Canada is a country in the northern part of North America. Its ten provinces and three territories extend from the Atlantic to the Pacific and northward into the Arctic Ocean, covering 9.98 million square kilometres, making it the world's second-largest country by total area. Canada's southern border with the United States is the world's longest bi-national land border, its capital is Ottawa, its three largest metropolitan areas are Toronto and Vancouver. As a whole, Canada is sparsely populated, the majority of its land area being dominated by forest and tundra, its population is urbanized, with over 80 percent of its inhabitants concentrated in large and medium-sized cities, many near the southern border. Canada's climate varies across its vast area, ranging from arctic weather in the north, to hot summers in the southern regions, with four distinct seasons. Various indigenous peoples have inhabited what is now Canada for thousands of years prior to European colonization. Beginning in the 16th century and French expeditions explored, settled, along the Atlantic coast.
As a consequence of various armed conflicts, France ceded nearly all of its colonies in North America in 1763. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces; this began an accretion of provinces and territories and a process of increasing autonomy from the United Kingdom. This widening autonomy was highlighted by the Statute of Westminster of 1931 and culminated in the Canada Act of 1982, which severed the vestiges of legal dependence on the British parliament. Canada is a parliamentary democracy and a constitutional monarchy in the Westminster tradition, with Elizabeth II as its queen and a prime minister who serves as the chair of the federal cabinet and head of government; the country is a realm within the Commonwealth of Nations, a member of the Francophonie and bilingual at the federal level. It ranks among the highest in international measurements of government transparency, civil liberties, quality of life, economic freedom, education.
It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many other countries. Canada's long and complex relationship with the United States has had a significant impact on its economy and culture. A developed country, Canada has the sixteenth-highest nominal per capita income globally as well as the twelfth-highest ranking in the Human Development Index, its advanced economy is the tenth-largest in the world, relying chiefly upon its abundant natural resources and well-developed international trade networks. Canada is part of several major international and intergovernmental institutions or groupings including the United Nations, the North Atlantic Treaty Organization, the G7, the Group of Ten, the G20, the North American Free Trade Agreement and the Asia-Pacific Economic Cooperation forum. While a variety of theories have been postulated for the etymological origins of Canada, the name is now accepted as coming from the St. Lawrence Iroquoian word kanata, meaning "village" or "settlement".
In 1535, indigenous inhabitants of the present-day Quebec City region used the word to direct French explorer Jacques Cartier to the village of Stadacona. Cartier used the word Canada to refer not only to that particular village but to the entire area subject to Donnacona. From the 16th to the early 18th century "Canada" referred to the part of New France that lay along the Saint Lawrence River. In 1791, the area became two British colonies called Upper Canada and Lower Canada collectively named the Canadas. Upon Confederation in 1867, Canada was adopted as the legal name for the new country at the London Conference, the word Dominion was conferred as the country's title. By the 1950s, the term Dominion of Canada was no longer used by the United Kingdom, which considered Canada a "Realm of the Commonwealth"; the government of Louis St. Laurent ended the practice of using'Dominion' in the Statutes of Canada in 1951. In 1982, the passage of the Canada Act, bringing the Constitution of Canada under Canadian control, referred only to Canada, that year the name of the national holiday was changed from Dominion Day to Canada Day.
The term Dominion was used to distinguish the federal government from the provinces, though after the Second World War the term federal had replaced dominion. Indigenous peoples in present-day Canada include the First Nations, Métis, the last being a mixed-blood people who originated in the mid-17th century when First Nations and Inuit people married European settlers; the term "Aboriginal" as a collective noun is a specific term of art used in some legal documents, including the Constitution Act 1982. The first inhabitants of North America are hypothesized to have migrated from Siberia by way of the Bering land bridge and arrived at least 14,000 years ago; the Paleo-Indian archeological sites at Old Crow Flats and Bluefish Caves are two of the oldest sites of human habitation in Canada. The characteristics of Canadian indigenous societies included permanent settlements, complex societal hierarchies, trading networks; some of these cultures had collapsed by the time European explorers arrived in the late 15th and early 16th centuries and have only been discovered through archeological investigations.
The indigenous population at the time of the first European settlements is estimated to have been between 200,000
Limnoscelis is a genus of large reptile-like diadectomorph from the Early Permian of North America. Contrary to other diadectomorphans, Limnoscelis appear to have been carnivorous. Though the post cranial skeleton is similar to the early large bodied reptiles like pelycosaurs and pareiasaurs, the digits lacked claws, the bones of the ankle bones were fused like in other reptile-like amphibians; this would not allow them to use their feet in traction, but rather as holdfasts, indicating Limnoscelis hunted slow moving prey. Bringing Fossils To Life: An Introduction To Paleobiology by Donald R. Prothero
Anacondas or water boas are a group of large snakes of the genus Eunectes. They are found in tropical South America. Four species are recognized. Although the name applies to a group of snakes, it is used to refer only to one species, in particular, the common or green anaconda, the largest snake in the world by weight, the second longest; the South American names anacauchoa and anacaona were suggested in an account by Peter Martyr d'Anghiera but the idea of a South American origin was questioned by Henry Walter Bates who, in his travels in South America, failed to find any similar name in use. The word anaconda is derived from the name of a snake from Ceylon that John Ray described in Latin in his Synopsis Methodica Animalium as serpens indicus bubalinus anacandaia zeylonibus, ides bubalorum aliorumque jumentorum membra conterens. Ray used a catalogue of snakes from the Leyden museum supplied by Dr. Tancred Robinson, but the description of its habit was based on Andreas Cleyer who in 1684 described a gigantic snake that crushed large animals by coiling around their bodies and crushing their bones.
Henry Yule in his Hobson-Jobson notes that the word became more popular due to a piece of fiction published in 1768 in the Scots Magazine by a certain R. Edwin. Edwin described a'tiger' being crushed to death by an anaconda, when there never were any tigers in Sri Lanka. Yule and Frank Wall noted that the snake was in fact a python and suggested a Tamil origin anai-kondra meaning elephant killer. A Sinhalese origin was suggested by Donald Ferguson who pointed out that the word Henakandaya was used in Sri Lanka for the small whip snake and somehow got misapplied to the python before myths were created; the name used for the anaconda in Brazil is sucuri, sucuriju or sucuriuba. The term "anaconda" has been used to refer to: Any member of the genus Eunectes, a group of large, aquatic snakes found in South America: Eunectes murinus, the green anaconda – the largest species, found east of the Andes in Colombia, the Guianas, Peru, Bolivia and Trinidad and Tobago Eunectes notaeus, the yellow anaconda – a small species, found in eastern Bolivia, southern Brazil and northeastern Argentina Eunectes deschauenseei, the darkly-spotted anaconda – a rare species, found in northeastern Brazil and coastal French Guiana Eunectes beniensis, the Bolivian anaconda – the most defined species, found in the Departments of Beni and Pando in Bolivia The giant anaconda, a mythical snake of enormous proportions said to be found in South America The term was applied imprecisely, indicating any large snake that constricts its prey, though this usage is now archaic.
South American jaguar, a competitor or predator
Biology is the natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms and evolution. Despite the complexity of the science, there are certain unifying concepts that consolidate it into a single, coherent field. Biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, evolution as the engine that propels the creation and extinction of species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy to maintain a stable and vital condition defined as homeostasis. Sub-disciplines of biology are defined by the research methods employed and the kind of system studied: theoretical biology uses mathematical methods to formulate quantitative models while experimental biology performs empirical experiments to test the validity of proposed theories and understand the mechanisms underlying life and how it appeared and evolved from non-living matter about 4 billion years ago through a gradual increase in the complexity of the system.
See branches of biology. The term biology is derived from the Greek word βίος, bios, "life" and the suffix -λογία, -logia, "study of." The Latin-language form of the term first appeared in 1736 when Swedish scientist Carl Linnaeus used biologi in his Bibliotheca botanica. It was used again in 1766 in a work entitled Philosophiae naturalis sive physicae: tomus III, continens geologian, phytologian generalis, by Michael Christoph Hanov, a disciple of Christian Wolff; the first German use, was in a 1771 translation of Linnaeus' work. In 1797, Theodor Georg August Roose used the term in the preface of a book, Grundzüge der Lehre van der Lebenskraft. Karl Friedrich Burdach used the term in 1800 in a more restricted sense of the study of human beings from a morphological and psychological perspective; the term came into its modern usage with the six-volume treatise Biologie, oder Philosophie der lebenden Natur by Gottfried Reinhold Treviranus, who announced: The objects of our research will be the different forms and manifestations of life, the conditions and laws under which these phenomena occur, the causes through which they have been effected.
The science that concerns itself with these objects we will indicate by the name biology or the doctrine of life. Although modern biology is a recent development, sciences related to and included within it have been studied since ancient times. Natural philosophy was studied as early as the ancient civilizations of Mesopotamia, the Indian subcontinent, China. However, the origins of modern biology and its approach to the study of nature are most traced back to ancient Greece. While the formal study of medicine dates back to Hippocrates, it was Aristotle who contributed most extensively to the development of biology. Important are his History of Animals and other works where he showed naturalist leanings, more empirical works that focused on biological causation and the diversity of life. Aristotle's successor at the Lyceum, wrote a series of books on botany that survived as the most important contribution of antiquity to the plant sciences into the Middle Ages. Scholars of the medieval Islamic world who wrote on biology included al-Jahiz, Al-Dīnawarī, who wrote on botany, Rhazes who wrote on anatomy and physiology.
Medicine was well studied by Islamic scholars working in Greek philosopher traditions, while natural history drew on Aristotelian thought in upholding a fixed hierarchy of life. Biology began to develop and grow with Anton van Leeuwenhoek's dramatic improvement of the microscope, it was that scholars discovered spermatozoa, bacteria and the diversity of microscopic life. Investigations by Jan Swammerdam led to new interest in entomology and helped to develop the basic techniques of microscopic dissection and staining. Advances in microscopy had a profound impact on biological thinking. In the early 19th century, a number of biologists pointed to the central importance of the cell. In 1838, Schleiden and Schwann began promoting the now universal ideas that the basic unit of organisms is the cell and that individual cells have all the characteristics of life, although they opposed the idea that all cells come from the division of other cells. Thanks to the work of Robert Remak and Rudolf Virchow, however, by the 1860s most biologists accepted all three tenets of what came to be known as cell theory.
Meanwhile and classification became the focus of natural historians. Carl Linnaeus published a basic taxonomy for the natural world in 1735, in the 1750s introduced scientific names for all his species. Georges-Louis Leclerc, Comte de Buffon, treated species as artificial categories and living forms as malleable—even suggesting the possibility of common descent. Although he was opposed to evolution, Buffon is a key figure in the history of evolutionary thought. Serious evolutionary thinking originated with the works of Jean-Baptiste Lamarck, the first to present a coherent theory of evolution, he posited that evolution was the result of environmental stress on properties of animals, meaning that the more and rigorously an organ was used, the more complex and efficient it would become, thus adapting the animal to its environment. Lamarck believed that these acquired traits could be passed on to the animal's offspring, who would
Scallop is a common name, applied to any one of numerous species of saltwater clams or marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is sometimes applied to species in other related families within the superfamily Pectinoidea, which includes the thorny oysters. Scallops are a cosmopolitan family of bivalves which are found in all of the world's oceans, although never in fresh water, they are one of few groups of bivalves to be "free-living", with many species capable of swimming short distances and of migrating some distance across the ocean floor. A small minority of scallop species live cemented to rocky substrates as adults, while others attach themselves to stationary or rooted objects such as sea grass at some point in their lives by means of a filament they secrete called a byssal thread; the majority of species, live recumbent on sandy substrates, when they sense the presence of a predator such as a starfish, they may attempt to escape by swimming swiftly but erratically through the water using jet propulsion created by clapping their shells together.
Scallops have a well-developed nervous system, unlike most other bivalves all scallops have a ring of numerous simple eyes situated around the edge of their mantles. Many species of scallops are prized as a food source, some are farmed as aquaculture; the word "scallop" is applied to the meat of these bivalves, the adductor muscle, sold as seafood. The brightly coloured, fan-shaped shells of scallops with their radiating and fluted ornamentation are valued by shell collectors, have been used since ancient times as motifs in art and design. Owing to their widespread distribution, scallop shells are a common sight on beaches and are brightly coloured, making them a popular object to collect among beachcombers and vacationers; the shells have a significant place in popular culture, including symbolism. Scallops inhabit all the oceans of the world, with the largest number of species living in the Indo-Pacific region. Most species live in shallow waters from the low tide line to 100 m, while others prefer much deeper water.
Although some species only live in narrow environments, most are opportunistic and can live under a wide variety of conditions. Scallops can be found living within, upon, or under either rocks, rubble, sea grass, sand, or mud. Most scallops begin their lives as byssally attached juveniles, an ability that some retain throughout their lives while others grow into freeliving adults. Little variation occurs in the internal arrangement of organs and systems within the scallop family, what follows can be taken to apply to the anatomy of any given scallop species; the shell of a scallop consists of two sides or valves, a left valve and a right one, divided by a plane of symmetry. Most species of scallops rest on their right valve, this valve is deeper and more rounded than the left valve, which in many species is concave. With the hinge of the two valves oriented towards the top, one side corresponds to the animal's morphological anterior or front, the other is the posterior or rear, the hinge is the dorsal or back/ top region, the bottom corresponds to the ventral or underside/ belly.
However, as many scallop shells are more or less bilaterally symmetrical, as well as symmetrical front/back, determining which way a given animal is "facing" requires detailed information about its valves. The model scallop shell consists of two shaped valves with a straight hinge line along the top, devoid of teeth, producing a pair of flat wings or "ears" on either side of its midpoint, a feature, unique to and apparent in all adult scallops; these ears may be of similar size and shape. As is the case in all bivalves, a series of lines and/or growth rings originates at the center of the hinge, at a spot called the "beak" surrounded by a raised area called the "umbo"; these growth rings increase in size downwards. The shells of most scallops are streamlined to facilitate ease of movement during swimming at some point in their lifecycles, while providing protection from predators. Scallops with ridged valves have the advantage of the architectural strength provided by these ridges called "ribs", although the ribs are somewhat costly in terms of weight and mass.
A unique feature of the scallop family is the presence, at some point during the animal's lifecycle, of a distinctive and taxonomically important shell feature, a comb-like structure called a ctenolium located on the anterior edge of the right valve next to the valve's byssal notch. Though many scallops lose this feature as they become free-swimming adults, all scallops have a ctenolium at some point during their lives, no other bivalve has an analogous shell feature; the ctenolium is found in modern scallops only. Like the true oysters, scallops have a single central adductor muscle, thus the inside of their shells has a characteristic central scar, marking the point of attachment for this muscle; the adductor muscle of scallops is larger and more developed than those of oysters, because scallops are active swimmers.
Harvard University is a private Ivy League research university in Cambridge, with about 6,700 undergraduate students and about 15,250 postgraduate students. Established in 1636 and named for its first benefactor, clergyman John Harvard, Harvard is the United States' oldest institution of higher learning, its history and wealth have made it one of the world's most prestigious universities; the Harvard Corporation is its first chartered corporation. Although never formally affiliated with any denomination, the early College trained Congregational and Unitarian clergy, its curriculum and student body were secularized during the 18th century, by the 19th century, Harvard had emerged as the central cultural establishment among Boston elites. Following the American Civil War, President Charles W. Eliot's long tenure transformed the college and affiliated professional schools into a modern research university. A. Lawrence Lowell, who followed Eliot, further reformed the undergraduate curriculum and undertook aggressive expansion of Harvard's land holdings and physical plant.
James Bryant Conant led the university through the Great Depression and World War II and began to reform the curriculum and liberalize admissions after the war. The undergraduate college became coeducational after its 1977 merger with Radcliffe College; the university is organized into eleven separate academic units—ten faculties and the Radcliffe Institute for Advanced Study—with campuses throughout the Boston metropolitan area: its 209-acre main campus is centered on Harvard Yard in Cambridge 3 miles northwest of Boston. Harvard's endowment is worth $39.2 billion, making it the largest of any academic institution. Harvard is a large residential research university; the nominal cost of attendance is high, but the university's large endowment allows it to offer generous financial aid packages. The Harvard Library is the world's largest academic and private library system, comprising 79 individual libraries holding over 18 million items; the University is cited as one of the world's top tertiary institutions by various organizations.
Harvard's alumni include eight U. S. presidents, more than thirty foreign heads of state, 62 living billionaires, 359 Rhodes Scholars, 242 Marshall Scholars. As of October 2018, 158 Nobel laureates, 18 Fields Medalists, 14 Turing Award winners have been affiliated as students, faculty, or researchers. In addition, Harvard students and alumni have won 10 Academy Awards, 48 Pulitzer Prizes and 108 Olympic medals, have founded a large number of companies worldwide. Harvard was established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. In 1638, it acquired British North America's first known printing press. In 1639, it was named Harvard College after deceased clergyman John Harvard, an alumnus of the University of Cambridge, who had left the school £779 and his scholar's library of some 400 volumes; the charter creating the Harvard Corporation was granted in 1650. A 1643 publication gave the school's purpose as "to advance learning and perpetuate it to posterity, dreading to leave an illiterate ministry to the churches when our present ministers shall lie in the dust".
It offered a classic curriculum on the English university model—many leaders in the colony had attended the University of Cambridge—but conformed to the tenets of Puritanism. It was never affiliated with any particular denomination, but many of its earliest graduates went on to become clergymen in Congregational and Unitarian churches; the leading Boston divine Increase Mather served as president from 1685 to 1701. In 1708, John Leverett became the first president, not a clergyman, marking a turning of the college from Puritanism and toward intellectual independence. Throughout the 18th century, Enlightenment ideas of the power of reason and free will became widespread among Congregational ministers, putting those ministers and their congregations in tension with more traditionalist, Calvinist parties; when the Hollis Professor of Divinity David Tappan died in 1803 and the president of Harvard Joseph Willard died a year in 1804, a struggle broke out over their replacements. Henry Ware was elected to the chair in 1805, the liberal Samuel Webber was appointed to the presidency of Harvard two years which signaled the changing of the tide from the dominance of traditional ideas at Harvard to the dominance of liberal, Arminian ideas.
In 1846, the natural history lectures of Louis Agassiz were acclaimed both in New York and on the campus at Harvard College. Agassiz's approach was distinctly idealist and posited Americans' "participation in the Divine Nature" and the possibility of understanding "intellectual existences". Agassiz's perspective on science combined observation with intuition and the assumption that a person can grasp the "divine plan" in all phenomena; when it came to explaining life-forms, Agassiz resorted to matters of shape based on a presumed archetype for his evidence. This dual view of knowledge was in concert with the teachings of Common Sense Realism derived from Scottish philosophers Thomas Reid and Dugald Stewart, whose works were part of the Harvard curriculum at the time; the popularity of Agassiz's efforts to "soar with Plato" also derived from other writings to which Harvard students