Meaning & Origin of the Name"/ref> and remained so throughout the Middle Ages and into the modern era. It is sometimes abbreviated "Wm." Shortened familiar versions in English include Will, Wills, Willy, Willie, Bill, and Billy. A common Irish form is Liam. Scottish diminutives include Wull, Willie or Wullie (as in Oor Wullie or the play ''Douglas''). Female forms are Willa, Willemina, Wilma and Wilhelmina. Etymology William is related to the given name ''Wilhelm'' (cf. Proto-Germanic ᚹᛁᛚᛃᚨᚺᛖᛚᛗᚨᛉ, ''*Wiljahelmaz'' > German '' Wilhelm'' and Old Norse ᚢᛁᛚᛋᛅᚼᛅᛚᛘᛅᛋ, ''Vilhjálmr''). By regular sound changes, the native, inherited English form of the na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutbow
A cutbow (''Oncorhynchus clarkii'' × ''mykiss'') is an interspecific fertile hybrid between a rainbow trout (''Oncorhynchus mykiss'') and a cutthroat trout (''O. clarkii''). Cutbow hybrids may occur naturally where the native ranges of both species overlap, such as between coastal rainbow trout (''O. mykiss irideus'') and coastal cutthroat trout (''O. clarkii clarkii'') and between Columbia River redband trout (''O. mykiss gardineri'') and westslope cutthroat trout (''O. clarkii lewisi''). While natural separation of spawning habitat limited hybridization in most native populations of rainbows and cutthroats, introduction of non-native hatchery-raised rainbow trout into the native ranges of cutthroat subspecies increased the rate of hybridization. Some native cutthroat populations are, as a result, at risk due to genetic pollution.Cutb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid (biology)
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Trout
The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morpha ''fario'', a lacustrine ecotype, ''S. trutta'' morpha ''lacustris'', also called the lake trout, and anadromous forms known as the sea trout, ''S. trutta'' morpha ''trutta''. The latter migrates to the oceans for much of its life and returns to fresh water only to spawn. Sea trout in Ireland and Britain have many regional names: sewin in Wales, finnock in Scotland, peal in the West Country, mort in North West England, and white trout in Ireland. The lacustrine morph of brown trout is most usually potamodromous, migrating from lakes into rivers or streams to spawn, although evidence indicates some stocks spawn on wind-swept shorelines of lakes. ''S. trutta'' morpha ''fario'' forms stream-resident populations, typically in alpine s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brook Trout
The brook trout (''Salvelinus fontinalis'') is a species of freshwater fish in the char genus ''Salvelinus'' of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere in North America, as well as to Iceland, Europe, and Asia. In parts of its range, it is also known as the eastern brook trout, speckled trout, brook charr, squaretail, brookie or mud trout, among others. A potamodromous population in Lake Superior, as well as an anadromous population in Maine, is known as coaster trout or, simply, as coasters. The brook trout is the state fish of nine U.S. states: Michigan, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Vermont, Virginia, and West Virginia, and the Provincial Fish of Nova Scotia in Canada. Systematics and taxonomy The brook trout was first scientifically described as ''Salmo fontinalis'' by the naturalist Samuel Latham Mitchill in 1814. The specific epithet "''fonti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overfishing
Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the species becoming increasingly underpopulated in that area. Overfishing can occur in water bodies of any sizes, such as ponds, wetlands, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass levels. Sustained overfishing can lead to critical depensation, where the fish population is no longer able to sustain itself. Some forms of overfishing, such as the overfishing of sharks, has led to the upset of entire marine ecosystems. Types of overfishing include: growth overfishing, recruitment overfishing, ecosystem overfishing. The ability of a fishery to recover from overfishing depends on whether its overall carrying capacity and the variety of ecological conditions are suitable f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in cities. The history of agriculture began thousands of years ago. After gathering wild grains beginning at least 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Sheep, goats, pigs and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. Industrial agriculture based on large-scale monoculture in the twentieth century came to dominate agricultural output, though about 2 billion people still depended on subsistence agriculture. The major agricultural products can be broadly grouped into foods, fibers, fuels, and raw materials (such as rubber). Food classes include cereals (grains), vegetables, fruits, cooking oils, meat, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
