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top 10 words in brain distribution (in article): animal horse wear species breed cat wolf male human hunt |
top 10 words in brain distribution (in article): animal city cell human people build form species store state |
top 10 words in brain distribution (not in article): woman century lion elephant saddle cattle dress cell fashion deer |
top 10 words in brain distribution (not in article): love sexual house god male woman female street town live |
times more probable under dog 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under car (words not in the model) | |
The dog'" ("Canis lupus familiaris",) is a domesticated subspecies of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The domestic dog has been one of the most widely kept working and companion animals in human history. The domestication of the gray wolf took place in a handful of events roughly 15,000 years ago in central Asia. The dog quickly became ubiquitous across culture in all parts of the world, and was extremely valuable to early human settlements. For instance, it is believed that the successful emigration across the Bering Strait might not have been possible without sled dogs. As a result of the domestication process, the dog developed a sophisticated intelligence that includes unparalleled social cognition and a simple theory of mind that is important to their interaction with humans. These social skills have helped the dog to perform in myriad roles, such as hunting, herding, protection, and, more recently, assisting handicapped individuals. Currently, there are estimated to be 400 million dogs in the world. Over the 15,000 year span that the dog had been domesticated, it diverged into only a handful of landraces, groups of similar animals whose morphology and behavior have been shaped by environmental factors and functional roles. Humans did not take an active, intentional role in this process until the last few hundred years. As the modern understanding of genetics developed, humans began to intentionally breed dogs for a wide range of specific traits. Through this process, the dog has developed into hundreds of varied breeds, and shows more behavioral and morphological variation than any other land mammal. For example, height measured to the withers ranges from a few inches in the Chihuahua to a few feet in the Irish Wolfhound; color varies from white through grays (usually called "blue'") to black, and browns from light (tan) to dark ("red" or "chocolate") in a wide variation of patterns; coats can be short or long, coarse-haired to wool-like, straight, curly, or smooth. It is common for most breeds to shed this coat, but non-shedding breeds are also popular. Etymology and related terminology. "Dog" is the common use term that refers to members of the subspecies "Canis lupus familiaris". The term is sometimes used to refer to a wider range of species: it can be used to refer to any mammal belonging to the family Canidae, which includes wolves, foxes, jackals, and coyotes; it can be used to refer to the subfamily of Caninae, or the genus Canis, also often called the "true dogs". Some members of the family have "dog" in their common names, such as the raccoon dog and the African wild dog. A few animals have "dog" in their common names but are not canids, such as the prairie dog and the dog fish. The English word "dog" can be traced back to the Old English "docga", a "powerful breed of canine". The term may derive from Proto-Germanic "*dukkōn", represented in Old English "finger-docce" ("finger-muscle"). Due to the linguistically archaic structure of the word, the term "dog" may ultimately derive from the earliest layer of Proto-Indo-European vocabulary, reflecting the role of the dog as the earliest domesticated animal. The English word "hound", which refers to a specific breed group in English, means "dog" in general in other Germanic languages; it is cognate to German "hund", Dutch "hond", common Scandinavian "hund", and Icelandic "hundur". "Hound" itself is derived from the Proto-Indo-European "*kwon-", which is also the direct root of the Greek κυων (kuōn) and the indirect root of the Latin "canis" through the variant form "*kani-". In breeding circles, a male canine is referred to as a "dog", while a female is called a "bitch". A group of offspring is a "litter". The father of a litter is called the "sire", and the mother is called the "dam". Offspring are generally called "pups" or "puppies" until they are about a year old. The process of birth is "whelping". Taxonomy and evolution. The domestic dog was originally classified as "Canis familiaris" and "Canis familiarus domesticus" by Linnaeus in 1758, and is currently classified as "Canis lupus familiaris", a subspecies of the gray wolf "Canis lupus", by the Smithsonian Institution and the American Society of Mammalogists. Overwhelming evidence from behavior, vocalizations, morphology, and molecular biology led to the contemporary scientific understanding that a single species, the gray wolf, is the common ancestor for all breeds of domestic dogs, however the timeframe and mechanisms by which dogs diverged are controversial. The current consensus among biologists and archaeologists is that no one can be sure when dogs were domesticated. There is conclusive evidence that dogs genetically diverged from their wolf ancestors at least 15,000 years ago but most believe domestication to have occurred much earlier. The evidence cited for an earlier divergence comes from archaeological findings and mitochondrial DNA studies, both of which are inconclusive. The archaeological evidence demonstrates that the domestication of dogs occurred prior to 15,000 years ago. Some genetic evidence indicates that the domestication of dogs from their wolf ancestors began in the late Upper Paleolithic close to the Pleistocene Holocene boundary, between 17,000 and 14,000 years ago. The earliest dog fossils, two large skulls from Russia and a mandible from Germany, date from roughly 14,000 years ago. Their likely ancestor is the large Eurasian wolf ("Canis lupus lupus"). Remains of smaller dogs from Natufian cave deposits in the Middle East have been dated to around 10,000 to 12,000 years ago. There is a great deal of archealogical evidence for dogs throughout Europe and Asia around this period and through the next two thousand years (roughly 8,000 to 10,000 years ago), with fossils uncovered in Germany, the French Alps, and Iraq, and cave paintings in Turkey. DNA studies have provided a wider range of possible divergence dates, from 15,000 to 40,000 years ago, to as much as 100,000 to 140,000 years ago. This evidence depends on a number of assumptions that others claim are violated. Genetic studies are based in comparisons of genetic diversity between species, and depend on a calibration date, such as the wolf-coyote divergence date, which is estimated to be roughly 1 million years ago. If this divergence date is closer to 750,000 or 2 million years ago, then genetic analyses would be interpreted very differently. Furthermore, it is believed that the genetic diversity of wolves has been in decline for the last 200 years, and that the genetic diversity of dogs has been reduced by selective breeding, which could bias DNA analyses to support an earlier divergence. The genetic evidence for the domestication event occurring in East Asia is also subject to violations of assumptions. These conclusions are based on the location of maximal genetic divergence, assumes that hybridization does not occur, and that breeds remain geographically localized. Although these assumptions hold for many species, there is good reason to believe that they do not hold for canines. Genetic analyses indicate all dogs are likely descended from a handful of domestication events with a small number of founding females, although there is evidence that domesticated dogs interbred with local populations of wild wolves on several occasions. Data suggests that dogs first diverged from wolves in East Asia, and that these domesticated dogs then quickly migrated throughout the world, reaching the North American continent around 8000 B.C. The oldest groups of dogs, which show the greatest genetic variability and are the most similar to their wolf ancestors, are primarily Asian and African breeds, including the Basenji, Saluki, Afghan Hound, Tibetan Terrier, Lhasa Apso, Chow Chow, Pekingese, Shar-Pei, Shi Tzu, Akita, Shiba Inu, Alaskan Malamute, Siberian Husky, and Samoyed. Some breeds that were thought to be very old, such as the Pharaoh Hound, Ibizan Hound, and Norwegian Elkhound, are now known to have been recreated more recently. There is a great deal of controversy surrounding the evolutionary framework for the domestication of dogs. At least three early species of the "Homo" genus began spreading out of Africa roughly 400,000 years ago, and thus lived for a considerable period in contact with canine species. Despite this, there is no evidence of any adaptation of these canine species to the presence of the close relatives of modern man. If dogs were domesticated, as believed, roughly 15,000 years ago, the event (or events) would have coincided with a large expansion in human territory and the development of agriculture. This has led some biologists to suggest that one of the forces that led to the domestication of dogs was a shift in human lifestyle in the form of established human settlements. Permanent settlements would have coincided with a greater amount of disposable food and would have created a barrier between wild and anthropogenic canine populations. Biology. Domestic dogs have been selectively bred for millennia for various behaviors, sensory capabilities, and physical attributes. Modern dog breeds show more variation in size, appearance, and behavior than any other domestic animal. Nevertheless, their morphology is based on that of their wild ancestors, gray wolves. Dogs are predators and scavengers, and like many other predatory mammals, the dog has powerful muscles, fused wrist bones, a cardiovascular system that supports both sprinting and endurance, and teeth for catching and tearing. Dogs are highly variable in height and weight. The smallest known dog was a Yorkshire Terrier, who stood only 6.3 cm (2.5 in) at the shoulder, 9.5 cm (3.75 in) in length along the head-and-body, and weighed only 113 grams (4 ounces). The largest known dog was an English Mastiff which weighed 155.6 kg (343 lbs) and was 250 cm (8.2 feet) from the snout to the tail. The tallest dog is a Great Dane that stands 106.7 cm (42.2 in) at the shoulder. Sight. The dog's visual system is engineered to serve the purposes of a hunter. While a dog's visual acuity is poor (that of a poodle's has been estimated to translate to a Snellen rating of 20 75), their visual discrimination for moving objects is very high; dogs have been shown to be able to discriminate between humans (i.e., identifying their owner) from distances up to a mile. As crepuscular hunters, dogs often rely on their vision in low light situations: they have very large pupils, a high density of rods in the fovea, an increased flicker rate, and a tapetum lucidum. The tapetum is a reflective surface behind the retina that reflects light back to give the photoreceptors a second chance to catch the photons. Like most mammals, dogs are dichromats and have color vision equivalent to red-green color blindness in humans. The eyes of different breeds of dogs have different shapes, dimensions, and retina configurations. Many long-nosed breeds have a "visual streak" — a wide foveal region that runs across the width of the retina and gives them a very wide field of excellent vision. Some long-muzzled breeds, particularly the sighthounds, have a field of vision up to 270° (compared to 180° for humans). Short-nosed breeds, on the other hand, have an "area centralis": a central patch with up to three times the density of nerve endings as the visual streak, giving them detailed sight much more like a human's. Some broad-headed breeds with short noses have a field of vision similar to that of humans. Most breeds have good vision, but some show a genetic predisposition for myopia — such as Rottweilers, where one out of every two has been found to be myopic. Hearing. The frequency range of dog hearing is approximately 40 Hz to 60,000 Hz, which means that dogs can detect sounds outside both ends of the human auditory spectrum. Additionally, dogs have ear mobility which allows them to rapidly pinpoint the exact location of a sound. Eighteen or more muscles can tilt, rotate, raise, or lower a dog's ear. A dog can identify a sound's location much faster than a human can, as well as hear sounds at four times the distance. Smell. While the human brain is dominated by a large visual cortex, the dog brain is largely dominated by an olfactory cortex. The olfactory bulb in dogs is roughly forty times bigger than the olfactory bulb in humans, relative to total brain size, with 125 to 220 million smell-sensitive receptors. The bloodhound exceeds this standard with nearly 300 million receptors. Dogs can discriminate odors at concentrations nearly 100 million times lower than humans can. Coat. The coats of domestic dogs are either "double", made up of a coarse topcoat and a soft undercoat, like a wolf, or "single", with the topcoat only. Dogs with double coats tend to originate in colder climates. Domestic dogs often display the remnants of countershading, a common natural camouflage pattern. The general theory of countershading is that an animal that is lit from above will appear lighter on its upper half and darker on its lower half, where it will usually be in its own shade. This is a pattern that predators can learn to watch for. A countershaded animal will have dark coloring on its upper surfaces and light coloring below, which reduces its general visibility. Thus many breeds will have an occasional "blaze", stripe, or "star" of white fur on their chest or underside. Tail. There are many different shapes for dog tails: straight, straight up, sickle, curled, or cork-screw. In some breeds, the tail is traditionally docked to avoid injuries (especially for hunting dogs). In some breeds, puppies can be born with a short tail or no tail at all. This occurs more frequently in those breeds that are frequently docked and thus have no breed standard regarding the tail. Types and breeds. While all dogs are genetically very similar, natural selection and selective breeding have reinforced certain characteristics in certain populations of dogs, giving rise to dog types and dog breeds. Dog types are broad categories based on function, genetics, or characteristics. Dog breeds are groups of animals that possess a set of inherited characteristics that distinguishes them from other animals within the same species. Modern dog breeds are non-scientific classifications of dogs kept by modern kennel clubs. Purebred dogs of one breed are genetically distinguishable from purebred dogs of other breeds, but the means by which kennel clubs classify dogs is unsystematic. Systematic analyses of the dog genome has revealed only four major types of dogs that can be said to be statistically distinct. These include the "old world dogs" (e.g., Malamute and Shar-Pei), "Mastiff"-type (e.g., Labrador Retriever), "herding"-type (e.g., St. Bernard), and "all others" (also called "modern"- or "hunting"-type). Health. Dogs are susceptible to various diseases, ailments, and poisons, some of which can affect humans. To defend against many common diseases, dogs are often vaccinated. Some breeds of dogs are prone to certain genetic ailments such as elbow or hip dysplasia, blindness, deafness, pulmonic stenosis, cleft palate, and trick knees. Two serious medical conditions particularly affecting dogs are pyometra, affecting unspayed females of all types and ages, and bloat, which affects the larger breeds or deep-chested dogs. Both of these are acute conditions, and can kill rapidly. Dogs are also susceptible to parasites such as fleas, ticks, and mites, as well as hookworms, tapeworms, roundworms, and heartworms. Dogs are also vulnerable to some of the same health conditions as humans, including diabetes, dental and heart disease, epilepsy, cancer, hypothyroidism, and arthritis. Mortality. The typical lifespan of dogs varies widely among breeds, but for most the median longevity, the age at which half the dogs in a population have died and half are still alive, ranges from 10 to 13 years. Individual dogs may live well beyond the median of their breed. The breed with the shortest lifespan (among breeds for which there is a questionnaire survey with a reasonable sample size) is the Dogue de Bordeaux, with a median longevity of about 5.2 years, but several breeds, including Miniature Bull Terriers, Bulldogs, Nova Scotia Duck-Tolling Retrievers, Bloodhounds, Irish Wolfhounds, Greater Swiss Mountain Dogs, Great Danes, and Mastiffs, are nearly as short-lived, with median longevities of 6 to 7 years. The longest-lived breeds, including Toy Poodles, Border Terriers, Miniature Dachshunds, Miniature Poodles, and Tibetan Spaniels, have median longevities of 14 to 15 years. The median longevity of mixed breed dogs, taken as an average of all sizes, is one or more years longer than that of purebred dogs when all breeds are averaged. The dog widely reported to be the longest-lived is "Bluey," who died in 1939 and was claimed to be 29.5 years old at the time of his death; however, the Bluey record is anecdotal and unverified. The longest verified records are of dogs living for 24 years. Predation. Although wild dogs, like wolves, are apex predators, they can be killed in territory disputes with wild animals. Furthermore, in areas where both dogs and other large predators live, dogs can be a major food source for big cats or canines. Reports from Croatia indicate that dogs are killed more frequently than sheep. Wolves in Russia apparently limit feral dog populations. In Wisconsin, more compensation has been paid for dog losses than livestock. Some wolf pairs have been reported to prey on dogs by having one wolf lure the dog out into heavy brush where the second animal waits in ambush. In some instances, wolves have displayed an uncharacteristic fearlessness of humans and buildings when attacking dogs, to the extent that they have to be beaten off or killed. Coyotes and big cats have also been known to attack dogs. Leopards in particular are known to have a predilection for dogs, and have been recorded to kill and consume them regardless of the dog's size or ferocity. Tigers in Manchuria, Indochina, Indonesia, and Malaysia, are reputed to kill dogs with the same vigor as leopards. Striped Hyenas are major predators of village dogs in Turkmenistan, India, and the Caucasus. Diet. Despite its descent from wolves, the domestic dog is an omnivore, though it is classified in the order Carnivora. Unlike an obligate carnivore, such as a member of the cat family with its shorter small intestine, a dog is neither dependent on meat-specific protein nor a very high level of protein in order to fulfill its basic dietary requirements. Dogs are able to healthily digest a variety of foods, including vegetables and grains, and can consume a large proportion of these in their diet. In the wild, canines often eat available plants and fruits. Reproduction. In domestic dogs, sexual maturity begins to happen around age six to twelve months for both males and females, although this can be delayed until up to two years old for some large breeds. This is the time at which female dogs will have their first estrous cycle. They will experience subsequent estrous cycles biannually, during which the body prepares for pregnancy. At the peak of the cycle, females will come into estrus, being mentally and physically receptive to copulation. Because the ova survive and are capable of being fertilized for a week after ovulation, it is possible for a female to mate with more than one male. Adolescence for most domestic dogs is around 12 to 15 months, beyond which they are for the most part more adult than puppy. Domestication has selectively bred for higher libido and earlier and more frequent breeding cycles in dogs than in their wild ancestors, and dogs remain reproductively active until old age. Dogs bear their litters roughly 56 to 72 days after fertilization, with an average of 63 days, although the length of gestation can vary. An average litter consists of about six puppies, though this number may vary widely based on the breed of dog. Toy dogs generally produce from one to four puppies in each litter, while much larger breeds may average as many as twelve. Some dog breeds have acquired traits through selective breeding that interfere with reproduction. Male French Bulldogs, for instance, are incapable of mounting the female. For many dogs of this breed, the female must be artificially inseminated in order to reproduce. Spaying and neutering. Neutering refers to the sterilization of animals, usually by removal of the male's testicles or the female's ovaries and uterus, in order to eliminate the ability to procreate and reduce sex drive. Because of the overpopulation of dogs in some countries, animal control agencies, such as the American Society for the Prevention of Cruelty to Animals (ASPCA), advise that dogs not intended for further breeding should be neutered, so that they do not have undesired puppies that may have to be destroyed later. According to the Humane Society of the United States, 3–4 million dogs and cats are put down each year in the United States and many more are confined to cages in shelters because there are many more animals than there are homes. Spaying or castrating dogs helps keep overpopulation down. Local humane societies, SPCAs, and other animal protection organizations urge people to neuter their pets and to adopt animals from shelters instead of purchasing them. Several notable public figures have spoken out against animal overpopulation, including Bob Barker. On his game show, "The Price Is Right", Barker stressed the problem at the end of every episode, saying: "Help control the pet population. Have your pets spayed or neutered." The current host, Drew Carey, makes a similar plea at the conclusion of each episode. Neutering reduces problems caused by hypersexuality, especially in male dogs. Spayed female dogs are less likely to develop some forms of cancer, affecting mammary glands, ovaries, and other reproductive organs. However, neutering increases the risk of urinary incontinence in female dogs, and prostate cancer in males, as well as osteosarcoma, hemangiosarcoma, cruciate ligament rupture, obesity, and diabetes mellitus in either gender. The hormonal changes involved with sterilization can change the animal's personality and metabolism. Recent studies proved that spayed and neutered dogs in general are more aggressive towards people and other dogs, and more fearful and sensitive to touch than dogs than had not been sterilized. Spaying or neutering very young animals ("early-age spay"), can result in increased health concerns later on in life for both sexes. Incontinence in female dogs is made worse by spaying too early. In both males and females, alteration causes changes in hormones during development. This inhibits the natural signals needed for proper body development, leading to larger animals with greater risk for hip dysplasia, osteoporosis, and other joint disorders. Other studies have shown, however, that early-age neutering of male dogs is associated with no major risks compared to neutering at the more traditional age of six months. Behavior and intelligence. Although dogs have been the subject of a great deal of Behaviorist psychology (e.g.,Pavlov's Dog), they do not enter the world with a psychological "blank slate". Rather, dog behavior is affected by genetic factors as well as environmental factors. Domestic dogs exhibit a number of behaviors and predispositions that were inherited from wolves. The grey wolf is a social animal that has evolved a sophisticated means of communication and social structure. The domestic dog has inherited some of these predispositions, but many of the salient characteristics in dog behavior have been largely shaped by selective breeding by humans. Thus, some of these characteristics, such as the dog's highly developed social cognition, are found only in primitive forms in grey wolves. Intelligence. "Intelligence" is an umbrella term that encompasses the faculties involved in a wide range of mental tasks, such as learning, problem-solving, and communication. The domestic dog has a predisposition to exhibit a social intelligence that is uncommon in the animal world. Dogs are capable of learning in a number of ways, such as through simple reinforcement learning (e.g.,classical or operant conditioning) and by observation. Dogs go through a series of stages of cognitive development. They are not born with an understanding of object permanence; the understanding that objects which are not being actively perceived still remain in existence. The understanding of object permanence occurs during as the infant is learning the coordination of secondary circular reactions, as described by Jean Piaget. That is, as the infants learn to interact intentionally with objects around it. For dogs, this occurs at roughly 8 weeks of age. Handlers of working dogs such as herding dogs and sled dogs know that pups learn behaviors quickly by following examples set by experienced dogs. Many of these behaviors are allelomimetic in that they depend on a genetic predisposition to learn and imitate behaviors of other dogs. This form of intelligence is not peculiar to those tasks dogs have been bred to perform, but can be generalized to myriad | An automobile'" or "'motor car'" is a wheeled motor vehicle for transporting passengers, which also carries its own engine or motor. Most definitions of the term specify that automobiles are designed to run primarily on roads, to have seating for one to eight people, to typically have four wheels, and to be constructed principally for the transport of people rather than goods. However, the term "automobile" is far from precise, because there are many types of vehicles that do similar tasks. As of 2002, there were 590 million passenger cars worldwide (roughly one car per eleven people). Etymology. The word automobile'" comes, via the French "automobile", from the Ancient Greek word αὐτός ("autós", "self") and the Latin "mobilis" ("movable"); meaning a vehicle that moves itself, rather than being pulled or pushed by a separate animal or another vehicle. The alternative name "car" is believed to originate from the Latin word "carrus" or "carrum" ("wheeled vehicle"), or the Middle English word "carre" ("cart") (from Old North French), or "karros" (a Gallic wagon). History. Although Nicolas-Joseph Cugnot is often credited with building the first self-propelled mechanical vehicle or automobile in about 1769 by adapting an existing horse-drawn vehicle, this claim is disputed by some, who doubt Cugnot's three-wheeler ever ran or was stable. Ferdinand Verbiest, a member of a Jesuit mission in China, built the first steam-powered vehicle around 1672 which was of small scale and designed as a toy for the Chinese Emperor that was unable to carry a driver or a passenger, but quite possibly, was the first working steam-powered vehicle ('auto-mobile'). What is not in doubt is that Richard Trevithick built and demonstrated his "Puffing Devil" road locomotive in 1801, believed by many to be the first demonstration of a steam-powered road vehicle although it was unable to maintain sufficient steam pressure for long periods, and would have been of little practical use. In Russia, in the 1780s, Ivan Kulibin developed a human-pedalled, three-wheeled carriage with modern features such as a flywheel, brake, gear box, and bearings; however, it was not developed further. François Isaac de Rivaz, a Swiss inventor, designed the first internal combustion engine, in 1806, which was fueled by a mixture of hydrogen and oxygen and used it to develop the world's first vehicle, albeit rudimentary, to be powered by such an engine. The design was not very successful, as was the case with others such as Samuel Brown, Samuel Morey, and Etienne Lenoir with his hippomobile, who each produced vehicles (usually adapted carriages or carts) powered by clumsy internal combustion engines. In November 1881 French inventor Gustave Trouvé demonstrated a working three-wheeled automobile that was powered by electricity. This was at the International Exhibition of Electricity in Paris. Although several other German engineers (including Gottlieb Daimler, Wilhelm Maybach, and Siegfried Marcus) were working on the problem at about the same time, Karl Benz'" generally is acknowledged as the inventor of the modern automobile. An automobile powered by his own four-stroke cycle gasoline engine was built in Mannheim, Germany by Karl Benz in 1885 and granted a patent in January of the following year under the auspices of his major company, Benz & Cie., which was founded in 1883. It was an integral design, without the adaptation of other existing components and including several new technological elements to create a new concept. This is what made it worthy of a patent. He began to sell his production vehicles in 1888. In 1879 Benz was granted a patent for his first engine, which had been designed in 1878. Many of his other inventions made the use of the internal combustion engine feasible for powering a vehicle. His first "Motorwagen" was built in 1885 and he was awarded the patent for its invention as of his application on January 29, 1886. Benz began promotion of the vehicle on July 3, 1886 and approximately 25 Benz vehicles were sold between 1888 and 1893, when his first four-wheeler was introduced along with a model intended for affordability. They also were powered with four-stroke engines of his own design. Emile Roger of France, already producing Benz engines under license, now added the Benz automobile to his line of products. Because France was more open to the early automobiles, initially more were built and sold in France through Roger than Benz sold in Germany. In 1896, Benz designed and patented the first internal-combustion flat engine, called a "boxermotor" in German. During the last years of the nineteenth century, Benz was the largest automobile company in the world with 572 units produced in 1899 and because of its size, Benz & Cie., became a joint-stock company. Daimler and Maybach founded Daimler Motoren Gesellschaft (Daimler Motor Company, DMG) in Cannstatt in 1890 and under the brand name, "Daimler", sold their first automobile in 1892, which was a horse-drawn stagecoach built by another manufacturer, that they retrofitted with an engine of their design. By 1895 about 30 vehicles had been built by Daimler and Maybach, either at the Daimler works or in the Hotel Hermann, where they set up shop after falling out with their backers. Benz and the Maybach and Daimler team seem to have been unaware of each other's early work. They never worked together because by the time of the merger of the two companies, Daimler and Maybach were no longer part of DMG. Daimler died in 1900 and later that year, Maybach designed an engine named "Daimler-Mercedes", that was placed in a specially-ordered model built to specifications set by Emil Jellinek. This was a production of a small number of vehicles for Jellinek to race and market in his country. Two years later, in 1902, a new model DMG automobile was produced and the model was named Mercedes after the Maybach engine which generated 35 hp. Maybach quit DMG shortly thereafter and opened a business of his own. Rights to the "Daimler" brand name were sold to other manufacturers. Karl Benz proposed co-operation between DMG and Benz & Cie. when economic conditions began to deteriorate in Germany following the First World War, but the directors of DMG refused to consider it initially. Negotiations between the two companies resumed several years later when these conditions worsened and, in 1924 they signed an "Agreement of Mutual Interest", valid until the year 2000. Both enterprises standardized design, production, purchasing, and sales and they advertised or marketed their automobile models jointly—although keeping their respective brands. On June 28, 1926, Benz & Cie. and DMG finally merged as the "Daimler-Benz" company, baptizing all of its automobiles "Mercedes Benz" as a brand honoring the most important model of the DMG automobiles, the Maybach design later referred to as the "1902 Mercedes-35hp", along with the Benz name. Karl Benz remained a member of the board of directors of Daimler-Benz until his death in 1929 and at times, his two sons participated in the management of the company as well. In 1890, Emile Levassor and Armand Peugeot of France began producing vehicles with Daimler engines and so laid the foundation of the automobile industry in France. The first design for an American automobile with a gasoline internal combustion engine was drawn in 1877 by George Selden of Rochester, New York, who applied for a patent for an automobile in 1879, but the patent application expired because the vehicle was never built and proved to work (a requirement for a patent). After a delay of sixteen years and a series of attachments to his application, on November 5, 1895, Selden was granted a United States patent for a two-stroke automobile engine, which hindered, more than encouraged, development of automobiles in the United States. His patent was challenged by Henry Ford and others, and overturned in 1911. In Britain there had been several attempts to build steam cars with varying degrees of success with Thomas Rickett even attempting a production run in 1860. Santler from Malvern is recognized by the Veteran Car Club of Great Britain as having made the first petrol-powered car in the country in 1894 followed by Frederick William Lanchester in 1895 but these were both one-offs. The first production vehicles in Great Britain came from the Daimler Motor Company, a company founded by Harry J. Lawson in 1896 after purchasing the right to use the name of the engines. Lawson's company made its first automobiles in 1897 and they bore the name "Daimler". In 1892, German engineer Rudolf Diesel was granted a patent for a "New Rational Combustion Engine". In 1897 he built the first Diesel Engine. Steam-, electric-, and gasoline-powered vehicles competed for decades, with gasoline internal combustion engines achieving dominance in the 1910s. Although various pistonless rotary engine designs have attempted to compete with the conventional piston and crankshaft design, only Mazda's version of the Wankel engine has had more than very limited success. Production. The large-scale, production-line manufacturing of affordable automobiles was debuted by Ransom Olds at his Oldsmobile factory in 1902. This concept was greatly expanded by Henry Ford, beginning in 1914. As a result, Ford's cars came off the line in fifteen minute intervals, much faster than previous methods, increasing productivity eight fold (requiring 12.5 man-hours before, 1 hour 33 minutes after), while using less manpower. It was so successful, paint became a bottleneck. Only Japan black would dry fast enough, forcing the company to drop the variety of colors available before 1914, until fast-drying Duco lacquer was developed in 1926. This is the source of Ford's apocryphal remark, "any color as long as it's black". In 1914, an assembly line worker could buy a Model T with four months' pay. Ford's complex safety procedures—especially assigning each worker to a specific location instead of allowing them to roam about—dramatically reduced the rate of injury. The combination of high wages and high efficiency is called "Fordism," and was copied by most major industries. The efficiency gains from the assembly line also coincided with the economic rise of the United States. The assembly line forced workers to work at a certain pace with very repetitive motions which led to more output per worker while other countries were using less productive methods. In the automotive industry, its success was dominating, and quickly spread worldwide seeing the founding of Ford France and Ford Britain in 1911, Ford Denmark 1923, Ford Germany 1925; in 1921, Citroen was the first native European manufacturer to adopt the production method. Soon, companies had to have assembly lines, or risk going broke; by 1930, 250 companies which did not, had disappeared. Development of automotive technology was rapid, due in part to the hundreds of small manufacturers competing to gain the world's attention. Key developments included electric ignition and the electric self-starter (both by Charles Kettering, for the Cadillac Motor Company in 1910-1911), independent suspension, and four-wheel brakes. Since the 1920s, nearly all cars have been mass-produced to meet market needs, so marketing plans often have heavily influenced automobile design. It was Alfred P. Sloan who established the idea of different makes of cars produced by one company, so buyers could "move up" as their fortunes improved. Reflecting the rapid pace of change, makes shared parts with one another so larger production volume resulted in lower costs for each price range. For example, in the 1930s, LaSalles, sold by Cadillac, used cheaper mechanical parts made by Oldsmobile; in the 1950s, Chevrolet shared hood, doors, roof, and windows with Pontiac; by the 1990s, corporate drivetrains and shared platforms (with interchangeable brakes, suspension, and other parts) were common. Even so, only major makers could afford high costs, and even companies with decades of production, such as Apperson, Cole, Dorris, Haynes, or Premier, could not manage: of some two hundred American car makers in existence in 1920, only 43 survived in 1930, and with the Great Depression, by 1940, only 17 of those were left. In Europe much the same would happen. Morris set up its production line at Cowley in 1924, and soon outsold Ford, while beginning in 1923 to follow Ford's practise of vertical integration, buying Hotchkiss (engines), Wrigley (gearboxes), and Osberton (radiators), for instance, as well as competitors, such as Wolseley: in 1925, Morris had 41% of total British car production. Most British small-car assemblers, from Abbey to Xtra had gone under. Citroen did the same in France, coming to cars in 1919; between them and other cheap cars in reply such as Renault's 10CV and Peugeot's 5CV, they produced 550,000 cars in 1925, and Mors, Hurtu, and others could not compete. Germany's first mass-manufactured car, the Opel 4PS "Laubfrosch" (Tree Frog), came off the line at Russelsheim in 1924, soon making Opel the top car builder in Germany, with 37.5% of the market. Fuel and propulsion technologies. Most automobiles in use today are propelled by gasoline (also known as petrol) or diesel internal combustion engines, which are known to cause air pollution and are also blamed for contributing to climate change and global warming. Increasing costs of oil-based fuels, tightening environmental laws and restrictions on greenhouse gas emissions are propelling work on alternative power systems for automobiles. Efforts to improve or replace existing technologies include the development of hybrid vehicles, and electric and hydrogen vehicles which do not release pollution into the air. Diesel. Diesel-engined cars have long been popular in Europe with the first models being introduced in the 1930s by Mercedes Benz and Citroen. The main benefit of diesel engines is a 50% fuel burn efficiency compared with 27% in the best gasoline engines. A down-side of the Diesel engine is that better filters are required to reduce the presence in the exhaust gases of fine soot particulates called diesel particulate matter. Manufacturers are now starting to fit diesel particulate filters to remove the soot. Many diesel-powered cars can run with little or no modifications on 100% biodiesel and combinations of other organic oils. Gasoline. Gasoline engines have the advantage over diesel in being lighter and able to work at higher rotational speeds and they are the usual choice for fitting in high-performance sports cars. Continuous development of gasoline engines for over a hundred years has produced improvements in efficiency and reduced pollution. The carburetor was used on nearly all road car engines until the 1980s but it was long realised better control of the fuel air mixture could be achieved with fuel injection. Indirect fuel injection was first used in aircraft engines from 1909, in racing car engines from the 1930s, and road cars from the late 1950s. Gasoline Direct Injection (GDI) is now starting to appear in production vehicles such as the 2007 (Mark II) BMW Mini. Exhaust gases are also cleaned up by fitting a catalytic converter into the exhaust system. Clean air legislation in many of the car industries most important markets has made both catalysts and fuel injection virtually universal fittings. Most modern gasoline engines also are capable of running with up to 15% ethanol mixed into the gasoline; older vehicles may have seals and hoses that can be harmed by ethanol. With a small amount of redesign, gasoline-powered vehicles can run on ethanol concentrations as high as 85%. 100% ethanol is used in some parts of the world (such as Brazil), but vehicles must be started on pure gasoline and switched over to ethanol once the engine is running. Most gasoline engined cars can also run on LPG with the addition of an LPG tank for fuel storage and carburettor modifications to add an LPG mixer. LPG produces fewer toxic emissions and is a popular fuel for fork-lift trucks that have to operate inside buildings. Biofuels. Ethanol, other alcohol fuels (biobutanol) and biogasoline have widespread use an automotive fuel. Most alcohols have less energy per liter than gasoline and are usually blended with gasoline. Alcohols are used for a variety of reasons: to increase octane, to improve emissions, and as an alternative to petroleum based fuel, since they can be made from agricultural crops. Brazil's ethanol program provides about 20% of the nation's automotive fuel needs, as a result of the mandatory use of E25 blend of gasoline throughout the country, 3 million cars that operate on pure ethanol, and 6 million dual or flexible-fuel vehicles sold since 2003. that run on any mix of ethanol and gasoline. The commercial success of "flex" vehicles, as they are popularly known, have allowed sugarcane based ethanol fuel to achieve a 50% market share of the gasoline market by April 2008. Electric. The first electric cars were built around 1832, well before internal combustion powered cars appeared. For a period of time electrics were considered superior due to the silent nature of electric motors compared to the very loud noise of the gasoline engine. This advantage was removed with Hiram Percy Maxim's invention of the muffler in 1897. Thereafter internal combustion powered cars had two critical advantages: 1) long range and 2) high specific energy (far lower weight of petrol fuel versus weight of batteries). The building of battery electric vehicles that could rival internal combustion models had to wait for the introduction of modern semiconductor controls and improved batteries. Because they can deliver a high torque at low revolutions electric cars do not require such a complex drive train and transmission as internal combustion powered cars. Some post-2000 electric car designs such as the Venturi Fétish are able to accelerate from 0-60 mph (96 km h) in 4.0 seconds with a top speed around 130 mph (210 km h). Others have a range of 250 miles (400 km) on the United States Environmental Protection Agency (EPA) highway cycle requiring 31 2 hours to completely charge. Equivalent fuel efficiency to internal combustion is not well defined but some press reports give it at around. Steam. Steam power, usually using an oil- or gas-heated boiler, was also in use until the 1930s but had the major disadvantage of being unable to power the car until boiler pressure was available (although the newer models could achieve this in well under a minute). It has the advantage of being able to produce very low emissions as the combustion process can be carefully controlled. Its disadvantages include poor heat efficiency and extensive requirements for electric auxiliaries.. Air. A compressed air car is an alternative fuel car that uses a motor powered by compressed air. The car can be powered solely by air, or by air combined (as in a hybrid electric vehicle) with gasoline diesel ethanol or electric plant and regenerative braking. Instead of mixing fuel with air and burning it to drive pistons with hot expanding gases; "compressed air cars" use the expansion of compressed air to drive their pistons. Several prototypes are available already and scheduled for worldwide sale by the end of 2008, though this has not happened as of January 2009. Companies releasing this type of car include Tata Motors and Motor Development International (MDI). Gas turbine. In the 1950s there was a brief interest in using gas turbine engines and several makers including Rover and Chrysler produced prototypes. In spite of the power units being very compact, high fuel consumption, severe delay in throttle response, and lack of engine braking meant no cars reached production. Rotary (Wankel) engines. Rotary Wankel engines were introduced into road cars by NSU with the Ro 80 and later were seen in the Citroën GS Birotor and several Mazda models. In spite of their impressive smoothness, poor reliability and fuel economy led to them largely disappearing. Mazda, beginning with the R100 then RX-2, has continued research on these engines, overcoming most of the earlier problems with the RX-7 and RX-8. Rocket and jet cars. A rocket car holds the record in drag racing. However, the fastest of those cars are used to set the Land Speed Record, and are propelled by propulsive jets emitted from rocket, turbojet, or more recently and most successfully turbofan engines. The ThrustSSC car using two Rolls-Royce Spey turbofans with reheat was able to exceed the speed of sound at ground level in 1997. Safety. There are three main statistics to which automobile safety can be compared: While road traffic injuries represent the leading cause in worldwide injury-related deaths, their popularity undermines this statistic. Mary Ward became one of the first documented automobile fatalities in 1869 in Parsonstown, Ireland and Henry Bliss one of the United States' first pedestrian automobile casualties in 1899 in New York. There are now standard tests for safety in new automobiles, like the EuroNCAP and the US NCAP tests, as well as insurance-backed IIHS tests. Costs and benefits. The costs of automobile usage, which may include the cost of: acquiring the vehicle, repairs, maintenance, fuel, depreciation, parking fees, tire replacement, taxes and insurance, are weighed against the cost of the alternatives, and the value of the benefits, perceived and real, of vehicle usage. The benefits may include on-demand transportation, mobility, independence and convenience. Similarly the costs to society of encompassing automobile use, which may include those of: maintaining roads, land use, pollution, public health, health care, and of disposing of the vehicle at the end of its life, can be balanced against the value of the benefits to society that automobile use generates. The societal benefits may include: economy benefits, such as job and wealth creation, of automobile production and maintenance, transportation provision, society wellbeing derived from leisure and travel opportunities, and revenue generation from the opportunities. The ability for humans to move flexibly from place to place has far reaching implications for the nature of societies. Environmental impact. Transportation is a major contributor to air pollution in most industrialised nations. According to the American Surface Transportation Policy Project nearly half of all Americans are breathing unhealthy air. Their study showed air quality in dozens of metropolitan areas has got worse over the last decade. In the United States the average passenger car emits 11,450 lbs (5 tonnes) of carbon dioxide, along with smaller amounts of carbon monoxide, hydrocarbons, and nitrogen. Residents of low-density, residential-only sprawling communities are also more likely to die in car collisions, which kill 1.2 million people worldwide each year, and injure about forty times this number. Sprawl is more broadly a factor in inactivity and obesity, which in turn can lead to increased risk of a variety of diseases. Other species are often negatively impacted by automobiles via habitat destruction and pollution. Over the lifetime of the average automobile the "loss of habitat potential" may be over 50,000 square meters (538,195 square feet) based on Primary production correlations. Fuel taxes may act as an incentive for the production of more efficient, hence less polluting, car designs (e.g. hybrid vehicles) and the development of alternative fuels. High fuel taxes may provide a strong incentive for consumers to purchase lighter, smaller, more fuel-efficient cars, or to not drive. On average, today's automobiles are about 75 percent recyclable, and using recycled steel helps reduce energy use and pollution. In the United States Congress, federally mandated fuel efficiency standards have been debated regularly, passenger car standards have not risen above the standard set in 1985. Light truck standards have changed more frequently, and were set at in 2007. Alternative fuel vehicles are another option that is less polluting than conventional petroleum powered vehicles. Future car technologies. Automobile propulsion technology under development include electric and plug-in hybrids, battery electric vehicles, hydrogen cars, biofuels, and various alternative fuels. Research into future alternative forms of power include the development of fuel cells, Homogeneous Charge Compression Ignition (HCCI), stirling engines, and even using the stored energy of compressed air or liquid nitrogen. New materials which may replace steel car bodies include duraluminum, fiberglass, carbon fiber, and carbon nanotubes. Telematics technology is allowing more and more people to share cars, on a pay-as-you-go basis, through such schemes as City Car Club in the UK, Mobility in mainland Europe, and Zipcar in the US. Alternatives to the automobile. Established alternatives for some aspects of automobile use include public transit (buses, trolleybuses, trains, subways, monorails, tramways), cycling, walking, rollerblading, skateboarding, horseback riding and using a velomobile. Car-share arrangements and carpooling are also increasingly popular–the U.S. market leader in car-sharing has experienced double-digit growth in revenue and membership growth between 2006 and 2007, offering a service that enables urban residents to "share" a vehicle rather than own a car in already congested neighborhoods. Bike-share systems have been tried in some European cities, including Copenhagen and Amsterdam. Similar programs have been experimented with in a number of U.S. Cities. Additional individual modes of transport, such as personal rapid transit could serve as an alternative to automobiles if they prove to be socially accepted. |