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Agamenón (hominin)
Agamenón, also known as Agamemnon, is a fossil calvarium belonging to an early Neanderthal that lived at the site of Atapuerca around 430,000 years ago. The crania recovered from Sima de los Huesos have multiple specimen catalogues including Sima de los Huesos 4, SH 4, Cranium 4, Cr4, and Skull 4. Original analyses of the specimen concluded that the individual was deaf, although further study has proven that this is not the case. It is now held at the Museum of Human Evolution. History The specimen was discovered by paleontologists in 1992 and was catalogued as Skull 4. In 1997, the hearing capacity of the individual was evaluated and determined to be deaf based on a singular tomographic image, contrary to more recent advances. It was discovered alongside Miguelón, SH 5. Description Agamenón is one of the most complete skulls for its chronological age of 430,000 years. In life, the Sima de los Huesos hominins had a hearing capacity that was very similar from ''Homo sap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homo Neanderthalensis
Neanderthals ( ; ''Homo neanderthalensis'' or sometimes ''H. sapiens neanderthalensis'') are an extinct group of archaic humans who inhabited Europe and Western and Central Asia during the Middle to Late Pleistocene. Neanderthal extinction occurred roughly 40,000 years ago with the immigration of modern humans ( Cro-Magnons), but Neanderthals in Gibraltar may have persisted for thousands of years longer. The first recognised Neanderthal fossil, Neanderthal 1, was discovered in 1856 in the Neander Valley, Germany. At first, Neanderthal 1 was considered to be one of the lower races in accord with historical race concepts. As more fossils were discovered through the early 20th century, Neanderthals became characterised most especially by Marcellin Boule as a unique species of underdeveloped human. By the mid-20th century, human evolution was described as progressing from an apelike ancestor, through a "Neanderthal phase", ending in modern humans. This gave way to the " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cranial Vault
The cranial vault is the space in the skull within the neurocranium, occupied by the brain. Development In humans, the cranial vault is imperfectly composed in newborns, to allow the large human head to pass through the birth canal. During birth, the various bones, connected only by cartilage and ligaments, will move relatively to each other. The open portion between the major bones of the upper part of the vault, called fontanelles, normally remain soft up to two years after birth. As the fontanelles close, the vault loses some of its plasticity. The sutures between the bones remain until 30 to 40 years of age, allowing for growth of the brain. Cranial vault size is directly proportional to skull size and is developed early."Changes in vault dimensions must occur by early childhood because of the early development of the vault.Secular change in craniofacial morphology"During the 125 years under consideration, cranial vaults have become markedly higher and somewhat narrower, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1992 In Paleontology
References * Tanke, D.H. and Brett-Surman, M.K. 2001. Evidence of Hatchling and Nestling-Size Hadrosaurs (Reptilia:Ornithischia) from Dinosaur Provincial Park (Dinosaur Park Formation: Campanian), Alberta, Canada. pp. 206–218. In: Mesozoic Vertebrate Life—New Research Inspired by the Paleontology of Philip J. Currie. Edited by D.H. Tanke and K. Carpenter. Indiana University Press: Bloomington. xviii + 577 pp. * Trexler, D., 2001, Two Medicine Formation, Montana: geology and fauna: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 298–309. 1992 in paleontology, 1990s in paleontology 1992 in science, Paleontology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neanderthal Fossils
Neanderthals ( ; ''Homo neanderthalensis'' or sometimes ''H. sapiens neanderthalensis'') are an extinct group of archaic humans who inhabited Europe and Western and Central Asia during the Middle to Late Pleistocene. Neanderthal extinction occurred roughly 40,000 years ago with the immigration of modern humans (Cro-Magnons), but Neanderthals in Gibraltar may have persisted for thousands of years longer. The first recognised Neanderthal fossil, Neanderthal 1, was discovered in 1856 in the Neander Valley, Germany. At first, Neanderthal 1 was considered to be one of the lower races in accord with historical race concepts. As more fossils were discovered through the early 20th century, Neanderthals became characterised most especially by Marcellin Boule as a unique species of underdeveloped human. By the mid-20th century, human evolution was described as progressing from an apelike ancestor, through a "Neanderthal phase", ending in modern humans. This gave way to the "Out of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population
Population is a set of humans or other organisms in a given region or area. Governments conduct a census to quantify the resident population size within a given jurisdiction. The term is also applied to non-human animals, microorganisms, and plants, and has specific uses within such fields as ecology and genetics. Etymology The word ''population'' is derived from the Late Latin ''populatio'' (a people, a multitude), which itself is derived from the Latin word ''populus'' (a people). Use of the term Social sciences In sociology and population geography, population refers to a group of human beings with some predefined feature in common, such as location, Race (human categorization), race, ethnicity, nationality, or religion. Ecology In ecology, a population is a group of organisms of the same species which inhabit the same geographical area and are capable of Sexual reproduction, interbreeding. The area of a sexual population is the area where interbreeding is possi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heritability
Heritability is a statistic used in the fields of Animal husbandry, breeding and genetics that estimates the degree of ''variation'' in a phenotypic trait in a population that is due to genetic variation between individuals in that population. The concept of heritability can be expressed in the form of the following question: "What is the proportion of the variation in a given trait within a population that is ''not'' explained by the environment or random chance?" Other causes of measured variation in a trait are characterized as environment (biophysical), environmental factors, including observational error. In human studies of heritability these are often apportioned into factors from "shared environment" and "non-shared environment" based on whether they tend to result in persons brought up in the same household being more or less similar to persons who were not. Heritability is estimated by comparing individual phenotypic variation among related individuals in a population, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purulent
Pus is an exudate, typically white-yellow, yellow, or yellow-brown, formed at the site of inflammation during infections, regardless of cause. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule, pimple or spot. Description Pus consists of a thin, protein-rich fluid (historically known as ''liquor puris'') and dead leukocytes (white blood cells) from the body's immune response (mostly neutrophils). During infection, T helper cells release cytokines, which trigger neutrophils to seek the site of infection by chemotaxis. There, the neutrophils release granules, which destroy the bacteria. The bacteria resist the immune response by releasing toxins called leukocidins.Madigan, Michael T. and Martin, John M. Brock Biology of Microorganisms 11th ed. Pearson Prentice Hall. US. 2006: 734 As the neutrophils die off from toxins and old age, they are destroyed by macrophages, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otitis Externa
Otitis externa, also called swimmer's ear, is inflammation of the ear canal. It often presents with ear pain, swelling of the ear canal, and occasionally decreased hearing. Typically there is pain with movement of the outer ear. A high fever is typically not present except in severe cases. Otitis externa may be acute (lasting less than six weeks) or chronic (lasting more than three months). Acute cases are typically due to bacterial infection, and chronic cases are often due to allergies and autoimmune disorders. The most common cause of otitis externa is bacterial. Risk factors for acute cases include swimming, minor trauma from cleaning, using hearing aids and ear plugs, and other skin problems, such as psoriasis and dermatitis. People with diabetes are at risk of a severe form of ''malignant otitis externa''. Diagnosis is based on the signs and symptoms. Culturing the ear canal may be useful in chronic or severe cases. Acetic acid ear drops may be used as a preventive m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surfer's Ear
Surfer's ear is the common name for an exostosis or abnormal bone growth within the ear canal. They are otherwise benign hyperplasias (growths) of the tympanic bone thought to be caused by frequent cold-water exposure. Cases are often asymptomatic. Surfer's ear is not the same as swimmer's ear, although infection can result as a side effect. Irritation from cold wind and water exposure causes the bone surrounding the ear canal to develop lumps of new bony growth which constrict the ear canal. Where the ear canal is actually blocked by this condition, water and wax can become trapped and give rise to infection. The condition is so named due to its high prevalence among cold water surfers, although it can occur in any water temperature due to the evaporative cooling caused by wind and the presence of water in the ear canal. Most avid surfers have at least some mild bone growths, causing little to no problems. The condition is gradually progressive and can generally be prevented b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ear Canal
The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the auricle to the eardrum and is about in length and in diameter. Structure The human ear canal is divided into two parts. The elastic cartilage part forms the outer third of the canal; its anterior and lower wall are cartilaginous, whereas its superior and back wall are fibrous. The cartilage is the continuation of the cartilage framework of auricle. The cartilaginous portion of the ear canal contains small hairs and specialized sweat glands, called apocrine glands, which produce cerumen ( ear wax). The bony part forms the inner two thirds. The bony part is much shorter in children and is only a ring (''annulus tympanicus'') in the newborn. The layer of epithelium encompassing the bony portion of the ear canal is much thinner and therefore, more sensitive in comparison to the cartilaginous portion. Size ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochlea
The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus (cochlea), modiolus. A core component of the cochlea is the organ of Corti, the sensory organ of hearing, which is distributed along the partition separating the fluid chambers in the coiled tapered tube of the cochlea. Etymology The name 'cochlea' is derived from the Latin word for ''snail shell'', which in turn is from the Greek language, Ancient Greek κοχλίας ''kokhlias'' ("snail, screw"), and from κόχλος ''kokhlos'' ("spiral shell") in reference to its coiled shape; the cochlea is coiled in mammals with the exception of monotremes. Structure The cochlea (: cochleae) is a spiraled, hollow, conical chamber of bone, in which waves propagate from the base (near the middle ear and the oval window) to the apex (the top or center of the spiral). The spiral canal of the cochlea is a section of the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
