Ardipithecus is a genus of an extinct hominine that lived during the Late Miocene and Early Pliocene epochs in the Afar Depression, Ethiopia. Described as one of the earliest ancestors of humans after they diverged from the chimpanzees, the relation of this genus to human ancestors and whether it is a hominin is now a matter of debate. Two fossil species are described in the literature: A. ramidus, which lived about 4.4 million years ago during the early Pliocene, A. kadabba, dated to 5.6 million years ago. Behavioral analysis showed that Ardipithecus could be similar to chimpanzees, indicating that the early human ancestors were chimpanzee-like in behavior. A. ramidus was named in September 1994. The first fossil found was dated to 4.4 million years ago on the basis of its stratigraphic position between two volcanic strata: the basal Gaala Tuff Complex and the Daam Aatu Basaltic Tuff. The name Ardipithecus ramidus stems from the Afar language, in which Ardi means "ground/floor" and ramid means "root".
The pithecus portion of the name is from the Greek word for "ape". Like most hominids, but unlike all recognized hominins, it had a grasping hallux or big toe adapted for locomotion in the trees, it is not confirmed how much other features of its skeleton reflect adaptation to bipedalism on the ground as well. Like hominins, Ardipithecus had reduced canine teeth. In 1992–1993 a research team headed by Tim White discovered the first A. ramidus fossils—seventeen fragments including skull, mandible and arm bones—from the Afar Depression in the Middle Awash river valley of Ethiopia. More fragments were recovered in 1994; this fossil was described as a species of Australopithecus, but White and his colleagues published a note in the same journal renaming the fossil under a new genus, Ardipithecus. Between 1999 and 2003, a multidisciplinary team led by Sileshi Semaw discovered bones and teeth of nine A. ramidus individuals at As Duma in the Gona Western Margin of Ethiopia's Afar Region. The fossils were dated to between 4.35 and 4.45 million years old.
Ardipithecus ramidus had a small brain, measuring between 300 and 350 cm3. This is smaller than a modern bonobo or female common chimpanzee brain, but much smaller than the brain of australopithecines like Lucy and 20% the size of the modern Homo sapiens brain. Like common chimpanzees, A. ramidus was much more prognathic than modern humans. The teeth of A. ramidus lacked the specialization of other apes, suggest that it was a generalized omnivore and frugivore with a diet that did not depend on foliage, fibrous plant material, or hard and or abrasive food. The size of the upper canine tooth in A. ramidus males was not distinctly different from that of females. Their upper canines were less sharp than those of modern common chimpanzees in part because of this decreased upper canine size, as larger upper canines can be honed through wear against teeth in the lower mouth; the features of the upper canine in A. ramidus contrast with the sexual dimorphism observed in common chimpanzees, where males have larger and sharper upper canine teeth than females.
The less pronounced nature of the upper canine teeth in A. ramidus has been used to infer aspects of the social behavior of the species and more ancestral hominids. In particular, it has been used to suggest that the last common ancestor of hominids and African apes was characterized by little aggression between males and between groups; this is markedly different from social patterns in common chimpanzees, among which intermale and intergroup aggression are high. Researchers in a 2009 study said that this condition "compromises the living chimpanzee as a behavioral model for the ancestral hominid condition."A. ramidus existed more than the most recent common ancestor of humans and chimpanzees and thus is not representative of that common ancestor. It is in some ways unlike chimpanzees, suggesting that the common ancestor differs from the modern chimpanzee. After the chimpanzee and human lineages diverged, both underwent substantial evolutionary change. Chimp feet are specialized for grasping trees.
The canine teeth of A. ramidus are smaller, equal in size between males and females, which suggests reduced male-to-male conflict, increased pair-bonding, increased parental investment. "Thus, fundamental reproductive and social behavioral changes occurred in hominids long before they had enlarged brains and began to use stone tools," the research team concluded. On October 1, 2009, paleontologists formally announced the discovery of the complete A. ramidus fossil skeleton first unearthed in 1994. The fossil is the remains of a small-brained 50-kilogram female, nicknamed "Ardi", includes most of the skull and teeth, as well as the pelvis and feet, it was discovered in Ethiopia's harsh Afar desert at a site called Aramis in the Middle Awash region. Radiometric dating of the layers of volcanic ash encasing the deposits suggest that Ardi lived about 4.3-4.5 million years ago. This date, has been questioned by others. Fleagle and Kappelman suggest that the region in which Ardi was found is difficult to date radiometrically, they argue that Ardi should be dated at 3.9 million years.
The fossil is regarded by its describers as shedding light on a stage of human evolution about which little was known, more than a million years before Lucy, the iconic early human ancestor candidate who lived 3.2 million years ago, was discovered in 1974 just 74 km (46
The wolf known as the grey/gray wolf or timber wolf, is a canine native to the wilderness and remote areas of Eurasia and North America. It is the largest extant member of its family, with males averaging 43 -- females 36 -- 38.5 kg. It is distinguished from other Canis species by its larger size and less pointed features on the ears and muzzle, its winter fur is long and bushy and predominantly a mottled gray in color, although nearly pure white and brown to black occur. Mammal Species of the World, a standard reference work in zoology, recognises 38 subspecies of C. lupus. The gray wolf is the second most specialized member of the genus Canis, after the Ethiopian wolf, as demonstrated by its morphological adaptations to hunting large prey, its more gregarious nature, its advanced expressive behavior, it is nonetheless related enough to smaller Canis species, such as the coyote, golden jackal, to produce fertile hybrids. It is the only species of Canis to have a range encompassing both Eurasia and North America, originated in Eurasia during the Pleistocene, colonizing North America on at least three separate occasions during the Rancholabrean.
It is a social animal, travelling in nuclear families consisting of a mated pair, accompanied by the pair's adult offspring. The gray wolf is an apex predator throughout its range, with only humans and tigers posing a serious threat to it, it feeds on large ungulates, though it eats smaller animals, livestock and garbage. A seven-year-old wolf is considered to be old, the maximum lifespan is about 16 years; the global gray wolf population is estimated to be 300,000. The gray wolf is one of the world's best-known and most-researched animals, with more books written about it than any other wildlife species, it has a long history of association with humans, having been despised and hunted in most pastoral communities because of its attacks on livestock, while conversely being respected in some agrarian and hunter-gatherer societies. Although the fear of wolves is pervasive in many human societies, the majority of recorded attacks on people have been attributed to animals suffering from rabies. Non-rabid wolves have attacked and killed people children, but this is rare, as wolves are few, live away from people, have developed a fear of humans from hunters and shepherds.
The English'wolf' stems from the Old English wulf, itself thought to be derived from the Proto-Germanic *wulfaz. The Latin lupus is a Sabine loanword. Both derive from the Proto-Indo-European root * lukwos; the species Canis lupus was first recorded by Carl Linnaeus in his publication Systema Naturae in 1758, with the Latin classification translating into the English words "dog wolf". The 37 subspecies of Canis lupus are listed under the designated common name of "wolf" in Mammal Species of the World, published in 2005; the nominate subspecies is the Eurasian wolf known as the common wolf. The subspecies includes the domestic dog, eastern wolf and red wolf, but lists C. l. italicus as a synonym of C. l. lupus. However, the classification of several as either species or subspecies has been challenged; the evolution of the wolf occurred over a geologic time scale of at least 300,000 years. The gray wolf Canis lupus is a adaptable species, able to exist in a range of environments and which possesses a wide distribution across the Holarctic.
Studies of modern gray wolves have identified distinct sub-populations that live in close proximity to each other. This variation in sub-populations is linked to differences in habitat – precipitation, temperature and prey specialization – which affect cranio-dental plasticity; the archaeological and paleontological records show gray wolf continuous presence for at least the last 300,000 years. This continuous presence contrasts with genomic analyses, which suggest that all modern wolves and dogs descend from a common ancestral wolf population that existed as as 20,000 years ago; these analyses indicate a population bottleneck, followed by a rapid radiation from an ancestral population at a time during, or just after, the Last Glacial Maximum. However, the geographic origin of this radiation is not known. In 2018, whole genome sequencing was used to compare members of the genus Canis, along with the dhole and the African hunting dog. There is evidence of gene flow between African golden wolves, golden jackals, gray wolves.
One African golden wolf from the Egyptian Sinai Peninsula showed high admixture with the Middle Eastern gray wolves and dogs, highlighting the role of the land bridge between the African and Eurasian continents in canid evolution. There was evidence of gene flow between golden jackals and Middle Eastern wolves, less so with European and Asian wolves, least with North American wolves; the study proposes that the golden jackal ancestry found in North American wolves may have occurred before the divergence of the Eurasian and North American gray wolves. The study indicates that the common ancestor of the coyote and gray wolf has genetically admixed with a ghost population of an extinct unidentified canid; the canid is genetically close to the dhole and has evolved after the divergence of the African hunting dog from the other canid species. The basal position of the coyote compared to the wolf is proposed to be due to the coyote retaining more of the mitochondrial genome of this unknown canid.
In 2013, a genetic study found that the wolf population in Europe was divided along a north-south axis and formed five major clusters. Three clusters were identified occupying southern and
The Hominidae, whose members are known as great apes or hominids, are a taxonomic family of primates that includes eight extant species in four genera: Pongo, the Bornean and Tapanuli orangutan. Several revisions in classifying the great apes have caused the use of the term "hominid" to vary over time, its original meaning referred only to their closest extinct relatives. That restrictive meaning has now been assumed by the term "hominin", which comprises all members of the human clade after the split from the chimpanzees; the current, 21st-century meaning of "hominid" includes all the great apes including humans. Usage still varies and some scientists and laypersons still use "hominid" in the original restrictive sense. Within the taxon Hominidae, a number of extant and known extinct, that is, genera are grouped with the humans and gorillas in the subfamily Homininae; the most recent common ancestor of all Hominidae lived 14 million years ago, when the ancestors of the orangutans speciated from the ancestral line of the other three genera.
Those ancestors of the family Hominidae had speciated from the family Hylobatidae 15 million to 20 million years ago. In the early Miocene, about 22 million years ago, there were many species of arboreally adapted primitive catarrhines from East Africa. Fossils at 20 million years ago include fragments attributed to Victoriapithecus, the earliest Old World monkey. Among the genera thought to be in the ape lineage leading up to 13 million years ago are Proconsul, Dendropithecus, Nacholapithecus, Nyanzapithecus, Afropithecus and Kenyapithecus, all from East Africa. At sites far distant from East Africa, the presence of other generalized non-cercopithecids, that is, non-monkey primates, of middle Miocene age—Otavipithecus from cave deposits in Namibia, Pierolapithecus and Dryopithecus from France and Austria—is further evidence of a wide diversity of ancestral ape forms across Africa and the Mediterranean basin during the warm and equable climatic regimes of the early and middle Miocene; the most recent of these far-flung Miocene apes is Oreopithecus, from the fossil-rich coal beds in northern Italy and dated to 9 million years ago.
Molecular evidence indicates that the lineage of gibbons, the lesser apes, diverged from that of the great apes some 18–12 million years ago, that of orangutans diverged from the other great apes at about 12 million years. There are no fossils that document the ancestry of gibbons, which may have originated in a still-unknown South East Asian hominoid population. Species close to the last common ancestor of gorillas and humans may be represented by Nakalipithecus fossils found in Kenya and Ouranopithecus found in Greece. Molecular evidence suggests that between 8 and 4 million years ago, first the gorillas, the chimpanzees split off from the line leading to the humans. Human DNA is 98.4% identical to that of chimpanzees when comparing single nucleotide polymorphisms. The fossil record, however, of gorillas and chimpanzees is limited. Other hominins adapted to the drier environments outside the African equatorial belt; the wet equatorial belt contracted after about 8 million years ago, there is little fossil evidence for the divergence of the hominin lineage from that of gorillas and chimpanzees—which split was thought to have occurred around that time.
The earliest fossils argued by some to belong to the human lineage are Sahelanthropus tchadensis and Orrorin tugenensis, followed by Ardipithecus, with species Ar. kadabba and Ar. ramidus. The classification of the great apes has been revised several times in the last few decades; the original meaning of the term referred to only humans and their closest relatives—what is now the modern meaning of the term "hominin". The meaning of the taxon Hominidae changed leading to a different usage of "hominid" that today includes all the great apes including humans; the term hominid is confused with a number of similar words: A hominoid called an ape, is a member of the superfamily Hominoidea: extant members are the gibbons and the hominids. A hominid is a member of the family Hominidae, the great apes: orangutans, gorillas and humans. A hominine is a member of the subfamily Homininae: gorillas and humans. A hominin is a member of the tribe Hominini: humans. A homininan, following a suggestion by Wood and Richmond, would be a member of the subtribe Homin
A landrace is a domesticated, locally adapted, traditional variety of a species of animal or plant that has developed over time, through adaptation to its natural and cultural environment of agriculture and pastoralism, due to isolation from other populations of the species. Landraces are distinguished from cultivars, from breeds in the standardized sense, although the term landrace breed is sometimes used as distinguished from the term standardized breed when referring to cattle. Specimens of a landrace tend to be genetically uniform, but are more diverse than members of a standardized or formal breed; some standardized animal breeds originate from attempts to make landraces more consistent through selective breeding and a landrace may become a more formal breed with the creation of a breed registry and/or publication of a breed standard. In such a case, the landrace may be thought of as a "stage" in breed development. However, in other cases, formalizing a landrace may result in the genetic resource of a landrace being lost through crossbreeding.
Landraces are distinct from ancestral wild species of modern stock, from separate species or subspecies derived from the same ancestor as modern domestic stock. Landraces are not all derived from ancient stock unmodified by human breeding interests. In a number of cases, most dogs and horses, domestic animals have escaped in sufficient numbers in an area to breed feral populations that, through evolutionary pressure, can form new landraces in only a few centuries. In other cases, simple failure to maintain breeding regimens can do the same. For example, selectively bred cultivars can become new landraces when loosely selective reproduction is applied. Increasing adoption of and reliance upon modern, purposefully selected plant strains, considered improved – "scientifically bred to be uniform and stable" – has led to a reduction in biodiversity; the majority of the genetic diversity of domesticated species lies in landraces and other traditionally used varieties, a "reservoir of genetic resources".
General features that characterize a landrace may include: It is morphologically distinctive and identifiable, yet remains "dynamic". It is genetically adapted to, has a reputation for being able to withstand, the conditions of the local environment, including climate and pests cultural practices, it is not the product of formal breeding programs, may lack systematic selection and improvement by breeders. It is maintained and fostered less deliberately than a standardized breed, with its genetic isolation principally a matter of geography acting upon whatever animals that happened to be brought by humans to a given area, it has a historical origin in a specific geographic area, will have its own local name, will be classified according to intended purpose. Where yield can be measured, a landrace will show high stability of yield under adverse conditions, but a moderate yield level under managed conditions. At the level of genetic testing, its heredity will show a degree of integrity, but still some genetic heterogeneity.
Not every source on the topic enumerates each of these criteria, they may be weighted differently depending on a given source's focus. Additionally, not all cultivars agreed to be landraces exhibit all possible landrace characteristics. Plant landraces have been the subject of more intensive study, the majority of the academic literature about landraces is focused on agricultural botany, not animal husbandry. Most plant landraces are associated with traditional agricultural systems. While many landrace animals are associated with farming, other domestic animals have been put to use as modes of transportation, as companion animals, for sporting purposes, for other non-farming uses, so their geographic distribution may differ. For example, horse landraces are less common because human use of them for transport has meant that they have moved with people more and than most other domestic animals, reducing the incidence of populations locally genetically isolated for extensive periods of time; the word landrace means'country-breed' and close cognates of it are found in various Germanic languages.
The term was first defined by Kurt von Rümker in 1908, more described in 1909 by U. J. Mansholt, who wrote that landraces have better "stability of their characteristics" and "resistance capacity to tolerate adverse influences" but lower production capacity than cultivars, are apt to change genetically when moved to another environment. H. Kiessling added in 1912 that a landrace is a mixture of phenotypic forms despite relative outward uniformity, a great adaptability to its natural and human environment; the word entered non-academic English in the early 1930s, by way of the Danish Landrace pig, a particular breed of lop-eared swine. Aside from some standardized breeds having "Landrace" in their names, actual landraces and standardized breeds are sometimes further confused when the word "breed" is used broadly; as one example, a glossary in a Food and Agriculture Organization of the United Nations guideline defines landrace or landrace breed as "a breed that has developed through adaptation to the natural environment and traditional production system in which it has been raised".
It defines breed expansively and in multiple ways, with a focus on t
Houghton Mifflin Harcourt
Houghton Mifflin Harcourt is a publisher of textbooks, instructional technology materials, reference works, fiction and non-fiction for both young readers and adults. The company is based in Boston's Financial District; the company was known as Houghton Mifflin Company but changed its name following the 2007 acquisition of Harcourt Publishing. Prior to March 2010, it was a subsidiary of Education Media and Publishing Group Limited, an Irish-owned holding company registered in the Cayman Islands and known as Riverdeep. In 1832, William Ticknor and John Allen purchased a bookselling business in Boston and began to involve themselves in publishing. James Thomas Fields joined as a partner in 1843 and with Tickner gathered an impressive list of writers, including Ralph Waldo Emerson, Nathaniel Hawthorne, Henry David Thoreau; the duo formed a close relationship with Riverside Press, a Boston printing company owned by Henry Oscar Houghton. Houghton founded his own publishing company with partner Melancthon Hurd in 1864, with George Mifflin joining the partnership in 1872.
In 1878, Ticknor and Fields, now under the leadership of James R. Osgood, found itself in financial difficulties and merged its operations with Hurd and Houghton; the new partnership, named Houghton and Company, held the rights to the literary works of both publishers. When Osgood left the firm two years the business reemerged as Houghton and Company. Despite a lucrative partnership with Lawson Valentine, Houghton and Company still had debt it had inherited from Ticknor and Fields, so it decided to add partners. In 1884 James D. Hurd, the son of Melancthon Hurd, became a partner. In 1888, three others became partners as well: James Murray Kay, Thurlow Weed Barnes, Henry Oscar Houghton Jr. Shortly thereafter, the company established an Educational Department, from 1891 to 1908 sales of educational materials increased by 500 percent; the firm incorporated in 1908. Soon after 1916, Houghton Mifflin became involved in publishing standardized tests and testing materials, working with such test developers as E. F. Lindquist.
By 1921, the company was the fourth-largest educational publisher in the United States. In 1961, Houghton Mifflin famously passed on Julia Child's Mastering the Art of French Cooking, giving it up to Alfred A. Knopf who published it in 1962, it is considered by many to be the bible of French cooking. Houghton Mifflin's strategic error was depicted in the 2009 film Julia. In 1967, Houghton Mifflin became a publicly traded company on the New York Stock Exchange under the stock symbol HTN. In 1979, Houghton Mifflin acquired the children's division of Seabury Press. Under president Nader F. Darehshori Houghton Mifflin acquired McDougal Littell in 1994 for $138 million, an educational publisher of secondary school materials, the following year acquired D. C. Heath and Company, a publisher of supplemental educational resources. In 1996, the company created their Great Source Education Group to combine the supplemental material product lines of their School Division and these two companies. In 1998, HMH announced a sub-brand called LOGAL Software, to release a new line of interactive science software called Science Gateways, to support the United States curriculum.
As of 2017, Houghton Mifflin Harcourt is offering the "Logal Science" brand as a licensing opportunity on its website. In 2017, it was announced that Houghton Mifflin Harcourt would be getting involved in TV production with a planned 2019 Netflix series that will revive the Carmen Sandiego franchise. Mergers and acquisitions activities have had major effects on this company. In 2001, Houghton Mifflin was acquired by French media giant Vivendi Universal for $2.2 billion including assumed debt. In 2002, facing mounting financial and legal pressures, Vivendi sold Houghton to private equity investors Thomas H. Lee Partners, Bain Capital, Blackstone Group for $1.66 billion, including assumed debt. On December 22, 2006, it was announced that Riverdeep PLC had completed its acquisition of Houghton Mifflin; the new joint enterprise would be called the Houghton Mifflin Riverdeep Group. Riverdeep paid $1.75 billion in cash and assumed $1.61 billion in debt from the private investment firms Thomas H. Lee Partners, Bain Capital and Blackstone Group.
Tony Lucki, a former non-executive director of Riverdeep, remained in his position as the company's chief executive officer until April 2009. Houghton Mifflin sold its professional testing unit, Promissor, to Pearson plc in 2006; the company combined its remaining assessment products within Riverside Publishing, including San Francisco-based Edusoft. On July 16, 2007, Houghton Mifflin Riverdeep announced that it signed a definitive agreement to acquire the Harcourt Education, Harcourt Trade and Greenwood-Heinemann divisions of Reed Elsevier for $4 billion; the expanded company would become Houghton Mifflin Harcourt. McDougal Littell was merged with Harcourt's Rinehart & Winston to form Holt McDougal. On December 3, 2007, Cengage Learning announced that it had agreed to acquire the assets of the Houghton Mifflin College Division for $750 million, pending regulatory approval. On November 25, 2008, Houghton Mifflin Harcourt announced a temporary freeze on acquisition of new trade division titles in response to the economic crisis of 2008.
The publisher of the trade division resigned in protest. Many observers familiar with the publishing industry saw the move as a devastating blunder. Harcourt Religion was sold to Our Sunday Visitor in 2009. On July 27, 2009, the Irish
Social Darwinism is the application of the evolutionary concept of natural selection to human society. The term itself emerged in the 1880s, it gained widespread currency when used after 1944 by opponents of these ways of thinking; the majority of those who have been categorized as social Darwinists did not identify themselves by such a label. Scholars debate the extent to which the various social Darwinist ideologies reflect Charles Darwin's own views on human social and economic issues, his writings have passages that can be interpreted as opposing aggressive individualism, while other passages appear to promote it. Darwin's early evolutionary views and his opposition to slavery ran counter to many of the claims that social Darwinists would make about the mental capabilities of the poor and colonial indigenes. After the publication of On the Origin of Species in 1859, one strand of Darwins' followers, led by Sir John Lubbock, argued that natural selection ceased to have any noticeable effect on humans once organised societies had been formed.
But some scholars argue that Darwin's view changed and came to incorporate views from other theorists such as Herbert Spencer. Spencer published his Lamarckian evolutionary ideas about society before Darwin first published his hypothesis in 1859, both Spencer and Darwin promoted their own conceptions of moral values. Spencer supported laissez-faire capitalism on the basis of his Lamarckian belief that struggle for survival spurred self-improvement which could be inherited. An important proponent in Germany was Ernst Haeckel, who popularized Darwin's thought and used it as well to contribute to a new creed, the monist movement; the term Darwinism was coined by Thomas Henry Huxley in his March 1861 review of On the Origin of Species, by the 1870s it was used to describe a range of concepts of evolution or development, without any specific commitment to Charles Darwin's theory of natural selection. The first use of the phrase "social Darwinism" was in Joseph Fisher's 1877 article on The History of Landholding in Ireland, published in the Transactions of the Royal Historical Society.
Fisher was commenting on how a system for borrowing livestock, called "tenure" had led to the false impression that the early Irish had evolved or developed land tenure. It has appeared necessary to devote some space to this subject, inasmuch as that acute writer Sir Henry Maine has accepted the word " tenure " in its modern interpretation, has built up a theory under which the Irish chief " developed " into a feudal baron. I can find nothing in the Brehon laws to warrant this theory of social Darwinism, believe further study will show that the Cain Saerrath and the Cain Aigillue relate to what we now call chattels, did not in any way affect what we now call the freehold, the possession of the land. Despite the fact that Social Darwinism bears Charles Darwin's name, it is linked today with others, notably Herbert Spencer, Thomas Malthus, Francis Galton, the founder of eugenics. In fact, Spencer was not described as a social Darwinist until the 1930s, long after his death; the social Darwinism term first appeared in Europe in 1880, journalist Emilie Gautier had coined the term with reference to a health conference in Berlin 1877.
Around 1900 it was used by some being opposed to the concept. The term was popularized in the United States in 1944 by the American historian Richard Hofstadter who used it in the ideological war effort against fascism to denote a reactionary creed which promoted competitive strife and chauvinism. Hofstadter also recognized the influence of Darwinist and other evolutionary ideas upon those with collectivist views, enough to devise a term for the phenomenon, "Darwinist collectivism". Before Hofstadter's work the use of the term "social Darwinism" in English academic journals was quite rare. In fact... There is considerable evidence that the entire concept of "social Darwinism" as we know it today was invented by Richard Hofstadter. Eric Foner, in an introduction to a then-new edition of Hofstadter's book published in the early 1990s, declines to go quite that far. "Hofstadter did not invent the term Social Darwinism", Foner writes, "which originated in Europe in the 1860s and crossed the Atlantic in the early twentieth century.
But before he wrote, it was used only on rare occasions. Social Darwinism has many definitions, some of them are incompatible with each other; as such, social Darwinism has been criticized for being an inconsistent philosophy, which does not lead to any clear political conclusions. For example, The Concise Oxford Dictionary of Politics states:Part of the difficulty in establishing sensible and consistent usage is that commitment to the biology of natural selection and to'survival of the fittest' entailed nothing uniform either for sociological method or for political doctrine. A'social Darwinist' could just as well be a defender of laissez-faire as a defender of state socialism, just as much an imperialist as a domestic eugenist; the term "Social Darwinism" has been used by advocates of the supposed ideologies or ideas. The term draws upon the common meaning of Darwinism, which includes a range of evolutionary views, but in the late 19th century was applied more to natural selection as first advanced by Charles Darwin to explain
Mutualism describes the ecological interaction between two or more species where each species benefits. Mutualism is thought to be the most common type of ecological interaction, it is dominant in most communities worldwide. Prominent examples include most vascular plants engaged in mutualistic interactions with mycorrhizae, flowering plants being pollinated by animals, vascular plants being dispersed by animals, corals with zooxanthellae, among many others. Mutualism can be contrasted with interspecific competition, in which each species experiences reduced fitness, exploitation, or parasitism, in which one species benefits at the "expense" of the other. Mutualism is conflated with two other types of ecological phenomena: cooperation and symbiosis. Cooperation refers to increases in fitness through within-species interactions. Symbiosis involves two species living in close proximity and may be mutualistic, parasitic, or commensal, so symbiotic relationships are not always mutualistic. Mutualism plays a key part in ecology.
For example, mutualistic interactions are vital for terrestrial ecosystem function as more than 48% of land plants rely on mycorrhizal relationships with fungi to provide them with inorganic compounds and trace elements. As another example, the estimate of tropical forest trees with seed dispersal mutualisms with animals ranges from 70–90%. In addition, mutualism is thought to have driven the evolution of much of the biological diversity we see, such as flower forms and co-evolution between groups of species. However, mutualism has received less attention than other interactions such as predation and parasitism; the term mutualism was introduced by Pierre-Joseph van Beneden in his 1876 book Animal Parasites and Messmates. Mutualistic relationships can be thought of as a form of "biological barter" in mycorrhizal associations between plant roots and fungi, with the plant providing carbohydrates to the fungus in return for phosphate but nitrogenous compounds. Other examples include rhizobia bacteria that fix nitrogen for leguminous plants in return for energy-containing carbohydrates.
Service-resource relationships are common. Three important types are pollination, cleaning symbiosis, zoochory. In pollination, a plant trades food resources in the form of nectar or pollen for the service of pollen dispersal. Phagophiles feed on ectoparasites, as in cleaning symbiosis. Elacatinus and Gobiosoma, genera of gobies feed on ectoparasites of their clients while cleaning them. Zoochory is the dispersal of the seeds of plants by animals; this is similar to pollination in that the plant produces food resources for animals that disperse the seeds. Another type is ant protection of aphids, where the aphids trade sugar-rich honeydew in return for defense against predators such as ladybugs. Strict service-service interactions are rare, for reasons that are far from clear. One example is the relationship between sea anemones and anemone fish in the family Pomacentridae: the anemones provide the fish with protection from predators and the fish defend the anemones against butterflyfish, which eat anemones.
However, in common with many mutualisms, there is more than one aspect to it: in the anemonefish-anemone mutualism, waste ammonia from the fish feed the symbiotic algae that are found in the anemone's tentacles. Therefore, what appears to be a service-service mutualism in fact has a service-resource component. A second example is that of the relationship between some ants in the genus Pseudomyrmex and trees in the genus Acacia, such as the whistling thorn and bullhorn acacia; the ants nest inside the plant's thorns. In exchange for shelter, the ants protect acacias from attack by herbivores and competition from other plants by trimming back vegetation that would shade the acacia. In addition, another service-resource component is present, as the ants feed on lipid-rich food-bodies called Beltian bodies that are on the Acacia plant. In the neotropics, the ant Myrmelachista schumanni makes its nest in special cavities in Duroia hirsute. Plants in the vicinity that belong to other species are killed with formic acid.
This selective gardening can be so aggressive that small areas of the rainforest are dominated by Duroia hirsute. These peculiar patches are known by local people as "devil's gardens". In some of these relationships, the cost of the ant’s protection can be quite expensive. Cordia sp. trees in the Amazonian rainforest have a kind of partnership with Allomerus sp. ants, which make their nests in modified leaves. To increase the amount of living space available, the ants will destroy the tree’s flower buds; the flowers leaves develop instead, providing the ants with more dwellings. Another type of Allomerus sp. ant lives with the Hirtella sp. tree in the same forests, but in this relationship the tree has turned the tables on the ants. When the tree is ready to produce flowers, the ant abodes on certain branches begin to wither and shrink, forcing the occupants to flee, leaving the tree’s flowers to develop free from ant attack; the term "species group" can be used to describe the manner in which individual organisms group together.
In this non-taxonomic context one can refer to "same-species groups" and "mixed-species groups." While same-species groups are the norm, examples of mixed-species groups abound. For example and wildebeest can