Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone and gypsum. It is characterized by underground drainage systems with sinkholes and caves and it has 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, 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 be connected to the oronym Karsádios oros cited by Ptolemy, and perhaps 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 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 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, limestone pavement, medium-sized surface features may include sinkholes or cenotes, vertical shafts, disappearing streams, and reappearing springs. Large-scale features may include limestone pavements 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
The cave hyena, known as the Ice Age spotted hyena, was a paleosubspecies of spotted hyena which ranged from the Iberian Peninsula to eastern Siberia. It is one of the best known mammals of the Ice Age and is represented in many European bone caves. The cave hyena was a specialised animal, with its progressive and regressive features being more developed than in its modern African relative. The cause of the cave hyenas extinction is not fully understood, though it could have been due to a combination of factors, including climate change, the European cave hyena was much larger than its modern African cousin, having been estimated to weigh 190 kg. As with the African subspecies, female cave hyenas were larger than their male counterparts, paleolithic rock art depicting the cave hyena shows that it retained the spotted pelt of its African relative. Several den sites found in Europe indicate that the cave hyena preferentially targeted large prey, with wild horses predominating, followed by steppe bison, the cave hyenas favouring of horses is consistent with the behaviour of the modern African spotted hyena, which mostly hunts zebras.
Secondary prey species included reindeer, red deer, giant deer, European ass, chamois, a small number of wolf remains have been discovered in hyena den sites. The cave hyena likely killed wolves due to competition, though their presence in the cave site indicates that they were fed upon. Similarly, cave lion and bear remains have been discovered in hyena den sites, the first recorded mention of the cave hyena in literature occurs in Kundmanns 1737 tome Rariora Naturæ et Artis, where the author misidentified a hyenas mandibular ramus as that of a calf. In 1774, Esper erroneously described hyena teeth discovered in Gailenreuth as those of a lion, bucklands findings were followed by further discoveries by Clift and Whidbey in Oreston, Plymouth. He elaborated his view in his Ossemens Fossiles, noting how the cave hyenas digital extremities were shorter and thicker than those of the spotted hyena and his views were largely accepted throughout the first half of the 19th century, finding support in de Blainville and Richard Owen among others.
Further justifications in separating the two animals included differences in the portion of the lower carnassial. Writing again in 1877, he stated after comparing the two animals skulls that there are no characters of specific value. Analyses of the DNA sequences of the cytochrome b genes in both modern African and Pleistocene spotted hyenas demonstrated that the two were the same species. Kills partially processed by Neanderthals and by cave hyenas indicate that hyenas would occasionally steal Neanderthal kills, many caves show alternating occupations by hyenas and Neanderthals. The presence of large populations in the Russian Far East may have delayed the human colonisation of North America. There is fossil evidence of humans in Middle Pleistocene Europe butchering, the cave hyena is depicted in a few examples of Upper Palaeolithic rock art in France. A painting from the Chauvet Cave depicts a hyena outlined and represented in profile, because of the specimens steeped profile, it is thought that the painting was originally meant to represent a cave bear, but was modified as a hyena
The Holocene is the geological epoch that began after the Pleistocene at approximately 11,700 years before present. The term Recent has often used as an exact synonym of Holocene. The Holocene is part of the Quaternary period and its name comes from the Ancient Greek words ὅλος and καινός, meaning entirely recent. It has been identified with the current warm period, known as MIS1, given these, a new term, Anthropocene, is specifically proposed and used informally only for the very latest part of modern history involving significant human impact. It is accepted by the International Commission on Stratigraphy that the Holocene started approximately 11,700 years ago, the epoch follows the Pleistocene and the last glacial period. The Holocene can be subdivided into five time intervals, or chronozones, based on climatic fluctuations, Boreal, Atlantic and they find a general correspondence across Eurasia and North America, though the method was once thought to be of no interest. The scheme was defined for Northern Europe, but the changes were claimed to occur more widely.
The periods of the include a few of the final pre-Holocene oscillations of the last glacial period. Paleontologists have not defined any faunal stages for the Holocene, if subdivision is necessary, periods of human technological development, such as the Mesolithic and Bronze Age, are usually used. However, the time periods referenced by these terms vary with the emergence of those technologies in different parts of the world, the Holocene may be divided evenly into the Hypsithermal and Neoglacial periods, the boundary coincides with the start of the Bronze Age in Europe. According to some scholars, a division, the Anthropocene, has now begun. Continental motions due to plate tectonics are less than a kilometre over a span of only 10,000 years, ice melt caused world sea levels to rise about 35 m in the early part of the Holocene. The sea level rise and temporary land depression allowed temporary marine incursions into areas that are now far from the sea, Holocene marine fossils are known, for example, from Vermont and Michigan.
Other than higher-latitude temporary marine incursions associated with depression, Holocene fossils are found primarily in lakebed, floodplain. Holocene marine deposits along low-latitude coastlines are rare because the rise in sea levels during the period exceeds any likely tectonic uplift of non-glacial origin, post-glacial rebound in the Scandinavia region resulted in the formation of the Baltic Sea. The region continues to rise, still causing weak earthquakes across Northern Europe, the equivalent event in North America was the rebound of Hudson Bay, as it shrank from its larger, immediate post-glacial Tyrrell Sea phase, to near its present boundaries. Climate has been stable over the Holocene. It appears that this was influenced by the glacial ice remaining in the Northern Hemisphere until the date
Homo sapiens is the binomial nomenclature for the only extant human species. Homo is the genus, which includes Neanderthals and many other extinct species of hominid. Modern humans are the subspecies Homo sapiens sapiens, which differentiates them from what has been argued to be their direct ancestor, the binomial name Homo sapiens was coined by Carl Linnaeus. The Latin noun homō means man, human being, subspecies of H. sapiens include Homo sapiens idaltu and the only extant subspecies, Homo sapiens sapiens. Some sources show Neanderthals as a subspecies, the discovered specimens of the Homo rhodesiensis species have been classified by some as a subspecies, but these last two subspecies classifications are not widely accepted by scientists. Traditionally, there are two competing views in paleoanthropology about the origin of H. sapiens, the recent African origin, since 2010, genetic research has led to the emergence of an intermediate position, characterised by mostly recent African origin plus limited admixture with archaic humans.
The recent African origin of humans is the mainstream model that describes the origin. The theory is called the Out-of-Africa model in the press, and academically the recent single-origin hypothesis, Replacement Hypothesis. The hypothesis that humans have a single origin was published in Charles Darwins Descent of Man, the concept was speculative until the 1980s, when it was corroborated by a study of present-day mitochondrial DNA, combined with evidence based on physical anthropology of archaic specimens. The recent single origin of humans in East Africa is the near-consensus position held within the scientific community. However, recent sequencing of the full Neanderthal genome suggests Neanderthals, the authors of the study suggest that their findings are consistent with Neanderthal admixture of up to 4% in some populations. But the study suggests that there may be other reasons why humans. That study however does not explain why only a fraction of humans have Neanderthal DNA. The multiregional origin model provides an explanation for the pattern of evolution proposed by Milford H.
Wolpoff in 1988. Scientific study of evolution is concerned, with the development of the genus Homo. Modern humans are defined as the Homo sapiens species, of which the extant subspecies is known as Homo sapiens sapiens. Homo sapiens idaltu, the known subspecies, is now extinct. Similarly, the specimens of the Homo rhodesiensis species have been classified by some as a subspecies
The Pleistocene is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the worlds most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period, the Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. In the ICS timescale, the Pleistocene is divided into four stages or ages, all of these stages were defined in southern Europe. In addition to this subdivision, various regional subdivisions are often used. Charles Lyell introduced the term pleistocene in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today and this distinguished it from the older Pliocene Epoch, which Lyell had originally thought to be the youngest fossil rock layer. The Pleistocene has been dated from 2.588 million to 11,700 years before present and it covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold spell.
The end of the Younger Dryas has been dated to about 9640 BC, the IUGS has yet to approve a type section, Global Boundary Stratotype Section and Point, for the upper Pleistocene/Holocene boundary. The proposed section is the North Greenland Ice Core Project ice core 75°06 N 42°18 W, the lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils, Discoaster pentaradiatus, the Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age. The revised definition of the Quaternary, by pushing back the date of the Pleistocene to 2.58 Ma. Pleistocene climate was marked by repeated glacial cycles in which continental glaciers pushed to the 40th parallel in some places and it is estimated that, at maximum glacial extent, 30% of the Earths surface was covered by ice.
In addition, a zone of permafrost stretched southward from the edge of the sheet, a few hundred kilometres in North America. The mean annual temperature at the edge of the ice was −6 °C, during interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions. The effects of glaciation were global, antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap, there were glaciers in New Zealand and Tasmania. The current decaying glaciers of Mount Kenya, Mount Kilimanjaro, glaciers existed in the mountains of Ethiopia and to the west in the Atlas mountains. In the northern hemisphere, many glaciers fused into one, the Cordilleran ice sheet covered the North American northwest, the east was covered by the Laurentide
Stratigraphy is a branch of geology which studies rock layers and layering. It is primarily used in the study of sedimentary and layered volcanic rocks, stratigraphy has two related subfields, lithologic stratigraphy or lithostratigraphy, and biologic stratigraphy or biostratigraphy. The first practical application of stratigraphy was by William Smith in the 1790s. Another influential application of stratigraphy in the early 19th century was a study by Georges Cuvier, variation in rock units, most obviously displayed as visible layering, is due to physical contrasts in rock type. This variation can occur vertically as layering, or laterally, and these variations provide a lithostratigraphy or lithologic stratigraphy of the rock unit. Key concepts in stratigraphy involve understanding how certain geometric relationships between rock layers arise and what these geometries imply about their original depositional environment. The basic concept in stratigraphy, called the law of superposition, states, in a stratigraphic sequence.
Chemostratigraphy studies the changes in the proportions of trace elements and isotopes within. Carbon and oxygen isotope ratios vary with time, and researchers can use those to map subtle changes that occurred in the paleoenvironment and this has led to the specialized field of isotopic stratigraphy. Biostratigraphy or paleontologic stratigraphy is based on evidence in the rock layers. Strata from widespread locations containing the fossil fauna and flora are said to be correlatable in time. Biologic stratigraphy was based on William Smiths principle of succession, which predated. It provides strong evidence for the formation and extinction of species, the geologic time scale was developed during the 19th century, based on the evidence of biologic stratigraphy and faunal succession. One important development is the Vail curve, which attempts to define a global historical sea-level curve according to inferences from worldwide stratigraphic patterns, stratigraphy is commonly used to delineate the nature and extent of hydrocarbon-bearing reservoir rocks and traps of petroleum geology.
Chronostratigraphy is the branch of stratigraphy that places an absolute age, a gap or missing strata in the geological record of an area is called a stratigraphic hiatus. This may be the result of a halt in the deposition of sediment, the gap may be due to removal by erosion, in which case it may be called a stratigraphic vacuity. It is called a hiatus because deposition was on hold for a period of time, a physical gap may represent both a period of non-deposition and a period of erosion. A geologic fault may cause the appearance of a hiatus, magnetostratigraphy is a chronostratigraphic technique used to date sedimentary and volcanic sequences
Ursus deningeri is an extinct species of mammal of the family Ursidae, endemic to Eurasia during the Pleistocene for approximately 1.7 million years, from ~1.8 Mya to 100,000 years ago. The range of this bear has been found to encompass both Europe and Asia, demonstrating the ability of the species to adapt to many Pleistocene environments, U. deningeri is a descendant of U. savini and an ancestor of U. spelaeus. Ursus deningeri has a combination of primitive and derived characters that distinguishes it from all other Pleistocene bears and its mandible is slender like that of living brown bears and Ursus etruscus. It has derived characters of cave bears and is considered to be the descendant of Ursus savini and specimen ages, Mongolia, ~1. The Pleistocene Human Settlement in Gilan, Southwest Caspian Sea, Recent Research
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 used wood and bone tools. Other organic commodities were adapted for use as tools, including leather and vegetable fibers, 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 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, old, and λίθος, 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
Fauna is all of the animal life of any particular region or time. The corresponding term for plants is flora, flora and other forms of life such as fungi are collectively referred to as biota. Zoologists and paleontologists use fauna to refer to a collection of animals found in a specific time or place. Paleontologists sometimes refer to a sequence of stages, which is a series of rocks all containing similar fossils. Fauna comes from the Greek names Fauna, a Roman goddess of earth and fertility, the Roman god Faunus, all three words are cognates of the name of the Greek god Pan, and panis is the Greek equivalent of fauna. Fauna is the word for a book that catalogues the animals in such a manner, the term was first used by Carl Linnaeus from Sweden in the title of his 1745 work Fauna Suecica. Cryofauna are animals that live in, or very close to, cryptofauna are the fauna that exist in protected or concealed microhabitats. Infauna are benthic organisms that live within the substratum of a body of water, especially within the bottom-most oceanic sediments.
Bacteria and microalgae may live in the interstices of bottom sediments, called epibenthos, are aquatic animals that live on the bottom substratum as opposed to within it, that is, the benthic fauna that live on top of the sediment surface at the seafloor. Macrofauna are benthic or soil organisms which are retained on a 0.5 mm sieve, studies in the deep sea define macrofauna as animals retained on a 0.3 mm sieve to account for the small size of many of the taxa. Megafauna are large animals of any region or time. Meiofauna are small invertebrates that live in both marine and fresh water environments. The term Meiofauna loosely defines a group of organisms by their size, larger than microfauna but smaller than macrofauna, one environment for meiofauna is between grains of damp sand. In practice these are metazoan animals that can pass unharmed through a 0.5 –1 mm mesh but will be retained by a 30–45 μm mesh, but the exact dimensions will vary from researcher to researcher. Whether an organism passes through a 1 mm mesh depends upon whether it is alive or dead at the time of sorting, mesofauna are macroscopic soil invertebrates such as arthropods or nematodes.
Mesofauna are extremely diverse, considering just the springtails, as of 1998, microfauna are microscopic or very small animals. Other terms include avifauna, which means bird fauna and piscifauna, which means fish fauna
Charles Darwin recognized the small number of traits that made domestic species different from their wild ancestors. There is a difference between domestic and wild populations. The dog was the first domesticated vertebrate, and was established across Eurasia before the end of the Late Pleistocene era, well before cultivation and before the domestication of other animals. Among birds, the domestic species today is the chicken, important for meat and eggs, though economically valuable poultry include the turkey, guineafowl. Birds are kept as cagebirds, from songbirds to parrots. The longest established invertebrate domesticates are the bee and the silkworm. Terrestrial snails are raised for food, while species from several phyla are kept for research, the domestication of plants began at least 12,000 years ago with cereals in the Middle East, and the bottle gourd in Asia. Agriculture developed in at least 11 different centres around the world, domesticating different crops, Domestication means belonging to the house.
Animals domesticated for home companionship are usually called pets, while those domesticated for food or work are called livestock or farm animals and this definition recognizes both the biological and the cultural components of the domestication process and the impacts on both humans and the domesticated animals and plants. All past definitions of domestication have included a relationship between humans with plants and animals, but their differences lay in who was considered as the partner in the relationship. This new definition recognizes a mutualistic relationship in both partners gain benefits. Domestication has vastly enhanced the reproductive output of crop plants, Domestication syndrome is the suite of phenotypic traits arising during domestication that distinguish crops from their wild ancestors. The domestication of animals is the relationship between animals with the humans who have influence on their care and reproduction. Charles Darwin recognized the small number of traits that made domestic species different from their wild ancestors, there is a genetic difference between domestic and wild populations.
Domestication should not be confused with taming, the beginnings of animal domestication involved a protracted coevolutionary process with multiple stages along different pathways. The dog was the first domesticant, and was established across Eurasia before the end of the Late Pleistocene era, well before cultivation and before the domestication of other animals. Humans did not intend to domesticate animals from, or at least they did not envision a domesticated animal resulting from, in both of these cases, humans became entangled with these species as the relationship between them, and the human role in their survival and reproduction, intensified. Although the directed pathway proceeded from capture to taming, the two pathways are not as goal-oriented and archaeological records suggest that they take place over much longer time frames