Ballıca Cave ( Turkish : Ballıca Mağarası ) is a small cave situated 6 km (3.7 mi) southeast of Pazar , Tokat Province , Turkey . The cave is 600 m (2,000 ft) southeast of the Ballıca village.
112-431: Ballıca Cave is a fossil cave. Its overall length is 68 m (223 ft). The upper sections are composed of Permian–Triassic marble and lime . There are two layers above the entrance and five layers below, making a total of seven layers. Five layers were formed over three periods. One section stretches northeast and southwest, consisting of two layers. The second section, containing layers #3 and 34 were formed during
224-430: A community on inert (e.g. rocks, glass, plastic) or organic (e.g. skin, cuticle, mucosa) surfaces. The properties of the surface, such as charge, hydrophobicity and roughness, determine initial bacterial attachment. A common principle of all biofilms is the production of extracellular matrix (ECM) composed of different organic substances, such as extracellular proteins, exopolysaccharides and nucleic acids . While
336-404: A conserved set of genes. This indicates that biomineralisation is likely ancestral to all lophotrochozoans. The most ancient example of biomineralization, dating back 2 billion years, is the deposition of magnetite , which is observed in some bacteria, as well as the teeth of chitons and the brains of vertebrates; it is possible that this pathway, which performed a magnetosensory role in
448-472: A constant rate. These " molecular clocks ", however, are fallible, and provide only approximate timing: for example, they are not sufficiently precise and reliable for estimating when the groups that feature in the Cambrian explosion first evolved, and estimates produced by different techniques may vary by a factor of two. Organisms are only rarely preserved as fossils in the best of circumstances, and only
560-417: A diverse group of organisms that belong to the eukaryotic domain. Studies of their significant roles in geological processes, "geomycology", have shown that fungi are involved with biomineralization, biodegradation , and metal-fungal interactions. In studying fungi's roles in biomineralization, it has been found that fungi deposit minerals with the help of an organic matrix, such as a protein, that provides
672-426: A fraction of such fossils have been discovered. This is illustrated by the fact that the number of species known through the fossil record is less than 5% of the number of known living species, suggesting that the number of species known through fossils must be far less than 1% of all the species that have ever lived. Because of the specialized and rare circumstances required for a biological structure to fossilize, only
784-420: A framework for differentiating these terms. Biomineralization, biologically controlled mineralization , occurs when crystal morphology, growth, composition, and location are completely controlled by the cellular processes of a specific organism. Examples include the shells of invertebrates, such as molluscs and brachiopods . Additionally, the mineralization of collagen provides crucial compressive strength for
896-499: A hierarchical classification system still in use today. Darwin and his contemporaries first linked the hierarchical structure of the tree of life with the then very sparse fossil record. Darwin eloquently described a process of descent with modification, or evolution, whereby organisms either adapt to natural and changing environmental pressures, or they perish. When Darwin wrote On the Origin of Species by Means of Natural Selection, or
1008-418: A mid-Ordovician age. Such index fossils must be distinctive, be globally distributed and occupy a short time range to be useful. Misleading results are produced if the index fossils are incorrectly dated. Stratigraphy and biostratigraphy can in general provide only relative dating ( A was before B ), which is often sufficient for studying evolution. However, this is difficult for some time periods, because of
1120-536: A mutation first appeared. Phylogenetics and paleontology work together in the clarification of science's still dim view of the appearance of life and its evolution. Niles Eldredge 's study of the Phacops trilobite genus supported the hypothesis that modifications to the arrangement of the trilobite's eye lenses proceeded by fits and starts over millions of years during the Devonian . Eldredge's interpretation of
1232-411: A nucleation site for the growth of biominerals. Fungal growth may produce a copper-containing mineral precipitate, such as copper carbonate produced from a mixture of (NH 4 ) 2 CO 3 and CuCl 2 . The production of the copper carbonate is produced in the presence of proteins made and secreted by the fungi. These fungal proteins that are found extracellularly aid in the size and morphology of
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#17327986499331344-458: A number of less common types of biominerals, usually resulting from a need for specific physical properties or the organism inhabiting an unusual environment. For example, teeth that are primarily used for scraping hard substrates may be reinforced with particularly tough minerals, such as the iron minerals magnetite in chitons or goethite in limpets . Gastropod molluscs living close to hydrothermal vents reinforce their carbonate shells with
1456-433: A passive filling rather than as a smart designable material. A future challenge is to develop ways to control the timing and the location of mineral formation, as well as the physical properties of the mineral itself, by environmental input. Bacillus subtilis has already been shown to respond to its environment, by changing the production of its ECM. It uses the polymers produced by single cells during biofilm formation as
1568-435: A physical cue to coordinate ECM production by the bacterial community. Biomineralization may be used to remediate groundwater contaminated with uranium . The biomineralization of uranium primarily involves the precipitation of uranium phosphate minerals associated with the release of phosphate by microorganisms. Negatively charged ligands at the surface of the cells attract the positively charged uranyl ion (UO 2 ). If
1680-570: A portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates , or the chitinous or calcareous exoskeletons of invertebrates . Fossils may also consist of the marks left behind by the organism while it was alive, such as animal tracks or feces ( coprolites ). These types of fossil are called trace fossils or ichnofossils , as opposed to body fossils . Some fossils are biochemical and are called chemofossils or biosignatures . Gathering fossils dates at least to
1792-410: A remarkable experiment whereby the nacreous layer of a molluscan shell was implanted into a human tooth , and rather than experiencing an immune response, the molluscan nacre was incorporated into the host bone matrix. This points to the exaptation of an original biomineralization pathway. The biomineralisation capacity of brachiopods and molluscs has also been demonstrated to be homologous, building on
1904-400: A richly diverse assembly of early multicellular eukaryotes . The fossil record and faunal succession form the basis of the science of biostratigraphy or determining the age of rocks based on embedded fossils. For the first 150 years of geology , biostratigraphy and superposition were the only means for determining the relative age of rocks. The geologic time scale was developed based on
2016-448: A small percentage of life-forms can be expected to be represented in discoveries, and each discovery represents only a snapshot of the process of evolution. The transition itself can only be illustrated and corroborated by transitional fossils, which will never demonstrate an exact half-way point. The fossil record is strongly biased toward organisms with hard-parts, leaving most groups of soft-bodied organisms with little to no role. It
2128-406: A substance as a mineral. A 2011 article defined icosahedrite , an aluminium-iron-copper alloy as mineral; named for its unique natural icosahedral symmetry , it is a quasicrystal . Unlike a true crystal, quasicrystals are ordered but not periodic. Examples of biogenic minerals include: Biominerals could be important indicators of extraterrestrial life and thus could play an essential role in
2240-429: A supracellular scale, biominerals are usually deposited by a dedicated organ, which is often defined very early in embryological development. This organ will contain an organic matrix that facilitates and directs the deposition of crystals. The matrix may be collagen , as in deuterostomes , or based on chitin or other polysaccharides, as in molluscs . The mollusc shell is a biogenic composite material that has been
2352-407: Is hydroxyapatite (HA), a calcium phosphate (Ca 10 (PO 4 ) 6 (OH) 2 ) and a naturally occurring form of apatite . It is a primary constituent of bone , teeth , and fish scales . Bone is made primarily of HA crystals interspersed in a collagen matrix—65 to 70% of the mass of bone is HA. Similarly, HA is 70 to 80% of the mass of dentin and enamel in teeth. In enamel, the matrix for HA
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#17327986499332464-589: Is CaCO 3 . The most common polymorphs in biomineralization are calcite (e.g. foraminifera , coccolithophores ) and aragonite (e.g. corals ), although metastable vaterite and amorphous calcium carbonate can also be important, either structurally or as intermediate phases in biomineralization. Some biominerals include a mixture of these phases in distinct, organised structural components (e.g. bivalve shells ). Carbonates are particularly prevalent in marine environments, but also present in freshwater and terrestrial organisms. The most common biogenic phosphate
2576-449: Is a notable example of how knowledge encoded by the fossil record continues to contribute otherwise unattainable information on the emergence and development of life on Earth. For example, the research suggests Markuelia has closest affinity to priapulid worms, and is adjacent to the evolutionary branching of Priapulida , Nematoda and Arthropoda . Despite significant advances in uncovering and identifying paleontological specimens, it
2688-406: Is a topic of contention among geologists and mineralogists. For example, Lowenstam (1981) stated that "organisms are capable of forming a diverse array of minerals, some of which cannot be formed inorganically in the biosphere." Skinner (2005) views all solids as potential minerals and includes biominerals in the mineral kingdom, which are created by organisms' metabolic activities. Skinner expanded
2800-408: Is also evidence that silicification is used as a detoxification response in snails and plants, biosilica has even been suggested to play a role as a pH buffer for the enzymatic activity of carbonic anhydrase , aiding the acquisition of inorganic carbon for photosynthesis. There are questions which have yet to be resolved, such as why some organisms biomineralize while others do not, and why
2912-501: Is carried out through a process known as neogenesis. The order of most to least oxalic acid secreted by the fungi studied are Aspergillus niger , followed by Serpula himantioides , and finally Trametes versicolor . It is less clear what purpose biominerals serve in bacteria. One hypothesis is that cells create them to avoid entombment by their own metabolic byproducts. Iron oxide particles may also enhance their metabolism. Biomineralization plays significant global roles terraforming
3024-419: Is desirable for materials engineering applications, there is interest in understanding and elucidating the mechanisms of biologically-controlled biomineralization. Mineralization can be subdivided into different categories depending on the following: the organisms or processes that create chemical conditions necessary for mineral formation, the origin of the substrate at the site of mineral precipitation, and
3136-406: Is formed by amelogenins and enamelins instead of collagen. Remineralisation of tooth enamel involves the reintroduction of mineral ions into demineralised enamel. Hydroxyapatite is the main mineral component of enamel in teeth. During demineralisation, calcium and phosphorus ions are drawn out from the hydroxyapatite. The mineral ions introduced during remineralisation restore the structure of
3248-479: Is generally accepted that the fossil record is vastly incomplete. Approaches for measuring the completeness of the fossil record have been developed for numerous subsets of species, including those grouped taxonomically, temporally, environmentally/geographically, or in sum. This encompasses the subfield of taphonomy and the study of biases in the paleontological record. Paleontology seeks to map out how life evolved across geologic time. A substantial hurdle
3360-657: Is known as the fossil record . Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of Tiktaalik in the arctic of Canada . Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. The observation in
3472-550: Is often deemed as toxic to living organisms, certain fungi such as Aspergillus niger and Paecilomyces javanicus can tolerate it. Though minerals can be produced by fungi, they can also be degraded, mainly by oxalic acid –producing strains of fungi. Oxalic acid production is increased in the presence of glucose for three organic acid producing fungi: Aspergillus niger , Serpula himantioides , and Trametes versicolor . These fungi have been found to corrode apatite and galena minerals. Degradation of minerals by fungi
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3584-438: Is replete with the mollusks , the vertebrates , the echinoderms , the brachiopods and some groups of arthropods . Fossil sites with exceptional preservation—sometimes including preserved soft tissues—are known as Lagerstätten —German for "storage places". These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus slowing decomposition. Lagerstätten span geological time from
3696-470: Is the difficulty of working out fossil ages. Beds that preserve fossils typically lack the radioactive elements needed for radiometric dating . This technique is our only means of giving rocks greater than about 50 million years old an absolute age, and can be accurate to within 0.5% or better. Although radiometric dating requires careful laboratory work, its basic principle is simple: the rates at which various radioactive elements decay are known, and so
3808-534: Is the process by which living organisms produce minerals , often resulting in hardened or stiffened mineralized tissues . It is an extremely widespread phenomenon: all six taxonomic kingdoms contain members that are able to form minerals, and over 60 different minerals have been identified in organisms. Examples include silicates in algae and diatoms , carbonates in invertebrates , and calcium phosphates and carbonates in vertebrates . These minerals often form structural features such as sea shells and
3920-413: Is the science of deciphering the "layer-cake" that is the sedimentary record. Rocks normally form relatively horizontal layers, with each layer younger than the one underneath it. If a fossil is found between two layers whose ages are known, the fossil's age is claimed to lie between the two known ages. Because rock sequences are not continuous, but may be broken up by faults or periods of erosion , it
4032-705: Is there such a diversity of biominerals besides silicon when silicon is so abundant, comprising 28% of the Earth's crust. The answer to these questions lies in the evolutionary interplay between biomineralization and geochemistry, and in the competitive interactions that have arisen from these dynamics. Fundamentally whether an organism produces silica or not involves evolutionary trade-offs and competition between silicifiers themselves, and non-silicifying organisms (both those which use other biominerals, and non-mineralizing groups). Mathematical models and controlled experiments of resource competition in phytoplankton have demonstrated
4144-408: Is to mimic the natural way of producing minerals such as apatites . Many man-made crystals require elevated temperatures and strong chemical solutions, whereas the organisms have long been able to lay down elaborate mineral structures at ambient temperatures. Often, the mineral phases are not pure but are made as composites that entail an organic part, often protein , which takes part in and controls
4256-467: Is very difficult to match up rock beds that are not directly adjacent. However, fossils of species that survived for a relatively short time can be used to match isolated rocks: this technique is called biostratigraphy . For instance, the conodont Eoplacognathus pseudoplanus has a short range in the Middle Ordovician period. If rocks of unknown age have traces of E. pseudoplanus , they have
4368-801: The Cambrian period to the present . Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan Shales and Burgess Shale , the Devonian Hunsrück Slates , the Jurassic Solnhofen Limestone , and the Carboniferous Mazon Creek localities. A fossil is said to be recrystallized when the original skeletal compounds are still present but in a different crystal form, such as from aragonite to calcite . Replacement occurs when
4480-629: The Mushroom , Column , and the New Hall. Dwarf bat colonies live in different parts of the cave and can be heard and smelled, but not often seen. The many colours in the cave are astonishing, and the filtered air is rich in oxygen . About 45–50 m (148–164 ft) from the entrance, there is a wide saloon. The New Hall contains the remains (plastered walls, plastered material depot etc.) of use at some point in history. There are numerous stalactites , stalagmites , pillars and water ponds inside
4592-586: The Phacops fossil record was that the aftermaths of the lens changes, but not the rapidly occurring evolutionary process, were fossilized. This and other data led Stephen Jay Gould and Niles Eldredge to publish their seminal paper on punctuated equilibrium in 1971. Synchrotron X-ray tomographic analysis of early Cambrian bilaterian embryonic microfossils yielded new insights of metazoan evolution at its earliest stages. The tomography technique provides previously unattainable three-dimensional resolution at
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4704-569: The Renaissance . Leonardo da Vinci concurred with Aristotle's view that fossils were the remains of ancient life. For example, Leonardo noticed discrepancies with the biblical flood narrative as an explanation for fossil origins: If the Deluge had carried the shells for distances of three and four hundred miles from the sea it would have carried them mixed with various other natural objects all heaped up together; but even at such distances from
4816-602: The Song dynasty during the 11th century, who kept a specific seashell fossil with his own poem engraved on it. In his Dream Pool Essays published in 1088, Song dynasty Chinese scholar-official Shen Kuo hypothesized that marine fossils found in a geological stratum of mountains located hundreds of miles from the Pacific Ocean was evidence that a prehistoric seashore had once existed there and shifted over centuries of time . His observation of petrified bamboos in
4928-593: The bone in mammals and birds. Organisms have been producing mineralized skeletons for the past 550 million years. Calcium carbonates and calcium phosphates are usually crystalline, but silica organisms (such as sponges and diatoms) are always non-crystalline minerals. Other examples include copper, iron, and gold deposits involving bacteria. Biologically formed minerals often have special uses such as magnetic sensors in magnetotactic bacteria (Fe 3 O 4 ), gravity-sensing devices (CaCO 3 , CaSO 4 , BaSO 4 ) and iron storage and mobilization (Fe 2 O 3 •H 2 O in
5040-418: The carbonate minerals precipitated by the fungi. In addition to precipitating carbonate minerals, fungi can also precipitate uranium -containing phosphate biominerals in the presence of organic phosphorus that acts as a substrate for the process. The fungi produce a hyphal matrix , also known as mycelium , that localizes and accumulates the uranium minerals that have been precipitated. Although uranium
5152-497: The hydrosphere , atmosphere , and biosphere . The group's scope includes mineral-forming microorganisms, which exist on nearly every rock, soil, and particle surface spanning the globe to depths of at least 1,600 metres below the sea floor and 70 kilometres into the stratosphere (possibly entering the mesosphere ). Biogeochemical cycles have contributed to the formation of minerals for billions of years. Microorganisms can precipitate metals from solution , contributing to
5264-402: The law of superposition ) preserved different assemblages of fossils, and that these assemblages succeeded one another in a regular and determinable order. He observed that rocks from distant locations could be correlated based on the fossils they contained. He termed this the principle of faunal succession . This principle became one of Darwin's chief pieces of evidence that biological evolution
5376-403: The thunderbird . There is no such direct mythological connection known from prehistoric Africa, but there is considerable evidence of tribes there excavating and moving fossils to ceremonial sites, apparently treating them with some reverence. In Japan, fossil shark teeth were associated with the mythical tengu , thought to be the razor-sharp claws of the creature, documented some time after
5488-571: The water column at the point in time when they became biomineralized, and stuck with that form for the remainder of their biological history (but see for a more detailed analysis). The stability is dependent on the Ca/Mg ratio of seawater , which is thought to be controlled primarily by the rate of sea floor spreading , although atmospheric CO 2 levels may also play a role. Biomineralization evolved multiple times, independently, and most animal lineages first expressed biomineralized components in
5600-453: The 16th century. Roman naturalist Pliny the Elder wrote of " tongue stones ", which he called glossopetra . These were fossil shark teeth, thought by some classical cultures to look like the tongues of people or snakes. He also wrote about the horns of Ammon , which are fossil ammonites , whence the group of shelled octopus-cousins ultimately draws its modern name. Pliny also makes one of
5712-739: The 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host. There are many processes that lead to fossilization , including permineralization , casts and molds, authigenic mineralization , replacement and recrystallization, adpression, carbonization , and bioimmuration. Fossils vary in size from one- micrometre (1 μm) bacteria to dinosaurs and trees, many meters long and weighing many tons. A fossil normally preserves only
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#17327986499335824-466: The 78 mineral classes listed in the Dana classification scheme. Skinner's (2005) definition of a mineral considers this matter by stating that a mineral can be crystalline or amorphous. Although biominerals are not the most common form of minerals, they help to define the limits of what constitutes a mineral properly. Nickel's (1995) formal definition explicitly mentioned crystallinity as a key to defining
5936-413: The 8th century AD. In medieval China, the fossil bones of ancient mammals including Homo erectus were often mistaken for " dragon bones" and used as medicine and aphrodisiacs . In addition, some of these fossil bones are collected as "art" by scholars, who left scripts on various artifacts, indicating the time they were added to a collection. One good example is the famous scholar Huang Tingjian of
6048-668: The Cambrian period. Many of the same processes are used in unrelated lineages, which suggests that biomineralization machinery was assembled from pre-existing "off-the-shelf" components already used for other purposes in the organism. Although the biomachinery facilitating biomineralization is complex – involving signalling transmitters, inhibitors, and transcription factors – many elements of this 'toolkit' are shared between phyla as diverse as corals , molluscs , and vertebrates . The shared components tend to perform quite fundamental tasks, such as designating that cells will be used to create
6160-615: The Preservation of Favoured Races in the Struggle for Life , the oldest animal fossils were those from the Cambrian Period, now known to be about 540 million years old. He worried about the absence of older fossils because of the implications on the validity of his theories, but he expressed hope that such fossils would be found, noting that: "only a small portion of the world is known with accuracy." Darwin also pondered
6272-566: The Proterozoic and deeper still in the Archean is only "recounted by microscopic fossils and subtle chemical signals." Molecular biologists, using phylogenetics , can compare protein amino acid or nucleotide sequence homology (i.e., similarity) to evaluate taxonomy and evolutionary distances among organisms, with limited statistical confidence. The study of fossils, on the other hand, can more specifically pinpoint when and in what organism
6384-666: The Second Evolutionary Period, and the 5th layer was formed in the 20th century. The gallery, which leads to some open space with a pond , is the first section in the northeast-southwest direction. It consists of the Stalactite and Stalagmite Hall on the first level, and the Fossil Hall and the Bat Hall on the second level. The Magnificent Gallery on the third floor is formed by three adjoining halls:
6496-399: The ability to generate ECM appears to be a common feature of multicellular bacterial communities, the means by which these matrices are constructed and function are diverse. Bacterially induced calcium carbonate precipitation can be used to produce "self-healing" concrete. Bacillus megaterium spores and suitable dried nutrients are mixed and applied to steel-reinforced concrete. When
6608-403: The animal kingdom, including in sponges , implying an ancestral role. Far from being a rare trait that evolved a few times and remained stagnant, biomineralization pathways in fact evolved many times and are still evolving rapidly today; even within a single genus, it is possible to detect great variation within a single gene family. The homology of biomineralization pathways is underlined by
6720-413: The beach, indicating the fossils were once living animals. He had previously explained them in terms of vaporous exhalations , which Persian polymath Avicenna modified into the theory of petrifying fluids ( succus lapidificatus ). Recognition of fossil seashells as originating in the sea was built upon in the 14th century by Albert of Saxony , and accepted in some form by most naturalists by
6832-714: The beginning of recorded history. The fossils themselves are referred to as the fossil record. The fossil record was one of the early sources of data underlying the study of evolution and continues to be relevant to the history of life on Earth . Paleontologists examine the fossil record to understand the process of evolution and the way particular species have evolved. Fossils have been visible and common throughout most of natural history, and so documented human interaction with them goes back as far as recorded history, or earlier. There are many examples of paleolithic stone knives in Europe, with fossil echinoderms set precisely at
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#17327986499336944-413: The biomineralization. These composites are often not only as hard as the pure mineral but also tougher, as the micro-environment controls biomineralization. One biological system that might be of key importance in the future development of architecture is bacterial biofilm. The term biofilm refers to complex heterogeneous structures comprising different populations of microorganisms that attach and form
7056-460: The bones, cartilage, and teeth of vertebrates. This type of mineralization includes both biologically induced mineralization and biologically influenced mineralization. Biological mineralization can also take place as a result of fossilization . See also calcification . Among animals, biominerals composed of calcium carbonate , calcium phosphate , or silica perform a variety of roles such as support, defense, and feeding. If present on
7168-599: The celestite ensures their shells function as mineral ballast , resulting in fast sedimentation to bathypelagic depths. High settling fluxes of acantharian cysts have been observed at times in the Iceland Basin and the Southern Ocean, as much as half of the total gravitational organic carbon flux. In nature, there is a wide array of biominerals, ranging from iron oxide to strontium sulfate, with calcareous biominerals being particularly notable. However,
7280-503: The common ancestor of all bilaterians , was duplicated and modified in the Cambrian to form the basis for calcium-based biomineralization pathways. Iron is stored in close proximity to magnetite-coated chiton teeth, so that the teeth can be renewed as they wear. Not only is there a marked similarity between the magnetite deposition process and enamel deposition in vertebrates, but some vertebrates even have comparable iron storage facilities near their teeth. Most traditional approaches to
7392-583: The concentrations of phosphate and UO 2 are sufficiently high, minerals such as autunite (Ca(UO 2 ) 2 (PO 4 ) 2 •10-12H 2 O) or polycrystalline HUO 2 PO 4 may form thus reducing the mobility of UO 2 . Compared to the direct addition of inorganic phosphate to contaminated groundwater, biomineralization has the advantage that the ligands produced by microbes will target uranium compounds more specifically rather than react actively with all aqueous metals. Stimulating bacterial phosphatase activity to liberate phosphate under controlled conditions limits
7504-409: The concrete cracks, water ingress dissolves the nutrients and the bacteria germinate triggering calcium carbonate precipitation, resealing the crack and protecting the steel reinforcement from corrosion. This process can also be used to manufacture new hard materials, such as bio-cement. However, the full potential of bacteria-driven biomineralization is yet to be realized, as it is currently used as
7616-453: The degree of control that the substrate has on crystal morphology, composition, and growth. These subcategories include biomineralization, organomineralization, and inorganic mineralization, which can be subdivided further. However, the usage of these terms varies widely in the scientific literature because there are no standardized definitions. The following definitions are based largely on a paper written by Dupraz et al. (2009), which provided
7728-670: The deity Sopdu , the Morning Star, equivalent of Venus in Roman mythology. Fossils appear to have directly contributed to the mythology of many civilizations, including the ancient Greeks. Classical Greek historian Herodotos wrote of an area near Hyperborea where gryphons protected golden treasure. There was indeed gold mining in that approximate region , where beaked Protoceratops skulls were common as fossils. A later Greek scholar, Aristotle , eventually realized that fossil seashells from rocks were similar to those found on
7840-489: The divergence of the animal lineages. The galaxins are one probable example of a gene being co-opted from a different ancestral purpose into controlling biomineralization, in this case, being 'switched' to this purpose in the Triassic scleractinian corals ; the role performed appears to be functionally identical to that of the unrelated pearlin gene in molluscs. Carbonic anhydrase serves a role in mineralization broadly in
7952-466: The dry northern climate zone of what is now Yan'an , Shaanxi province, China, led him to advance early ideas of gradual climate change due to bamboo naturally growing in wetter climate areas. In medieval Christendom , fossilized sea creatures on mountainsides were seen as proof of the biblical deluge of Noah's Ark . After observing the existence of seashells in mountains, the ancient Greek philosopher Xenophanes (c. 570 – 478 BC) speculated that
8064-415: The earlier known references to toadstones , thought until the 18th century to be a magical cure for poison originating in the heads of toads, but which are fossil teeth from Lepidotes , a Cretaceous ray-finned fish. The Plains tribes of North America are thought to have similarly associated fossils, such as the many intact pterosaur fossils naturally exposed in the region, with their own mythology of
8176-550: The earliest known stromatolites are over 3.4 billion years old. The fossil record is life's evolutionary epic that unfolded over four billion years as environmental conditions and genetic potential interacted in accordance with natural selection. The Virtual Fossil Museum Paleontology has joined with evolutionary biology to share the interdisciplinary task of outlining the tree of life, which inevitably leads backwards in time to Precambrian microscopic life when cell structure and functions evolved. Earth's deep time in
8288-464: The earth during earthquake and subsidences, and petrifies whatever comes into contact with it. As a matter of fact, the petrifaction of the bodies of plants and animals is not more extraordinary than the transformation of waters. From the 13th century to the present day, scholars pointed out that the fossil skulls of Deinotherium giganteum , found in Crete and Greece, might have been interpreted as being
8400-478: The existence of a world previous to ours, destroyed by some kind of catastrophe. Interest in fossils, and geology more generally, expanded during the early nineteenth century. In Britain, Mary Anning 's discoveries of fossils, including the first complete ichthyosaur and a complete plesiosaurus skeleton, sparked both public and scholarly interest. Early naturalists well understood the similarities and differences of living species leading Linnaeus to develop
8512-775: The formation of ore deposits. They can also catalyze the dissolution of minerals. Before the International Mineralogical Association's listing, over 60 biominerals had been discovered, named, and published. These minerals (a sub-set tabulated in Lowenstam (1981) ) are considered minerals proper according to Skinner's (2005) definition. These biominerals are not listed in the International Mineral Association official list of mineral names, however, many of these biomineral representatives are distributed amongst
8624-519: The hand grip, dating back to Homo heidelbergensis and Neanderthals . These ancient peoples also drilled holes through the center of those round fossil shells, apparently using them as beads for necklaces. The ancient Egyptians gathered fossils of species that resembled the bones of modern species they worshipped. The god Set was associated with the hippopotamus , therefore fossilized bones of hippo-like species were kept in that deity's temples. Five-rayed fossil sea urchin shells were associated with
8736-455: The hydroxyapatite crystals. The clubbing appendages of the peacock mantis shrimp are made of an extremely dense form of the mineral which has a higher specific strength; this has led to its investigation for potential synthesis and engineering use. Their dactyl appendages have excellent impact resistance due to the impact region being composed of mainly crystalline hydroxyapatite, which offers significant hardness. A periodic layer underneath
8848-401: The impact layer composed of hydroxyapatite with lower calcium and phosphorus content (thus resulting in a much lower modulus) inhibits crack growth by forcing new cracks to change directions. This periodic layer also reduces the energy transferred across both layers due to the large difference in modulus, even reflecting some of the incident energy. Beyond these main three categories, there are
8960-402: The interpretations that can be built on them. The first evidence of biomineralization dates to some 750 million years ago , and sponge-grade organisms may have formed calcite skeletons 630 million years ago . But in most lineages, biomineralization first occurred in the Cambrian or Ordovician periods. Organisms used whichever form of calcium carbonate was more stable in
9072-462: The iron-sulphur minerals pyrite and greigite . Magnetotactic bacteria also employ magnetic iron minerals magnetite and greigite to produce magnetosomes to aid orientation and distribution in the sediments. Celestine , the heaviest mineral in the ocean, consists of strontium sulfate , SrSO 4 . The mineral is named for the delicate blue colour of its crystals. Planktic acantharean radiolarians form celestine crystal shells. The denseness of
9184-535: The limits of fossilization. Fossils of two enigmatic bilaterians, the worm-like Markuelia and a putative, primitive protostome , Pseudooides , provide a peek at germ layer embryonic development. These 543-million-year-old embryos support the emergence of some aspects of arthropod development earlier than previously thought in the late Proterozoic. The preserved embryos from China and Siberia underwent rapid diagenetic phosphatization resulting in exquisite preservation, including cell structures. This research
9296-441: The major silicifiers in terrestrial ecosystems are the land plants ( embryophytes ), with other silicifying groups (e.g., testate amoebae ) having a minor role. Broadly, biomineralized structures evolve and diversify when the energetic cost of biomineral production is less than the expense of producing an equivalent organic structure. The energetic costs of forming a silica structure from silicic acid are much less than forming
9408-422: The minerals, whereas genes controlling more finely tuned aspects that occur later in the biomineralization process, such as the precise alignment and structure of the crystals produced, tend to be uniquely evolved in different lineages. This suggests that Precambrian organisms were employing the same elements, albeit for a different purpose – perhaps to avoid the inadvertent precipitation of calcium carbonate from
9520-402: The most taxonomically widespread biomineral is silica (SiO 2 ·nH 2 O), being present in all eukaryotic supergroups. Notwithstanding, the degree of silicification can vary even between closely related taxa, from being found in composite structures with other biominerals (e.g., limpet teeth ; to forming minor structures (e.g., ciliate granules; or being a major structural constituent of
9632-506: The organism. The most extreme degree of silicification is evident in the diatoms, where almost all species have an obligate requirement for silicon to complete cell wall formation and cell division. Biogeochemically and ecologically, diatoms are the most important silicifiers in modern marine ecosystems, with radiolarians ( polycystine and phaeodarian rhizarians ), silicoflagellates ( dictyochophyte and chrysophyte stramenopiles ), and sponges with prominent roles as well. In contrast,
9744-422: The planet, as well as in biogeochemical cycles and as a carbon sink . Most biominerals can be grouped by chemical composition into one of three distinct mineral classes: silicates, carbonates, or phosphates. Silicates (glass) are common in marine biominerals, where diatoms form frustules and radiolaria form capsules from hydrated amorphous silica ( opal ). The major carbonate in biominerals
9856-568: The previous definition of a mineral to classify "element or compound, amorphous or crystalline, formed through biogeochemical processes," as a mineral. Recent advances in high-resolution genetics and X-ray absorption spectroscopy are providing revelations on the biogeochemical relations between microorganisms and minerals that may shed new light on this question. For example, the IMA-commissioned "Working Group on Environmental Mineralogy and Geochemistry " deals with minerals in
9968-545: The problems involved in matching rocks of the same age across continents . Family-tree relationships also help to narrow down the date when lineages first appeared. For instance, if fossils of B or C date to X million years ago and the calculated "family tree" says A was an ancestor of B and C, then A must have evolved earlier. It is also possible to estimate how long ago two living clades diverged, in other words approximately how long ago their last common ancestor must have lived, by assuming that DNA mutations accumulate at
10080-594: The production of much stronger structures, such as siliceous diatom frustules having the highest strength per unit density of any known biological material, or sponge spicules being many times more flexible than an equivalent structure made of pure silica. As a result, biogenic silica structures are used for support, feeding, predation defense and environmental protection as a component of cyst walls. Biogenic silica also has useful optical properties for light transmission and modulation in organisms as diverse as plants, diatoms, sponges, and molluscs. There
10192-519: The protein ferritin ). In terms of taxonomic distribution, the most common biominerals are the phosphate and carbonate salts of calcium that are used in conjunction with organic polymers such as collagen and chitin to give structural support to bones and shells. The structures of these biocomposite materials are highly controlled from the nanometer to the macroscopic level, resulting in complex architectures that provide multifunctional properties. Because this range of control over mineral growth
10304-539: The rate of bacterial hydrolysis of organophosphate and the release of phosphate to the system, thus avoiding clogging of the injection location with metal phosphate minerals. The high concentration of ligands near the cell surface also provides nucleation foci for precipitation, which leads to higher efficiency than chemical precipitation. The geological definition of mineral normally excludes compounds that occur only in living beings. However, some minerals are often biogenic (such as calcite ) or are organic compounds in
10416-443: The ratio of the radioactive element to its decay products shows how long ago the radioactive element was incorporated into the rock. Radioactive elements are common only in rocks with a volcanic origin, and so the only fossil-bearing rocks that can be dated radiometrically are volcanic ash layers, which may provide termini for the intervening sediments. Consequently, palaeontologists rely on stratigraphy to date fossils. Stratigraphy
10528-462: The relative ages of rock strata as determined by the early paleontologists and stratigraphers . Since the early years of the twentieth century, absolute dating methods, such as radiometric dating (including potassium/argon , argon/argon , uranium series , and, for very recent fossils, radiocarbon dating ) have been used to verify the relative ages obtained by fossils and to provide absolute ages for many fossils. Radiometric dating has shown that
10640-418: The rise to dominance of different algal species based on nutrient backgrounds in defined media. These have been part of fundamental studies in ecology. However, the vast diversity of organisms that thrive in a complex array of biotic and abiotic interactions in oceanic ecosystems are a challenge to such minimal models and experimental designs, whose parameterization and possible combinations, respectively, limit
10752-549: The saloon. This article about a Black Sea Region of Turkey location is a stub . You can help Misplaced Pages by expanding it . Fossil A fossil (from Classical Latin fossilis , lit. ' obtained by digging ' ) is any preserved remains, impression, or trace of any once-living thing from a past geological age . Examples include bones , shells , exoskeletons , stone imprints of animals or microbes , objects preserved in amber , hair , petrified wood and DNA remnants. The totality of fossils
10864-531: The same volume from an organic structure (≈20-fold less than lignin or 10-fold less than polysaccharides like cellulose). Based on a structural model of biogenic silica , Lobel et al. (1996) identified by biochemical modeling a low-energy reaction pathway for nucleation and growth of silica. The combination of organic and inorganic components within biomineralized structures often results in enhanced properties compared to exclusively organic or inorganic materials. With respect to biogenic silica, this can result in
10976-429: The sea and that they were still living when the strait of Gibraltar was cut through. In the mountains of Parma and Piacenza multitudes of shells and corals with holes may be seen still sticking to the rocks.... In 1666, Nicholas Steno examined a shark, and made the association of its teeth with the "tongue stones" of ancient Greco-Roman mythology, concluding that those were not in fact the tongues of venomous snakes, but
11088-423: The sea we see the oysters all together and also the shellfish and the cuttlefish and all the other shells which congregate together, found all together dead; and the solitary shells are found apart from one another as we see them every day on the sea-shores. And we find oysters together in very large families, among which some may be seen with their shells still joined together, indicating that they were left there by
11200-547: The sense of chemistry (such as mellite ). Moreover, living beings often synthesize inorganic minerals (such as hydroxylapatite ) that also occur in rocks. The International Mineralogical Association (IMA) is the generally recognized standard body for the definition and nomenclature of mineral species. As of December 2020 , the IMA recognizes 5,650 official mineral species out of 5,862 proposed or traditional ones. The IMA's decision to exclude biogenic crystalline substances
11312-406: The shell its remarkable mechanical strength. The application of biomimetic principles elucidated from mollusc shell assembly and structure may help in fabricating new composite materials with enhanced optical, electronic, or structural properties. The most described arrangement in mollusc shells is the nacre , known in large shells such as Pinna or the pearl oyster ( Pinctada ). Not only does
11424-669: The shell, bone, or other tissue is replaced with another mineral. In some cases mineral replacement of the original shell occurs so gradually and at such fine scales that microstructural features are preserved despite the total loss of original material. Scientists can use such fossils when researching the anatomical structure of ancient species. Several species of saurids have been identified from mineralized dinosaur fossils. Mineralization (biology) Biomineralization : Complete conversion of organic substances to inorganic derivatives by living organisms, especially micro-organisms. Biomineralization , also written biomineralisation ,
11536-586: The skulls of the Cyclopes of Greek mythology , and are possibly the origin of that Greek myth. Their skulls appear to have a single eye-hole in the front, just like their modern elephant cousins, though in fact it's actually the opening for their trunk. In Norse mythology , echinoderm shells (the round five-part button left over from a sea urchin) were associated with the god Thor , not only being incorporated in thunderstones , representations of Thor's hammer and subsequent hammer-shaped crosses as Christianity
11648-554: The structure of the layers differ, but so do their mineralogy and chemical composition. Both contain organic components (proteins, sugars, and lipids), and the organic components are characteristic of the layer and of the species. The structures and arrangements of mollusc shells are diverse, but they share some features: the main part of the shell is crystalline calcium carbonate ( aragonite , calcite ), though some amorphous calcium carbonate occurs as well; and although they react as crystals, they never show angles and facets. Fungi are
11760-536: The subject of much interest in materials science because of its unusual properties and its model character for biomineralization. Molluscan shells consist of 95–99% calcium carbonate by weight, while an organic component makes up the remaining 1–5%. The resulting composite has a fracture toughness ≈3000 times greater than that of the crystals themselves. In the biomineralization of the mollusc shell, specialized proteins are responsible for directing crystal nucleation, phase, morphology, and growths dynamics and ultimately give
11872-467: The sudden appearance of many groups (i.e. phyla ) in the oldest known Cambrian fossiliferous strata. Since Darwin's time, the fossil record has been extended to between 2.3 and 3.5 billion years. Most of these Precambrian fossils are microscopic bacteria or microfossils . However, macroscopic fossils are now known from the late Proterozoic. The Ediacara biota (also called Vendian biota) dating from 575 million years ago collectively constitutes
11984-422: The supersaturated Proterozoic oceans. Forms of mucus that are involved in inducing mineralization in most animal lineages appear to have performed such an anticalcifatory function in the ancestral state. Further, certain proteins that would originally have been involved in maintaining calcium concentrations within cells are homologous in all animals, and appear to have been co-opted into biomineralization after
12096-806: The synthesis of nanoscale materials are energy inefficient, requiring stringent conditions (e.g., high temperature, pressure, or pH), and often produce toxic byproducts. Furthermore, the quantities produced are small, and the resultant material is usually irreproducible because of the difficulties in controlling agglomeration. In contrast, materials produced by organisms have properties that usually surpass those of analogous synthetically manufactured materials with similar phase composition. Biological materials are assembled in aqueous environments under mild conditions by using macromolecules. Organic macromolecules collect and transport raw materials and assemble these substrates and into short- and long-range ordered composites with consistency and uniformity. The aim of biomimetics
12208-451: The teeth of some long-extinct species of shark. Robert Hooke (1635–1703) included micrographs of fossils in his Micrographia and was among the first to observe fossil forams . His observations on fossils, which he stated to be the petrified remains of creatures some of which no longer existed, were published posthumously in 1705. William Smith (1769–1839) , an English canal engineer, observed that rocks of different ages (based on
12320-524: The world was once inundated in a great flood that buried living creatures in drying mud. In 1027, the Persian Avicenna explained fossils' stoniness in The Book of Healing : If what is said concerning the petrifaction of animals and plants is true, the cause of this (phenomenon) is a powerful mineralizing and petrifying virtue which arises in certain stony spots, or emanates suddenly from
12432-458: Was adopted, but also kept in houses to garner Thor's protection. These grew into the shepherd's crowns of English folklore, used for decoration and as good luck charms, placed by the doorway of homes and churches. In Suffolk , a different species was used as a good-luck charm by bakers, who referred to them as fairy loaves , associating them with the similarly shaped loaves of bread they baked. More scientific views of fossils emerged during
12544-408: Was real. Georges Cuvier came to believe that most if not all the animal fossils he examined were remains of extinct species. This led Cuvier to become an active proponent of the geological school of thought called catastrophism . Near the end of his 1796 paper on living and fossil elephants he said: All of these facts, consistent among themselves, and not opposed by any report, seem to me to prove
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