1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Animal
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Animals are multicellular, eukaryotic organisms of the kingdom Animalia. The animal kingdom emerged as a clade within Apoikozoa as the group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives and their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs, they must ingest other organisms or their products for sustenance, most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates, vertebrates have a backbone or spine, and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals, the remaining animals are the invertebrates, which lack a backbone. These include molluscs, arthropods, annelids, nematodes, flatworms, cnidarians, ctenophores, the study of animals is called zoology. The word animal comes from the Latin animalis, meaning having breath, the biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans. Aristotle divided the world between animals and plants, and this was followed by Carl Linnaeus, in the first hierarchical classification. In Linnaeuss original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then the last four have all been subsumed into a single phylum, in 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms, Metazoa and Protozoa. The protozoa were later moved to the kingdom Protista, leaving only the metazoa, thus Metazoa is now considered a synonym of Animalia. Animals have several characteristics that set apart from other living things. Animals are eukaryotic and multicellular, which separates them from bacteria and they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at life stages. In most animals, embryos pass through a stage, which is a characteristic exclusive to animals. With a few exceptions, most notably the sponges and Placozoa and these include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals
3.
Chordate
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Chordates are deuterostomes, as during the embryo development stage the anus forms before the mouth. They are also bilaterally symmetric coelomates, in the case of vertebrate chordates, the notochord is usually replaced by a vertebral column during development, and they may have body plans organized via segmentation. There are also additional extinct taxa, the Vertebrata are sometimes considered as a subgroup of the clade Craniata, consisting of chordates with a skull, the Craniata and Tunicata compose the clade Olfactores. Of the more than 65,000 living species of chordates, the worlds largest and fastest animals, the blue whale and peregrine falcon respectively, are chordates, as are humans. Fossil chordates are known from at least as early as the Cambrian explosion, Hemichordata, which includes the acorn worms, has been presented as a fourth chordate subphylum, but it now is usually treated as a separate phylum. The Hemichordata, along with the Echinodermata, form the Ambulacraria, the Chordata and Ambulacraria form the superphylum Deuterostomia, composed of the deuterostomes. Attempts to work out the relationships of the chordates have produced several hypotheses. All of the earliest chordate fossils have found in the Early Cambrian Chengjiang fauna. Because the fossil record of early chordates is poor, only molecular phylogenetics offers a prospect of dating their emergence. However, the use of molecular phylogenetics for dating evolutionary transitions is controversial and it has also proved difficult to produce a detailed classification within the living chordates. Attempts to produce family trees shows that many of the traditional classes are paraphyletic. While this has been known since the 19th century, an insistence on only monophyletic taxa has resulted in vertebrate classification being in a state of flux. Although the name Chordata is attributed to William Bateson, it was already in prevalent use by 1880, ernst Haeckel described a taxon comprising tunicates, cephalochordates, and vertebrates in 1866. Though he used the German vernacular form, it is allowed under the ICZN code because of its subsequent latinization, among the vertebrate sub-group of chordates the notochord develops into the spine, and in wholly aquatic species this helps the animal to swim by flexing its tail. In fish and other vertebrates, this develops into the spinal cord, the pharynx is the part of the throat immediately behind the mouth. In fish, the slits are modified to form gills, a muscular tail that extends backwards behind the anus. This is a groove in the wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus and it also stores iodine, and may be a precursor of the vertebrate thyroid gland
4.
Actinopterygii
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Actinopterygii /ˌæktᵻnˌɒptəˈrɪdʒi. aɪ/, or the ray-finned fishes, constitute a class or subclass of the bony fishes. These actinopterygian fin rays attach directly to the proximal or basal skeletal elements, the radials, numerically, actinopterygians are the dominant class of vertebrates, comprising nearly 99% of the over 30,000 species of fish. They are ubiquitous throughout freshwater and marine environments from the sea to the highest mountain streams. Extant species can range in size from Paedocypris, at 8 mm, to the ocean sunfish, at 2,300 kg. Ray-finned fishes occur in variant forms. The main features of a typical ray-finned fish are shown in the diagram at the left. In nearly all ray-finned fish, the sexes are separate, development then proceeds with a free-swimming larval stage. However other patterns of ontogeny exist, with one of the commonest being sequential hermaphroditism, in most cases this involves protogyny, fish starting life as females and converting to males at some stage, triggered by some internal or external factor. This may be advantageous as females become less prolific as they age while male fecundity increases with age, protandry, where a fish converts from male to female, is much less common than protogyny. Most families use external rather than internal fertilization, of the oviparous teleosts, most do not provide parental care. Viviparity is relatively rare and is found in about 6% of teleost species, male territoriality preadapts a species for evolving male parental care. There are a few examples of fish that self-fertilise, the mangrove rivulus is an amphibious, simultaneous hermaphrodite, producing both eggs and spawn and having internal fertilisation. This mode of reproduction may be related to the habit of spending long periods out of water in the mangrove forests it inhabits. Males are occasionally produced at temperatures below 19 °C and can fertilise eggs that are spawned by the female. This maintains genetic variability in a species that is otherwise highly inbred, the earliest known fossil actinopterygiian is Andreolepis hedei, dating back 420 million years. Remains have been found in Russia, Sweden, and Estonia, actinopterygians are divided into the subclasses Chondrostei and Neopterygii. The Neopterygii, in turn, are divided into the infraclasses Holostei and Teleostei, during the Mesozoic and Cenozoic the teleosts in particular diversified widely, and as a result, 96% of all known fish species are teleosts. The cladogram shows the groups of actinopterygians and their relationship to the terrestrial vertebrates that evolved from a related group of fish
5.
Goby
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Gobies are fishes of the family Gobiidae, one of the largest fish families comprising more than 2,000 species in more than 200 genera. Most of them are small, typically less than 10 cm in length. Gobies include some of the smallest vertebrates in the world, such as Trimmatom nanus and Pandaka pygmaea, some large gobies, such as some species of the genera Gobioides or Periophthalmodon, can reach over 30 cm in length, but that is exceptional. Generally, they are benthic, or bottom-dwellers, although few are important as food for humans, they are of great significance as prey species for commercially important fish such as cod, haddock, sea bass, and flatfish. Several gobies are also of interest as aquarium fish, such as the bumblebee gobies of the genus Brachygobius, phylogenetic relationships of gobies have been studied using molecular data. The most distinctive aspects of morphology are the fused pelvic fins that form a disc-shaped sucker. Gobies can often be seen using the sucker to adhere to rocks and corals, gobies are spread all over the world in tropical and temperate near shore-marine, brackish and freshwater environments. Their range extends from the Old World coral reefs to the seas of the New World, on coral reefs, gobies constitute 35% of the total number of fishes and 20% of the species diversity. Gobies are generally bottom-dwellers and live inside the bodies or burrows of invertebrates, Gobiidae contains six subfamilies, Members of the subfamily Amblyopinae are elongated mud-dwelling gobies commonly known as the eel gobies or worm gobies. Their two dorsal fins are connected by a structure and their eyes are highly reduced. They are usually pink, red, or purple in coloration, Amblyopinae contain 12 genera and about 23 species. Members of Benthophilinae are endemic to the Ponto-Caspian region, the representatives of the subfamily have fused pelvic fins and elongated dorsal and anal fins. They are distinguished from the related subfamily Gobiinae by the absence of a swimbladder in adults. Its members include tadpole gobies, monkey gobies, and bighead gobies, Members of Gobiinae are known as true gobies. It is the most widespread and most diverse of the subfamilies under Gobiidae, Members of Gobionellinae mostly inhabit estuarine habitats, though some are freshwater and a single genus, Gnatholepis, is marine. They are found in tropical and temperate regions around the world with the exception of the northeastern Atlantic Ocean, the Mediterranean Sea, and it includes around 370 species and 55 genera. Members of Oxudercinae are commonly known as mudskippers and they are highly specialized members of the family. Mudskippers live in areas, particularly on mudflats and in mangrove forests
6.
Georges Cuvier
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Jean Léopold Nicolas Frédéric Cuvier, known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the father of paleontology. Cuvier is also known for establishing extinction as a fact—at the time, in his Essay on the Theory of the Earth Cuvier was interpreted to have proposed that new species were created after periodic catastrophic floods. In this way, Cuvier became the most influential proponent of catastrophism in geology in the early 19th century and his study of the strata of the Paris basin with Alexandre Brongniart established the basic principles of biostratigraphy. Cuvier is also remembered for strongly opposing theories of evolution, which at the time were mainly proposed by Jean-Baptiste de Lamarck, Cuvier believed there was no evidence for evolution, but rather evidence for cyclical creations and destructions of life forms by global extinction events such as deluges. Cuvier supported function and rejected Lamarcks thinking and his most famous work is Le Règne Animal. In 1819, he was created a peer for life in honor of his scientific contributions, thereafter, he was known as Baron Cuvier. He died in Paris during an epidemic of cholera, some of Cuviers most influential followers were Louis Agassiz on the continent and in the United States, and Richard Owen in Britain. His name is one of the 72 names inscribed on the Eiffel Tower, Cuvier was born in Montbéliard, France, where his Protestant ancestors had lived since the time of the Reformation. His father, Jean George Cuvier, was a lieutenant in the Swiss Guards, at the time, the town, which was annexed to France on 10 October 1793, belonged to the Duchy of Württemberg. His mother, who was younger than his father, tutored him diligently throughout his early years. During his gymnasium years, he had trouble acquiring Latin and Greek, and was always at the head of his class in mathematics, history. At the age of 10, soon entering the gymnasium, he encountered a copy of Conrad Gessners Historiae Animalium. He then began frequent visits to the home of a relation, all of these he read and reread, retaining so much of the information, that by the age of 12, he was as familiar with quadrupeds and birds as a first-rate naturalist. He remained at the gymnasium for four years, Cuvier spent an additional four years at the Caroline Academy in Stuttgart, where he excelled in all of his coursework. Although he knew no German on his arrival, after nine months of study. Upon graduation, he had no money on which to live as he awaited appointment to an academic office, so in July 1788, he took a job at Fiquainville chateau in Normandy as tutor to the only son of the Comte dHéricy, a Protestant noble. There, during the early 1790s, he began his comparisons of fossils with extant forms, Cuvier regularly attended meetings held at the nearby town of Valmont for the discussion of agricultural topics. There, he acquainted with Henri Alexandre Tessier, who had assumed a false identity
7.
Family (biology)
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In biological classification, family is one of the eight major taxonomic ranks, it is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks above the rank of genus. In vernacular usage, a family may be named one of its common members, for example, walnuts and hickory trees belong to the family Juglandaceae. What does or does not belong to a family—or whether a family should be recognized at all—are proposed and determined by practicing taxonomists. There are no rules for describing or recognizing a family. Taxonomists often take different positions about descriptions of taxa, and there may be no broad consensus across the community for some time. Some described taxa are accepted broadly and quickly, but others only rarely, if at all, the naming of families is codified by various international codes. In zoological nomenclature, the names of animals end with the suffix -idae. The concept of rank at time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera. Carolus Linnaeus used the word familia in his Philosophia botanica to denote groups of plants, trees, herbs, ferns, palms. He used this term only in the section of the book. In zoology, the family as an intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes. He used families in some but not in all his orders of insects, families can be used for evolutionary, palaeontological and generic studies because they are more stable than lower taxonomic levels such as genera and species
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