1.
Paleolithic
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It extends from the earliest known use of stone tools, probably by Homo habilis initially,2.6 million years ago, to the end of the Pleistocene around 10,000 BP. The Paleolithic era is followed by the Mesolithic, the date of the Paleolithic–Mesolithic boundary may vary by locality as much as several thousand years. During the Paleolithic period, humans grouped together in small societies such as bands, the Paleolithic is characterized by the use of knapped stone tools, although at the time humans also used wood and bone tools. Other organic commodities were adapted for use as tools, including leather and vegetable fibers, however, due to their nature, surviving artifacts of the Paleolithic era are known as paleoliths. About 50,000 years ago, there was a increase in the diversity of artifacts. For the first time in Africa, bone artifacts and the first art appear in the archaeological record, the first evidence of human fishing is also noted, from artifacts in places such as Blombos cave in South Africa. The new technology generated an explosion of modern humans which is believed to have led to the extinction of the Neanderthals. Humankind gradually evolved from members of the genus Homo—such as Homo habilis. The climate during the Paleolithic consisted of a set of glacial and interglacial periods in which the climate periodically fluctuated between warm and cool temperatures, by c. 50,000 – c. 40,000 BP, the first humans set foot in Australia. By c. 45,000 BP, humans lived at 61°N latitude in Europe, by c. 30,000 BP, Japan was reached, and by c. 27,000 BP humans were present in Siberia, above the Arctic Circle. At the end of the Upper Paleolithic, a group of humans crossed Beringia, the term Paleolithic was coined by archaeologist John Lubbock in 1865. It derives from Greek, παλαιός, palaios, old, and λίθος, lithos, stone, human evolution is the part of biological evolution concerning the emergence of anatomically modern humans as a distinct species. The Paleolithic Period coincides almost exactly with the Pleistocene epoch of geologic time and this epoch experienced important geographic and climatic changes that affected human societies. During the preceding Pliocene, continents had continued to drift from possibly as far as 250 km from their present locations to positions only 70 km from their current location. South America became linked to North America through the Isthmus of Panama, most of Central America formed during the Pliocene to connect the continents of North and South America, allowing fauna from these continents to leave their native habitats and colonize new areas. Africas collision with Asia created the Mediterranean Sea, cutting off the remnants of the Tethys Ocean, climates during the Pliocene became cooler and drier, and seasonal, similar to modern climates. The formation of an Arctic ice cap around 3 million years ago is signaled by a shift in oxygen isotope ratios and ice-rafted cobbles in the North Atlantic. Mid-latitude glaciation probably began before the end of the epoch, the global cooling that occurred during the Pliocene may have spurred on the disappearance of forests and the spread of grasslands and savannas
2.
Homo antecessor
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Homo antecessor is an extinct human species dating from 1.2 million to 800,000 years ago, that was discovered by Eudald Carbonell, Juan Luis Arsuaga and J. M. Bermúdez de Castro. The unique mix of modern and primitive traits led the researchers to deem the fossils a new species, H. antecessor, in 1997. Regarding its great age the species must be related to Out of Africa I, author Richard Klein argues that it was a separate species that evolved from H. ergaster. Some scientists consider H. antecessor to be the species as H. heidelbergensis. It’s possible that H. antecessor adults didn’t really look much like H. sapiens at all, the best-preserved fossil is a maxilla that belonged to a ten-year-old individual found in Spain. Based on palaeomagnetic measurements, it is thought to be older than 857–780 ka, in 1994 and 1995,80 fossils of six individuals who may have belonged to the species were found in Atapuerca, Spain. At the site were numerous examples of cuts where the flesh had been flensed from the bones, footprints presumed to be from H. antecessor dating to more than 800,000 years ago have been found at Happisburgh on the coast of Norfolk, England. A2013 DNA analysis from a 400, 000-year-old femur from Spains Sima de los Huesos in the Atapuerca Mountains – the oldest hominin sequence yet published – did not help to overcome contradictions. Results left researchers baffled as the sequence suggests link to mystery population of the Denisovans instead of the Neanderthals as was anticipated. According to the Science X Network the excavation team at the site of Gran Dolina has succeeded to provide conclusive dating of the strata where the Homo antecessor fossils were found. A2014 publication in the Journal of Archaeological Science states that the sediment of Gran Dolina is 900,000 years old, a speciation event could have occurred in Africa/Western Eurasia, originating a new Homo clade, and further, Homo antecessor. Could be a branch of this clade placed at the westernmost region of the Eurasian continent. H. antecessor was about 1. 6–1.8 m tall and their brain sizes were roughly 1, 000–1,150 cm³, smaller than the 1,350 cm³ average of modern humans. Due to fossil scarcity, very little more is known about the physiology of H. antecessor, yet it was likely to have been more robust than H. heidelbergensis. According to Juan Luis Arsuaga, one of the co-directors of the excavation in Burgos, H. antecessor might have been right-handed and this hypothesis is based on tomography techniques. Arsuaga also claims that the range of audition is similar to H. sapiens. Arsuagas team is currently pursuing a DNA map of H. antecessor, based on teeth eruption pattern, the researchers think that H. antecessor had the same development stages as H. sapiens, though probably at a faster pace. Other significant features demonstrated by the species are a protruding occipital bun, a low forehead, some of the remains are almost indistinguishable from the fossil attributable to the 1.5 million year old Turkana Boy, belonging to H. ergaster
3.
Homo heidelbergensis
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Homo heidelbergensis – also Homo rhodesiensis – is an extinct species of the genus Homo that lived in Africa, Europe and western Asia between 600,000 and 200,000 years ago. The skulls of this species share features with both Homo erectus and anatomically modern Homo sapiens, its brain was nearly as large as that of Homo sapiens. The Sima de los Huesos cave at Atapuerca in northern Spain holds particularly rich layers of deposits that represent an exceptional reserve of data where excavations are still in progress. Neanderthals, Denisovans, and modern humans are all considered to have descended from Homo heidelbergensis that appeared around 700,000 years ago in Africa, fossils have been recovered in Ethiopia, Namibia and South Africa. Between 300,000 and 400,000 years ago a group of Homo heidelbergensis migrated into Europe and West Asia via yet unknown routes, archaeological sites exist in Spain, Italy, France, England, Germany, Hungary and Greece. Another Homo heidelbergensis group ventured eastwards into continental Asia, eventually developing into Denisovans, some researchers suggest that the finds associated to Homo heidelbergensis are mere variants of Homo erectus. Both Homo antecessor and Homo heidelbergensis are likely to have descended from the very similar Homo ergaster from Africa. The anatomy is more primitive than that of Neanderthal, but the harmoniously rounded dental arch. Heidelbergensis from other known human species, the species name heidelbergensis only experienced a renaissance with the many discoveries of the past 30 years and appears now to be recognized by an increasing number of researchers. Any form of segregation is considered arbitrary, which is why these researchers forgo the name H. heidelbergensis altogether. Paleoanthropologists often refer to the surrounding the specimens, their dating and morphology, as “the muddle in the middle. ”The fact that there seem to be no clear transitions makes it difficult to draw up a list of unique characteristics of H. heidelbergensis that distinguishes it from H. erectus. In general, the show a continuation of evolutionary trends that are emerging from around the Lower into Middle Pleistocene. Along with changes in the robustness of cranial and dental features, male H. heidelbergensis averaged about 1.75 m tall and 62 kg. Females averaged 1.57 m and 51 kg, the available space would allow for a far greater flexibility of development and It shows a combination of features, which has been previously found neither on a recent nor a fossil human mandible. The actual proof that we are dealing with human parts here only lies within the nature of the dentition, the completely preserved teeth bear the stamp human as evidence, The canines show no trace of a stronger expression in relation to the other groups of teeth. They suggest a moderate and harmonious co-evolution, as it is the case in recent humans, recent findings in a pit in Atapuerca of 28 human skeletons suggest that H. heidelbergensis might have been the first species of the Homo genus to bury its dead. Steven Mithen believes that H. heidelbergensis, like its descendant H. neanderthalensis, acquired a pre-linguistic system of communication. No forms of art have been uncovered, although red ochre, the morphology of the outer and middle ear suggests they had an auditory sensitivity similar to modern humans and very different from chimpanzees
4.
Neanderthal
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Neanderthals, or more rarely Neandertals, were a species or subspecies of archaic humans in the genus Homo that became extinct about 40,000 years ago. Neanderthals and modern humans share 99. 7% of their DNA and are closely related. Neanderthals left bones and stone tools in Eurasia, from Western Europe to Central, from the 1950s to the early 1980s, however, Neanderthals were widely considered a subspecies of Homo sapiens and a minority of scholars still hold this view. Several cultural assemblages have been linked to the Neanderthals in Europe, the earliest, the Mousterian stone tool culture, dates to about 160,000 years ago. Late Mousterian artifacts were found in Gorhams Cave on the south-facing coast of Gibraltar, male Neanderthals had cranial capacities averaging 1600 cm3, females 1300 cm3, extending to 1736 cm3 in Amud 1. This is notably larger than the 1250–1400 cm3 typical of modern humans, males stood 164–168 cm and females 152–156 cm tall. Recent studies also show that a few Neanderthals began mating with ancestors of modern humans long before the out of Africa migration of present day non-Africans. Claims that Neanderthals deliberately buried their dead, and if they did, the debate on deliberate Neanderthal burials has been active since the 1908 discovery of the well-preserved Chapelle-aux-Saints 1 skeleton in a small hole in a cave in southwestern France. In 2013, scientists sequenced the genome of a Neanderthal for the first time. The genome was extracted from the bone of a 50. In 2016, elaborate constructions of rings of broken stalagmites made by early Neanderthals around 176,000 years ago were discovered 336 m inside Bruniquel Cave in southwestern France and this would have required a more advanced social structure than previously known for Neanderthals. Thal is a spelling of the German word Tal, which means valley. Nevertheless, Kings name had priority over the proposal put forward in 1866 by Ernst Haeckel, the practice of referring to the Neanderthals and a Neanderthal emerged in the popular literature of the 1920s. The German pronunciation of Neanderthaler or Neandertaler is in the International Phonetic Alphabet, in British English, Neanderthal is pronounced with the /t/ as in German, but different vowels. In laymans American English, Neanderthal is pronounced with a /θ/ and /ɔ/ instead of the longer British /aː/, during the early 20th century the prevailing view was heavily influenced by Arthur Keith and Marcellin Boule, who wrote the first scientific description of a nearly complete Neanderthal skeleton. During the 1930s scholars Ernst Mayr, George Gaylord Simpson and Theodosius Dobzhansky reinterpreted the existing fossil record, Neanderthal man was classified as Homo sapiens neanderthalensis - an early subspecies contrasted with what was now called Homo sapiens sapiens. The obviously unbroken succession of fossil sites of both subspecies in Europe was considered evidence that there was a slow and gradual evolutionary transition from Neanderthals to modern humans, contextual interpretations of similar excavation sites in Asia lead to the hypothesis of multiregional origin of modern man in the 1980s. Current scientific ideas hold that both evolved from a common African ancestor, Homo erectus
5.
Karst
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Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves and it has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes, the English word karst was borrowed from German Karst in the late 19th century. The German word came into use before the 19th century, according to the prevalent interpretation, the term is derived from the German name for the Karst region, a limestone plateau above the city of Trieste in the northern Adriatic. Scholars disagree, however, on whether the German word was borrowed from Slovene, the Slovene common noun kras was first attested in the 18th century, and the adjective form kraški in the 16th century. The Slovene words arose through metathesis from the reconstructed form *korsъ, ultimately, the word is of Mediterranean origin, believed to derive from some Romanized Illyrian base. It has been suggested that the word may derive from the Proto-Indo-European root karra- rock, the name may also be connected to the oronym Karsádios oros cited by Ptolemy, and perhaps also to Latin Carusardius. The development of karst occurs whenever acidic water starts to break down the surface of bedrock near its cracks, as the bedrock continues to degrade, its cracks tend to get bigger. As time goes on, these fractures will become wider, if this underground drainage system does form, it will speed up the development of karst formations there because more water will be able to flow through the region, giving it more erosive power. The carbonic acid that causes karstic features is formed as rain passes through the atmosphere picking up carbon dioxide, once the rain reaches the ground, it may pass through soil that can provide much more CO2 to form a weak carbonic acid solution, which dissolves calcium carbonate. The oxidation of sulfides leading to the formation of acid can also be one of the corrosion factors in karst formation. As oxygen -rich surface waters seep into deep anoxic karst systems, they bring oxygen, sulfuric acid then reacts with calcium carbonate, causing increased erosion within the limestone formation. This chain of reactions is, This reaction chain forms gypsum, the karstification of a landscape may result in a variety of large- or small-scale features both on the surface and beneath. On exposed surfaces, small features may include solution flutes, runnels, limestone pavement, medium-sized surface features may include sinkholes or cenotes, vertical shafts, foibe, disappearing streams, and reappearing springs. Large-scale features may include limestone pavements, poljes, and karst valleys, mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers, or haystack/eggbox landscapes. Beneath the surface, complex underground systems and extensive caves. Some of the most dramatic of these formations can be seen in Thailands Phangnga Bay, calcium carbonate dissolved into water may precipitate out where the water discharges some of its dissolved carbon dioxide. Rivers which emerge from springs may produce tufa terraces, consisting of layers of calcite deposited over extended periods of time, in caves, a variety of features collectively called speleothems are formed by deposition of calcium carbonate and other dissolved minerals
6.
Fossil
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Fossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous rock formations and sedimentary layers is known as the fossil record. The study of fossils across geological time, how they were formed, such a preserved specimen is called a fossil if it is older than some minimum age, most often the arbitrary date of 10,000 years. The observation that fossils were associated with certain rock strata led early geologists to recognize a geological timescale in the 19th century. The development of dating techniques in the early 20th century allowed geologists to determine the numerical or absolute age of the various strata. Like extant organisms, fossils vary in size from microscopic, even single bacterial cells one micrometer in diameter, to gigantic, such as dinosaurs, Fossils may also consist of the marks left behind by the organism while it was alive, such as animal tracks or feces. These types of fossil are called trace fossils, as opposed to body fossils, finally, past life leaves some markers that cannot be seen but can be detected in the form of biochemical signals, these are known as chemofossils or biosignatures. The process of fossilization varies according to type and external conditions. Permineralization is a process of fossilization that occurs when an organism is buried, the empty spaces within an organism become filled with mineral-rich groundwater. Minerals precipitate from the groundwater, occupying the empty spaces and this process can occur in very small spaces, such as within the cell wall of a plant cell. Small scale permineralization can produce very detailed fossils, for permineralization to occur, the organism must become covered by sediment soon after death or soon after the initial decay process. The degree to which the remains are decayed when covered determines the later details of the fossil, some fossils consist only of skeletal remains or teeth, other fossils contain traces of skin, feathers or even soft tissues. This is a form of diagenesis, in some cases the original remains of the organism completely dissolve or are otherwise destroyed. The remaining organism-shaped hole in the rock is called an external mold, if this hole is later filled with other minerals, it is a cast. An endocast or internal mold is formed when sediments or minerals fill the cavity of an organism. This is a form of cast and mold formation. If the chemistry is right, the organism can act as a nucleus for the precipitation of minerals such as siderite, if this happens rapidly before significant decay to the organic tissue, very fine three-dimensional morphological detail can be preserved. Nodules from the Carboniferous Mazon Creek fossil beds of Illinois, USA, are among the best documented examples of such mineralization, replacement occurs when the shell, bone or other tissue is replaced with another mineral
7.
Douro
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The Douro is one of the major rivers of the Iberian Peninsula, flowing from its source near Duruelo de la Sierra in Soria Province across northern-central Spain and Portugal to its outlet at Porto. The Latinized name Durius, likely came from the Celtic tribes that inhabited the area before Roman times, in modern Welsh, dŵr is water, as well as dour in modern Breton with cognate dobhar in Irish. In Roman times, the river was personified as a god, the Douro vinhateiro, an area of the Douro Valley in Portugal long devoted to vineyards, has been designated by UNESCO as a World Heritage Site. Traditionally, the wine was taken down river in boats called rabelos, to be stored in barrels in cellars in Vila Nova de Gaia. In the 1950s and 1960s, dams were built along the river, now Port wine is transported in tanker trucks. In 1998, Portugal and Spain signed the Albufeira Convention, an agreement on the sharing of trans-boundary rivers to include the Douro, Tagus, the convention superseded an original agreement on the Douro, signed in 1927, that was expanded in 1964 and 1968 to include tributaries. It is the third-longest river in the Iberian Peninsula after the Tagus and its total length is 897 kilometres, of which only sections of the Portuguese extension below the fall line are navigable, by light rivercraft. In this region, there are few tributaries of the Douro, the most important are the Pisuerga, passing through Valladolid, and the Esla, which passes through Zamora. This region is generally semi-arid plains, with wheat and in places, especially near Aranda de Duero, with vineyards. Sheep rearing is still important. For 112 kilometres, the forms part of the national border line between Spain and Portugal, in a region of narrow canyons. It formed a barrier to invasions, creating a cultural/linguistic divide. In these isolated areas, in which the Aldeadávila Dam impounds the river, there are protected areas, the International Douro Natural Park and the Arribes del Duero Natural Park. The Douro fully enters Portuguese territory just after the confluence with the Águeda River, once the Douro enters Portugal, except for Porto and Vila Nova de Gaia at the river mouth, the only population centres of any note are Foz do Tua, Pinhão and Peso da Régua. Tributaries here are small, merging into the Douro along the canyons, the most important are Côa, Tua, Sabor, Corgo, Tavora, Paiva, Tâmega, none of these small, fast-flowing rivers is navigable. The most populous cities along the Douro River are Valladolid and Zamora in Spain, the latter two are located at the mouth of the Douro at the Atlantic Ocean. In Portugal, the Douro flows through the districts of Bragança, Guarda, Viseu, Vila Real, Aveiro, Porto is the main hub city in northern Portugal. Its historic centre has designated as a UNESCO World Heritage Site because of its significant architecture
8.
Cantabrian Mountains
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The Cantabrian Mountains or Cantabrian Range are one of the main systems of mountain ranges in Spain. They stretch for over 300 km across northern Spain, from the limit of the Pyrenees to the Galician Massif in Galicia. Their easternmost end meets the Sistema Ibérico and these mountains are a distinct physiographic province of the larger Alpine System physiographic division. The Cantabrian Mountains offer a range of trails for hiking. Skiing is possible in the ski resorts of Alto Campoo, Valgrande-Pajares, the Cantabrian Mountains stretch east-west, nearly parallel to the sea, as far as the pass of Leitariegos, also extending south between León and Galicia. The ranges western boundary is marked by the valley of the river Miño, by the lower Sil, which flows into the Miño, and by the Cabrera River, Cantabrian mountains reach its south-western limit in Portugal. In some parts the coastal range rises sheer above the sea, the descent from the southern range to the high plateaux of Castile is more gradual, and several large rivers, notably the Ebro, rise here and flow to the south or west. The breadth of the Cantabrian chain, with all its ramifications, increases from about 60 mi, many peaks are over 6000 ft high, but the greatest altitudes are attained in the central ridges on the borders of León, Asturias, Palencia and Cantabria. A conspicuous feature of the chain, as of the adjacent tableland, is the number of its parameras, the Cantabrian Mountains make a sharp divide between Green Spain to the north, and the dry central plateau. The north facing slopes receive heavy rainfall from the Bay of Biscay. The Cantabrian Range has three distinct sections from west to east, The Asturian Massif and its foothills. Geologically it is a prolongation of the Galician Massif with Paleozoic folds. It is cut by deep east-west oriented canyons such as the Cares River valley, highest point Torre de Cerredo 2,648 m. They are composed of Carboniferous limestone and marl, the Paramo de Masa and La Lora grasslands are located in the south crossed by the Rudrón Valley. Other animals associated with the range include the Iberian wolf and the rebeco, some of the sites are included in the European Unions Natura 2000 network and Special Protection Areas for the Conservation of Wild Birds
9.
Ebro
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The Ebro or Ebre is one of the most important rivers on the Iberian Peninsula. It is the second longest river in the Iberian peninsula after the Tagus, the source of the river Ebro is in Fontibre, from the Latin words Fontes Iberis, source of the Ebro. Close by is the big artificial lake Embalse del Ebro created by the damming of the river, the upper Ebro rushes through rocky gorges in Burgos Province. Karst geological processes shaped the landscape of layers of carbonate rock of extensive limestone bedrock formed in an ancient seabed. Aragonite, a named for Aragon, attests to the fact that carbonates are abundant in the central Ebro Valley. The valley expands and the Ebros flow then becomes slower as its volume increases. There, larger tributaries flowing from the Central Pyrenees and the Iberian System discharge large amounts of water, as it flows through Zaragoza the Ebro, is already a sizeable river. There, the Basilica of Our Lady of the Pillar stands next to the Ebro, the soils in most of the valley are primarily poor soils, calcareous, pebbly, stony, and sometimes salted with saltwater endorheic lagoons. The semi-arid interior of the Ebro Valley has either drought summers and it is covered with chaparral vegetation. Summers are hot and winters are cold, the dry summer season has temperatures of more than 35 °C, occasionally reaching over 40 °C. In winter, the temperatures drop below 0 °C. In some areas the vegetation depends heavily on moisture produced by condensation fogs and it is a continental Mediterranean climate with extreme temperatures. There are many ground frosts on clear nights, and sporadic snowfalls, the biomes are diverse in these Mediterranean climate zones, Mediterranean forests, woodlands, and scrub. Hinterlands are particularly distinctive on account of extensive sclerophyll shrublands known as maquis, the dominant species are Quercus coccifera and Quercus ilex. These trees form monospecific communities or communities integrated with Pinus, Mediterranean buckthorns, Myrtus, Chamaerops humilis, junipers, Pistacia, Rosmarinus, Thymus, etc. The mountain vegetation is mostly coniferous forests that are drought adapted and their presence is related to the marine origin of the Ebro valley and the extensive marine deposits in the same area. After reaching Catalonia, the Ebro Valley narrows, and the river becomes constrained by mountain ranges, massive dams have been built in this area, such as the dams at Mequinenza, Riba-roja, Flix. In the final section of its course the river bends southwards, the massive calcareous cliffs of the Serra de Cardó range constrain the river during this last stretch, separating the Ebro Valley from the Mediterranean coastal area
10.
Mediterranean Sea
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The sea is sometimes considered a part of the Atlantic Ocean, although it is usually identified as a separate body of water. The name Mediterranean is derived from the Latin mediterraneus, meaning inland or in the middle of land and it covers an approximate area of 2.5 million km2, but its connection to the Atlantic is only 14 km wide. The Strait of Gibraltar is a strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Gibraltar. In oceanography, it is called the Eurafrican Mediterranean Sea or the European Mediterranean Sea to distinguish it from mediterranean seas elsewhere. The Mediterranean Sea has a depth of 1,500 m. The sea is bordered on the north by Europe, the east by Asia and it is located between latitudes 30° and 46° N and longitudes 6° W and 36° E. Its west-east length, from the Strait of Gibraltar to the Gulf of Iskenderun, the seas average north-south length, from Croatia’s southern shore to Libya, is approximately 800 km. The Mediterranean Sea, including the Sea of Marmara, has an area of approximately 2,510,000 square km. The sea was an important route for merchants and travelers of ancient times that allowed for trade, the history of the Mediterranean region is crucial to understanding the origins and development of many modern societies. In addition, the Gaza Strip and the British Overseas Territories of Gibraltar and Akrotiri, the term Mediterranean derives from the Latin word mediterraneus, meaning amid the earth or between land, as it is between the continents of Africa, Asia and Europe. The Ancient Greek name Mesogeios, is similarly from μέσο, between + γη, land, earth) and it can be compared with the Ancient Greek name Mesopotamia, meaning between rivers. The Mediterranean Sea has historically had several names, for example, the Carthaginians called it the Syrian Sea and latter Romans commonly called it Mare Nostrum, and occasionally Mare Internum. Another name was the Sea of the Philistines, from the people inhabiting a large portion of its shores near the Israelites, the sea is also called the Great Sea in the General Prologue by Geoffrey Chaucer. In Ottoman Turkish, it has also been called Bahr-i Sefid, in Modern Hebrew, it has been called HaYam HaTikhon, the Middle Sea, reflecting the Seas name in ancient Greek, Latin, and modern languages in both Europe and the Middle East. Similarly, in Modern Arabic, it is known as al-Baḥr al-Mutawassiṭ, in Turkish, it is known as Akdeniz, the White Sea since among Turks the white colour represents the west. Several ancient civilisations were located around the Mediterranean shores, and were influenced by their proximity to the sea. It provided routes for trade, colonisation, and war, as well as food for numerous communities throughout the ages, due to the shared climate, geology, and access to the sea, cultures centered on the Mediterranean tended to have some extent of intertwined culture and history. Two of the most notable Mediterranean civilisations in classical antiquity were the Greek city states, later, when Augustus founded the Roman Empire, the Romans referred to the Mediterranean as Mare Nostrum
11.
Ecosystem
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An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These biotic and abiotic components are regarded as linked together through nutrient cycles, as ecosystems are defined by the network of interactions among organisms, and between organisms and their environment, they can be of any size but usually encompass specific, limited spaces. Energy, water, nitrogen and soil minerals are other essential components of an ecosystem. The energy that flows through ecosystems is obtained primarily from the sun and it generally enters the system through photosynthesis, a process that also captures carbon from the atmosphere. By feeding on plants and on one another, animals play an important role in the movement of matter and they also influence the quantity of plant and microbial biomass present. Ecosystems are controlled both by external and internal factors, other external factors include time and potential biota. Ecosystems are dynamic entities—invariably, they are subject to disturbances and are in the process of recovering from some past disturbance. Ecosystems in similar environments that are located in different parts of the world can have different characteristics simply because they contain different species. The introduction of species can cause substantial shifts in ecosystem function. Internal factors not only control ecosystem processes but are controlled by them and are often subject to feedback loops. Other internal factors include disturbance, succession and the types of species present, although humans exist and operate within ecosystems, their cumulative effects are large enough to influence external factors like climate. Biodiversity affects ecosystem function, as do the processes of disturbance, classifying ecosystems into ecologically homogeneous units is an important step towards effective ecosystem management, but there is no single, agreed-upon way to do this. The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley, Tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment. He later refined the term, describing it as The whole system, including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment. Tansley regarded ecosystems not simply as natural units, but as mental isolates, Tansley later defined the spatial extent of ecosystems using the term ecotope. G. Raymond Lindeman took these ideas one step further to suggest that the flow of energy through a lake was the driver of the ecosystem. Most mineral nutrients, on the hand, are recycled within ecosystems. Ecosystems are controlled both by external and internal factors, external factors, also called state factors, control the overall structure of an ecosystem and the way things work within it, but are not themselves influenced by the ecosystem
