1.
Conservation status
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The conservation status of a group of organisms indicates whether the group still exists and how likely the group is to become extinct in the near future. Various systems of conservation status exist and are in use at international, multi-country, the IUCN Red List of Threatened Species is the best known worldwide conservation status listing and ranking system. Also included are species that have gone extinct since 500 AD, when discussing the IUCN Red List, the official term threatened is a grouping of three categories, critically endangered, endangered, and vulnerable. Widespread and abundant taxa are included in this category, Data deficient – Not enough data to make an assessment of its risk of extinction Not evaluated – Has not yet been evaluated against the criteria. The Convention on International Trade in Endangered Species of Wild Fauna and Flora aims to ensure that trade in specimens of wild animals. Many countries require CITES permits when importing plants and animals listed on CITES, in the European Union, the Birds and Habitats Directives are the legal instruments that evaluate the conservation status within the EU of species and habitats. NatureServe conservation status focuses on Latin America, United States, Canada, and it has been developed by scientists from NatureServe, The Nature Conservancy, and the network of natural heritage programs and data centers. It is increasingly integrated with the IUCN Red List system and its categories for species include, presumed extinct, possibly extinct, critically imperiled, imperiled, vulnerable, apparently secure, and secure. The system also allows ambiguous or uncertain ranks including inexact numeric ranks, NatureServe adds a qualifier for captive or cultivated only, which has a similar meaning to the IUCN Red List extinct in the wild status. The Red Data Book of the Russian Federation is used within the Russian Federation, in Australia, the Environment Protection and Biodiversity Conservation Act 1999 describes lists of threatened species, ecological communities and threatening processes. The categories resemble those of the 1994 IUCN Red List Categories & Criteria, prior to the EPBC Act, a simpler classification system was used by the Endangered Species Protection Act 1992. Some state and territory governments also have their own systems for conservation status, in Belgium, the Flemish Research Institute for Nature and Forest publishes an online set of more than 150 nature indicators in Dutch. In Canada, the Committee on the Status of Endangered Wildlife in Canada is a group of experts that assesses and designates which wild species are in danger of disappearing from Canada. Under the Species at Risk Act, it is up to the federal government, in China, the State, provinces and some counties have determined their key protected wildlife species. There is the China red data book, in Finland, a large number of species are protected under the Nature Conservation Act, and through the EU Habitats Directive and EU Birds Directive. In Germany, the Federal Agency for Nature Conservation publishes red lists of endangered species, india has the Wild Life Protection Act,1972, Amended 2003 and the Biological Diversity Act,2002. In Japan, the Ministry of Environment publishes a Threatened Wildlife of Japan Red Data Book, in the Netherlands, the Dutch Ministry of Agriculture, Nature and Food Quality publishes a list of threatened species, and conservation is enforced by the Nature Conservation Act 1998. Species are also protected through the Wild Birds and Habitats Directives, in New Zealand, the Department of Conservation publishes the New Zealand Threat Classification System lists
2.
Endangered species
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An endangered species is a species which has been categorized as likely to become extinct. In 2012, the IUCN Red List featured 3079 animal and 2655 plant species as endangered worldwide, the figures for 1998 were, respectively,1102 and 1197. Many nations have laws that protect conservation-reliant species, for example, population numbers, trends and species conservation status can be found in the lists of organisms by population. The conservation status of a species indicates the likelihood that it will become extinct, the IUCN Red List of Threatened Species is the best-known worldwide conservation status listing and ranking system. Over 40% of the species are estimated to be at risk of extinction. Internationally,199 countries have signed an accord to create Biodiversity Action Plans that will protect endangered, in the United States, such plans are usually called Species Recovery Plans. Those species of Near Threatened and Least Concern status have been assessed and found to have relatively robust and healthy populations, though these may be in decline. The IUCN categories, with examples of animals classified by them, include, Extinct Extinct in the wild Captive individuals survive, critically endangered Faces an extremely high risk of extinction in the immediate future. Endangered Faces a high risk of extinction in the near future, vulnerable Faces a high risk of endangerment in the medium term. Near-threatened May be considered threatened in the near future, Least concern No immediate threat to species survival. A population size reduction of ≥ 50%, projected or suspected to be met within the next 10 years or three generations, whichever is the longer, based on any of to under A1. E) Quantitative analysis showing the probability of extinction in the wild is at least 20% within 20 years or five generations, there is data from the United States that shows a correlation between human populations and threatened and endangered species. Under the Endangered Species Act in the United States, species may be listed as endangered or threatened, the Salt Creek tiger beetle is an example of an endangered subspecies protected under the ESA. Some endangered species laws are controversial, also lobbying from hunters and various industries like the petroleum industry, construction industry, and logging, has been an obstacle in establishing endangered species laws. The Bush administration lifted a policy that required federal officials to consult an expert before taking actions that could damage endangered species. Under the Obama administration, this policy has been reinstated, being listed as an endangered species can have negative effect since it could make a species more desirable for collectors and poachers. This effect is potentially reducible, such as in China where commercially farmed turtles may be reducing some of the pressure to poach endangered species. Another problem with the species is its effect of inciting the use of the shoot, shovel
3.
IUCN Red List
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The IUCN Red List of Threatened Species, founded in 1964, is the worlds most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the main authority on the conservation status of species. A series of Regional Red Lists are produced by countries or organizations, the IUCN Red List is set upon precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world, the aim is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to try to reduce species extinction. Major species assessors include BirdLife International, the Institute of Zoology, the World Conservation Monitoring Centre, collectively, assessments by these organizations and groups account for nearly half the species on the Red List. The IUCN aims to have the category of every species re-evaluated every five years if possible, the 1964 IUCN Red List of Threatened Plants used the older pre-criteria Red List assessment system. Plants listed may not, therefore, appear in the current Red List, IUCN advise that is best to check both the online Red List and the 1997 plants Red List publication. The 2006 Red List, released on 4 May 2006 evaluated 40,168 species as a whole, plus an additional 2,160 subspecies, varieties, aquatic stocks, on 12 September 2007, the World Conservation Union released the 2007 IUCN Red List of Threatened Species. Russ Mittermeier, chief of Swiss-based IUCNs Primate Specialist Group, stated that 16,306 species are endangered with extinction,188 more than in 2006, the Red List includes the Sumatran orangutan in the Critically Endangered category and the Bornean orangutan in the Endangered category. The study shows at least 1,141 of the 5,487 mammals on Earth are known to be threatened with extinction, and 836 are listed as Data Deficient. The Red List of 2012 was released 19 July 2012 at Rio+20 Earth Summit, nearly 2,000 species were added, the IUCN assessed a total of 63,837 species which revealed 19,817 are threatened with extinction. With 3,947 described as endangered and 5,766 as endangered. At threat are 41% of amphibian species, 33% of reef-building corals, 30% of conifers, 25% of mammals, the IUCN Red List has listed 132 species of plants and animals from India as Critically Endangered. Extinct – No known individuals remaining, extinct in the wild – Known only to survive in captivity, or as a naturalized population outside its historic range. Critically endangered – Extremely high risk of extinction in the wild, Endangered – High risk of extinction in the wild. Vulnerable – High risk of endangerment in the wild, near threatened – Likely to become endangered in the near future. Does not qualify for a more at-risk category, widespread and abundant taxa are included in this category. Data deficient – Not enough data to make an assessment of its risk of extinction, Not evaluated – Has not yet been evaluated against the criteria
4.
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
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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
6.
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
7.
Mammal
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Mammals are any vertebrates within the class Mammalia, a clade of endothermic amniotes distinguished from reptiles by the possession of a neocortex, hair, three middle ear bones and mammary glands. All female mammals nurse their young with milk, secreted from the mammary glands, Mammals include the largest animals on the planet, the great whales. The basic body type is a quadruped, but some mammals are adapted for life at sea, in the air, in trees. The largest group of mammals, the placentals, have a placenta, Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale. With the exception of the five species of monotreme, all modern mammals give birth to live young, most mammals, including the six most species-rich orders, belong to the placental group. The largest orders are the rodents, bats and Soricomorpha, the next three biggest orders, depending on the biological classification scheme used, are the Primates, the Cetartiodactyla, and the Carnivora. Living mammals are divided into the Yinotheria and Theriiformes There are around 5450 species of mammal, in some classifications, extant mammals are divided into two subclasses, the Prototheria, that is, the order Monotremata, and the Theria, or the infraclasses Metatheria and Eutheria. The marsupials constitute the group of the Metatheria, and include all living metatherians as well as many extinct ones. Much of the changes reflect the advances of cladistic analysis and molecular genetics, findings from molecular genetics, for example, have prompted adopting new groups, such as the Afrotheria, and abandoning traditional groups, such as the Insectivora. The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade, the early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period, this group diverged from the line that led to todays reptiles. Some mammals are intelligent, with some possessing large brains, self-awareness, Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals, singing, and echolocation. Mammals can organize themselves into fission-fusion societies, harems, and hierarchies, most mammals are polygynous, but some can be monogamous or polyandrous. They provided, and continue to provide, power for transport and agriculture, as well as commodities such as meat, dairy products, wool. Mammals are hunted or raced for sport, and are used as model organisms in science, Mammals have been depicted in art since Palaeolithic times, and appear in literature, film, mythology, and religion. Defaunation of mammals is primarily driven by anthropogenic factors, such as poaching and habitat destruction, Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is accepted, McKenna & Bell and Wilson & Reader provide useful recent compendiums. Though field work gradually made Simpsons classification outdated, it remains the closest thing to a classification of mammals
8.
Odd-toed ungulate
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Members of the order Perissodactyla, otherwise known as odd-toed ungulates, are mammals characterized by an odd number of toes and by hindgut fermentation with somewhat simple stomachs. Perissodactyla comes from the Ancient Greek περισσός + δάκτυλος, unlike the even-toed ungulates, they digest plant cellulose in their intestines rather than in one or more stomach chambers. The order includes three extant families, Equidae, Rhinocerotidae, and Tapiridae, with a total of about 17 species. In spite of their different appearances, they were recognized as related families in the 19th century by the zoologist Richard Owen. The largest odd-toed ungulates are rhinoceroses, and the extinct Paraceratherium, at the other extreme, an early member of the order, the prehistoric horse Hyracotherium, had a shoulder height of only 30 to 60 cm. Apart from dwarf varieties of the horse and donkey, perissodactyls reach a body length of 180–420 cm. While rhinos have only sparse hair and exhibit a thick epidermis, tapirs and horses have dense, most species are grey or brown, although zebras and young tapirs are striped. The main axes of both the front and rear feet pass through the toe, which is always the largest. The remaining toes have been reduced in size to varying degrees, tapirs, which are adapted to walking on soft ground, have four toes on their fore feet and three on their hind feet. Living rhinos have three toes on both the front and hind feet, modern equines possess only a single toe, however, their feet are equipped with hooves, which almost completely cover the toe. Rhinos and tapirs, by contrast, have hooves covering only the edge of the toes. The ulnae and fibulae are reduced in horses, a common feature that clearly distinguishes this group from other mammals is the saddle-shaped ankle between the astragalus and the scaphoid, which greatly restricts the mobility of the foot. The thigh is relatively short, and the clavicle is absent, odd-toed ungulates have a long upper jaw with an extended diastema between the front and cheek teeth, giving them an elongated head. The various forms of snout between families are due to differences in the form of the premaxilla, the lacrimal bone has projecting cusps in the eye sockets and a wide contact with the nasal bone. The temporomandibular joint is high and the mandible is enlarged, rhinos have one or two horns made of agglutinated keratin, unlike the horns of even-toed ungulates, which have a bony core. The number and form of the teeth vary according to diet, the incisors and canines can be very small or completely absent, as in the two African species of rhinoceros. In the horses, usually only the males possess canines, the surface shape and height of the molars is heavily dependent on whether soft leaves or hard grass makes up the main component of their diets. Three or four teeth are present on each jaw half, so the dental formula of odd-toed ungulates is
9.
Equidae
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Equidae is the taxonomic family of horses and related animals, including the extant horses, donkeys, and zebras, and many other species known only from fossils. All extant species are in the genus Equus, Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families. The term equid refers to any member of family, including any equine. The oldest known fossils assigned to Equidae date from the early Eocene,54 million years ago and they used to be assigned to the genus Hyracotherium, but the type species of that genus now is regarded to be not a member of this family. The other species have split off into different genera. These early Equidae were fox-sized animals with three toes on the feet, and four on the front feet. They were herbivorous browsers on relatively soft plants, and already adapted for running, the complexity of their brains suggest that they already were alert and intelligent animals. Later species reduced the number of toes, and developed teeth more suited for grinding up grasses, the family became relatively diverse during the Miocene, with many new species appearing. By this time, equids were more truly horse-like, having developed the body shape of the modern animals. Many of these bore the main weight of their bodies on their central, third, toe, with the others becoming reduced. The sole surviving genus, Equus, had evolved by the early Pleistocene, order Perissodactyla † indicates extinct taxa
10.
Equus (genus)
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Equus is a genus of mammals in the family Equidae, which includes horses, asses, and zebras. Within Equidae, Equus is the only recognized extant genus, comprising seven living species, the term equine refers to any member of this genus, including horses. Like Equidae more broadly, Equus has numerous species known only from fossils. The genus most likely originated in North America and spread quickly to the Old World, Equines are odd-toed ungulates with slender legs, long heads, relatively long necks, manes and long tails. All species are herbivorous, and mostly grazers with simpler digestive systems than ruminants, while the domestic horse and donkey exist worldwide, wild equine populations are limited to Africa and Asia. In both systems, females take care of their offspring but males may play a role as well, Equines communicate with each other both visually and vocally. Human activities have threatened wild equine populations and out of the seven living species, only the plains zebra remains widespread and abundant. The word equus is Latin for horse, and is cognate with the Greek ἵππος, horse, and Mycenaean Greek i-qo /ikkʷos/, the genus Equus was first described by Carl Linnaeus in 1758. It is the only recognized extant genus in the family Equidae, the first equids were small, dog-sized mammals adapted for browsing on shrubs during the Eocene, around 54 million years ago. These animals had three toes on the feet and four on the front feet with small hooves in place of claws. Equids developed into larger, three-toed animals during the Oligocene and Miocene, from there, the tridactyl toes became progressively smaller through the Pleistocene until the emergence of the single-toed Equus. The genus Equus, which all extant equines, is believed to have evolved from Dinohippus. One of the oldest species is Equus simplicidens, described as zebra-like with a head shape. The oldest material to date was found in Idaho, USA, the genus appears to have spread quickly into the Old World, with the similarly aged E. livenzovensis documented from western Europe and Russia. Molecular phylogenies indicate that the most recent common ancestor of all modern equines lived ~5.6 mya, mitochondrial evidence supports the division of Equus species into non-caballoid and caballoids or true horses. Of the extant equine species, the lineage of the asses may have diverged first, zebras appear to be monophyletic and differentiated in Africa where they are endemic. Molecular dating indicates the caballoid lineage diverged from the non-caballoids 4 mya, genetic results suggest that all North American fossils of caballine equines, as well as South American fossils traditionally placed in the subgenus E. belong to E. ferus. Remains attributed to a variety of species and lumped together as New World stilt-legged horses probably all belong to a species that was endemic to North America
11.
Wild horse
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The wild horse is a species of the genus Equus, which includes as subspecies the modern domesticated horse as well as the undomesticated tarpan, now extinct, and the endangered Przewalskis horse. Przewalskis horse was saved from the brink of extinction and reintroduced successfully to the wild, the tarpan became extinct in the 19th century, though it was a possible ancestor of the domestic horse, and roamed the steppes of Eurasia at the time of domestication. However, other subspecies of Equus ferus may have existed and could have been the stock from which domesticated horses are descended, since the extinction of the tarpan, attempts have been made to reconstruct its phenotype, resulting in horse breeds such as the Konik and Heck horse. However, the makeup and foundation bloodstock of those breeds is substantially derived from domesticated horses. The term wild horse is used colloquially to refer to free-roaming herds of feral horses such as the mustang in the United States, the brumby in Australia. These feral horses are untamed members of the domestic horse subspecies, three survived into modern times, The domestic horse. Przewalskis horse, also known as the Mongolian wild horse or Takhi, is native to Central Asia, the latter two are the only never-domesticated wild groups that survived into historic times. However, other subspecies of Equus ferus may have existed and could have been the stock from which domesticated horses are descended. Przewalskis horse occupied the eastern Eurasian Steppes, perhaps from the Urals to Mongolia, Przewalskis horse is still found today, though it is an endangered species and for a time was considered extinct in the wild. Roughly 1500 Przewalskis horses are in zoos around the world, a small breeding population has been reintroduced in Mongolia. As of 2005, a venture between the Zoological Society of London and Mongolian scientists has resulted in a free-ranging population of 248 animals in the wild. However, the offspring of Przewalski and domestic horses are fertile, the horse family Equidae and the genus Equus evolved in North America, before the species moved into the Eastern Hemisphere. Currently, three subspecies that lived during recorded history are recognized. One subspecies is the domestic horse, as well as two wild subspecies, the recently extinct tarpan and the endangered Przewalskis horse. Genetically, the horse, E. f. ferus. The genetic variation within this clade shows only a regional variation. At present, the domesticated and wild horses are considered a single species, the wild tarpan subspecies is E. f. ferus, Przewalskis horse is E. f. przewalskii, and the domesticated horse is E. f. caballus. Horses that live in a state but have ancestors that have been domesticated are not truly wild horses
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Synonym (taxonomy)
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For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies. This name is no longer in use, it is now a synonym of the current scientific name which is Picea abies, unlike synonyms in other contexts, in taxonomy a synonym is not interchangeable with the name of which it is a synonym. In taxonomy, synonyms are not equals, but have a different status, for any taxon with a particular circumscription, position, and rank, only one scientific name is considered to be the correct one at any given time. A synonym cannot exist in isolation, it is always an alternative to a different scientific name, given that the correct name of a taxon depends on the taxonomic viewpoint used a name that is one taxonomists synonym may be another taxonomists correct name. Synonyms may arise whenever the same taxon is described and named more than once, independently. They may also arise when existing taxa are changed, as when two taxa are joined to one, a species is moved to a different genus. To the general user of scientific names, in such as agriculture, horticulture, ecology, general science. A synonym is a name that was used as the correct scientific name but which has been displaced by another scientific name. Thus Oxford Dictionaries Online defines the term as a name which has the same application as another. In handbooks and general texts, it is useful to have mentioned as such after the current scientific name. Synonyms used in this way may not always meet the strict definitions of the synonym in the formal rules of nomenclature which govern scientific names. Changes of scientific name have two causes, they may be taxonomic or nomenclatural, a name change may be caused by changes in the circumscription, position or rank of a taxon, representing a change in taxonomic, scientific insight. A name change may be due to purely nomenclatural reasons, that is, based on the rules of nomenclature, the earliest such name is called the senior synonym, while the later name is the junior synonym. One basic principle of zoological nomenclature is that the earliest correctly published name, synonyms are important because if the earliest name cannot be used, then the next available junior synonym must be used for the taxon. Objective synonyms refer to taxa with the type and same rank. For example, John Edward Gray published the name Antilocapra anteflexa in 1855 for a species of pronghorn, however, it is now commonly accepted that his specimen was an unusual individual of the species Antilocapra americana published by George Ord in 1815. Ords name thus takes precedence, with Antilocapra anteflexa being a subjective synonym. Objective synonyms are common at the level of genera, because for various reasons two genera may contain the type species, these are objective synonyms
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Matschie
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Paul Matschie was a German zoologist. He studied mathematics and natural sciences at the Universities of Halle and Berlin, in 1892 he was in charge of the department of mammals at the museum, later becoming a curator, and in 1902 attaining the title of professor. In 1924 he was appointed director at the museum. During the years 1891–1893, he described 11 new species of reptiles, a species of gecko, Hemidactylus matschiei, is named in his honor. Matschies tree-kangaroo and Matschies galago are two species of mammals which bear his name, die Megachiroptera des Berliner Museums für Naturkunde,1899. Die Fledermäuse des Berliner Museums für Naturkunde, etc.1899, die Säugetiere der von W. Kükenthal auf Halmahera, Batjan und Nord-Celebes gemachten Ausbeute by Paul Matschie and W G Kükenthal,1900. Le sanglier noir de lIturi Hylochoerus ituriensis,1906, mammalia, Aves, Reptilia, Amphibia, Pisces by Paul Matschie, et al. The eponym dictionary of mammals by Bo Beolens, Michael Watkins, Michael Grayson
14.
James Cossar Ewart
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James Cossar Ewart FRS FRSE was a Scottish zoologist. He is mainly remembered for his experiments with zebras, creating zebroid, zedonk, Zorse, zonkey and zebrule as new species. Ewart was born in Penicuik, Midlothian, Scotland, the son of John Ewart, a joiner and he studied medicine from 1871 to 1874 at the University of Edinburgh where he graduated MB ChB. Here he collaborated with Ray Lankester, later director of the Natural History Museum, in 1878 he returned to Scotland to take a post of Professor of Natural History at Aberdeen University from where he moved to Edinburgh University in 1882, staying in the post until 1927. In 1879 he was elected a Fellow of the Royal Society of Edinburgh and his proposers were Sir William Turner, William Rutherford, William Rutherford Sanders and John Chiene. He won the Societys Neill Prize for 1895-98 and served as their Vice-President 1907 to 1912 and he was elected a Fellow of the Royal Society in June,1893, having jointly delivered their Croonian Lecture in 1881. Among various other studies, he performed breeding experiments with horses and zebras, Ewart crossed a male zebra with a female pony to show that the theory of telegony inherited from the Greeks was unsound. Telegony held that a female with a history of mating with multiple males would pass on genetic qualities of all partners to her offspring. Ewart later bred the mare which had produced zebra-horse hybrids with a pony, ewarts goal was also to produce a draught animal for South African conditions, resistant to African diseases and more tractable than a mule. In 1883 he commissioned George Washington Browne to design a new house in Penicuik, finished in 1885. It is now the Craigiebield House Hotel and he married three times, his first wife being the sister of Edward Albert Sharpey-Schafer. The Penycuik Experiments Works by or about James Cossar Ewart at Internet Archive Index at NAHSTE Biography
15.
Tuvan language
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Tuvan, also known as Tuvinian, Tyvan or Tuvin, is a Turkic language spoken in the Republic of Tuva in south-central Siberia in Russia. The language has borrowed a number of roots from the Mongolian language, Tibetan. There are small groups of Tuvan people that speak distinct dialects of Tuvan in the Peoples Republic of China. While this history focuses on mostly the people of Tuva, many argue that language is inevitably intertwined with the socio-historical situation of a language itself. The earliest record of Tuvan is from the early 19th century by Wū lǐ yǎ sū tái zhì è, Klaproth 1823, Castrén 1857, the name Tuva goes back as early as the publication of the Secret History of the Mongols. The Tuva have also referred to as Soyons, Soyots or Uriankhais historically. The Tuvan people have ruled by China, Russia. Their most recent time of independence was from 1921-1944, when they were considered the Tuvan’s Peoples Republic, many sources say there has been extreme tension between the Soviet Union/Russian Federation government and leaders in the Tuvan nation since 1944, when Tuva lost its independence to the USSR. In 1990, violence broke out between Tuvans and the USSR government and they especially emphasized their want for independence in terms of their language and culture. The study demonstrates that the reason behind this was based on prejudice. The many minority ethnic and linguistic groups in Russia compete for resources and hold closely on to their individual identities, by emphasizing the importance of language. Since 2000, the Russian federation has been trying to reduce separatist tendencies of ethnic minorities in Russia, Tuvan is linguistically classified as a Northeastern or Siberian Turkic language, closely related to several other Siberian Turkic languages including Khakas and Altai languages. Its closest relative is the moribund Tofa, Tuvan, as spoken in Tuva, is principally divided into four dialect groups, Western, Central, Northeastern, Southeastern. Central, forms the basis of the language and includes Ovyur. The geographical centrality of this meant it was similar to the language spoken by most Tuvans. Western, can be found spoken near the course of the Khemchik River. It is influenced by the Altai language, Northeastern, also known as the Todzhi dialect, is spoken near the upper course of the Bii-Khem River. The speakers of this dialect utilize nasalization and it contains a large vocabulary related to hunting and reindeer breeding not found in the other dialects
16.
Subspecies
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In biological classification, subspecies is either a taxonomic rank subordinate to species, or a taxonomic unit in that rank. A subspecies cannot be recognized independently, a species will either be recognized as having no subspecies at all or at least two, in zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, in bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether to recognize a subspecies or not, the differences between subspecies are usually less distinct than the differences between species. In zoology, the International Code of Zoological Nomenclature accepts only one rank below that of species, other groupings, infrasubspecific entities do not have names regulated by the ICZN. Such forms have no official ICZN status, though they may be useful in describing altitudinal or geographical clines, pet breeds, transgenic animals, etc. While the scientific name of a species is a binomen, the name of a subspecies is a trinomen - a binomen followed by a subspecific name. A tigers binomen is Panthera tigris, so for a Sumatran tiger the trinomen is, for example, names published before 1992 in the rank of variety are taken to be names of subspecies. In botany, subspecies is one of many ranks below that of species, such as variety, subvariety, form, the subspecific name is preceded by subsp. or ssp. as Schoenoplectus californicus ssp. tatora. A botanical name consists of at most three parts, an infraspecific name includes the species binomial, and one infraspecific epithet, such as subspecies or variety. For example, Motacilla alba alba is the subspecies of the white wagtail. The subspecies name that repeats the name is referred to in botanical nomenclature as the subspecies autonym. When zoologists disagree over whether a population is a subspecies or a full species. A subspecies is a rank below species – the only recognized rank in the zoological code. Botanists and mycologists have the choice of ranks lower than subspecies, such as variety or form, in biological terms, rather than in relation to nomenclature, a polytypic species has two or more subspecies, races, or more generally speaking, populations that need a separate description. These are separate groups that are distinct from one another and do not generally interbreed. These subspecies, races, or populations, can be named as subspecies by zoologists, a monotypic species has no distinct population or races, or rather one race comprising the whole species. A taxonomist would not name a subspecies within such a species, monotypic species can occur in several ways, All members of the species are very similar and cannot be sensibly divided into biologically significant subcategories
17.
Steppe
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In South Africa they are referred to as Veld. The prairie is an example of a steppe, though it is not usually called such and it may be semi-desert, or covered with grass or shrubs or both, depending on the season and latitude. The term is used to denote the climate encountered in regions too dry to support a forest. The soil is typically of chernozem type, steppes are usually characterized by a semi-arid and continental climate. Extremes can be recorded in the summer of up to 45 °C and in winter, besides this huge difference between summer and winter, the differences between day and night are also very great. In the highlands of Mongolia,30 °C can be reached during the day with sub-zero °C readings at night, the mid-latitude steppes can be summarized by hot summers and cold winters, averaging 250–510 mm of precipitation per year. Precipitation level alone is not what defines a steppe climate, potential evapotranspiration must also be taken into account, the Eurasian Grass-Steppe of the temperate grasslands, savannas, and shrublands had a role in the spread of the horse, the wheel, and the Indo-European languages. The Indo-European expansion and diverse invasions of horse archer civilizations of the steppe eventually led to, the Pannonian Plain is another steppe region in eastern Europe, primarily Hungary. Another large steppe area is located in the central United States, western Canada, the shortgrass prairie steppe is the westernmost part of the Great Plains region. The Channeled Scablands in Southern British Columbia and Washington State is an example of a region in North America outside of the Great Plains. In South America, cold steppe can be found in Patagonia, relatively small steppe areas can be found in the interior of the South Island of New Zealand. In Asia, a subtropical steppe can be found in semi-arid lands that fringe the Thar Desert of the Indian subcontinent, in Australia, subtropical steppe can be found in a belt surrounding the most severe deserts of the continent and around the Musgrave Ranges. Ecology and Conservation of Steppe-land Birds by Manuel B. Morales, Santi Mañosa, Jordi Camprodón, international Symposium on Ecology and Conservation of steppe-land birds
18.
Extinct in the wild
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The tortoise was believed to be entirely extinct in the mid-20th century, until Hungarian malacologist József Vágvölgyi spotted Lonesome George on the Galapagos island of Pinta on 1 December 1971. Since then, Lonesome George has been a symbol for conservation efforts in general. With his death on 24 June 2012, the subspecies is believed to be extinct. With the discovery of 17 hybrid Pinta tortoises located at nearby Wolf Volcano a plan has made to attempt to breed the subspecies back into a pure state. Not all species that are extinct in the wild are rare, however, the ultimate purpose of preserving biodiversity is to maintain ecological function. When a species only in captivity, it is ecologically extinct. Reintroduction is the release of species into the wild, from captivity or relocated from other areas where the species survives. This may be an option for certain species that are endangered or extinct in the wild, while conservation efforts may preserve some of the genetics of a species, the species may never fully recover due to the loss of the natural memetics of the species
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Species reintroduction
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Species reintroduction is the deliberate release of a species into the wild, from captivity or other areas where the animal survives. A species that needs reintroduction is usually one whose existence has become threatened or endangered in the wild, however, reintroduction of a species can also be for pest control. For example, wolves being reintroduced to an area because of an overpopulation of elk or deer. Because reintroduction may involve returning native species to localities where they had been extirpated, Reintroduction has been practiced for many years. Reintroduction and translocation are both important tools for population and species management, translocation moves wild-caught animals from one natural location to another, while reintroduction moves captive-born animals into their natural historical range. Much of the research required to obtain reproduction will also be critical for reintroduction. More behavioral research to select the best candidates and prepare them for the different challenges that await them in nature will be essential also. Behaviorists will again play a role in post-release monitoring to determine the behavioral deficiencies that limit the success of reintroductions. There may be no other conservation action where the skills of behavioral researchers are more essential than reintroduction, in situ conservation means on site. In-situ conservation is the conservation of species diversity within normal and natural habitats, the challenge in using in-situ methods is to expand our vision of protected areas to include multiple use and extractive reserves to develop new models for conservation. In-Situ conservation uses innovative proposals such as damaged ecosystems to preserve rare, endangered, ex-situ conservation means literally, off-site conservation. It is the process of protecting an endangered species of plant or animal outside of its natural habitat, capturing and relocating part of a population from a threatened habitat and placing it in a new location where it may have a better chance of survival is one example. Ex-situ conservation should only be used when In-Situ conservation cannot, zoos are one of the most conventional methods of ex-situ conservation. Depending on their size and location, zoos receive between a few tens of thousands to several million visitors annually, zoos provide education to the public about the many endangered species and explain the factors contributing the threats they face in their native habitats. Through ex-situ conservation methods they provide protected specimens for breeding and reintroduction into the wild and it has been suggested that this method should be used only when necessary and when In-Situ conservation is not possible. Reintroduction biology is new and continues to be a work in progress, in other words, successful reintroduction programs should yield viable and self-sustainable populations on the long-term. The IUCN/SSC Re-introduction Specialist Group & Environment Agency, in their 2011 Global Re-introduction Perspectives,184 case studies were reported on a range of species which included invertebrates, fish, amphibians, reptiles, birds, mammals, and plants. Assessments from all of the studies included goals, success indicators, project summary, major difficulties faced, major lessons learned, the Siberian tiger population has rebounded from 40 individuals in the 1940s to around 500 in 2007
20.
Khustain Nuruu National Park
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Khustain Nuruu National Park, located in Töv Province, is a national park of Mongolia. It is also known as Hustai National Park, the Tuul River runs through the park. The Mongolian Government declared Hustai National Park as a Specially Protected Area in 1993, the HNP extends through the Khentii Mountains and includes the western edge of the Mongolian steppe at the boundaries of Altanbulag, Argalant and Bayankhangai Soums of Töv Province. The park is about 100 km from the city of Ulaanbaatar to the west. The HNP covers 50,600 ha land which is home to 459 species of plants,85 species of lichens,90 species of moss and 33 species of mushrooms. The 217 species of birds include golden eagle, lammergeier, great bustard, whooper swan, black stork, Daurian partridge, there are 16 species of fish,2 species of amphibians, and 385 species of insects. A new species of insect has been found in the Hustai. In 2002, the Man and the Biosphere Reserves organization of UNESCO certified the HNP as a member of the world biosphere network of natural reserves, the HNPT was enrolled as a member of IUCN in 2007. The HNP is one of the best-managed Specially Protected Areas in Mongolia and was the first park to be managed by a Non-governmental Organization specializing in nature, the park was managed by the Mongolian Association for the Conservation of Nature and the Environment during 1993-2003. A dedicated NGO, the Hustai National Park Trust, was established in 2003, the HNPT conducts operations in five main activity areas as follows, Conservation and protection of ecosystems and historical sites in the park. Reintroduction of the last species of wild horse – the Takhi –, Organization of international training courses and research. Development of the zone of the HNP
21.
Species
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In biology, a species is the basic unit of biological classification and a taxonomic rank. A species is defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is problematic, for example, with hybridisation, in a species complex of hundreds of similar microspecies, or in a ring species, the boundaries between closely related species become unclear. Other ways of defining species include similarity of DNA, morphology, all species are given a two-part name, a binomial. The first part of a binomial is the genus to which the species belongs, the second part is called the specific name or the specific epithet. For example, Boa constrictor is one of four species of the Boa genus, 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 that species could evolve given sufficient time, Charles Darwins 1859 book The Origin of Species explained how species could arise by natural selection. Genes can sometimes be exchanged between species by horizontal transfer, and species may become extinct for a variety of reasons. In his biology, Aristotle used the term γένος to mean a kind, such as a bird or fish, a kind was distinguished by its attributes, for instance, a bird has feathers, a beak, wings, a hard-shelled egg, and warm blood. A form was distinguished by being shared by all its members, Aristotle believed all kinds and forms to be distinct and unchanging. His approach remained influential until the Renaissance, when observers in the Early Modern period began to develop systems of organization for living things, they placed each kind of animal or plant into a context. Many of these early delineation schemes would now be considered whimsical, animals likewise that differ specifically preserve their distinct species permanently, one species never springs from the seed of another nor vice versa. In the 18th century, the Swedish scientist Carl Linnaeus classified organisms according to shared physical characteristics and he established the idea of a taxonomic hierarchy of classification based upon observable characteristics and intended to reflect natural relationships. At the time, however, it was widely believed that there was no organic connection between species, no matter how similar they appeared. However, whether or not it was supposed to be fixed, by the 19th century, naturalists understood that species could change form over time, and that the history of the planet provided enough time for major changes. Jean-Baptiste Lamarck, in his 1809 Zoological Philosophy, described the transmutation of species, proposing that a species could change over time, in 1859, Charles Darwin and Alfred Russel Wallace provided a compelling account of evolution and the formation of new species. Darwin argued that it was populations that evolved, not individuals and this required a new definition of species. Darwin concluded that species are what appear to be, ideas
22.
Nikolay Przhevalsky
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Nikolay Mikhaylovich Przhevalsky was a Russian geographer and a renowned explorer of Central and East Asia. Although he never reached his goal, the holy city of Lhasa in Tibet, he traveled through regions then unknown to the West, such as northern Tibet, Amdo. He contributed significantly to European knowledge of Central Asia and was the first known European to describe the only extant species of wild horse, Przhevalsky was born in Smolensk into a noble polonized Belarusian family, and studied there and at the military academy in St. Petersburg. In 1864, he became a teacher at the military school in Warsaw. In 1867, Przhevalsky successfully petitioned the Russian Geographical Society to be dispatched to Irkutsk and his intention was to explore the basin of the Ussuri River, a major tributary of the Amur on the Russian-Chinese frontier. This was his first expedition of importance and it lasted two years, after which Przhevalsky published a diary of the expedition under the title, Travels in the Ussuri Region, 1867-69. In the following years he made four journeys to Central Asia, 1870–1873 from Kyakhta he crossed the Gobi Desert to Beijing then explored the upper Yangtze, and in 1872 crossed into Tibet. He surveyed over 7,000 sq mi, collected and brought back with him 5000 plants,1000 birds and 3000 insect species, as well as 70 reptiles, during his expedition, the Dungan Revolt was raging in China. The Russian newspaper Golos Prikazchika called the one of the most daring of our time. 1876–1877 traveling through East Turkestan through the Tian Shan, he visited what he believed to be Qinghai Lake, which had reportedly not been visited by any European since Marco Polo. The expedition consisted of ten men, twenty-four camels, four horses, three tonnes of baggage and a budget of 25,000 rubles, but the expedition was beset by disease, 1879–1880 via Hami and through the Qaidam Basin to Qinghai Lake. The expedition then returned to Qinghai Lake and moved westwards to Hotan, among other things, he reported on the wild population of Bactrian camels as well as the Przewalskis horse and Przewalskis gazelle, named after him. The Royal Geographical Society awarded him their Founders Gold Medal in 1879 for his work, Przhevalsky died of typhus not long before the beginning of his fifth journey, at Karakol on the shore of Issyk Kul in present-day Kyrgyzstan. He contracted typhoid from the Chu River, which was acknowledged as being infected with the disease, the Tsar immediately changed the name of the town to Przhevalsk. There are monuments to him, and a museum about his life and work, there, less than a year after his premature death, Mikhail Pevtsov succeeded Przhevalsky at the head of his expedition into the depths of Central Asia. Przhevalskys work was continued by his young disciple Pyotr Kozlov. There is another named after Przhevalsky, he had lived in a small village called Sloboda, Smolensk Oblast, Russia from 1881-7. The village was renamed after him in 1964 and is now called Przhevalskoye, there is a memorial complex there that includes the old and new houses of Nikolay Przhevalsky, his bust, pond, garden, birch alleys, and khatka
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Mustang
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The mustang is a free-roaming horse of the American west that first descended from horses brought to the Americas by the Spanish. Mustangs are often referred to as wild horses, but because they are descended from once-domesticated horses, the original mustangs were Colonial Spanish horses, but many other breeds and types of horses contributed to the modern mustang, resulting in varying phenotypes. In the 21st century, mustang herds vary in the degree to which they can be traced to original Iberian horses, the free-roaming mustang population is managed and protected by the Bureau of Land Management. Advocates for mustangs also express concerns that the animals may be sold for horse meat, additional debate centers on the question of whether mustangs—and horses in general—are a native species or an introduced invasive species. Many methods of management are used, including the adoption by private individuals of horses taken from the range. Mustangs are often referred to as wild horses, but since all free-roaming horses now in the Americas descended from horses that were once domesticated, unlike Przewalskis horse, the only extant wild horse, the mustang descended from domesticated horses. According to the Oxford English Dictionary, the English word mustang comes from two essentially synonymous Spanish words, mestengo and mostrenco, both words referred to horses and cattle defined as wild, having no master. Mesteño was derived from mesta, associations of graziers, and one of their jobs was to deal with strayed cattle and it has no connection with the Mustang region of Tibet. They caught the horses that roamed the Great Plains and the San Joaquin Valley of California, the original mustangs were Colonial Spanish horses, but many other breeds and types of horses contributed to the modern mustang, resulting in varying phenotypes. Mustangs of all types are described as surefooted and having good endurance. They may be of any coat color, some herds show the signs of the introduction of Thoroughbred or other light racehorse-types into herds, a process that also led in part to the creation of the American Quarter Horse. The now-defunct American Mustang Association developed a standard for those mustangs that carry morphological traits associated with the early Spanish horses. These include a body with a clean, refined head with wide forehead. The facial profile may be straight or slightly convex, withers are moderate in height and the shoulder is to be long and sloping. The standard considers a short back, deep girth and muscular coupling over the loins as desirable. The croup is rounded, neither too flat nor goose-rumped, the legs are to be straight and sound. Dun color and primitive markings are common amongst horses of Spanish type. Height varies across the west, but most are small, generally 14 to 15 hands, the mustang of the modern west has several different breeding populations today which are genetically isolated from one another and thus have distinct traits traceable to particular herds
24.
Brumby
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A Brumby is a free-roaming feral horse in Australia. Although found in areas around the country, the best-known Brumbies are found in the Australian Alps region in south-eastern Australia. Today, most of them are found in the Northern Territory, a group of Brumbies is known as a mob or band. Today they live in places, including some National Parks. Occasionally they are mustered and domesticated for use as campdrafters, working horses on farms or stations. The term Brumby refers to a horse in Australia. Its first recorded use in print is in the Australasian magazine from Melbourne in 1880, an Aboriginal word baroomby meaning wild in the language of the Pitjara Indigenous Australians on the Warrego and Nogoa Rivers in southern Queensland. A letter in 1896 to the Sydney Morning Herald says that baroombie is the word for horse among the Aboriginal people of the Balonne, Nebine, Warrego and Bulloo Rivers. Baramba, which was the name of a creek and station in the Queensland district of Burnett, established in the 1840s and later abandoned and it has also been suggested that the name derives from the Irish word bromach or bromaigh. Horses first arrived in Australia in 1788 with the First Fleet and they were imported for farm and utility work, recreational riding and racing were not major activities. By 1800, only about 200 horses are thought to have reached Australia, Horse racing became popular around 1810, resulting in an influx of Thoroughbred imports, mostly from England. Roughly 3,500 horses were living in Australia by 1820, Horses were likely confined primarily to the Sydney region until the early 19th century, when settlers first crossed the Blue Mountains and opened expansion inland. Horses were required for travel, and for cattle and sheep droving as the industry grew. The first report of a horse is in 1804. After World War I, the demand for horses by defence forces declined with the growth in mechanization, throughout the 20th century, the replacement of horses with machines in farming led to further falls in demand, and therefore may have also contributed to increases in feral populations. Currently, Australia has at least 400,000 horses roaming the continent and it is also estimated that, during non-drought periods, the feral horse population increases at a rate of 20 percent per year. Drought conditions and brushfires are natural threats, despite population numbers, feral horses are generally considered to be a moderate pest. Where they are allowed to damage vegetation and cause erosion, the impact on the environment can be detrimental, however, because they also have cultural and potential economic value, the management of Brumbies presents a complex issue
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Feral horse
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A feral horse is a free-roaming horse of domesticated ancestry. As such, a horse is not a wild animal in the sense of an animal without domesticated ancestors. However, some populations of horses are managed as wildlife. Feral horses are descended from horses that strayed, escaped, or were deliberately released into the wild and remained to survive. Away from humans, over time, these patterns of behavior revert to behavior more closely resembling that of wild horses. Some horses that live in a condition but may be occasionally handled or managed by humans. Feral horses live in groups called a band, herd, harem, Feral horse herds, like those of wild horses, are usually made up of small bands led by a dominant mare, containing additional mares, their foals, and immature horses of both sexes. There is usually one herd stallion, though occasionally a few less-dominant males may remain with the group, horse herds in the wild are best described as groups of several small bands who share a common territory. Bands are usually on the side, as few as three to five animals, but sometimes over a dozen. The makeup of bands shifts over time as animals are driven out of the band they were born into and join other bands. However, in a closed ecosystem, to maintain genetic diversity. Horses which live in a state but have ancestors who have been domesticated are not true wild horses. The best-known examples of horses are the wild horses of the American west. When Europeans reintroduced the horse to the Americas, beginning with the arrival of the Conquistadors in the 15th century, Australia has the largest population of feral horses in the world, with in excess of 400,000 feral horses. The Australian name equivalent to the Mustang is the Brumby, feral descendants of horses brought to Australia by English settlers, in Portugal, there are two populations of free-ranging feral horses, known as Sorraia in the southern plains and Garrano in the northern mountain chains. Some of these horses are said to be the descendants of horses who managed to swim to land when they were shipwrecked, others may have been deliberately brought to various islands by settlers and either left to reproduce freely or abandoned when assorted human settlements failed. More than 400 feral horses live in the foothills of Cincar mountain and these animals, which descend from horses set free by their owners in the 1950s, enjoy a protected status since 2010. In North America, feral horses are descendants of horses that were domesticated in Europe, although many ancient, while there are similarities shown in certain genes of both modern and fossil North American horses, they are not believed to be members of the same species
26.
Domestication
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Charles Darwin recognized the small number of traits that made domestic species different from their wild ancestors. There is a difference between domestic and wild populations. The dog was the first domesticated vertebrate, and was established across Eurasia before the end of the Late Pleistocene era, well before cultivation and before the domestication of other animals. Among birds, the domestic species today is the chicken, important for meat and eggs, though economically valuable poultry include the turkey, guineafowl. Birds are also kept as cagebirds, from songbirds to parrots. The longest established invertebrate domesticates are the bee and the silkworm. Terrestrial snails are raised for food, while species from several phyla are kept for research, the domestication of plants began at least 12,000 years ago with cereals in the Middle East, and the bottle gourd in Asia. Agriculture developed in at least 11 different centres around the world, domesticating different crops, Domestication means belonging to the house. Animals domesticated for home companionship are usually called pets, while those domesticated for food or work are called livestock or farm animals and this definition recognizes both the biological and the cultural components of the domestication process and the impacts on both humans and the domesticated animals and plants. All past definitions of domestication have included a relationship between humans with plants and animals, but their differences lay in who was considered as the partner in the relationship. This new definition recognizes a mutualistic relationship in both partners gain benefits. Domestication has vastly enhanced the reproductive output of crop plants, livestock, Domestication syndrome is the suite of phenotypic traits arising during domestication that distinguish crops from their wild ancestors. The domestication of animals is the relationship between animals with the humans who have influence on their care and reproduction. Charles Darwin recognized the small number of traits that made domestic species different from their wild ancestors, there is a genetic difference between domestic and wild populations. Domestication should not be confused with taming, the beginnings of animal domestication involved a protracted coevolutionary process with multiple stages along different pathways. The dog was the first domesticant, and was established across Eurasia before the end of the Late Pleistocene era, well before cultivation and before the domestication of other animals. Humans did not intend to domesticate animals from, or at least they did not envision a domesticated animal resulting from, in both of these cases, humans became entangled with these species as the relationship between them, and the human role in their survival and reproduction, intensified. Although the directed pathway proceeded from capture to taming, the two pathways are not as goal-oriented and archaeological records suggest that they take place over much longer time frames
27.
Horse
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The horse is one of two extant subspecies of Equus ferus. It is an ungulate mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, Eohippus, into the large, humans began to domesticate horses around 4000 BC, and their domestication is believed to have been widespread by 3000 BC. Horses in the subspecies caballus are domesticated, although some domesticated populations live in the wild as feral horses. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior. Horses anatomy enables them to use of speed to escape predators and they have a well-developed sense of balance. Related to this need to flee from predators in the wild is an unusual trait, female horses, called mares, carry their young for approximately 11 months, and a young horse, called a foal, can stand and run shortly following birth. Most domesticated horses begin training under saddle or in harness between the ages of two and four and they reach full adult development by age five, and have an average lifespan of between 25 and 30 years. There are more than 300 breeds of horse in the world today, horses were historically used in warfare, from which a wide variety of riding and driving techniques developed, using many different styles of equipment and methods of control. Many products are derived from horses, including meat, milk, hide, hair, bone, humans provide domesticated horses with food, water and shelter, as well as attention from specialists such as veterinarians and farriers. Specific terms and specialized language are used to describe equine anatomy, different life stages, colors, depending on breed, management and environment, the modern domestic horse has a life expectancy of 25 to 30 years. Uncommonly, a few animals live into their 40s and, occasionally, the oldest verifiable record was Old Billy, a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, who had listed in Guinness World Records as the worlds oldest living pony. The exception is in endurance riding, where the age to compete is based on the animals actual calendar age. The following terminology is used to describe horses of various ages, Colt, a common terminology error is to call any young horse a colt, when the term actually only refers to young male horses. Filly, A female horse under the age of four, foal, A horse of either sex less than one year old. A nursing foal is sometimes called a suckling and a foal that has been weaned is called a weanling, most domesticated foals are weaned at five to seven months of age, although foals can be weaned at four months with no adverse physical effects. Gelding, A castrated male horse of any age, mare, A female horse four years old and older
28.
Tarpan
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The tarpan, also known as Eurasian wild horse, is an extinct subspecies of wild horse. Beginning in the 1930s, several attempts were made to horses that looked like tarpans through selective breeding. Some of these horses are now promoted as tarpans. However, those who study the history of the ancient wild horse assert that the word tarpan only describes the wild horse. The name tarpan or tarpani is from a Turkic language name meaning wild horse, the Tatars and the Cossacks distinguished the wild horse from the feral horse, the latter was called Takja or Muzin. The tarpan was first described by Johann Friedrich Gmelin in 1774, he had seen the animals in 1769 in the district of Bobrov, in 1784 Pieter Boddaert named the species Equus ferus, referring to Gmelins description. Unaware of Boddaerts name, Otto Antonius published the name Equus gmelini in 1912, since Antonius name refers to the same description as Boddaerts it is a junior objective synonym. It is now thought that the horse, named Equus caballus by Carl Linnaeus in 1758, is descended from the tarpan, indeed. By a strict application of the rules of the International Code of Zoological Nomenclature, however, biologists have generally ignored the letter of the rule and used E. ferus for the tarpan to avoid confusion with the domesticated subspecies. Most studies have been based on only two preserved specimens and research to date has not positively linked the tarpan to Pleistocene or Holocene-era animals. Traditionally, two subtypes have been proposed, the forest tarpan and steppe tarpan, although there seem to be only minor differences in type. The general view is there was only one subspecies, the tarpan. It is considered likely that at least some wild horses had a dun coat, some theorize that the tarpan had a standing mane because all other extant wild equines display this feature, and falling manes are considered an indication of domestication. However, historical accounts do not unambiguously describe a standing mane in European wild horses and this feature is advantageous in regions with much rainfall because it diverts rain and snow from the neck and face and prevents a loss of heat, as much as a bushy tail. Mummified Siberian wild horses display a hanging mane as well, the appearance of European wild horses is reconstructed with genetic, osteologic and historic data. One genetic study suggests that bay was the predominant color in European wild horses, during the Mesolithic, a gene coding a black coat color appeared on the Iberian peninsula. This color spread east but was less common than bay in the investigated sample, bay in combination with dun results in the bay dun color seen in Przewalskis horses, black with dun creates the grullo coat. A loss of dun dilution may have been advantageous in more forested western European landscapes, pangaré or mealy coloration, a characteristic of other wild equines, might have been present in at least some tarpans, as historic accounts report a light-colored belly
29.
Zebra
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Zebras are several species of African equids united by their distinctive black and white striped coats. Their stripes come in different patterns, unique to each individual and they are generally social animals that live in small harems to large herds. Unlike their closest relatives, horses and donkeys, zebras have never truly domesticated. There are three species of zebras, the zebra, the Grévys zebra and the mountain zebra. The plains zebra and the mountain zebra belong to the subgenus Hippotigris, the latter resembles an ass, to which it is closely related, while the former two are more horse-like. All three belong to the genus Equus, along with other living equids, the unique stripes of zebras make them one of the animals most familiar to people. They occur in a variety of habitats, such as grasslands, savannas, woodlands, thorny scrublands, mountains, however, various anthropogenic factors have had a severe impact on zebra populations, in particular hunting for skins and habitat destruction. Grévys zebra and the mountain zebra are endangered, the name zebra in English dates back to c. 1600, from Italian zebra, perhaps from Portuguese, which in turn is said to be Congolese, the Encarta Dictionary says its ultimate origin is uncertain, but perhaps it may come from Latin equiferus meaning wild horse, from equus and ferus. The pronunciation with an initial vowel remains standard in the United States. Zebras evolved among the Old World horses within the last 4 million years and it has been suggested that zebras are polyphyletic and that striped equids evolved more than once. Extensive stripes are posited to have been of use to equids that live in low densities in deserts or ones that live in colder climates with shaggy coats. However, molecular evidence supports zebras as a monophyletic lineage, collectively, two of the species have eight subspecies. Zebra populations are diverse, and the relationships between, and the status of, several of the subspecies are not well known. It, or particular subspecies of it, have also known as the common zebra, the dauw, Burchells zebra, Chapmans zebra, Wahlbergs zebra, Selous zebra, Grants zebra, Boehms zebra. The mountain zebra of southwest Africa tends to have a coat with a white belly. It has two subspecies and is classified as vulnerable, Grévys zebra is the largest type, with a long, narrow head, making it appear rather mule-like. It is an inhabitant of the grasslands of Ethiopia and northern Kenya
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African wild ass
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The African wild ass or African wild donkey is a wild member of the horse family, Equidae. This species is believed to be the ancestor of the domestic donkey and they live in the deserts and other arid areas of the Horn of Africa, in Eritrea, Ethiopia and Somalia. It formerly had a range north and west into Sudan, Egypt. About 570 individuals exist in the wild, different authors consider the African wild ass and the domesticated donkey one or two species, either view is technically legitimate, though the former is phylogenetically more accurate. The species name for the African wild ass is given as asinus, from the domestic donkey, whose specific name is older. But this usage is erroneous since the International Commission on Zoological Nomenclature has conserved the name Equus africanus in Opinion 2027 and this was done to prevent the confusing situation of the phylogenetic ancestor being taxonomically included in its descendant. Thus, if one species is recognized, the scientific name of the donkey is E. africanus asinus. The first published name for the African wild ass, Asinus africanus, the first available name thus becomes Asinus africanus von Heuglin & Fitzinger,1866. A lectotype is designated, a skull of a female collected by von Heuglin near Atbarah River, Sudan. The two subspecies recognized are the Nubian wild ass Equus africanus africanus, and the Somali wild ass Equus africanus somaliensis, the African wild ass is 2 metres long and 1.25 to 1.45 metres tall at the shoulders, with a tail 30–50 centimetres long. The short, smooth coat is a grey to fawn colour, fading quickly to white on the undersides. There is a slender, dark stripe in all subspecies, while in the Nubian wild ass, as well as the domestic donkey. The legs of the Somali wild ass are horizontally striped with black, on the nape of the neck, there is a stiff, upright mane, the hairs of which are tipped with black. The ears are large with black margins, the tail terminates with a black brush. The hooves are slender and approximately of the diameter as the legs, African wild asses are well suited to life in a desert or semidesert environment. They have tough digestive systems, which can break down desert vegetation and they can also go without water for a fairly long time. Their large ears give them an excellent sense of hearing and help in cooling, because of the sparse vegetation in their environment wild asses live somewhat separated from each other, unlike the tightly grouped herds of wild horses. They have very loud voices, which can be heard for over 3 km, the African wild ass is primarily active in the cooler hours between late afternoon and early morning, seeking shade and shelter amongst the rocky hills during the day
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Onager
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The onager, also known as hemione or Asiatic wild ass, is a species of the family Equidae native to Asia. A member of the subgenus Asinus, the onager was described, five subspecies have been recognized, one of which is extinct. The Asiatic wild ass is larger than African wild ass at about 290 kg and 2.1 m and they are reddish-brown or yellowish-brown in color and have broad dorsal stripe on the middle of the back. Unlike most horses and donkeys, onagers have never been domesticated and they are among the fastest mammals, as they can run as fast as 64 km/h to 70 km/h. The onager is closely related to the African wild ass, as both shared the same ancestor. The kiang, formerly considered a subspecies of Equus hemionus, diverged from the Asiatic wild ass and has acknowledged as a distinct species. The onager formerly had a range from southwest and central to northern Asian countries, such as Israel, Saudi Arabia, Iraq, Syria, Afghanistan, Russia. During early 20th century, the species lost most of its ranges in the Middle East and Eastern Asia. Today, onagers live in deserts and other regions of Iran, Pakistan, India, and Mongolia, including in Central Asian hot and cold deserts of Kazakhstan, Uzbekistan, Turkmenistan. Other than deserts, it lives in grasslands, plains, steppes, like many other large grazing animals, the onagers range has contracted greatly under the pressures of poaching and habitat loss. Previously listed as Endangered, onagers have been classified as Near Threatened by IUCN in 2015, of the five subspecies, one is extinct, two are endangered, and two are near threatened. Persian onagers are currently being reintroduced in the Middle East as replacement for the extinct Syrian wild ass in the Arabian Peninsula, Israel, the specific name is Ancient Greek ἡμίονος, from ἡμι-, half, and ὄνος, donkey, thus, half-donkey or mule. In Persian the archaic word gur preserves the second syllable of the common Indo-European term that includes ona/ono and ger/gur. The species was known as Asian wild ass, in which case the term onager was reserved for the E. h. onager subspecies. Until this day, the share the same name, onager. The onager is a member of the Subgenus Asinus, belonging to the genus Equus and is classified under the family Equidae, the species was described and given its binomial name Equus hemionus by German zoologist Peter Simon Pallas in 1775. The Asiatic wild ass, among Old World equids, existed for more than 4 million years, the oldest divergence of Equus was the onager followed by the zebras and onwards. Widely five recognized subspecies of the include, A sixth possible subspecies, the Gobi khulan has been proposed
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Mongolian wild ass
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The Mongolian wild ass, also known as Mongolian khulan is the nominate subspecies of the onager. It is found in Mongolia and northern China, and was found in eastern Kazakhstan. Previously in 2003, there were a population of less than 20,000 individuals. In 2009, the Mongolian wild ass population had decreased to 14,000 total individuals, in 2015, the Mongolian wild ass are listed as Near Threatened by the IUCN and it is also estimated that there are 23,000 mature individuals in total. The Mongolian wild ass may be synonymous with the possible proposed separate subspecies, the Mongolian wild ass, like most Asiatic wild asses, lives in deserts, cold deserts, steppes, shrublands and mountains. The Gobi Desert is the main stronghold. It may also be found at the Altai Mountains, the Mongolian wild ass is the most widespread subspecies, although despite that, the subspecies lost about 50% of its former distribution range in Mongolia in the past 70 years. Its distribution range then dramatically reduced during the 1990s, a 1994–1997 survey estimated its population size at 33,000 to 63,000 individuals over a continuous distribution range encompassing all of southern Mongolia. In 2003, a new survey found approximately 20,000 individuals over an area of 177,563 square kilometres in southern Mongolia, the species had decreased to 14,000 individuals in 2009. The population estimates of the Mongolian population should be treated with due to a lack of proven survey protocols. The Mongolian wild ass are herbivorous mammals and they feed on grasses, herbs and vegetation. They also feed on shrubs and trees in drier habitats, during spring and summer in Mongolia, the succulent plants of the Zygophyllaceae family form an important component of the diet of the Mongolian wild ass. Mongolian khulans are known to dig holes at dry river beds, watering holes dug by khulans are also used by other species as well as by humans to access to water. The Mongolian wild ass population is declining due to poaching and competition from grazing livestock, the conservation status of the species is evaluated as endangered. The Mongolian khulan are threatened by predators such as gray wolves, dholes. Poaching for meat appears to be a problem in Mongolia. For some parts of the population, wild ass and other wildlife meat seems to provide a substitute or even a cheap alternative to meat from domestic animals. In 2005, a survey based on questionnaires, suggested that as many as 4,500 wild asses, about 20% of the whole population
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Kiang
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The kiang is the largest of the wild asses. It is native to the Tibetan Plateau, where it inhabits montane and alpine grasslands and its current range is restricted to Ladakh in Jammu and Kashmir, plains of the Tibetan plateau and northern Nepal along the Tibetan border. Other common names for species include Tibetan wild ass, khyang. The kiang is closely related to the onager, and in some classifications it is considered a subspecies, molecular studies, however, indicate that it is a distinct species. Kiangs can crossbreed with onagers, horses, donkeys, and Burchells zebras in captivity, although, like mules, the kiang is the largest of the wild asses, with an average shoulder height of 13.3 hands. They range from 132 to 142 cm high at the shoulder, with a body 182 to 214 cm long, kiangs have only slight sexual dimorphism, with the males weighing from 350 to 400 kg, while females weigh 250 to 300 kg. They have a head, with a blunt muzzle and a convex nose. The mane is upright and relatively short, the coat is a rich chestnut colour, darker brown in winter and a sleek reddish brown in late summer, when the animal moults its woolly fur. The summer coat is 1.5 cm long and the coat is double that length. The legs, underparts, end of the muzzle, and the inside of the ears are all white, a broad, dark chocolate-coloured dorsal stripe extends from the mane to the end of the tail, which ends in a tuft of blackish brown hairs. Kiangs are found on the Tibetan Plateau, between the Himalayas in the south and the Kunlun Mountains in the north. This restricts them almost entirely to China, but small numbers are found across the borders in the Ladakh and Sikkim regions of India, the western kiang is slightly smaller than the eastern and also has a darker coat. However, no genetic information confirms the validity of the three subspecies, which may represent a cline, with gradual variation between the three forms. Kiangs inhabit alpine meadows and steppe country between 2,700 and 5,300 m elevation and they prefer relatively flat plateaus, wide valleys, and low hills, dominated by grasses, sedges, and smaller amounts of other low-lying vegetation. This open terrain, in addition to supplying them with suitable forage absent in the arid regions of central Asia, may make it easier for them to detect. Like all equids, kiangs are herbivores, feeding on grasses and sedges, especially Stipa, but also including other plants such as bog sedges, true sedges. When little grass is available, such as during winter or in the more arid margins of their habitat, they have been observed eating shrubs, herbs. Their only real predator other than humans is the wolf, kiangs defend themselves by forming a circle, and with heads down, kick out violently
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DNA
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Deoxyribonucleic acid is a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and RNA are nucleic acids, alongside proteins, lipids and complex carbohydrates, most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix. The two DNA strands are termed polynucleotides since they are composed of simpler units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases—cytosine, guanine, adenine, or thymine —a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two polynucleotide strands are bound together, according to base pairing rules, with hydrogen bonds to make double-stranded DNA. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037, in comparison the total mass of the biosphere has been estimated to be as much as 4 trillion tons of carbon. The DNA backbone is resistant to cleavage, and both strands of the double-stranded structure store the same biological information and this information is replicated as and when the two strands separate. A large part of DNA is non-coding, meaning that these sections do not serve as patterns for protein sequences, the two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases and it is the sequence of these four nucleobases along the backbone that encodes biological information. RNA strands are created using DNA strands as a template in a process called transcription, under the genetic code, these RNA strands are translated to specify the sequence of amino acids within proteins in a process called translation. Within eukaryotic cells DNA is organized into structures called chromosomes. During cell division these chromosomes are duplicated in the process of DNA replication, eukaryotic organisms store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast prokaryotes store their DNA only in the cytoplasm, within the eukaryotic chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed, DNA was first isolated by Friedrich Miescher in 1869. DNA is used by researchers as a tool to explore physical laws and theories, such as the ergodic theorem. The unique material properties of DNA have made it an attractive molecule for material scientists and engineers interested in micro-, among notable advances in this field are DNA origami and DNA-based hybrid materials. DNA is a polymer made from repeating units called nucleotides
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Genetic divergence
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The genetic differences among divergent populations can involve silent mutations or give rise to significant morphological and/or physiological changes. Genetic divergence will always accompany reproductive isolation, either due to novel adaptations via selection and/or due to genetic drift, on a molecular genetics level, genetic divergence is due to changes in a small number of genes in a species, resulting in speciation. Consequently, they could not reproduce and pass the mutation on to further generations, hence, it is more likely that divergence, and subsequently reproductive isolation, are the outcome of multiple small mutations over evolutionary time
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Ancient DNA
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Ancient DNA is DNA isolated from ancient specimens. It can be loosely described as any DNA recovered from biological samples that have not been preserved specifically for later DNA analyses. Unlike modern genetic analyses, ancient DNA studies are characterised by low-quality DNA and this places limits on what analyses can achieve. Allentoft et al. tried to calculate this limit by studying the decay of mitochondrial, the DNA degrades in an exponential decay process. According to their model, mitochondrial DNA is degraded to a length of 1 base pair after 6,830,000 years at −5 °C. The decay kinetics have been measured by accelerated aging experiments further displaying the influence of storage temperature. Nuclear DNA degrades at least twice as fast as mtDNA, as such, early studies that reported recovery of much older DNA, for example from Cretaceous dinosaur remains, may have stemmed from contamination of the sample. The laborious processes that were required at that time to sequence such DNA were an effective brake on the development of the field of ancient DNA, however, with the development of the Polymerase Chain Reaction in the late 1980s, the field began to progress rapidly. Double primer PCR amplification of aDNA can produce highly skewed and non-authentic sequence artifacts, multiple primer, nested PCR strategy was used to overcome those shortcomings. Single primer extension amplification was introduced in 2007 to address postmortem DNA modification damage, ADNA may contain a large number of postmortem mutations, increasing with time. Some regions of polynucleotide are more susceptible to degradation, so sequence data can bypass statistical filters used to check the validity of data. Due to sequencing errors, great caution should be applied to interpretation of population size, substitutions resulting from deamination cytosine residues are vastly over-represented in the ancient DNA sequences. Miscoding of C to T and G to A accounts for the majority of errors, another problem with ancient DNA samples is contamination by modern human DNA and by microbial DNA. The post-PCR era heralded a wave of publications as numerous groups tried their hands at aDNA. The majority of claims were based on the retrieval of DNA from organisms preserved in amber. Insects such as bees, termites, and wood gnats, as well as plant. Still older sources of Lebanese amber-encased weevils, dating to within the Cretaceous epoch, DNA retrieval was not limited to amber. Several sediment-preserved plant remains dating to the Miocene were successfully investigated, when in 1995 two further studies reported dinosaur DNA sequences extracted from a Cretaceous egg, it seemed that the field would revolutionize knowledge of the Earths evolutionary past
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Mitochondrial DNA
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Mitochondrial DNA is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate. Mitochondrial DNA is only a portion of the DNA in a eukaryotic cell, most of the DNA can be found in the cell nucleus and, in plants and algae. In humans, the 16,569 base pairs of mitochondrial DNA encode for only 37 genes, human mitochondrial DNA was the first significant part of the human genome to be sequenced. In most species, including humans, mtDNA is inherited solely from the mother, since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and this theory is called the endosymbiotic theory. Each mitochondrion is estimated to contain 2–10 mtDNA copies, the reasons why mitochondria have retained some genes are debated. Recent analysis of a range of mtDNA genomes suggests that both these features may dictate mitochondrial gene retention. In most multicellular organisms, mtDNA is inherited from the mother, mechanisms for this include simple dilution, degradation of sperm mtDNA in the male genital tract, in the fertilized egg, and, at least in a few organisms, failure of sperm mtDNA to enter the egg. Whatever the mechanism, this single parent pattern of inheritance is found in most animals, most plants. In sexual reproduction, mitochondria are inherited exclusively from the mother. Also, most mitochondria are present at the base of the sperms tail, in 1999 it was reported that paternal sperm mitochondria are marked with ubiquitin to select them for later destruction inside the embryo. Some in vitro techniques, particularly injecting a sperm into an oocyte. The fact that mitochondrial DNA is maternally inherited enables researchers to trace maternal lineage far back in time. This is usually accomplished on human mitochondrial DNA by sequencing the hypervariable control regions, hVR1, for example, consists of about 440 base pairs. These 440 base pairs are then compared to the regions of other individuals to determine maternal lineage. Most often, the comparison is made to the revised Cambridge Reference Sequence, vilà et al. have published studies tracing the matrilineal descent of domestic dogs to wolves. The concept of the Mitochondrial Eve is based on the type of analysis. MtDNA is highly conserved, and its relatively slow mutation rates make it useful for studying the evolutionary relationships—phylogeny—of organisms, biologists can determine and then compare mtDNA sequences among different species and use the comparisons to build an evolutionary tree for the species examined
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Feral animal
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A feral animal is an animal living in the wild but descended from domesticated individuals. As with a species, the introduction of feral animals or plants to non-native regions may disrupt ecosystems and has, in some cases. Other definitions define a feral animal as one that has changed from being domesticated to being wild, natural, some common examples of animals with feral populations are horses, dogs, goats, cats, and pigs. Wild species naturalized into a new territory are not normally considered feral animals, domesticated plants that revert to wild are referred to as escaped, introduced, naturalized, or sometimes as feral crops. Individual plants are known as volunteers, large numbers of escaped plants may become a noxious weed. The adaptive and ecological variables seen in plants that go wild closely resemble those of animals, the unintended presence of genetically modified crop plants or of the modified traits in other plants as a result of cross-breeding is known as adventitious presence. Certain familiar animals go feral easily and successfully, while others are less inclined to wander. Some species will detach readily from humans and pursue their own devices, others depart and are gone, seeking out new territory or range to exploit and displaying active invasiveness. Whether they leave readily and venture far, the criterion for success is longevity. Persistence depends on their ability to establish themselves and reproduce reliably in the new environment, neither the duration nor the intensity with which a species has been domesticated offers a useful correlation with its feral potential. The cat returns readily to a state if it has not been socialized when young. These cats, especially if left to proliferate, are considered to be pests in both rural and urban areas, and may be blamed for devastating the bird, reptile. A local population of cats living in an urban area. As feral cats multiply quickly, it is difficult to control their populations, animal shelters attempt to adopt out feral cats, especially kittens, but often are overwhelmed with sheer numbers and euthanasia is used. In rural areas, excessive numbers of cats are often shot. More recently, the method has been used in many locations as an alternate means of managing the feral cat population. The dog has some difficulty reverting into a feral state, not as efficient in predation like their wolf ancestors or even their big cat rivals, The goat is one of the oldest domesticated creatures, yet readily goes feral and does quite well on its own. The dromedary camel, which has been domesticated for well over 3,000 years, a substantial population of feral dromedaries, descended from pack animals that escaped in the 19th and early 20th centuries, thrives in the Australian interior today
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Karyotype
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A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryotic cell. The term is used for the complete set of chromosomes in a species or in an individual organism. Karyotypes describe the chromosome count of an organism and what these chromosomes look like under a light microscope, attention is paid to their length, the position of the centromeres, banding pattern, any differences between the sex chromosomes, and any other physical characteristics. The preparation and study of karyotypes is part of cytogenetics, the study of whole sets of chromosomes is sometimes known as karyology. The chromosomes are depicted in a format known as a karyogram or idiogram, in pairs, ordered by size. The basic number of chromosomes in the cells of an individual or a species is called the somatic number and is designated 2n. In the germ-line the chromosome number is n. p28 Thus, so, in normal diploid organisms, autosomal chromosomes are present in two copies. There may, or may not, be sex chromosomes, polyploid cells have multiple copies of chromosomes and haploid cells have single copies. The study of karyotypes is important for cell biology and genetics, Karyotypes can be used for many purposes, such as to study chromosomal aberrations, cellular function, taxonomic relationships, and to gather information about past evolutionary events. Chromosomes were first observed in plant cells by Carl Wilhelm von Nägeli in 1842 and their behavior in animal cells was described by Walther Flemming, the discoverer of mitosis, in 1882. The name was coined by another German anatomist, Heinrich von Waldeyer in 1888 and it is New Latin from Ancient Greek κάρυον karyon, kernel, seed, or nucleus, and τύπος typos, general form). The next stage took place after the development of genetics in the early 20th century, lev Delaunay seems to have been the first person to define the karyotype as the phenotypic appearance of the somatic chromosomes, in contrast to their genic contents. The subsequent history of the concept can be followed in the works of C. D. Darlington, investigation into the human karyotype took many years to settle the most basic question, how many chromosomes does a normal diploid human cell contain. In 1912, Hans von Winiwarter reported 47 chromosomes in spermatogonia and 48 in oogonia, concluding an XX/XO sex determination mechanism. Painter in 1922 was not certain whether the diploid of humans was 46 or 48, at first favouring 46, but revised his opinion from 46 to 48, considering the techniques of the time, these results were remarkable. In textbooks, the number of human chromosomes remained at 48 for over thirty years, New techniques were needed to correct this error. The work took place in 1955, and was published in 1956, the karyotype of humans includes only 46 chromosomes. Rather interestingly, the apes have 48 chromosomes
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Fission (biology)
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In biology, fission is the division of a single entity into two or more parts and the regeneration of those parts into separate entities resembling the original. The object experiencing fission is usually a cell, but the term may refer to how organisms, bodies, populations. The fission may be binary fission, in which a single entity produces two parts, or multiple fission, in which a single entity produces multiple parts, organisms in the domains of Archaea and Bacteria reproduce with binary fission. This form of reproduction and cell division is also used by some organelles within eukaryotic organisms. Binary fission results in the reproduction of a prokaryotic cell by dividing the cell into two parts, each with the potential to grow to the size of the original. Unlike the process of mitosis used by cells, binary fission takes place without the formation of a spindle apparatus in the cell. The single DNA molecule first replicates, then attaches each copy to a different part of the cell membrane, when the cell begins to pull apart, the replicated and original chromosomes are separated. The consequence of this method of reproduction is that all the cells are genetically identical. The process of fission in bacteria involves the following steps. First, the cells DNA is replicated, the replicated DNA copies then move to opposite poles of the cell in an energy-dependent process. Then, the plate of the cell constricts and separates the plasma membrane such that each new cell has exactly the same genetic material. More specifically, the following occur, The bacterium before binary fission is when the DNA is tightly coiled. The DNA of the bacterium has uncoiled and duplicated, the DNA is pulled to the separate poles of the bacterium as it increases size to prepare for splitting. The growth of a new cell wall begins to separate the bacterium, the new cell wall fully develops, resulting in the complete split of the bacterium. The new daughter cells have tightly coiled DNA rods, ribosomes, and plasmids, binary fission is generally rapid though its speed varies between species. For E. coli, cells typically divide about every 20 minutes at 37 °C and this time period can therefore be referred to as the doubling time. Some species other than E. coli may have faster or slower doubling times, some organelles in eukaryotic cells reproduce using binary fission. Mitochondrial fission occurs frequently within the cell, even when the cell is not actively undergoing mitosis, binary fission in organisms can occur in four ways, irregular, longitudinal, transverse, oblique
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Chromosomal translocation
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In genetics, a chromosome translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes. A gene fusion may be created when the translocation joins two otherwise-separated genes, it is detected on cytogenetics or a karyotype of affected cells, translocations can be balanced or unbalanced. Translocations can be reciprocal or nonreciprocal, reciprocal translocations are usually an exchange of material between nonhomologous chromosomes. Estimates of incidence range from about 1 in 500 to 1 in 625 human newborns, such translocations are usually harmless and may be found through prenatal diagnosis. However, carriers of balanced reciprocal translocations have increased risks of creating gametes with unbalanced chromosome translocations, genetic counseling and genetic testing are often offered to families that may carry a translocation. Most balanced translocation carriers are healthy and do not have any symptoms, but about 6% of them have a range of symptoms that may include autism, intellectual disability, or congenital anomalies. A gene disrupted or disregulated at the breakpoint of the carrier is likely the cause of these symptoms. The former results in a chromosomal abnormality featured in all cells of the offspring, somatic translocations, on the other hand, result in abnormalities featured only in the affected cell line, as in chronic myelogenous leukemia with the Philadelphia chromosome translocation. Robertsonian translocation is a type of translocation caused by breaks at or near the centromeres of two acrocentric chromosomes, the resulting karyotype in humans leaves only 45 chromosomes, since two chromosomes have fused together. This has no effect on the phenotype, since the only genes on the short arms of acrocentrics are common to all of them and are present in variable copy number. Robertsonian translocations have been seen involving all combinations of acrocentric chromosomes, the most common translocation in humans involves chromosomes 13 and 14 and is seen in about 0.97 /1000 newborns. Carriers of Robertsonian translocations are not associated with any phenotypic abnormalities, for example, carriers of Robertsonian translocations involving chromosome 21 have a higher chance of having a child with Down syndrome. This is known as a translocation Downs and this is due to a mis-segregation during gametogenesis. The mother has a risk of transmission than the father. Robertsonian translocations involving chromosome 14 also carry a risk of uniparental disomy 14 due to trisomy rescue. Some human diseases caused by translocations are, Cancer, Several forms of cancer are caused by acquired translocations, translocations have also been described in solid malignancies such as Ewings sarcoma. Infertility, One of the parents carries a balanced translocation. Down syndrome is caused in a minority of cases by a Robertsonian translocation of the chromosome 21 long arm onto the arm of chromosome 14
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Chromosomal inversion
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An inversion is a chromosome rearrangement in which a segment of a chromosome is reversed end to end. An inversion occurs when a single chromosome undergoes breakage and rearrangement within itself, inversions are of two types, paracentric and pericentric. Paracentric inversions do not include the centromere and both occur in one arm of the chromosome. Pericentric inversions include the centromere and there is a point in each arm. Cytogenetic techniques may be able to detect inversions, or inversions may be inferred from genetic analysis, nevertheless, in most species small inversions go undetected. In insects with polytene chromosomes, for example Drosophila, preparations of larval salivary gland chromosomes allow inversions to be seen when they are heterozygous and this useful characteristic of polytene chromosomes was first advertised by Theophilus Shickel Painter in 1933. Inversions usually do not cause any abnormalities in carriers as long as the rearrangement is balanced with no extra or missing DNA, however, in individuals which are heterozygous for an inversion, there is an increased production of abnormal chromatids. This leads to lowered fertility due to production of unbalanced gametes, the most common inversion seen in humans is on chromosome 9, at inv. This inversion is generally considered to have no effects. An inversion does not involve a loss of information. Families that may be carriers of inversions may be offered genetic counseling and genetic testing
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Centromere
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The centromere is the part of a chromosome that links sister chromatids or a dyad. During mitosis, spindle fibers attach to the centromere via the kinetochore, centromeres were first thought to be genetic loci that direct the behavior of chromosomes. e. There are, broadly speaking, two types of centromeres, point centromeres bind to specific proteins that recognise particular DNA sequences with high efficiency. Any piece of DNA with the point centromere DNA sequence on it will form a centromere if present in the appropriate species. The best characterised point centromeres are those of the budding yeast, regional centromeres is the term coined to describe most centromeres, which typically form on regions of preferred DNA sequence, but which can form on other DNA sequences as well. The signal for formation of a regional centromere appears to be epigenetic, most organisms, ranging from the fission yeast Schizosaccharomyces pombe to humans, have regional centromeres. Regarding mitotic chromosome structure, centromeres represent a region of the chromosome where two identical sister chromatids are most closely in contact. When cells enter mitosis, the chromatids are linked along their length by the action of the cohesin complex. Each chromosome has two arms, labeled p and q, many remember that the short arm p is named for the French word petit meaning small, although this explanation was shown to be apocryphal. They can be connected in either metacentric, submetacentric, acrocentric or telocentric manner and these are X-shaped chromosomes, with the centromere in the middle so that the two arms of the chromosomes are almost equal. A chromosome is metacentric if its two arms are equal in length. In a normal karyotype, five chromosomes are considered metacentric, chromosomes 1,3,16,19. In some cases, a chromosome is formed by balanced translocation. If arms lengths are unequal, the chromosome is said to be submetacentric, if the p arm is so short that it is hard to observe, but still present, then the chromosome is acrocentric. The human genome includes six acrocentric chromosomes,13,14,15,21,22, the domestic horse genome includes one metacentric chromosome that is homologous to two acrocentric chromosomes in the conspecific but undomesticated Przewalskis horse. A telocentric chromosomes centromere is located at the end of the chromosome. Telomeres may extend from both ends of the chromosome, for example, the standard house mouse karyotype has only telocentric chromosomes. Humans do not possess telocentric chromosomes, if the chromosomes centromere is located closer to its end than to its center, it may be described as subtelocentric
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Ploidy
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Ploidy is the number of sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Cells are described according to the number of present, monoploid, diploid, triploid, tetraploid, pentaploid, hexaploid, heptaploid or septaploid. The generic term polyploid is used to describe cells with three or more sets of chromosomes, humans are diploid organisms, carrying two complete sets of chromosomes, one set of 23 chromosomes from their father and one set of 23 chromosomes from their mother. The two sets combined provide a complement of 46 chromosomes. This total number of chromosomes is called the chromosome number, when a species has a varying chromosome number, e. g. a diploid and tetraploid form, the chromosome number is called diploid number in the diploid form, and tetraploid number in the tetraploid form. The number of found in a single complete set of chromosomes is called the monoploid number. The haploid number is unique to gametes, and refers to the number of chromosomes found in a gamete. The haploid number for humans is 23, and the monoploid number equals 46 divided by the level of 2. When a human germ cell undergoes meiosis the two sets of 23 chromosomes are split in half to form gametes, after fusion of a male and a female gamete both containing 1 set of 23 chromosomes, the resulting zygote has 46 chromosomes,2 sets of 23 chromosomes. The common potato is an example of an organism, carrying four sets of chromosomes. The potato plant inherits two sets of 12 chromosomes from the parent, and two sets of 12 chromosomes from the ovule parent. The four sets combined provide a complement of 48 chromosomes. The monoploid number equals the number divided by the ploidy level,48 chromosomes in total divided by a ploidy level of 4 equals a monoploid number of 12. Because the chromosome number is reduced only by the specialized process of meiosis. However, in many situations somatic cells double their number by means of endoreduplication as an aspect of cellular differentiation. When a germ cell with an number of chromosomes undergoes meiosis. Triploid organisms for instance are usually sterile, because of this, triploidy is a common way of making seedless fruit such as bananas and watermelons. If the fertilization of human gametes results in 3 sets of chromosomes the condition is called triploid syndrome, the term ploidy is a back-formation from haploidy and diploidy
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. PMID 21803766.
