In language, a clause is the smallest grammatical unit that can express a complete proposition. A typical clause consists of a subject and a predicate, the latter a verb phrase, a verb with any objects and other modifiers. However, the subject is sometimes not said or explicit the case in null-subject languages if the subject is retrievable from context, but it sometimes occurs in other languages such as English. A simple sentence consists of a single finite clause with a finite verb, independent. More complex sentences may contain multiple clauses. Main clauses are those. Subordinate clauses are those that would be incomplete if they were alone. A primary division for the discussion of clauses is the distinction between main clauses and subordinate clauses. A main clause can stand alone, i.e. it can constitute a complete sentence by itself. A subordinate clause, in contrast, is reliant on the appearance of a main clause. A second major distinction concerns the difference between non-finite clauses.
A finite clause contains a structurally central finite verb, whereas the structurally central word of a non-finite clause is a non-finite verb. Traditional grammar focuses on finite clauses, the awareness of non-finite clauses having arisen much in connection with the modern study of syntax; the discussion here focuses on finite clauses, although some aspects of non-finite clauses are considered further below. Clauses can be classified according to a distinctive trait, a prominent characteristic of their syntactic form; the position of the finite verb is one major trait used for classification, the appearance of a specific type of focusing word is another. These two criteria overlap to an extent, which means that no single aspect of syntactic form is always decisive in determining how the clause functions. There are, strong tendencies. Standard SV-clauses are the norm in English, they are declarative. The pig has not yet been fed. - Declarative clause, standard SV order I've been hungry for two hours.
- Declarative clause, standard SV order...that I've been hungry for two hours. - Declarative clause, standard SV order, but functioning as a subordinate clause due to the appearance of the subordinator thatDeclarative clauses like these are by far the most occurring type of clause in any language. They can be viewed as other clause types being derived from them. Standard SV-clauses can be interrogative or exclamative, given the appropriate intonation contour and/or the appearance of a question word, e.g. a. The pig has not yet been fed? - Rising intonation on fed makes the clause a yes/no-question.b. The pig has not yet been fed! - Spoken forcefully, this clause is exclamative.c. You've been hungry for how long? - Appearance of interrogative word how and rising intonation make the clause a constituent questionExamples like these demonstrate that how a clause functions cannot be known based on a single distinctive syntactic criterion. SV-clauses are declarative, but intonation and/or the appearance of a question word can render them interrogative or exclamative.
Verb first clauses in English play one of three roles: 1. They express a yes/no-question via subject–auxiliary inversion, 2, they express a condition as an embedded clause, or 3. They express a command via e.g. a. He must stop laughing. - Standard declarative SV-clause b. Should he stop laughing? - Yes/no-question expressed by verb first order c. Had he stopped laughing... - Condition expressed by verb first order d. Stop laughing! - Imperative formed with verb first ordera. They have done the job. - Standard declarative SV-clause b. Have they done the job? - Yes/no-question expressed by verb first order c. Had they done the job... - Condition expressed by verb first order d. Do the job! - Imperative formed with verb first orderMost verb first clauses are main clauses. Verb first conditional clauses, must be classified as embedded clauses because they cannot stand alone. Wh-clauses contain a wh-word. Wh-words serve to help express a constituent question, they are prevalent, though, as relative pronouns, in which case they serve to introduce a relative clause and are not part of a question.
The wh-word focuses a particular constituent and most of the time, it appears in clause-initial position. The following examples illustrate standard interrogative wh-clauses; the b-sentences are direct questions, the c-sentences contain the corresponding indirect questions: a. Sam likes the meat. - Standard declarative SV-clause b. Who likes the meat? - Matrix interrogative wh-clause focusing on the subject c. They asked. - Embedded interrogative wh-clause focusing on the subjecta. Larry sent Susan to the store. - Standard declarative SV-clause b. Whom did Larry send to the store? - Matrix interrogative wh-clause focusing on the object, subject-auxiliary inversion present c. We know. - Embedded wh-clause focusing on the object, subject-auxiliary inversion absenta. Larry sent Susan to the store. - Standard declarative SV-clause b. Where did Larry send Susan? - Matrix interrogative wh-clause focusing on the ob
European early modern humans
European early modern humans in the context of the Upper Paleolithic in Europe refers to the early presence of anatomically modern humans in Europe. The term "early modern" is taken to include fossils of the Bohunician, Aurignacian, Gravettian and Magdalenian, extending throughout the Last Glacial Maximum, covering the period of 48,000 to 15,000 years ago referred to as the Cro-Magnon; the earliest sites in Europe dated 48,000 years ago are Riparo Mochi, Geissenklösterle, Isturitz The upper limit of 15,000 marks the transition to the European Mesolithic, depending on the region given in the range of 12,000 to 10,000 years ago. Use of "Cro-Magnon" is to times after the beginning of the Aurignacian proper, c. 37 to 35 ka. Genetically, EEMH form an isolated population between 37 and 14 ka, with significant Mesolithic admixture from the Near East and Caucasus beginning around 14 ka; the description as "modern" is used as contrasting with the "archaic" Neanderthals who lived within Europe from 400,000 to 37,000 years ago.
The term EEMH is equivalent to Cro-Magnon Man, or Cro-Magnons, a term derived from the Cro-Magnon rock shelter in southwestern France, where the first EEMH were found in 1868. Louis Lartet proposed Homo sapiens fossilis as the systematic name for "Cro-Magnon Man". W. K. Gregory proposed the subspecies name Homo sapiens cro-magnonensis. In literature published since the late 1990s, the term EEMH is preferred over the common name Cro-Magnon, which has no formal taxonomic status, as it refers neither to a species or subspecies nor to an archaeological phase or culture. Another known remains of EEMH can be dated to before 40,000 years ago with some certainty: those from Grotta del Cavallo in Italy, from Kents Cavern in England, have been radiocarbon dated to 45–41 ka. A number of other early fossils are dated close to or just after 40ka, including fossils found in Romania and Russia; the Siberian Ust'-Ishim man, dated to 45 ka, was not geographically found in Europe, indeed is not part of the "Western Eurasian" genetic lineage, but intermediate between the Western Eurasian and East Asian lineages.
The EEMH lineage in the European Mesolithic is known as "West European Hunter-Gatherer". These mesolithic hunter-gatherers emerge after the end of the LGM ca. 15 ka and are described as more gracile than the Upper Paleolithic Cro-Magnons. The WHG lineage survives in contemporary Europeans, albeit only as a minor contribution overwhelmed by the Neolithic and Bronze Age migrations. While anatomically modern humans may have been present in West Asia since before 250 ka, modern non-Africans descend from the main successful out of Africa expansion at around 65 ka; this movement was an offshoot of the rapid expansion within East Africa associated with mtDNA haplogroup L3. EEMH are associated with mtDNA haplogroup N widespread in Central Asia, with Y-chromosomal haplogroup IJK. AMH are estimated to have interbred with Neanderthals during about 65 to 47 ka, most in West Asia, it is this basal West Eurasian lineage. Neanderthals became extinct shortly after this time being outcompeted or killed by the advancing EEMH.
Admixture with Neanderthals appears to cease entirely after 45 ka, in spite of several millennia of continued co-existence of AMH and Neanderthals in Europe. There are two main hypotheses as to the route taken by the earliest AMH entering Europe, following the Danubian corridor or the Mediterranean coast along the Balkans. Support for either hypothesis relies on accurate dating of the earliest known fossils in the region. High-precision dating of the earliest Proto-Aurignacian sites in Europe, Riparo Mochi, Geissenklösterle, Isturitz, have yielded dates of close to 42 ka, indicating that EEMH spread throughout Western Europe rapidly. EEMH sites in Europe earlier than 37 ka are termed Proto-Aurignacian; the Aurignacian proper, the stage associated with the original Cro-Magnon find, appears to have developed within Europe. It lasts from 37 ka until about 28 ka; the Gravettian is the European culture preceding the LGM, about 28 to 22 ka, but the early Gravettian overlaps with the Aurignacian, from as early as 33 ka.
During the LGM proper, beginning about 22 ka, there are two main refugia, the Solutrean in Southwestern Europe, the Epi-Gravettian in Italy and Southeastern Europe. With advancing deglaciation, after about 17 ka, finds associated with the Magdalenian, are transitional to the mesolithic hunter-gatherer populations; the European Mesolithic is taken to begin after about 14 ka. Cro-Magnons were anatomically modern, straight limbed and tall compared to the contemporaneous Neanderthals, they are thought to have stood on average 1.66 to 1.71 m tall. They differ from modern-day humans in having a more robust physique and a larger cranial capacity; the Cro-Magnons had low skulls, with wide faces, robust mandibles, blunted chins, narrow noses, moderate to no prognathism. A distinctive trait was the rectangular eye orbits, similar to those of modern Ainu people, their vocal apparatus was like that of present-day humans and they could speak. Their brain capacity was about 1,600 cc, larger than the average for modern Europeans.
Mitochondrial DNA analysis places the early European population as sister group to the East Asian groups of the Upper Paleolithic, dating the divergence to some 50,000 years ago. Analysis of ancient DNA of EEMH and Mesolithic fossils suggests that alleles related to the light skin characteristic of mode
In any given society, a taboo is an implicit prohibition on something based on a cultural sense that it is excessively repulsive or too sacred for ordinary people. Such prohibitions are present in all societies. On a comparative basis taboos, for example related to food items, seem to make no sense at all as what may be declared unfit for one group by custom or religion may be acceptable to another. Whether scientifically correct or not, taboos are meant to protect the human individual, but there are numerous other reasons for their existence. An ecological or medical background is apparent in many, including some that are seen as religious or spiritual in origin. Taboos can help use a resource more efficiently, but when applied to only a subsection of the community they can serve to suppress a subsection of the community. A taboo acknowledged by a particular group or tribe as part of their ways, aids in the cohesion of the group, helps that particular group to stand out and maintain its identity in the face of others and therefore creates a feeling of "belonging".
The meaning of the word "taboo" has been somewhat expanded in the social sciences to strong prohibitions relating to any area of human activity or custom, sacred or forbidden based on moral judgment, religious beliefs, or cultural norms. "Breaking a taboo" is considered objectionable by society in general, not a subset of a culture. The term "taboo" comes from the Tongan tapu or Fijian tabu, related among others to the Maori tapu and Hawaiian kapu, its English use dates to 1777 when the British explorer James Cook visited Tonga, referred to the Tongans' use of the term "taboo" for "any thing is forbidden to be eaten, or made use of". He wrote: Not one of them would sit down, or eat a bit of any thing.... On expressing my surprise at this, they were all taboo; the term was translated to him as "consecrated, forbidden, unclean or cursed." Tabu itself has been derived from alleged Tongan morphemes ta and bu, but this may be a folk etymology, tapu is treated as a unitary, non-compound word inherited from Proto-Polynesian *tapu, in turn inherited from Proto-Oceanic *tabu, with the reconstructed meaning "sacred, forbidden."
In its current use on Tonga, the word tapu means "sacred" or "holy" in the sense of being restricted or protected by custom or law. On the main island, the word is appended to the end of "Tonga" as Tongatapu, here meaning "Sacred South" rather than "Forbidden South". Sigmund Freud speculated that incest and patricide were the only two universal taboos and formed the basis of civilization. However, although cannibalism, in-group murder, incest are taboo in the majority of societies, exceptions can be found, such as marriages between brothers and sisters in Roman Egypt. Modern Western societies, however, do not condone such relationships; these familial sexual activities are criminalised if all parties are consenting adults. Through an analysis of the language surrounding these laws, it can be seen how the policy makers, society as a whole, find these acts to be immoral. Common taboos involve restrictions or ritual regulation of hunting. In Madagascar, a strong code of taboos, known as fady change and are formed from new experiences.
Each region, village or tribe may have its own fady. The word "taboo" gained popularity at times, with some scholars looking for ways to apply it where other English words had been applied. For example, J. M. Powis Smith, in his book The American Bible, used "taboo" in relation to Israel's Tabernacle and ceremonial laws, including Exodus 30:36, Exodus 29:37. Albert Schweitzer wrote a chapter about taboos of the people of Gabon; as an example, it was considered a misfortune for twins to be born, they would be subject to many rules not incumbent on other people. Communist and materialist theorists have argued that taboos can be used to reveal the histories of societies when other records are lacking. Marvin Harris endeavored to explain taboos as a consequence of ecologic and economic conditions; some argue that contemporary Western multicultural societies have taboos against tribalisms and prejudices. Changing social customs and standards create new taboos, such as bans on slavery. Incest itself has been pulled both ways, with some seeking to normalize consensual adult relationships regardless of the degree of kinship and others expanding the degrees of prohibited contact Although the term taboo implies negative connotations, it is sometimes associated with enticing propositions in proverbs such as forbidden fruit is the sweetest.
In medicine, professionals who practice in ethical and moral grey areas, or fields subject to social stigma such as late termination of pregnancy, may refrain from public d
Murray Gell-Mann is an American physicist who received the 1969 Nobel Prize in physics for his work on the theory of elementary particles. He is the Robert Andrews Millikan Professor of Theoretical Physics Emeritus at the California Institute of Technology, a distinguished fellow and co-founder of the Santa Fe Institute, a professor of physics at the University of New Mexico, the Presidential Professor of Physics and Medicine at the University of Southern California. Gell-Mann has spent several periods at CERN, among others as a John Simon Guggenheim Memorial Foundation fellow in 1972. Gell-Mann was born in lower Manhattan into a family of Jewish immigrants from the Austro-Hungarian Empire from Chernivtsi in present-day Ukraine, his parents were Arthur Isidore Gell-Mann, who taught English as a Second Language. Propelled by an intense boyhood curiosity and love for nature and mathematics, he graduated valedictorian from the Columbia Grammar & Preparatory School and subsequently entered Yale College at the age of 15 as a member of Jonathan Edwards College.
At Yale, he participated in the William Lowell Putnam Mathematical Competition and was on the team representing Yale University that won the second prize in 1947. Gell-Mann earned a bachelor's degree in physics from Yale in 1948 and a PhD in physics from Massachusetts Institute of Technology in 1951, his supervisor at MIT was Victor Weisskopf. In 1958, Gell-Mann and Richard Feynman, in parallel with the independent team of George Sudarshan and Robert Marshak, discovered the chiral structures of the weak interaction in physics; this work followed the experimental discovery of the violation of parity by Chien-Shiung Wu, as suggested by Chen Ning Yang and Tsung-Dao Lee, theoretically. Gell-Mann's work in the 1950s involved discovered cosmic ray particles that came to be called kaons and hyperons. Classifying these particles led him to propose that a quantum number called strangeness would be conserved by the strong and the electromagnetic interactions, but not by the weak interactions. Another of Gell-Mann's ideas is the Gell-Mann–Okubo formula, a formula based on empirical results, but was explained by his quark model.
Gell-Mann and Abraham Pais were involved in explaining several puzzling aspects of the physics of these particles. In 1961, this led him to introduce a classification scheme for hadrons, elementary particles that participate in the strong interaction; this scheme is now explained by the quark model. Gell-Mann referred to the scheme as the Eightfold Way, because of the octets of particles in the classification. In 1964, Gell-Mann and, George Zweig went on to postulate the existence of quarks, particles of which the hadrons of this scheme are composed; the name is a reference to the novel Finnegans Wake, by James Joyce. Zweig had referred to the particles as "aces". Quarks and gluons were soon established as the underlying elementary objects in the study of the structure of hadrons, he was awarded a Nobel Prize in physics in 1969 for his contributions and discoveries concerning the classification of elementary particles and their interactions. In 1972 he and Harald Fritzsch introduced the conserved quantum number "color charge", together with Heinrich Leutwyler, they coined the term quantum chromodynamics as the gauge theory of the strong interaction.
The quark model is a part of QCD, it has been robust enough to accommodate in a natural fashion the discovery of new "flavors" of quarks, which superseded the eightfold way scheme. He is the Robert Andrews Millikan Professor of Theoretical Physics Emeritus at California Institute of Technology as well as a University Professor in the Physics and Astronomy Department of the University of New Mexico in Albuquerque, New Mexico, the Presidential Professor of Physics and Medicine at the University of Southern California, he is a member of the editorial board of the Encyclopædia Britannica. In 1984 Gell-Mann co-founded the Santa Fe Institute—a non-profit theoretical research institute in Santa Fe, New Mexico—to study complex systems and disseminate the notion of a separate interdisciplinary study of complexity theory, he was a postdoctoral fellow at the Institute for Advanced Study in 1951, a visiting research professor at the University of Illinois at Urbana–Champaign from 1952 to 1953. He was a visiting associate professor at Columbia University and an associate professor at the University of Chicago in 1954–55 before moving to the California Institute of Technology, where he taught from 1955 until he retired in 1993.
During the 1990s, Gell-Mann's interest turned to the emerging study of complexity. He played a central role in the founding of the Santa Fe Institute, where he continues to work as a distinguished professor, he wrote a popular science book about these matters, The Quark and the Jaguar: Adventures in the Simple and the Complex. The title of the book is taken from a line of a poem by Arthur Sze: "The world of the quark has everything to do with a jaguar circling in the night"; the author George Johnson has written a biography of Gell-Mann, Strange Beauty: Murray Gell-Mann, the Revolution in 20th-Century Physics, shortlisted for the Royal Society Book Prize. Gell-Mann has criticized it as inaccurate; the Nobel Prize–winning physicist Philip Anderson, in his chapter on Gell-Mann from a 2011 book, says that Johnson's biography is excellent. Both Anderso
Recursion occurs when a thing is defined in terms of itself or of its type. Recursion is used in a variety of disciplines ranging from linguistics to logic; the most common application of recursion is in mathematics and computer science, where a function being defined is applied within its own definition. While this defines an infinite number of instances, it is done in such a way that no loop or infinite chain of references can occur. In mathematics and computer science, a class of objects or methods exhibit recursive behavior when they can be defined by two properties: A simple base case —a terminating scenario that does not use recursion to produce an answer A set of rules that reduce all other cases toward the base caseFor example, the following is a recursive definition of a person's ancestors: One's parents are one's ancestors; the ancestors of one's ancestors are one's ancestors. The Fibonacci sequence is a classic example of recursion: Fib = 0 as base case 1, Fib = 1 as base case 2, For all integers n > 1, Fib:= Fib + Fib.
Many mathematical axioms are based upon recursive rules. For example, the formal definition of the natural numbers by the Peano axioms can be described as: 0 is a natural number, each natural number has a successor, a natural number. By this base case and recursive rule, one can generate the set of all natural numbers. Recursively defined mathematical objects include functions and fractals. There are various more tongue-in-cheek "definitions" of recursion. Recursion is the process a procedure goes through when one of the steps of the procedure involves invoking the procedure itself. A procedure that goes through recursion is said to be'recursive'. To understand recursion, one must recognize the distinction between a procedure and the running of a procedure. A procedure is a set of steps based on a set of rules; the running of a procedure involves following the rules and performing the steps. An analogy: a procedure is like a written recipe. Recursion is related to, but not the same as, a reference within the specification of a procedure to the execution of some other procedure.
For instance, a recipe might refer to cooking vegetables, another procedure that in turn requires heating water, so forth. However, a recursive procedure is where one of its steps calls for a new instance of the same procedure, like a sourdough recipe calling for some dough left over from the last time the same recipe was made; this creates the possibility of an endless loop. If properly defined, a recursive procedure is not easy for humans to perform, as it requires distinguishing the new from the old invocation of the procedure. For this reason recursive definitions are rare in everyday situations. An example could be the following procedure to find a way through a maze. Proceed forward until reaching either an exit or a branching point. If the point reached is an exit, terminate. Otherwise try each branch in turn, using the procedure recursively. Whether this defines a terminating procedure depends on the nature of the maze: it must not allow loops. In any case, executing the procedure requires recording all explored branching points, which of their branches have been exhaustively tried.
Linguist Noam Chomsky among many others has argued that the lack of an upper bound on the number of grammatical sentences in a language, the lack of an upper bound on grammatical sentence length, can be explained as the consequence of recursion in natural language. This can be understood in terms of a recursive definition of a syntactic category, such as a sentence. A sentence can have a structure in which what follows the verb is another sentence: Dorothy thinks witches are dangerous, in which the sentence witches are dangerous occurs in the larger one. So a sentence can be defined recursively as something with a structure that includes a noun phrase, a verb, optionally another sentence; this is just a special case of the mathematical definition of recursion. This provides a way of understanding the creativity of language—the unbounded number of grammatical sentences—because it predicts that sentences can be of arbitrary length: Dorothy thinks that Toto suspects that Tin Man said that.... There are many structures apart from sentences that can be defined recursively, therefore many ways in which a sentence can embed instances of one
Polygenism is a theory of human origins which posits the view that the human races are of different origins. This view is opposite to the idea of monogenism. Modern scientific views no longer favor the polygenic model, with the monogenic "Out of Africa" theory and its variants being the most accepted models for human origins. Many oral traditions feature polygenesis in their creation stories. For example, Bambuti mythology and other creation stories from the pygmies of Congo state that the supreme God of the pygmies, created three different races of man separately out of three kinds of clay: one black, one white, one red. In some cultures, polygenism in the creation narrative served as an etiological function; these narratives provided an explanation as to why other people groups exist who are not affiliated with their tribe. Moreover, distinctions made between the creation of foreign people groups and the tribe or ethnic group to which the creation myth pertains served to reinforce tribal or ethnic unity, the need to exercise wariness and caution when dealing with outsiders, or the unique nature of the relationship between that tribe and the deities of their religious system.
An example may be found in the creation myth of the Asmat people, a hunter-gatherer tribe situated along the south-western coast of New Guinea. This creation myth asserts that the Asmat themselves came into being when a deity placed carved wooden statues in a ceremonial house and began to beat a drum; the statues began to dance. Some time a great crocodile attempted to attack this ceremonial house, but was defeated by the power of the deity; the crocodile was cut into several pieces and these were tossed in different directions. Each piece became one of the foreign tribes known to the Asmat; the idea is found in some ancient Greek and Roman literature. For example the Roman Emperor Julian the Apostate in his Letter to a Priest wrote that he believed Zeus made multiple creations of man and women. In his Against the Galilaens Julian presented his reasoning for this belief. Julian had noticed that the Germanics and Scythians were different in their bodies to the Ethiopians, he therefore could not imagine such difference in physical attributes as having originated from common ancestry, so maintained separate creations for different races.
In early classical and medieval geography the idea of polygenism surfaced because of the suggested possibility of there being inhabitants of the antipodes. These inhabitants were considered by some to have separate origins because of their geographical extremity; the religion of the Ainu people claims that the ancestors of the Ainu people arrived on Earth from the skies separate from the other races. See Ainu creation myth. Traditionally, most Jews and Muslims have embraced monogenism in the form that all modern humans are descended from a single mating pair, named Adam and Eve. In this context, polygenism described all alternative explanations for the origin of humankind that involved more than two individual "first people"; this definition of polygenism is still employed among some Creationists and within the Roman Catholic Church. With the development of the evolutionary paradigm of human origins, it has become recognized within the scientific community that at no point did there exist a single "first man" and a single "first woman" who constituted the first true humans and to whom all lineages of modern humans converge.
If Adam and Eve existed as distinct historical persons, they were members of a much larger population of the same species. However, a common scientific explanation of human origins asserts that the population directly ancestral to all modern humans remained united as a single population by constant gene flow. Therefore, on the level of the entire human population, this explanation of human origin is classified as monogenism. All modern humans share the same origin from this single ancestral population. Modern polygenists do not accept either scientific monogenism, they believe that the variation among human racial types cannot be accounted for by monogenism or by evolutionary processes occurring since the proposed recent African origin of modern humans. Polygenists reject the argument that human races must belong to a single species because they can interbreed. There are several polygenist hypotheses, including biblical creationist polygenism and polygenist evolution. To make polygenism compatible with the Biblical account in the early chapters of the Book of Genesis, some argument is needed to the effect that what is in the Bible is incomplete.
Three standard positions are: Pre-Adamism. In Christian terms, polygenesis remained an uncommon Biblical interpretation until the mid-19th century, was considered heretical. A major reason for the emergence of Biblical polygenism from around the 18th century was because it became noted that the number of races could not have developed within the commonly-accepted Biblical timeframe. Francis Dobbs, an eccentric member of the Irish Parliament, believed in a different kind of biblical polygenism. In his Concise View from History written in 1800 he maintained that there was a race resulting from a clandestine affair between Eve and the Devil. Polygenism was criticized in the 20th century Roman Catholic Church, by Pope Pius XII in the encyclical Humani
The Upper Paleolithic is the third and last subdivision of the Paleolithic or Old Stone Age. Broadly, it dates to between 50,000 and 10,000 years ago, according to some theories coinciding with the appearance of behavioral modernity and before the advent of agriculture. Anatomically modern humans are believed to have emerged out of Africa around 200,000 years ago, although these lifestyles changed little from that of archaic humans of the Middle Paleolithic, until about 50,000 years ago, when there was a marked increase in the diversity of artefacts; this period coincides with the expansion of modern humans from Africa throughout Asia and Eurasia, which contributed to the extinction of the Neanderthals. The Upper Paleolithic has the earliest known evidence of organized settlements, in the form of campsites, some with storage pits. Artistic work blossomed, with cave painting, petroglyphs and engravings on bone or ivory; the first evidence of human fishing is found, from artefacts in places such as Blombos cave in South Africa.
More complex social groupings emerged, supported by more varied and reliable food sources and specialized tool types. This contributed to increasing group identification or ethnicity; the peopling of Australia most took place before c. 60 ka. Europe was peopled after c. 45 ka. Anatomically modern humans are known to have expanded northward into Siberia as far as the 58th parallel by about 45 ka; the Upper Paleolithic is divided during about 25 to 15 ka. The peopling of the Americas occurred during this time, with East and Central Asia populations reaching the Bering land bridge after about 35 ka, expanding into the Americas by about 15 ka. In Western Eurasia, the Paleolithic eases into the so-called Epipaleolithic or Mesolithic from the end of the LGM, beginning 15 ka; the Holocene glacial retreat begins 11.7 ka, falling well into the Old World Epipaleolithic, marking the beginning of the earliest forms of farming in the Fertile Crescent. Both Homo erectus and Neanderthals used the same crude stone tools.
Archaeologist Richard G. Klein, who has worked extensively on ancient stone tools, describes the stone tool kit of archaic hominids as impossible to categorize, it was as if the Neanderthals made stone tools, were not much concerned about their final forms. He argues that everywhere, whether Asia, Africa or Europe, before 50,000 years ago all the stone tools are much alike and unsophisticated. Firstly among the artefacts of Africa, archeologists found they could differentiate and classify those of less than 50,000 years into many different categories, such as projectile points, engraving tools, knife blades, drilling and piercing tools; these new stone-tool types have been described as being distinctly differentiated from each other. The invaders referred to as the Cro-Magnons, left many sophisticated stone tools and engraved pieces on bone and antler, cave paintings and Venus figurines; the Neanderthals continued to use Mousterian stone tool technology and Chatelperronian technology. These tools disappeared from the archeological record at around the same time the Neanderthals themselves disappeared from the fossil record, about 40,000 cal BP.
Settlements were located in narrow valley bottoms associated with hunting of passing herds of animals. Some of them may have been occupied year round, though more they appear to have been used seasonally. Hunting was important, caribou/wild reindeer "may well be the species of single greatest importance in the entire anthropological literature on hunting."Technological advances included significant developments in flint tool manufacturing, with industries based on fine blades rather than simpler and shorter flakes. Burins and racloirs were used to work bone and hides. Advanced darts and harpoons appear in this period, along with the fish hook, the oil lamp and the eyed needle; the changes in human behavior have been attributed to changes in climate, encompassing a number of global temperature drops. These led to a worsening of the bitter cold of the last glacial period; such changes may have reduced the supply of usable timber and forced people to look at other materials. In addition, flint may not have functioned as a tool.
Some scholars argue that the appearance of complex or abstract language made these behavior changes possible. The complexity of the new human capabilities hints that humans were less capable of planning or foresight before 40,000 years, while the emergence of cooperative and coherent communication marked a new era of cultural development; the climate of the period in Europe saw dramatic changes, included the Last Glacial Maximum, the coldest phase of the last glacial period, which lasted from about 26.5 to 19 kya, being coldest at the end, before a rapid warming. During the Maximum, most of Northern Europe was covered by an ice-sheet, forcing human populations into the areas known as Last Glacial Maximum refugia, including modern Italy and the Balkans, parts of the Iberian Peninsula and areas around the Black Sea; this period saw cultures such as the Solutrean in Spain. Human life may have continued on top of the ice sheet, but we know next to nothing about it, little about the human life that preceded the European glaciers.
In the early part of the period, up to a