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Cape Dune Molerat
The Cape dune mole-rat (''Bathyergus suillus'') is a species of solitary burrowing rodent in the family Bathyergidae. It is endemic to South Africa and named for the Cape of Good Hope. Description The Cape dune mole-rat is the largest of all the blesmols, measuring in head-body length, with a short, tail. Males are generally much heavier than females, weighing anything from , compared with typical female weights of . Both sexes are sturdy, large-bodied rodents, with blunt snouts, cylindrical torsos and short limbs. The forefeet are heavily adapted for digging, with powerful curved claws. To enable to move more quickly through tight tunnels, the body has few visible external features; for example, there are no pinnae or scrotum, and the penis retracts into a concealed sheath. Lip-like flaps of skin are able to close behind the incisors, preventing soil from falling into the mouth. The eyes are small, but not permanently closed. Unlike its relative the naked mole-rat, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Christian Daniel Von Schreber
Johann Christian Daniel von Schreber (17 January 1739 in Weißensee, Thuringia – 10 December 1810 in Erlangen), often styled J.C.D. von Schreber, was a German naturalist. Career He was appointed professor of'' materia medica'' at the University of Erlangen in 1769. In 1774, he began writing a multivolume set of books entitled ''Die Säugethiere in Abbildungen nach der Natur mit Beschreibungen'', which focused on the mammals of the world. Many of the animals included were given a scientific name for the first time, following the binomial system of Carl Linnaeus. From 1791 until his death in 1810, he was the president of the German Academy of Sciences Leopoldina. He was elected a member of the Royal Swedish Academy of Sciences in 1787. In April 1795, he was elected a Fellow of the Royal Society Numerous honors were bestowed on him, including the office of an imperial count palatine. Schreber also wrote on entomology, notably ''Schreberi Novae Species Insectorvm''. His herbar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuber
Tubers are a type of enlarged structure used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growing season, and as a means of asexual reproduction. ''Stem tubers'' form thickened rhizomes (underground stems) or stolons (horizontal connections between organisms); well known species with stem tubers include the potato and yam. Some writers also treat modified lateral roots (''root tubers'') under the definition; these are found in sweet potatoes, cassava, and dahlias. Terminology The term originates from the Latin , meaning "lump, bump, swelling". Some writers define the term "tuber" to mean only structures derived from stems; others use the term for structures derived from stems or roots., p. 124 Stem tubers A stem tuber forms from thickened rhizomes or stolons. The top sides of the tuber produce shoots that grow into typical stems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austin Roberts (zoologist)
Austin Roberts (3 January 1883 – 5 May 1948) was a South African zoologist. He is best known for his ''Birds of South Africa'', first published in 1940. He also studied the mammalian fauna of the region: his work ''The mammals of South Africa'' was published posthumously in 1951. The 7th edition of ''Roberts' Birds of Southern Africa'' which appeared in 2005, is the standard work on the region's birds. Biography Roberts, son of Alfred Roberts (church minister) and Marianne Fannin (naturalist and flower artist), was born in Pretoria and grew up in Potchefstroom, South Africa. He gained much of his early knowledge of zoology from Thomas Ayres (1828–1913), one of South Africa's first amateur ornithologists. Ayres taught Roberts to skin birds and small mammals as well as the importance of keeping accurate records on every specimen. He also encouraged Roberts to study birds systematically. Roberts worked as a clerk in the Potchefstroom branch of Standard Bank from 1901 to 1903 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georges Cuvier
Jean Léopold Nicolas Frédéric, Baron Cuvier (; 23 August 1769 – 13 May 1832), known as Georges Cuvier, was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in natural sciences research in the early 19th century and was instrumental in establishing the fields of comparative anatomy and paleontology through his work in comparing living animals with fossils. Cuvier's work is considered the foundation of vertebrate paleontology, and he expanded Linnaean taxonomy by grouping classes into phylum, phyla and incorporating both fossils and living species into the classification. Cuvier is also known for establishing extinction as a fact—at the time, extinction was considered by many of Cuvier's contemporaries to be merely controversial speculation. In his ''Essay on the Theory of the Earth'' (1813) Cuvier proposed that now-extinct species had been wiped out by periodic catastrophi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrew Smith (zoologist)
Sir Andrew Smith (3 December 1797 – 11 August 1872) was a British surgeon, explorer, ethnologist and zoologist. He is considered the father of zoology in South Africa having described many species across a wide range of groups in his major work, ''Illustrations of the Zoology of South Africa''. Smith was born in Hawick, Roxburghshire. He qualified in medicine at the University of Edinburgh obtaining an M.D. degree in 1819, having joined the Army Medical Services in 1816. South Africa 1820–1837 In 1820 he was ordered to the Cape Colony and was sent to Grahamstown to supervise the medical care of European soldiers and soldiers of the Cape Corps. He was appointed the Albany district surgeon in 1822 and started the first free dispensary for indigent patients in South Africa. He led a scientific expedition into the interior and was able to indulge in his interests of natural history and anthropology. On several occasions, he was sent by governors on confidential missions to vis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Peter Thunberg
Carl Peter Thunberg, also known as Karl Peter von Thunberg, Carl Pehr Thunberg, or Carl Per Thunberg (11 November 1743 – 8 August 1828), was a Swedish naturalist and an "apostle" of Carl Linnaeus. After studying under Linnaeus at Uppsala University, he spent seven years travelling in southern Africa and Asia, collecting and describing many plants and animals new to European science, and observing local cultures. He has been called "the father of South African botany", "pioneer of Occidental Medicine in Japan", and the "Japanese Linnaeus". Early life Thunberg was born and grew up in Jönköping, Sweden. At the age of 18, he entered Uppsala University where he was taught by Carl Linnaeus, regarded as the "father of modern taxonomy". Thunberg graduated in 1767 after 6 years of studying. To deepen his knowledge in botany, medicine and natural history, he was encouraged by Linnaeus in 1770 to travel to Paris and Amsterdam. In Amsterdam and Leiden Thunberg met the Dutch botanist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Friedrich Gmelin
, fields = , workplaces = University of GöttingenUniversity of Tübingen , alma_mater = University of Tübingen , doctoral_advisor = Philipp Friedrich GmelinFerdinand Christoph Oetinger , academic_advisors = , doctoral_students = Georg Friedrich HildebrandtFriedrich StromeyerCarl Friedrich KielmeyerWilhelm August LampadiusVasily Severgin , notable_students = , known_for = Textbooks on chemistry, pharmaceutical science, mineralogy, and botany , author_abbrev_bot = J.F.Gmel. , author_abbrev_zoo = Gmelin , influences = Carl Linnaeus , influenced = , relatives = Leopold Gmelin (son) , awards = Johann Friedrich Gmelin (8 August 1748 – 1 November 1804) was a German naturalist, botanist, entomologist, herpetologist, and malacologist. Education Johann Friedrich Gmelin was born as the eldest son of Philipp Friedrich Gmelin in 1748 in Tübingen. He studied medicine under his father at University of Tübingen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weaning
Weaning is the process of gradually introducing an infant human or another mammal to what will be its adult diet while withdrawing the supply of its mother's milk. The process takes place only in mammals, as only mammals produce milk. The infant is considered to be fully weaned once it is no longer fed by any breast milk (or bottled substitute). Humans In some cultures, weaning progresses with the introduction of feeding the child food that has been prechewed by the parent along with continued breastfeeding, a practice known as premastication. The practice was important throughout human history in that it naturally gave a child a greatly improved protein source in addition to preventing iron deficiency. However, premasticated food from caregivers of lower socioeconomic status in areas of endemic diseases can result in the passing of the disease to the child. How and when to wean a human infant is controversial. The American Academy of Pediatrics recommends feeding a baby on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregnancy can have one or more gestations at the same time, for example in a multiple birth. The time interval of a gestation is called the '' gestation period''. In obstetrics, ''gestational age'' refers to the time since the onset of the last menses, which on average is fertilization age plus two weeks. Mammals In mammals, pregnancy begins when a zygote (fertilized ovum) implants in the female's uterus and ends once the fetus leaves the uterus during labor or an abortion (whether induced or spontaneous). Humans In humans, pregnancy can be defined clinically or biochemically. Clinically, pregnancy starts from first day of the mother's last period. Biochemically, pregnancy starts when a woman's human chorionic gonadotropin (hCG) levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoxia (environmental)
Hypoxia refers to low oxygen conditions. Normally, 20.9% of the gas in the atmosphere is oxygen. The partial pressure of oxygen in the atmosphere is 20.9% of the total barometric pressure. In water, oxygen levels are much lower, approximately 7 ppm or 0.0007% in good quality water, and fluctuate locally depending on the presence of photosynthetic organisms and relative distance to the surface (if there is more oxygen in the air, it will diffuse across the partial pressure gradient). Atmospheric hypoxia Atmospheric hypoxia occurs naturally at high altitudes. Total atmospheric pressure decreases as altitude increases, causing a lower partial pressure of oxygen, which is defined as hypobaric hypoxia. Oxygen remains at 20.9% of the total gas mixture, differing from hypoxic hypoxia, where the percentage of oxygen in the air (or blood) is decreased. This is common in the sealed burrows of some subterranean animals, such as blesmols. Atmospheric hypoxia is also the basis of altitude tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mole Snake
The mole snake (''Pseudaspis cana'') is a species of snake. It has been placed in the family Lamprophiidae, and more recently in the family Pseudaspididae, along with the genus ''Pythonodipsas''. It is native to much of southern Africa, and is the only member of the genus ''Pseudaspis''. A study showed that ''P. cana'' is caught and consumed by the honey badger, among other species. Remains of the mole snake were found in the faeces, and suggest the consumed individuals were larger specimens. Taxonomy ''P. cana'' was originally described by Carl Linnaeus in his landmark 1758 10th edition of ''Systema Naturae''. Its original binomial name was ''Coluber cana''. Since then, it has also been called ''Coronella cana'' by André Marie Constant Duméril, Gabriel Bibron and Auguste Duméril in 1854, before being reclassified as ''Pseudaspis cana'' by Edward Drinker Cope in 1864. ''P. cana'' is the only species in genus ''Pseudaspis''. The genus has been placed in the family Lamprophii ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molehill
A molehill (or mole-hill, mole mound) is a conical mound of loose soil raised by small burrowing mammals, including moles, but also similar animals such as mole-rats, and voles. The word is first recorded in the first half of the 15th century. Formerly the hill was known as a 'wantitump', a word still in dialect use for centuries afterwards. The phrase " making a mountain out of a molehill" is commonly used metaphorically to mean "to exaggerate a minor problem". Evidence of burrows Molehills are waste material which come from digging or repairing burrows, and so are usually found where the animal is establishing new burrows, or where existing ones are damaged (for example by the weight of grazing livestock). Where moles burrow beneath the roots of trees or shrubs, the roots support the tunnel, and molehills are less common, and so even a dense population of the animals may be inconspicuous in these places. Molehills are often the only sign to indicate the presence of the anima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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