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.
Reptile
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Reptiles are tetrapod animals in the class Reptilia, comprising todays turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. The study of these traditional reptile orders, historically combined with that of amphibians, is called herpetology. Because some reptiles are more related to birds than they are to other reptiles. For this reason, many scientists prefer to consider the birds part of Reptilia as well. Some early examples include the lizard-like Hylonomus and Casineria, in addition to the living reptiles, there are many diverse groups that are now extinct, in some cases due to mass extinction events. In particular, the K–Pg extinction wiped out the pterosaurs, plesiosaurs, ornithischians, and sauropods, as well as species of theropods, crocodyliforms. Modern non-avian reptiles inhabit every continent with the exception of Antarctica, several living subgroups are recognized, Testudines, approximately 400 species, Sphenodontia,1 species, Squamata, over 9,600 species, Crocodilia,25 species, and Aves,10,000 species. Reptiles are tetrapod vertebrates, creatures that either have four limbs or, unlike amphibians, reptiles do not have an aquatic larval stage. As amniotes, reptile eggs are surrounded by membranes for protection and transport, many of the viviparous species feed their fetuses through various forms of placenta analogous to those of mammals, with some providing initial care for their hatchlings. In the 18th century, the reptiles were, from the outset of classification, the terms reptile and amphibian were largely interchangeable, reptile being preferred by the French. Josephus Nicolaus Laurenti was the first to use the term Reptilia for an expanded selection of reptiles. Today, the two groups are commonly treated under the same heading as herptiles. He subsequently proposed the names of Sauropsida and Ichthyopsida for the two groups. In 1866, Haeckel demonstrated that vertebrates could be divided based on their strategies, and that reptiles, birds. The terms Sauropsida and Theropsida were used again in 1916 by E. S, Goodrich to distinguish between lizards, birds, and their relatives on the one hand and mammals and their extinct relatives on the other. Goodrich supported this division by the nature of the hearts and blood vessels in each group, according to Goodrich, both lineages evolved from an earlier stem group, Protosauria in which he included some animals today considered reptile-like amphibians, as well as early reptiles. Watson observed that the first two groups diverged very early in history, so he divided Goodrichs Protosauria between them. He also reinterpreted Sauropsida and Theropsida to exclude birds and mammals, thus his Sauropsida included Procolophonia, Eosuchia, Millerosauria, Chelonia, Squamata, Rhynchocephalia, Crocodilia, thecodonts, non-avian dinosaurs, pterosaurs, ichthyosaurs, and sauropterygians
5.
Squamata
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The Squamata, or the scaled reptiles, are the largest recent order of reptiles, comprising all lizards and snakes. With over 10,000 species, it is also the second-largest order of extant vertebrates, after the perciform fish, members of the order are distinguished by their skins, which bear horny scales or shields. They also possess movable quadrate bones, making it possible to move the upper jaw relative to the neurocranium and this is particularly visible in snakes, which are able to open their mouths very wide to accommodate comparatively large prey. They are the most variably sized order of reptiles, ranging from the 16 mm dwarf gecko to the 5.21 m green anaconda and the now-extinct mosasaurs, among the other reptiles, squamates are most closely related to the tuatara, which strongly resembles lizards. Squamates are a sister group to the tuatara. The squamates and tuatara together are a group to crocodiles and birds. Fossils of the sister group, the Rhynchocephalia, appear in the Early Triassic. Also appearing in the Cretaceous are the polyglyphanodonts, a group of uncertain affinities, and the mosasaurs. At the end of the Cretaceous, squamates suffered a major extinction at the K-T boundary which wiped out polyglyphanodonts, mosasaurs, the relationships of squamates have been debated. From morphological data, the iguanians were long thought to be the most ancient branch of the tree, however, iguanians are now united with snakes and anguimorphs in a group called the Toxicofera. DNA also suggests that the various limbless groups- snakes, amphisbaenians, and dibamids- are unrelated, the male members of the group Squamata have hemipenes, which are usually held inverted within their bodies, and are everted for reproduction via erectile tissue like that in the human penis. Only one is used at a time, and some evidence indicates that males alternate use between copulations, the hemipenis has a variety of shapes, depending on the species. Often it bears spines or hooks, to anchor the male within the female, some species even have forked hemipenes. Due to being everted and inverted, hemipenes do not have a completely enclosed channel for the conduction of sperm and this is also the only reptile group in which both viviparous and ovoviviparous species are found, as well as the usual oviparous reptiles. Some species, such as the Komodo dragon, can reproduce asexually through parthenogenesis. There have been studies on how sexual selection manifests itself in snakes, snakes use a variety of tactics in acquiring mates. It is common for neck biting to occur while the snakes are entwined, parthenogenesis is a natural form of reproduction in which growth and development of embryos occur without fertilization. Agkistrodon contortrix and Agkistrodon piscivorus can reproduce by facultative parthenogenesis and that is, they are capable of switching from a sexual mode of reproduction to an asexual mode
6.
Varanidae
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The Varanidae are a family of lizards of the superfamily Varanoidea. The family, a group of carnivorous and frugivorous lizards, includes the extinct Megalania, the Komodo dragon, the Varanidae contain the living genus Varanus and a number of extinct taxa. Their closest living relatives are the anguid and helodermatid lizards, Varanidae was defined by Estes, de Queiroz and Gauthier as the clade containing the most recent common ancestor of Lanthanotus and Varanus and all of its descendants. A similar definition was formulated by Conrad et al. who defined Varanidae as the clade containing Varanus varius, Lanthanotus borneensis, using one of these definitions leads to the inclusion of the earless monitor lizard in the family Varanidae. Genera marked with † are extinct Genera usually included in Varanidae ), †Ovoo Norell, Gao, & Conrad,2008 †Saniwa Leidy,1870 Varanus Shaw,1790 Genera sometimes included in Varanidae. Formerly included in Varanidae, †Pachyvaranus Arambourg,1952 - Moved to a group of varanoid squamates, Pachyvaranidae. Below is a cladogram from Conrad et al. that shows relationships within Varanoidea, most species forage widely and have large home ranges, and many have high stamina. Although most species are carnivorous, three species in the Philippines are primarily frugivores. Among species of living varanids, the show positive allometry, being larger in larger-bodied species. Varanids possess unidirectional pulmonary airflow, including airsacs akin to those of birds
7.
Monitor lizard
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Monitor lizard is the common name of several large lizard species, comprising the genus Varanus. They are native to Africa, Asia and Oceania, but are now also in the Americas as an invasive species. A total of 79 species are currently recognized, Monitor lizards have long necks, powerful tails and claws, and well-developed limbs. Most monitor species are terrestrial, but arboreal and semiaquatic monitors are also known, while most monitor lizards are carnivorous, eating eggs, smaller reptiles, fish, birds and small mammals, some also eat fruit and vegetation, depending on where they live. A large concentration of monitor lizards occurs on Tioman Island and the Perhentian Islands in the Malaysian state of Pahang, some are now found in South Florida, particularly in the Everglades, and Singapore. Monitor lizards are, as a rule, almost entirely carnivorous, consuming prey as varied as insects, crustaceans, arachnids, myriapods, mollusks, fish, amphibians, reptiles, birds, most species feed on invertebrates as juveniles and shift to feeding on vertebrates as adults. Deer make up about 50% of the diet of adults of the largest species, in contrast, three arboreal species from the Philippines, Varanus bitatawa, Varanus mabitang, and Varanus olivaceus, are primarily fruit eaters. The genus Varanus is considered unique among animals in that its members are relatively conservative and yet show a range in size that is equivalent to a mouse. Finer morphological features such as the shape of the skull and limbs do vary though, Monitor lizards maintain large territories and employ active pursuit hunting techniques that are reminiscent of similar sized mammals. The active nature of monitor lizards has led to studies on the metabolic capacities of these lizards. The general consensus is that monitor lizards have the highest standard metabolic rates of all extant reptiles, Monitor lizards have a high aerobic scope that is afforded, in part, by their heart anatomy. Anatomical and molecular studies indicate that all varanids are partially venomous, Monitor lizards are oviparous, laying from 7 to 37 eggs, which they often cover with soil or protect in a hollow tree stump. The family Varanidae probably originated in Asia at least 65 million years ago, varanids last shared a common ancestor with their closest living relatives, earless monitors, during the late Cretaceous. During the late Cretaceous era, monitor lizards or their relatives are believed to have evolved into amphibious and then fully marine forms, the mosasaurs. Like snakes, monitor lizards have forked tongues which they use to sense odors, during the Pleistocene epoch, giant monitor lizards lived in Southeast Asia and Australasia, the best known fossil being the megalania. This species is a member of the Pleistocene megafauna of Australia. Some monitor lizards, including the Komodo dragon, are capable of parthenogenesis, the generic name Varanus is derived from the Arabic word waral ورل. The name comes from a common Semitic root ouran, waran, or waral, the occasional habit of varanids to stand on their two hind legs and to appear to monitor their surroundings has been suggested to have led to this name, as it was Latinized into Varanus
8.
Binomial nomenclature
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Such a name is called a binomial name, a binomen, binominal name or a scientific name, more informally it is also called a Latin name. The first part of the name identifies the genus to which the species belongs, for example, humans belong to the genus Homo and within this genus to the species Homo sapiens. The formal introduction of system of naming species is credited to Carl Linnaeus. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus. Although the general principles underlying binomial nomenclature are common to these two codes, there are differences, both in the terminology they use and in their precise rules. Similarly, both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a name is usually given, at least when it is first mentioned. In zoology Patella vulgata Linnaeus,1758, the original name given by Linnaeus was Fringilla domestica, the parentheses indicate that the species is now considered to belong in a different genus. The ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, in botany Amaranthus retroflexus L. – L. is the standard abbreviation used in botany for Linnaeus. – Linnaeus first named this bluebell species Scilla italica, Rothmaler transferred it to the genus Hyacinthoides, the ICN does not require that the dates of either publication be specified. Prior to the adoption of the binomial system of naming species. Together they formed a system of polynomial nomenclature and these names had two separate functions. First, to designate or label the species, and second, to be a diagnosis or description, such polynomial names may sometimes look like binomials, but are significantly different. For example, Gerards herbal describes various kinds of spiderwort, The first is called Phalangium ramosum, Branched Spiderwort, is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia. The Latin phrases are short descriptions, rather than identifying labels, the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné. It was in his 1753 Species Plantarum that he first began using a one-word trivial name together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as an epithet or specific name
9.
Central Africa
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Central Africa is the core region of the African continent which includes Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, and Rwanda. All of the states in the UN subregion of Middle Africa, plus those otherwise commonly reckoned in Central Africa, since its independence in 2011, South Sudan has also been commonly included in the region. The Central African Federation, also called the Federation of Rhodesia and Nyasaland, was made up of what are now the nations of Malawi, Zambia and these states are now typically considered part of Southern Africa. Archeological finds in Central Africa have been discovered dating back over 100,000 years, according to Zangato and Holl, there is evidence of iron-smelting in the Central African Republic and Cameroon that may date back to 3000 to 2500 BCE. Extensive walled settlements have recently found in Northeast Nigeria, approximately 60 km southwest of Lake Chad dating to the first millennium BCE. Trade and improved agricultural techniques supported more sophisticated societies, leading to the civilizations of Sao, Kanem, Bornu, Shilluk, Baguirmi. Around 1000 BCE, Bantu migrants had reached the Great Lakes Region in Central Africa, halfway through the first millennium BCE, the Bantu had also settled as far south as what is now Angola. The Sao civilization flourished from ca. the sixth century BCE to as late as the sixteenth century CE in northern Central Africa, the Sao lived by the Chari River south of Lake Chad in territory that later became part of Cameroon and Chad. They are the earliest people to have clear traces of their presence in the territory of modern Cameroon. Today, several groups of northern Cameroon and southern Chad. Sao artifacts show that they were skilled workers in bronze, copper, finds include bronze sculptures and terra cotta statues of human and animal figures, coins, funerary urns, household utensils, jewelry, highly decorated pottery, and spears. The largest Sao archaeological finds have been south of Lake Chad. The Kanem-Bornu Empire was centered in the Chad Basin and it was known as the Kanem Empire from the 9th century CE onward and lasted as the independent kingdom of Bornu until 1900. The history of the Empire is mainly known from the Royal Chronicle or Girgam discovered in 1851 by the German traveller Heinrich Barth, Kanem rose in the 8th century in the region to the north and east of Lake Chad. The Kanem empire went into decline, shrank, and in the 14th century was defeated by Bilala invaders from the Lake Fitri region, the Kanuri people led by the Sayfuwa migrated to the west and south of the lake, where they established the Bornu Empire. By the late 16th century the Bornu empire had expanded and recaptured the parts of Kanem that had been conquered by the Bulala, satellite states of Bornu included the Damagaram in the west and Baguirmi to the southeast of Lake Chad. The Shilluk Kingdom was centered in South Sudan from the 15th century from along a strip of land along the bank of White Nile. The capital and royal residence was in the town of Fashoda, the kingdom was founded during the mid-fifteenth century CE by its first ruler, Nyikang
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