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Swamping Argument
The swamping argument is an objection against Darwinism made by Fleeming Jenkin. He asserted that an accidentally-appearing profitable variety cannot be preserved by natural selection in the population, but should be 'swamped' with ordinary traits. Population genetics helped to overcome this logical difficulty. Jenkin’s article was published anonymously in the ''North British Review'' in June 1867. It took Darwin a year and a half to discover that the author was Fleeming Jenkin, Regius Professor of Engineering (Edinburgh), Regius Professor of Engineering at the University of Edinburgh. The critical article was most valuable to Darwin. In 1869 he wrote to Alfred Russel Wallace: "Fleming Jenkyn’s arguments have convinced me". Darwin's son Francis Darwin, Francis said that Jenkin’s critique was the most valuable ever made on his father's views. Jenkin’s article was a critique intended to be based entirely on science, unlike most other critiques which were based on religion. J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fleeming Jenkin
Henry Charles Fleeming Jenkin Royal Society of London, FRS FRSE (; 25 March 1833 – 12 June 1885) was a British engineer, inventor, economist, linguist, actor and dramatist known as the inventor of the cable car or Aerial tramway#Telpherage, telpherage. He was Regius Professor of Engineering (Edinburgh), Regius Professor of Engineering at the University of Edinburgh. His descendants include the engineer Charles Frewen Jenkin and through him the Conservative Party (UK), Conservative MPs Patrick Jenkin, Baron Jenkin of Roding, Patrick, Lord Jenkin of Roding and Bernard Jenkin. Early life Background and childhood Generally called Fleeming Jenkin, named after Charles Elphinstone Fleeming, Admiral Fleeming, one of his father's patrons, he was born to an old and eccentric family in a government building near Dungeness (headland), Dungeness, Kent, England. His father, Captain Charles Jenkin, was at that time being in the coast-guard service. His mother, Henrietta Camilla Jenkin, Hen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saltation (biology)
In biology, saltation () is a sudden and large mutational change from one generation to the next, potentially causing single-step speciation. This was historically offered as an alternative to Darwinism. Some forms of mutationism were effectively saltationist, implying large discontinuous jumps. Speciation, such as by polyploidy in plants, can sometimes be achieved in a single and in evolutionary terms sudden step. Evidence exists for various forms of saltation in a variety of organisms. History Prior to Charles Darwin most evolutionary scientists had been saltationists. Jean-Baptiste Lamarck was a gradualist but similar to other scientists of the period had written that saltational evolution was possible. Étienne Geoffroy Saint-Hilaire endorsed a theory of saltational evolution that "monstrosities could become the founding fathers (or mothers) of new species by instantaneous transition from one form to the next." Geoffroy wrote that environmental pressures could produce sudde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haldane's Dilemma
Haldane's dilemma, also known as the waiting time problem, is a limit on the speed of beneficial evolution, calculated by J. B. S. Haldane in 1957. Before the invention of DNA sequencing technologies, it was not known how much gene polymorphism, polymorphism DNA harbored, although alloenzymes (variant forms of an enzyme which differ structurally but not functionally from other alloenzymes coded for by different alleles at the same locus) were beginning to make it clear that substantial polymorphism existed. This was puzzling because the amount of polymorphism known to exist seemed to exceed the theoretical limits that Haldane calculated, that is, the limits imposed if polymorphisms present in the population generally influence an organism's fitness. Motoo Kimura's landmark paper on neutral theory in 1968 built on Haldane's work to suggest that most molecular evolution is neutral, resolving the dilemma. Although neutral evolution remains the consensus theory among modern biologist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendelian Inheritance
Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularized by William Bateson. These principles were initially controversial. When Mendel's theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan in 1915, they became the core of classical genetics. Ronald Fisher combined these ideas with the theory of natural selection in his 1930 book '' The Genetical Theory of Natural Selection'', putting evolution onto a mathematical footing and forming the basis for population genetics within the modern evolutionary synthesis. History The principles of Mendelian inheritance were named for and first derived by Gregor Johann Mendel, a nineteenth-century Moravian monk who formulated his ideas after conducting simple hybridization experiments with pea p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blending Inheritance
Blending inheritance is an obsolete theory in biology from the 19th century. The theory is that the progeny inherits any characteristic as the average of the parents' values of that characteristic. As an example of this, a crossing of a red flower variety with a white variety of the same species would yield pink-flowered offspring. Charles Darwin's theory of inheritance by pangenesis, with contributions to egg or sperm from every part of the body, implied blending inheritance. His reliance on this mechanism led Fleeming Jenkin to attack Darwin's theory of natural selection on the grounds that blending inheritance would average out any novel beneficial characteristic before selection had time to act. Blending inheritance was discarded with the general acceptance of particulate inheritance during the development of modern genetics, after . History Darwin's pangenesis Charles Darwin developed his theory of evolution by natural selection on the basis of an understanding of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Selection (natural Selection)
In natural selection, negative selection or purifying selection is the selective removal of alleles that are deleterious. This can result in stabilising selection through the purging of deleterious genetic polymorphisms that arise through random mutations. Purging of deleterious alleles can be achieved on the population genetics level, with as little as a single point mutation being the unit of selection. In such a case, carriers of the harmful point mutation have fewer offspring each generation, reducing the frequency of the mutation in the gene pool. In the case of strong negative selection on a locus, the purging of deleterious variants will result in the occasional removal of linked variation, producing a decrease in the level of variation surrounding the locus under selection. The incidental purging of non-deleterious alleles due to such spatial proximity to deleterious alleles is called background selection. This effect increases with lower mutation rate but decreases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age Of The Earth
The age of Earth is estimated to be 4.54 ± 0.05 billion years. This age may represent the age of Earth's accretion (astrophysics), accretion, or Internal structure of Earth, core formation, or of the material from which Earth formed. This dating is based on evidence from Radiometric dating, radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial material and Moon rock, lunar samples. Following the development of radiometric age-dating in the early 20th century, uranium–lead dating, measurements of lead in uranium-rich minerals showed that some were in excess of a billion years old.For the abstract, see: The oldest such minerals analyzed to date—small crystals of zircon from the Jack Hills of Western Australia—are at least 4.404 billion years old. Calcium–aluminium-rich inclusions—the oldest known solid constituents within meteorites that are formed within the Solar System—are 4.567 billion years old, gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On The Origin Of Species
''On the Origin of Species'' (or, more completely, ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life'')The book's full original title was ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life''. In the 1872 sixth edition, "On" was omitted, so the full title is ''The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life.'' This edition is usually known as ''The Origin of Species.'' The 6th is Darwin's final edition; there were minor modifications in the text of certain subsequent issues. See Freeman, R. B. In Van Wyhe, John, ed. ''Darwin Online: On the Origin of Species'', 2002. is a work of scientific literature by Charles Darwin that is considered to be the foundation of evolutionary biology. It was published on 24 November 1859. Darwin's book introduced the scientific theory that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francis Darwin
Sir Francis Darwin (16 August 1848 – 19 September 1925) was a British botanist. He was the third son of the naturalist and scientist Charles Darwin. Biography Francis Darwin was born at Down House, Downe, Kent in 1848. He was the third son and seventh child of Charles Darwin and his wife Emma Wedgwood. He was educated at Clapham Grammar School. He then went to Trinity College, Cambridge, initially studying mathematics, then changing to natural sciences, graduating in 1870. He then went to study medicine at St George's Medical School, London, earning an MB in 1875, but did not practice medicine. Darwin was married three times and widowed twice. First, he married Amy Richenda Ruck in 1874, but she died in 1876 four days after the birth of their son Bernard Darwin, who was later to become a golf writer. In September 1883, he married Ellen Wordsworth Crofts (1856–1903) and they had a daughter Frances Crofts Darwin (1886–1960), a poet who married the poet Francis Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darwinism
''Darwinism'' is a term used to describe a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others. The theory states that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce. Also called ''Darwinian theory'', it originally included the broad concepts of transmutation of species or of evolution which gained general scientific acceptance after Darwin published ''On the Origin of Species'' in 1859, including concepts which predated Darwin's theories. English biologist Thomas Henry Huxley coined the term ''Darwinism'' in April 1860. Terminology ''Darwinism'' subsequently referred to the specific concepts of natural selection, the Weismann barrier, or the central dogma of molecular biology. Though the term usually refers strictly to biological evolution, creationists have appropriated it to refer to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Russel Wallace
Alfred Russel Wallace (8 January 1823 – 7 November 1913) was an English naturalist, explorer, geographer, anthropologist, biologist and illustrator. He independently conceived the theory of evolution through natural selection; his 1858 paper on the subject was published that year On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection, alongside extracts from Charles Darwin's earlier writings on the topic. It spurred Darwin to set aside the Natural Selection (manuscript), "big species book" he was drafting and to quickly write an Abstract (summary), abstract of it, which was published in 1859 as ''On the Origin of Species''. Wallace did extensive fieldwork, starting in the Amazon River basin. He then did fieldwork in the Malay Archipelago, where he identified the faunal divide now termed the Wallace Line, which separates the Indonesian archipelago into two distinct parts: a western portion in which the ani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Edinburgh
The University of Edinburgh (, ; abbreviated as ''Edin.'' in Post-nominal letters, post-nominals) is a Public university, public research university based in Edinburgh, Scotland. Founded by the City of Edinburgh Council, town council under the authority of a royal charter from King James VI and I, James VI in 1582 and officially opened in 1583, it is one of Scotland's Ancient universities of Scotland, four ancient universities and the List of oldest universities in continuous operation, sixth-oldest university in continuous operation in the English-speaking world. The university played a crucial role in Edinburgh becoming a leading intellectual centre during the Scottish Enlightenment and contributed to the city being nicknamed the "Etymology of Edinburgh#Athens of the North, Athens of the North". The three main global university rankings (Academic Ranking of World Universities, ARWU, Times Higher Education World University Rankings, THE, and QS World University Rankings, QS) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
