The even-toed ungulates are ungulates - hoofed animals - which bear weight on two of the five toes: their third and fourth toes. The other three toes are either present, vestigial, or pointing posteriorly. By contrast, odd-toed ungulates bear weight on one of the five toes: the third toe. Another difference between the two is that even-toed ungulates digest plant cellulose in one or more stomach chambers rather than in their intestine as the odd-toed ungulates do; the aquatic cetaceans evolved from even-toed ungulates, so modern taxonomic classification sometimes combines the Artiodactyla and Cetacea into the Cetartiodactyla. The 220 land-based even-toed ungulate species include pigs, hippopotamuses, llamas, mouse deer, giraffes, sheep and cattle. Many of these are of great dietary and cultural importance to humans; the oldest fossils of even-toed ungulates date back to the early Eocene. Since these findings simultaneously appeared in Europe and North America, it is difficult to determine the origin of artiodactyls.
The fossils are classified as belonging to the family Dichobunidae. These were small animals, some as small as a hare, with a slim build, lanky legs, a long tail, their hind legs were much longer than their front legs. The early to middle Eocene saw the emergence of the ancestors of most of today's mammals. Two widespread, but now extinct, families of even-toed ungulates were Enteledontidae and Anthracotheriidae. Entelodonts existed from the middle Eocene to the early Miocene in North America, they had a stocky body with short legs and a massive head, characterized by two humps on the lower jaw bone. Anthracotheres had a large, porcine build, with an elongated muzzle; this group appeared in the middle Eocene up until the Pliocene, spread throughout Eurasia and North America. Anthracothereres are thought to be the ancestors of hippos, probably led a similar aquatic lifestyle. Hippopotamuses appeared in the late Miocene and occupied Africa and Asia – they never got to the Americas; the camels were, during large parts of the Cenozoic, limited to North America.
Among the North American camels were groups like the short-legged Merycoidodontidae. They first developed a great diversity of species in North America. Only in the late Miocene or early Pliocene did they migrate from North America into Eurasia; the North American varieties became extinct around 10,000 years ago. Suina have been around since the Eocene. In the late Eocene or the Oligocene, two families stayed in Africa. South America was settled by even-toed ungulates only in the Pliocene, after the land bridge at the Isthmus of Panama formed some three million years ago. With only the peccaries and various species of capreoline deer, South America has comparatively fewer artiodactyl families than other continents, except Australia, which has no native species; the classification of artiodactyls was hotly debated because the ocean-dwelling cetaceans evolved from the land-dwelling even-toed ungulates. Some semiaquatic even-toed ungulates are more related to the ocean-dwelling cetaceans than to the other even-toed ungulates.
This makes the Artiodactyla as traditionally defined a paraphyletic taxon, since it includes animals descended from a common ancestor, but does not include all of its descendants. Phylogenetic classification only recognizes monophyletic taxa. To address this problem, the traditional order Artiodactyla and infraorder Cetacea are sometimes subsumed into the more inclusive Cetartiodactyla taxon. An alternative approach is to include both land-dwelling even-toed ungulates and ocean-dwelling cetaceans in a revised Artiodactyla taxon. Order Artiodactyla/Clade CetartiodactylaSuborder Tylopoda Family †Anoplotheriidae? Family †Cainotheriidae Family †Merycoidodontidae Family †Agriochoeridae Family Camelidae: camels and lamoids or llamas Family †Oromerycidae Family †Xiphodontidae Clade Artiofabula Suborder Suina Family Suidae: pigs Family Tayassuidae: peccaries Family †Sanitheriidae Clade Cetruminantia Clade CetancodontamorphaGenus †Andrewsarchus? Family †Entelodontidae Suborder Whippomorpha Family †Raoellidae Superfamily Dichobunoidea – paraphyletic to Cetacea and Raoellidae Family †Dichobunidae Family †Helohyidae Family †Choeropotamidae Family †Cebochoeridae Family †Mixtotheriidae Infraorder Ancodonta Family †Anthracotheriidae – paraphyletic to Hippopotamidae Family Hippopotamidae: hippos Infraorder Cetacea: whales Parvorder †Archaeoceti Family †Pakicetidae Family †Ambulocetidae Family †Remingtonocetidae Family †Basilosauridae Parvorder Mysticeti: baleen whales Superfamily Balaenoidea: right whales Family Balaenidae: greater right whales Family Cetotheriidae: pygmy right whale Superfamily Balaenopteroidea: large baleen whales Family Balaenopteridae: slender-back rorquals and humpback whale Family Eschrichtiidae: gray whale Parvorder Odontoceti: toothed whales Superfamily Delphinoidea: oceanic dolphins and others Family Delphinidae: oceanic t
Mammals are vertebrate animals constituting the class Mammalia, characterized by the presence of mammary glands which in females produce milk for feeding their young, a neocortex, fur or hair, three middle ear bones. These characteristics distinguish them from reptiles and birds, from which they diverged in the late Triassic, 201–227 million years ago. There are around 5,450 species of mammals; the largest orders are the rodents and Soricomorpha. The next three are the Primates, the Cetartiodactyla, the Carnivora. In cladistics, which reflect evolution, mammals are classified as endothermic amniotes, they are the only living Synapsida. The early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period around 300 million years ago, this group diverged from the sauropsid line that led to today's reptiles and birds; the line following the stem group Sphenacodontia split off several diverse groups of non-mammalian synapsids—sometimes referred to as mammal-like reptiles—before giving rise to the proto-mammals in the early Mesozoic era.
The modern mammalian orders arose in the Paleogene and Neogene periods of the Cenozoic era, after the extinction of non-avian dinosaurs, have been among the dominant terrestrial animal groups from 66 million years ago to the present. The basic body type is quadruped, most mammals use their four extremities for terrestrial locomotion. Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale—the largest animal on the planet. Maximum lifespan varies from two years for the shrew to 211 years for the bowhead whale. All modern mammals give birth to live young, except the five species of monotremes, which are egg-laying mammals; the most species-rich group of mammals, the cohort called placentals, have a placenta, which enables the feeding of the fetus during gestation. Most mammals are intelligent, with some possessing large brains, self-awareness, tool use. Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals and echolocation.
Mammals can organize themselves into fission-fusion societies and hierarchies—but can be solitary and territorial. Most mammals are polygynous. Domestication of many types of mammals by humans played a major role in the Neolithic revolution, resulted in farming replacing hunting and gathering as the primary source of food for humans; this led to a major restructuring of human societies from nomadic to sedentary, with more co-operation among larger and larger groups, the development of the first civilizations. Domesticated mammals provided, continue to provide, power for transport and agriculture, as well as food and leather. Mammals are hunted and raced for sport, are used as model organisms in science. Mammals have been depicted in art since Palaeolithic times, appear in literature, film and religion. Decline in numbers and extinction of many mammals is driven by human poaching and habitat destruction deforestation. Mammal classification has been through several iterations since Carl Linnaeus defined the class.
No classification system is universally accepted. George Gaylord Simpson's "Principles of Classification and a Classification of Mammals" provides systematics of mammal origins and relationships that were universally taught until the end of the 20th century. Since Simpson's classification, the paleontological record has been recalibrated, the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself through the new concept of cladistics. Though field work made Simpson's classification outdated, it remains the closest thing to an official classification of mammals. Most mammals, including the six most species-rich orders, belong to the placental group; the three largest orders in numbers of species are Rodentia: mice, porcupines, beavers and other gnawing mammals. The next three biggest orders, depending on the biological classification scheme used, are the Primates including the apes and lemurs. According to Mammal Species of the World, 5,416 species were identified in 2006.
These were grouped into 153 families and 29 orders. In 2008, the International Union for Conservation of Nature completed a five-year Global Mammal Assessment for its IUCN Red List, which counted 5,488 species. According to a research published in the Journal of Mammalogy in 2018, the number of recognized mammal species is 6,495 species included 96 extinct; the word "mammal" is modern, from the scientific name Mammalia coined by Carl Linnaeus in 1758, derived from the Latin mamma. In an influential 1988 paper, Timothy Rowe defined Mammalia phylogenetically as the crown group of mammals, the clade consisting of the most recent common ancestor of living monotremes and therian m
A fossil is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, petrified wood, coal, DNA remnants; the totality of fossils is known as the fossil record. Paleontology is the study of fossils: their age, method of formation, evolutionary significance. Specimens are considered to be fossils if they are over 10,000 years old; the oldest fossils are around 3.48 billion years old to 4.1 billion years old. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils; the development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host. There are many processes that lead to fossilization, including permineralization and molds, authigenic mineralization and recrystallization, adpression and bioimmuration.
Fossils vary in size from one-micrometre bacteria to dinosaurs and trees, many meters long and weighing many tons. A fossil preserves only a portion of the deceased organism that portion, mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates. Fossils may consist of the marks left behind by the organism while it was alive, such as animal tracks or feces; these types of fossil are called trace ichnofossils, as opposed to body fossils. Some fossils are called chemofossils or biosignatures; the process of fossilization varies according to external conditions. Permineralization is a process of fossilization; the empty spaces within an organism become filled with mineral-rich groundwater. Minerals precipitate from the groundwater; this process can occur in small spaces, such as within the cell wall of a plant cell. Small scale permineralization can produce detailed fossils. For permineralization to occur, the organism must become covered by sediment soon after death, otherwise decay commences.
The degree to which the remains are decayed when covered determines the details of the fossil. Some fossils consist only of skeletal teeth; this is a form of diagenesis. In some cases, the original remains of the organism dissolve or are otherwise destroyed; the remaining organism-shaped hole in the rock is called an external mold. If this hole is filled with other minerals, it is a cast. An endocast, or internal mold, is formed when sediments or minerals fill the internal cavity of an organism, such as the inside of a bivalve or snail or the hollow of a skull; this is a special form of mold formation. If the chemistry is right, the organism can act as a nucleus for the precipitation of minerals such as siderite, resulting in a nodule forming around it. If this happens before significant decay to the organic tissue fine three-dimensional morphological detail can be preserved. Nodules from the Carboniferous Mazon Creek fossil beds of Illinois, USA, are among the best documented examples of such mineralization.
Replacement occurs. In some cases mineral replacement of the original shell occurs so and at such fine scales that microstructural features are preserved despite the total loss of original material. A shell is said to be recrystallized when the original skeletal compounds are still present but in a different crystal form, as from aragonite to calcite. Compression fossils, such as those of fossil ferns, are the result of chemical reduction of the complex organic molecules composing the organism's tissues. In this case the fossil consists of original material, albeit in a geochemically altered state; this chemical change is an expression of diagenesis. What remains is a carbonaceous film known as a phytoleim, in which case the fossil is known as a compression. However, the phytoleim is lost and all that remains is an impression of the organism in the rock—an impression fossil. In many cases, however and impressions occur together. For instance, when the rock is broken open, the phytoleim will be attached to one part, whereas the counterpart will just be an impression.
For this reason, one term covers the two modes of preservation: adpression. Because of their antiquity, an unexpected exception to the alteration of an organism's tissues by chemical reduction of the complex organic molecules during fossilization has been the discovery of soft tissue in dinosaur fossils, including blood vessels, the isolation of proteins and evidence for DNA fragments. In 2014, Mary Schweitzer and her colleagues reported the presence of iron particles associated with soft tissues recovered from dinosaur fossils. Based on various experiments that studied the interaction of iron in haemoglobin with blood vessel tissue they proposed that solution hypoxia coupled with iron chelation enhances the stability and preservation of soft tissue and provides the basis for an explanation for the unforeseen preservation of fossil soft tissues. However, a older study based on eight taxa ranging in time from the Devonian to the Jurassic found that reasonably well-preserved fibrils that represent collagen were preser
A chordate is an animal constituting the phylum Chordata. During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, a post-anal tail: these five anatomical features define this phylum. Chordates are bilaterally symmetric; the Chordata and Ambulacraria together form the superphylum Deuterostomia. Chordates are divided into three subphyla: Vertebrata. There are extinct taxa such as the Vetulicolia. Hemichordata has been presented as a fourth chordate subphylum, but now is treated as a separate phylum: hemichordates and Echinodermata form the Ambulacraria, the sister phylum of the Chordates. Of the more than 65,000 living species of chordates, about half are bony fish that are members of the superclass Osteichthyes. Chordate fossils have been found from as early as the Cambrian explosion, 541 million years ago. Cladistically, vertebrates - chordates with the notochord replaced by a vertebral column during development - are considered to be a subgroup of the clade Craniata, which consists of chordates with a skull.
The Craniata and Tunicata compose the clade Olfactores. Chordates form a phylum of animals that are defined by having at some stage in their lives all of the following anatomical features: A notochord, a stiff rod of cartilage that extends along the inside of the body. Among the vertebrate sub-group of chordates the notochord develops into the spine, in wholly aquatic species this helps the animal to swim by flexing its tail. A dorsal neural tube. In fish and other vertebrates, this develops into the spinal cord, the main communications trunk of the nervous system. Pharyngeal slits; the pharynx is the part of the throat behind the mouth. In fish, the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts particles of food from the water in which the animals live. Post-anal tail. A muscular tail that extends backwards behind the anus. An endostyle; this is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus.
It stores iodine, may be a precursor of the vertebrate thyroid gland. There are soft constraints that separate chordates from certain other biological lineages, but are not part of the formal definition: All chordates are deuterostomes; this means. All chordates are based on a bilateral body plan. All chordates are coelomates, have a fluid filled body cavity called a coelom with a complete lining called peritoneum derived from mesoderm; the following schema is from the third edition of Vertebrate Palaeontology. The invertebrate chordate classes are from Fishes of the World. While it is structured so as to reflect evolutionary relationships, it retains the traditional ranks used in Linnaean taxonomy. Phylum Chordata †Vetulicolia? Subphylum Cephalochordata – Class Leptocardii Clade Olfactores Subphylum Tunicata – Class Ascidiacea Class Thaliacea Class Appendicularia Class Sorberacea Subphylum Vertebrata Infraphylum incertae sedis Cyclostomata Superclass'Agnatha' paraphyletic Class Myxini Class Petromyzontida or Hyperoartia Class †Conodonta Class †Myllokunmingiida Class †Pteraspidomorphi Class †Thelodonti Class †Anaspida Class †Cephalaspidomorphi Infraphylum Gnathostomata Class †Placodermi Class Chondrichthyes Class †Acanthodii Superclass Osteichthyes Class Actinopterygii Class Sarcopterygii Superclass Tetrapoda Class Amphibia Class Sauropsida Class Synapsida Craniates, one of the three subdivisions of chordates, all have distinct skulls.
They include the hagfish. Michael J. Benton commented that "craniates are characterized by their heads, just as chordates, or all deuterostomes, are by their tails". Most craniates are vertebrates; these consist of a series of bony or cartilaginous cylindrical vertebrae with neural arches that protect the spinal cord, with projections that link the vertebrae. However hagfish have incomplete braincases and no vertebrae, are therefore not regarded as vertebrates, but as members of the craniates, the group from which vertebrates are thought to have evolved; however the cladistic exclusion of hagfish from the vertebrates is controversial, as they ma
Tibet is a historical region covering much of the Tibetan Plateau in Inner Asia. It is the traditional homeland of the Tibetan people as well as some other ethnic groups such as Monpa, Qiang and Lhoba peoples and is now inhabited by considerable numbers of Han Chinese and Hui people. Tibet is the highest region on Earth, with an average elevation of 5,000 metres; the highest elevation in Tibet is Mount Everest, Earth's highest mountain, rising 8,848 m above sea level. The Tibetan Empire emerged in the 7th century, but with the fall of the empire the region soon divided into a variety of territories; the bulk of western and central Tibet was at least nominally unified under a series of Tibetan governments in Lhasa, Shigatse, or nearby locations. Thus Tibet remained a suzerainty of the Mongol and Chinese rulers in Nanjing and Beijing, with reasonable autonomy given to the Tibetan leaders; the eastern regions of Kham and Amdo maintained a more decentralized indigenous political structure, being divided among a number of small principalities and tribal groups, while often falling more directly under Chinese rule after the Battle of Chamdo.
The current borders of Tibet were established in the 18th century. Following the Xinhai Revolution against the Qing dynasty in 1912, Qing soldiers were disarmed and escorted out of Tibet Area; the region subsequently declared its independence in 1913 without recognition by the subsequent Chinese Republican government. Lhasa took control of the western part of Xikang, China; the region maintained its autonomy until 1951 when, following the Battle of Chamdo, Tibet became incorporated into the People's Republic of China, the previous Tibetan government was abolished in 1959 after a failed uprising. Today, China governs western and central Tibet as the Tibet Autonomous Region while the eastern areas are now ethnic autonomous prefectures within Sichuan and other neighbouring provinces. There are tensions regarding dissident groups that are active in exile. Tibetan activists in Tibet have been arrested or tortured; the economy of Tibet is dominated by subsistence agriculture, though tourism has become a growing industry in recent decades.
The dominant religion in Tibet is Tibetan Buddhism. Tibetan Buddhism is a primary influence on the art and festivals of the region. Tibetan architecture reflects Indian influences. Staple foods in Tibet are roasted barley, yak meat, butter tea; the Tibetan name for their land, Bod བོད་, means "Tibet" or "Tibetan Plateau", although it meant the central region around Lhasa, now known in Tibetan as Ü. The Standard Tibetan pronunciation of Bod, is transcribed Bhö in Tournadre Phonetic Transcription, Bö in the THL Simplified Phonetic Transcription and Poi in Tibetan pinyin; some scholars believe the first written reference to Bod "Tibet" was the ancient Bautai people recorded in the Egyptian Greek works Periplus of the Erythraean Sea and Geographia, itself from the Sanskrit form Bhauṭṭa of the Indian geographical tradition. The modern Standard Chinese exonym for the ethnic Tibetan region is Zangqu, which derives by metonymy from the Tsang region around Shigatse plus the addition of a Chinese suffix, 区 qū, which means "area, region, ward".
Tibetan people and culture, regardless of where they are from, are referred to as Zang although the geographical term Xīzàng is limited to the Tibet Autonomous Region. The term Xīzàng was coined during the Qing dynasty in the reign of the Jiaqing Emperor through the addition of a prefix meaning "west" to Zang; the best-known medieval Chinese name for Tibet is Tubo. This name first appears in Chinese characters as 土番 in the 7th century and as 吐蕃 in the 10th-century. In the Middle Chinese spoken during that period, as reconstructed by William H. Baxter, 土番 was pronounced thux-phjon and 吐蕃 was pronounced thux-pjon. Other pre-modern Chinese names for Tibet include Wusiguo, Wusizang and Tanggute. American Tibetologist Elliot Sperling has argued in favor of a recent tendency by some authors writing in Chinese to revive the term Tubote for modern use in place of Xizang, on the grounds that Tubote more includes the entire Tibetan plateau rather than the Tibet Autonomous Region; the English word Tibet or Thibet dates back to the 18th century.
Historical linguists agree that "Tibet" names in European languages are loanwords from Semitic Ṭībat orTūbātt, itself deriving from Turkic Töbäd, literally: "The Heights". Linguists classify the Tibetan language as a Tibeto-Burman language of the Sino-Tibetan language family although the boundaries between'Tibetan' and certain other Himalayan languages can be unclear. According to
The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, the notable volcanoes known as the High Cascades; the small part of the range in British Columbia is referred to as the Canadian Cascades or, locally, as the Cascade Mountains. The latter term is sometimes used by Washington residents to refer to the Washington section of the Cascades in addition to North Cascades, the more usual U. S. term, as in North Cascades National Park. The highest peak in the range is Mount Rainier in Washington at 14,411 feet; the Cascades are part of the Pacific Ocean's Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. All of the eruptions in the contiguous United States over the last 200 years have been from Cascade volcanoes; the two most recent were Lassen Peak from 1914 to 1921 and a major eruption of Mount St. Helens in 1980.
Minor eruptions of Mount St. Helens have occurred since, most from 2004 to 2008; the Cascade Range is a part of the American Cordillera, a nearly continuous chain of mountain ranges that form the western "backbone" of North America, Central America, South America. The Cascades extend northward from Lassen Peak in northern California to the confluence of the Nicola and Thompson rivers in British Columbia; the Fraser River separates the Cascades from the Coast Mountains in Canada, as does the Willamette Valley from the upper portion of the Oregon Coast Range. The highest volcanoes of the Cascades, known as the High Cascades, dominate their surroundings standing twice the height of the nearby mountains, they have a visual height of one mile or more. The highest peaks, such as the 14,411-foot Mount Rainier, dominate their surroundings for 50 to 100 miles; the northern part of the range, north of Mount Rainier, is known as the North Cascades in the United States but is formally named the Cascade Mountains north of the Canada–United States border, reaching to the northern extremity of the Cascades at Lytton Mountain.
Overall, the North Cascades and Canadian Cascades are rugged. The southern part of the Canadian Cascades the Skagit Range, is geologically and topographically similar to the North Cascades, while the northern and northeastern parts are less glaciated and more plateau-like, resembling nearby areas of the Thompson Plateau; because of the range's proximity to the Pacific Ocean and the region's prevailing westerly winds, precipitation is substantial on the western slopes due to orographic lift, with annual snow accumulations of up to 1,000 inches in some areas. Mount Baker in Washington recorded a national record single-season snowfall in the winter of 1998–99 with 1,140 inches. Prior to that year, Mount Rainier held the American record for snow accumulation at Paradise in 1978, it is not uncommon for some places in the Cascades to have over 500 inches of annual snow accumulation, such as at Lake Helen, near Lassen Peak. Most of the High Cascades are therefore white with ice year-round; the western slopes are densely covered with Douglas-fir, western hemlock and red alder, while the drier eastern slopes feature ponderosa pine, with some western larch, mountain hemlock and subalpine fir and subalpine larch at higher elevations.
Annual rainfall is as low as 9 inches on the eastern foothills due to a rain shadow effect. Beyond the eastern foothills is an arid plateau, created 17 to 14 million years ago by the many flows of the Columbia River Basalt Group. Together, these sequences of fluid volcanic rock form the 200,000-square-mile Columbia Plateau in eastern Washington and parts of western Idaho; the Columbia River Gorge is the only major break of the range in the United States. When the Cascades began to rise 7 million years ago in the Pliocene, the Columbia River drained the low Columbia Plateau; as the range grew, erosion from the Columbia River was able to keep pace, creating the gorge and major pass seen today. The gorge exposes uplifted and warped layers of basalt from the plateau. Indigenous peoples have inhabited the area for thousands of years and developed their own myths and legends about the Cascades. In these legends, St. Helens with its pre-1980 graceful appearance, was regarded as a beautiful maiden for whom Hood and Adams feuded.
Native tribes developed their own names for the High Cascades and many of the smaller peaks, including "Tahoma", the Lushootseed name for Mount Rainier, "Koma Kulshan" or "Kulshan" for Mount Baker, "Louwala-Clough", meaning "smoking mountain" for Mount St. Helens. In early 1792, British navigator George Vancouver explored Puget Sound and gave English names to the high mountains he saw. Mount Baker was named for Vancouver's third lieutenant, Joseph Baker, although the first European to see it was Manuel Quimper, who named it la gran montaña del Carmelo in 1790. Mount Rainier was named after Admiral Peter Rainier. In 1792, Vancouver had his lieutenant William Robert Broughton explore the lower Columbia River, he named Mount Hood after an admiral of the Royal Navy. Mount St. Helens was sighted by Vancouver from near the mouth of the Columbia River, it was named for Al
Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, country or other defined zone, or habitat type. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species, endemic is precinctive, which applies to species that are restricted to a defined geographical area; the word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, "native". Endēmos is formed of en meaning "in", dēmos meaning "the people"; the term "precinctive" has been suggested by some scientists, was first used in botany by MacCaughey in 1917. It is the equivalent of "endemism". Precinction was first used by Frank and McCoy. Precinctive seems to have been coined by David Sharp when describing the Hawaiian fauna in 1900: "I use the word precinctive in the sense of'confined to the area under discussion'...'precinctive forms' means those forms that are confined to the area specified." That definition excludes artificial confinement of examples by humans in far-off botanical gardens or zoological parks.
Physical and biological factors can contribute to endemism. The orange-breasted sunbird is found in the fynbos vegetation zone of southwestern South Africa; the glacier bear is found only in limited places in Southeast Alaska. Political factors can play a part if a species is protected, or hunted, in one jurisdiction but not another. There are two subcategories of endemism: neoendemism. Paleoendemism refers to species that were widespread but are now restricted to a smaller area. Neoendemism refers to species that have arisen, such as through divergence and reproductive isolation or through hybridization and polyploidy in plants. Endemic types or species are likely to develop on geographically and biologically isolated areas such as islands and remote island groups, such as Hawaii, the Galápagos Islands, Socotra. Hydrangea hirta is an example of an endemic species found in Japan. Endemics can become endangered or extinct if their restricted habitat changes, particularly—but not only—due to human actions, including the introduction of new organisms.
There were millions of both Bermuda petrels and "Bermuda cedars" in Bermuda when it was settled at the start of the seventeenth century. By the end of the century, the petrels were thought extinct. Cedars ravaged by centuries of shipbuilding, were driven nearly to extinction in the twentieth century by the introduction of a parasite. Bermuda petrels and cedars are now rare. Principal causes of habitat degradation and loss in endemistic ecosystems include agriculture, urban growth, surface mining, mineral extraction, logging operations and slash-and-burn agriculture