In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. While these definitions may seem adequate, when looked at more they represent problematic species concepts. For example, the boundaries between related species become unclear with hybridisation, in a species complex of hundreds of similar microspecies, in a ring species. Among organisms that reproduce only asexually, the concept of a reproductive species breaks down, each clone is a microspecies. All species are given a two-part name, a "binomial"; the first part of a binomial is the genus.
The second part is called the specific epithet. For example, Boa constrictor is one of four species of the genus Boa. None of these is satisfactory definitions, but scientists and conservationists need a species definition which allows them to work, regardless of the theoretical difficulties. If species were fixed and distinct from one another, there would be no problem, but evolutionary processes cause species to change continually, to grade into one another. Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped. Charles Darwin's 1859 book The Origin of Species explained how species could arise by natural selection; that understanding was extended in the 20th century through genetics and population ecology. Genetic variability arises from mutations and recombination, while organisms themselves are mobile, leading to geographical isolation and genetic drift with varying selection pressures.
Genes can sometimes be exchanged between species by horizontal gene transfer. Viruses are a special case, driven by a balance of mutation and selection, can be treated as quasispecies. Biologists and taxonomists have made many attempts to define species, beginning from morphology and moving towards genetics. Early taxonomists such as Linnaeus had no option but to describe what they saw: this was formalised as the typological or morphological species concept. Ernst Mayr emphasised reproductive isolation, but this, like other species concepts, is hard or impossible to test. Biologists have tried to refine Mayr's definition with the recognition and cohesion concepts, among others. Many of the concepts are quite similar or overlap, so they are not easy to count: the biologist R. L. Mayden recorded about 24 concepts, the philosopher of science John Wilkins counted 26. Wilkins further grouped the species concepts into seven basic kinds of concepts: agamospecies for asexual organisms biospecies for reproductively isolated sexual organisms ecospecies based on ecological niches evolutionary species based on lineage genetic species based on gene pool morphospecies based on form or phenotype and taxonomic species, a species as determined by a taxonomist.
A typological species is a group of organisms in which individuals conform to certain fixed properties, so that pre-literate people recognise the same taxon as do modern taxonomists. The clusters of variations or phenotypes within specimens would differentiate the species; this method was used as a "classical" method of determining species, such as with Linnaeus early in evolutionary theory. However, different phenotypes are not different species. Species named in this manner are called morphospecies. In the 1970s, Robert R. Sokal, Theodore J. Crovello and Peter Sneath proposed a variation on this, a phenetic species, defined as a set of organisms with a similar phenotype to each other, but a different phenotype from other sets of organisms, it differs from the morphological species concept in including a numerical measure of distance or similarity to cluster entities based on multivariate comparisons of a reasonably large number of phenotypic traits. A mate-recognition species is a group of sexually reproducing organisms that recognize one another as potential mates.
Expanding on this to allow for post-mating isolation, a cohesion species is the most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms. A further development of the recognition concept is provided by the biosemiotic concept of species. In microbiology, genes can move even between distantly related bacteria extending to the whole bacterial domain; as a rule of thumb, microbiologists have assumed that kinds of Bacteria or Archaea with 16S ribosomal RNA gene sequences more similar than 97% to each other need to be checked by DNA-DNA hybridisation to decide if they belong to the same species or not. This concept was narrowed in 2006 to a similarity of 98.7%. DNA-DNA hybri
Natural History Museum, London
The Natural History Museum in London is a natural history museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum and the Victoria and Albert Museum; the Natural History Museum's main frontage, however, is on Cromwell Road. The museum is home to life and earth science specimens comprising some 80 million items within five main collections: botany, mineralogy and zoology; the museum is a centre of research specialising in taxonomy and conservation. Given the age of the institution, many of the collections have great historical as well as scientific value, such as specimens collected by Charles Darwin; the museum is famous for its exhibition of dinosaur skeletons and ornate architecture—sometimes dubbed a cathedral of nature—both exemplified by the large Diplodocus cast that dominated the vaulted central hall before it was replaced in 2017 with the skeleton of a blue whale hanging from the ceiling.
The Natural History Museum Library contains extensive books, journals and artwork collections linked to the work and research of the scientific departments. The museum is recognised as the pre-eminent centre of natural history and research of related fields in the world. Although referred to as the Natural History Museum, it was known as British Museum until 1992, despite legal separation from the British Museum itself in 1963. Originating from collections within the British Museum, the landmark Alfred Waterhouse building was built and opened by 1881 and incorporated the Geological Museum; the Darwin Centre is a more recent addition designed as a modern facility for storing the valuable collections. Like other publicly funded national museums in the United Kingdom, the Natural History Museum does not charge an admission fee; the museum is an exempt charity and a non-departmental public body sponsored by the Department for Culture and Sport. Catherine, Duchess of Cambridge is a patron of the museum.
There are 850 staff at the Museum. The two largest strategic groups are Science Group; the foundation of the collection was that of the Ulster doctor Sir Hans Sloane, who allowed his significant collections to be purchased by the British Government at a price well below their market value at the time. This purchase was funded by a lottery. Sloane's collection, which included dried plants, animal and human skeletons, was housed in Montagu House, Bloomsbury, in 1756, the home of the British Museum. Most of the Sloane collection had disappeared by the early decades of the nineteenth century. Dr George Shaw sold many specimens to the Royal College of Surgeons and had periodic cremations of material in the grounds of the museum, his successors applied to the trustees for permission to destroy decayed specimens. In 1833 the Annual Report states that, of the 5,500 insects listed in the Sloane catalogue, none remained; the inability of the natural history departments to conserve its specimens became notorious: the Treasury refused to entrust it with specimens collected at the government's expense.
Appointments of staff were bedevilled by gentlemanly favoritism. J. E. Gray complained of the incidence of mental illness amongst staff: George Shaw threatened to put his foot on any shell not in the 12th edition of Linnaeus' Systema Naturae; the huge collection of the conchologist Hugh Cuming was acquired by the museum, Gray's own wife had carried the open trays across the courtyard in a gale: all the labels blew away. That collection is said never to have recovered; the Principal Librarian at the time was Antonio Panizzi. The general public was not encouraged to visit the Museum's natural history exhibits. In 1835 to a Select Committee of Parliament, Sir Henry Ellis said this policy was approved by the Principal Librarian and his senior colleagues. Many of these faults were corrected by the palaeontologist Richard Owen, appointed Superintendent of the natural history departments of the British Museum in 1856, his changes led Bill Bryson to write that "by making the Natural History Museum an institution for everyone, Owen transformed our expectations of what museums are for".
Owen saw that the natural history departments needed more space, that implied a separate building as the British Museum site was limited. Land in South Kensington was purchased, in 1864 a competition was held to design the new museum; the winning entry was submitted by the civil engineer Captain Francis Fowke, who died shortly afterwards. The scheme was taken over by Alfred Waterhouse who revised the agreed plans, designed the façades in his own idiosyncratic Romanesque style, inspired by his frequent visits to the Continent; the original plans included wings on either side of the main building, but these plans were soon abandoned for budgetary reasons. The space these would have occupied are now taken by the Earth Galleries and Darwin Centre. Work began in 1873 and was completed in 1880; the new museum opened in 1881, although the move from the old museum was not completed until 1883. Both the interiors and exteriors of the Waterhouse building make extensive use of
Film preservation, or film restoration, describes a series of ongoing efforts among film historians, museums and non-profit organizations to rescue decaying film stock and preserve the images which they contain. In the widest sense, preservation nowadays assures that a movie will continue to exist in as close to its original form as possible. For many years the term "preservation" was synonymous with "duplication" of film; the goal of a preservationist was to create a durable copy without any significant loss of quality. In more modern terms, film preservation now includes the concepts of handling, duplication and access; the archivist seeks to share the content with the public. Film preservation is not to be confused with film revisionism, in which long-completed films are subjected to outtakes never seen being inserted, newly inserted music scores or sound effects being added, black-and-white film being colorized or converted to Dolby stereo, or minor edits and other cosmetic changes being made.
By the 1980s, it was becoming apparent that the collections of motion picture heritage were at risk of becoming lost. Not only was the preservation of nitrate film an ongoing problem, but the discovery that safety film, used as a replacement for the more volatile nitrate stock, was beginning to be affected by a unique form of decay known as "vinegar syndrome", color film manufactured, in particular, by Eastman Kodak, was found to be at risk of fading. At that time, the best known solution was to duplicate the original film onto a more secure medium. 90 percent of all American silent films made before 1929 and 50 percent of American sound films made before 1950 are lost films. Although institutional practices of film preservation date back to the 1930s, the field received an official status only in 1980, when UNESCO recognized "moving images" as an integral part of the world's cultural heritage; the great majority of films made in the silent era are now considered lost forever. Movies of the first half of the 20th century were filmed on an unstable flammable cellulose nitrate film base, which required careful storage to slow its inevitable process of decomposition over time.
Most films made on nitrate stock were not preserved. Many of them were destroyed in studio or vault fires; the largest cause, was intentional destruction. As film preservationist Robert A. Harris explains, "Most of the early films did not survive because of wholesale junking by the studios. There was no thought of saving these films, they needed vault space and the materials were expensive to house." Silent films had little or no commercial value after the advent of sound films in the 1930s, as such, they were not kept. As a result, preserving the now rare silent films has been a high priority amongst film historians; because of the fragility of film stock, proper preservation of film involves storing the original negatives and prints in climate-controlled facilities. The vast majority of films were not stored in this manner, which resulted in the widespread decay of film stocks; the problem of film decay is not limited to films made on cellulose nitrate. Film industry researchers and specialists have found that color films are decaying at an rapid rate.
A number of well-known films only exist as copies of original film productions or exhibition elements because the originals have decomposed beyond use. Cellulose acetate film, the initial replacement for nitrate, has been found to suffer from "vinegar syndrome"; the ongoing preservation of color films is now presented with an issue, as low temperatures, which inhibit color fading increase the effects of vinegar syndrome, while higher temperatures cause color fading. In 2002, filmmaker Bill Morrison produced Decasia, a film based on fragments of old unrestored nitrate-based films in various states of decay and disrepair, providing a somewhat eerie aesthetic to the film; the film was paired together with a soundtrack composed by Michael Gordon, performed by his orchestra. The footage used was from old newsreel & archive film, was obtained by Morrison from several sources, such as the Fox Movietone Newsfilm Archives at the University of South Carolina, the archives of the Museum of Modern Art.
The "preservation" of film refers to physical storage of the film in a climate-controlled vault, sometimes to the actual repair and copying of the film element. Preservation is different from "restoration", as restoration is the act of returning the film to a version most faithful to its initial release to the public and involves combining various fragments of film elements. Film is best preserved by proper protection from external forces while in storage along with being under controlled temperatures. For most film materials, the Image Permanence Institute finds that storing film media in frozen temperatures, with RH between 30% and 50% extends its useful life; these measures inhibit deterioration better than any other methods and is a cheaper solution than replicating deteriorating films. In most cases, when a film is chosen for preservation or restoration work, new prints are created from the original camera negative or the composite restoration negative, made from a combination of elements for general screening.
The composite restoration negative is a compilation of duplicated sections of the best remaining material, recombined to approximate the original configuration of the original camera negative at some time in the film's release cycle, while the original camera negative
Habitat destruction is the process by which natural habitat becomes incapable of supporting its native species. In this process, the organisms that used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity is for the purpose of harvesting natural resources for industrial production and urbanization. Clearing habitats for agriculture is the principal cause of habitat destruction. Other important causes of habitat destruction include mining, logging and urban sprawl. Habitat destruction is ranked as the primary cause of species extinction worldwide, it is a process of natural environmental change that may be caused by habitat fragmentation, geological processes, climate change or by human activities such as the introduction of invasive species, ecosystem nutrient depletion, other human activities. The terms habitat loss and habitat reduction are used in a wider sense, including loss of habitat from other factors, such as water and noise pollution. In the simplest term, when a habitat is destroyed, the plants and other organisms that occupied the habitat have a reduced carrying capacity so that populations decline and extinction becomes more likely.
The greatest threat to organisms and biodiversity is the process of habitat loss. Temple found that 82% of endangered bird species were threatened by habitat loss. Most amphibian species are threatened by habitat loss, some species are now only breeding in modified habitat. Endemic organisms with limited ranges are most affected by habitat destruction because these organisms are not found anywhere else within the world, thus have less chance of recovering. Many endemic organisms have specific requirements for their survival that can only be found within a certain ecosystem, resulting in their extinction. Extinction may take place long after the destruction of habitat, a phenomenon known as extinction debt. Habitat destruction can decrease the range of certain organism populations; this can result in the reduction of genetic diversity and the production of infertile youths, as these organisms would have a higher possibility of mating with related organisms within their population, or different species.
One of the most famous examples is the impact upon China's giant panda, once found across the nation. Now it is only found in fragmented and isolated regions in the southwest of the country, as a result of widespread deforestation in the 20th century. Biodiversity hotspots are chiefly tropical regions that feature high concentrations of endemic species and, when all hotspots are combined, may contain over half of the world’s terrestrial species; these hotspots are suffering from habitat destruction. Most of the natural habitat on islands and in areas of high human population density has been destroyed. Islands suffering extreme habitat destruction include New Zealand, the Philippines, Japan. South and East Asia — China, Malaysia and Japan — and many areas in West Africa have dense human populations that allow little room for natural habitat. Marine areas close to populated coastal cities face degradation of their coral reefs or other marine habitat; these areas include the eastern coasts of Asia and Africa, northern coasts of South America, the Caribbean Sea and its associated islands.
Regions of unsustainable agriculture or unstable governments, which may go hand-in-hand experience high rates of habitat destruction. Central America, Sub-Saharan Africa, the Amazonian tropical rainforest areas of South America are the main regions with unsustainable agricultural practices and/or government mismanagement. Areas of high agricultural output tend to have the highest extent of habitat destruction. In the U. S. less than 25 % of native vegetation remains in many parts of the Midwest. Only 15% of land area remains unmodified by human activities in all of Europe. Tropical rainforests have received most of the attention concerning the destruction of habitat. From the 16 million square kilometers of tropical rainforest habitat that existed worldwide, less than 9 million square kilometers remain today; the current rate of deforestation is 160,000 square kilometers per year, which equates to a loss of 1% of original forest habitat each year. Other forest ecosystems have suffered as more destruction as tropical rainforests.
Farming and logging have disturbed at least 94% of temperate broadleaf forests. Tropical deciduous dry forests are easier to clear and burn and are more suitable for agriculture and cattle ranching than tropical rainforests. Plains and desert areas have been degraded to a lesser extent. Only 10-20% of the world's drylands, which include temperate grasslands and shrublands, deciduous forests, have been somewhat degraded, but included in that 10-20% of land is the 9 million square kilometers of seasonally dry-lands that humans have converted to deserts through the process of desertification. The tallgrass prairies of North America, on the other hand, have less than 3% of natural habitat remaining that has not been converted to farmland. Wetlands and marine areas have endured high levels of habitat destruction. More than 50% of wetlands in the U. S. have been destroyed in just the last 200 years. Between 60% and 70% of European wetlands have been destroyed. In the United Kingdom, there has been an i
The United Kingdom the United Kingdom of Great Britain and Northern Ireland, sometimes referred to as Britain, is a sovereign country located off the north-western coast of the European mainland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, many smaller islands. Northern Ireland is the only part of the United Kingdom that shares a land border with another sovereign state, the Republic of Ireland. Apart from this land border, the United Kingdom is surrounded by the Atlantic Ocean, with the North Sea to the east, the English Channel to the south and the Celtic Sea to the south-west, giving it the 12th-longest coastline in the world; the Irish Sea lies between Great Ireland. With an area of 242,500 square kilometres, the United Kingdom is the 78th-largest sovereign state in the world, it is the 22nd-most populous country, with an estimated 66.0 million inhabitants in 2017. The UK is constitutional monarchy; the current monarch is Queen Elizabeth II, who has reigned since 1952, making her the longest-serving current head of state.
The United Kingdom's capital and largest city is London, a global city and financial centre with an urban area population of 10.3 million. Other major urban areas in the UK include Greater Manchester, the West Midlands and West Yorkshire conurbations, Greater Glasgow and the Liverpool Built-up Area; the United Kingdom consists of four constituent countries: England, Scotland and Northern Ireland. Their capitals are London, Edinburgh and Belfast, respectively. Apart from England, the countries have their own devolved governments, each with varying powers, but such power is delegated by the Parliament of the United Kingdom, which may enact laws unilaterally altering or abolishing devolution; the nearby Isle of Man, Bailiwick of Guernsey and Bailiwick of Jersey are not part of the UK, being Crown dependencies with the British Government responsible for defence and international representation. The medieval conquest and subsequent annexation of Wales by the Kingdom of England, followed by the union between England and Scotland in 1707 to form the Kingdom of Great Britain, the union in 1801 of Great Britain with the Kingdom of Ireland created the United Kingdom of Great Britain and Ireland.
Five-sixths of Ireland seceded from the UK in 1922, leaving the present formulation of the United Kingdom of Great Britain and Northern Ireland. There are fourteen British Overseas Territories, the remnants of the British Empire which, at its height in the 1920s, encompassed a quarter of the world's land mass and was the largest empire in history. British influence can be observed in the language and political systems of many of its former colonies; the United Kingdom is a developed country and has the world's fifth-largest economy by nominal GDP and ninth-largest economy by purchasing power parity. It has a high-income economy and has a high Human Development Index rating, ranking 14th in the world, it was the world's first industrialised country and the world's foremost power during the 19th and early 20th centuries. The UK remains a great power, with considerable economic, military and political influence internationally, it is sixth in military expenditure in the world. It has been a permanent member of the United Nations Security Council since its first session in 1946.
It has been a leading member state of the European Union and its predecessor, the European Economic Community, since 1973. The United Kingdom is a member of the Commonwealth of Nations, the Council of Europe, the G7, the G20, NATO, the Organisation for Economic Co-operation and Development and the World Trade Organization; the 1707 Acts of Union declared that the kingdoms of England and Scotland were "United into One Kingdom by the Name of Great Britain". The term "United Kingdom" has been used as a description for the former kingdom of Great Britain, although its official name from 1707 to 1800 was "Great Britain"; the Acts of Union 1800 united the kingdom of Great Britain and the kingdom of Ireland in 1801, forming the United Kingdom of Great Britain and Ireland. Following the partition of Ireland and the independence of the Irish Free State in 1922, which left Northern Ireland as the only part of the island of Ireland within the United Kingdom, the name was changed to the "United Kingdom of Great Britain and Northern Ireland".
Although the United Kingdom is a sovereign country, Scotland and Northern Ireland are widely referred to as countries. The UK Prime Minister's website has used the phrase "countries within a country" to describe the United Kingdom; some statistical summaries, such as those for the twelve NUTS 1 regions of the United Kingdom refer to Scotland and Northern Ireland as "regions". Northern Ireland is referred to as a "province". With regard to Northern Ireland, the descriptive name used "can be controversial, with the choice revealing one's political preferences"; the term "Great Britain" conventionally refers to the island of Great Britain, or politically to England and Wales in combination. However, it is sometimes used as a loose synonym for the United Kingdom as a whole; the term "Britain" is used both as a synonym for Great Britain, as a synonym for the United Kingdom. Usage is mixed, with the BBC preferring to use Britain as shorthand only for Great Britain and the UK Government, while accepting that both terms refer to the United K
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
A fungus is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separate from the other eukaryotic life kingdoms of plants and animals. A characteristic that places fungi in a different kingdom from plants and some protists is chitin in their cell walls. Similar to animals, fungi are heterotrophs. Fungi do not photosynthesize. Growth is their means of mobility, except for spores, which may travel through the water. Fungi are the principal decomposers in ecological systems; these and other differences place fungi in a single group of related organisms, named the Eumycota, which share a common ancestor, an interpretation, strongly supported by molecular phylogenetics. This fungal group oomycetes; the discipline of biology devoted to the study of fungi is known as mycology. In the past, mycology was regarded as a branch of botany, although it is now known fungi are genetically more related to animals than to plants.
Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and parasites, they may become noticeable when fruiting, either as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment, they have long been used in the form of mushrooms and truffles. Since the 1940s, fungi have been used for the production of antibiotics, more various enzymes produced by fungi are used industrially and in detergents. Fungi are used as biological pesticides to control weeds, plant diseases and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals including humans; the fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies.
Fungi can break down manufactured materials and buildings, become significant pathogens of humans and other animals. Losses of crops due to fungal diseases or food spoilage can have a large impact on human food supplies and local economies; the fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of Kingdom Fungi, estimated at 2.2 million to 3.8 million species. Of these, only about 120,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christian Hendrik Persoon, Elias Magnus Fries, fungi have been classified according to their morphology or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits.
Phylogenetic studies published in the last decade have helped reshape the classification within Kingdom Fungi, divided into one subkingdom, seven phyla, ten subphyla. The English word fungus is directly adopted from the Latin fungus, used in the writings of Horace and Pliny; this in turn is derived from the Greek word sphongos, which refers to the macroscopic structures and morphology of mushrooms and molds. The word mycology is derived from the Greek logos, it denotes the scientific study of fungi. The Latin adjectival form of "mycology" appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon; the word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. Refers to mycology as the study of fungi. A group of all the fungi present in a particular area or geographic region is known as mycobiota, e.g. "the mycobiota of Ireland". Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are immobile, have similarities in general morphology and growth habitat.
Like plants, fungi grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago; some morphological and genetic features are shared with other organisms, while others are unique to the fungi separating them from the other kingdoms: Shared features: With other euka