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Experimental Evolution
Experimental evolution is the use of laboratory experiments or controlled field manipulations to explore evolutionary dynamics. Evolution may be observed in the laboratory as individuals/populations adapt to new environmental conditions by natural selection. There are two different ways in which adaptation can arise in experimental evolution. One is via an individual organism gaining a novel beneficial mutation. The other is from allele frequency change in standing genetic variation already present in a population of organisms. Other evolutionary forces outside of mutation and natural selection can also play a role or be incorporated into experimental evolution studies, such as genetic drift and gene flow. The organism used is decided by the experimenter, based on the hypothesis to be tested. Many generations are required for adaptive mutation to occur, and experimental evolution via mutation is carried out in viruses or unicellular organisms with rapid generation times, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evolution by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guppy
The guppy (), also known as millionfish and rainbow fish, is one of the world's most widely distributed tropical fish and one of the most popular freshwater aquarium fish species. It is a member of the family Poeciliidae and, like almost all American members of the family, is live-bearing. Guppies originate from northeast South America, but have been introduced to many environments and are now found all over the world. They are highly adaptable and thrive in many different environmental and ecological conditions. Male guppies, which are smaller than females, have ornamental caudal and dorsal fins. Wild guppies generally feed on a variety of food sources, including benthic algae and aquatic insect larvae. Guppies are used as a model organism in the fields of ecology, evolution, and behavioural studies. Taxonomy Guppies were first described in Venezuela as ''Poecilia reticulata'' by Wilhelm Peters in 1859 and as ''Lebistes poecilioides'' in Barbados by De Filippi in 1861. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodosius Dobzhansky
Theodosius Grigorievich Dobzhansky (russian: Феодо́сий Григо́рьевич Добржа́нский; uk, Теодо́сій Григо́рович Добржа́нський; January 25, 1900 – December 18, 1975) was a prominent Russian-American geneticist and evolutionary biologist, and a central figure in the field of evolutionary biology for his work in shaping the modern synthesis. Born in the Russian Empire, Dobzhansky emigrated to the United States in 1927, aged 27. He was a distant relation of the Russian writer Feodor Dostoevsky. His 1937 work ''Genetics and the Origin of Species'' became a major influence on the modern synthesis. He was awarded the US National Medal of Science in 1964 and the Franklin Medal in 1973. Biography Early life Dobzhansky was born on January 25, 1900, in Nemirov, Russian Empire (now Nemyriv, Ukraine), the only child of Grigory Dobzhansky, a mathematics teacher, and Sophia Voinarsky. He was given a rare name, Theodosius, bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicellular Organism
A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and eukaryotic organisms. All prokaryotes are unicellular and are classified into bacteria and archaea. Many eukaryotes are multicellular, but some are unicellular such as protozoa, unicellular algae, and unicellular fungi. Unicellular organisms are thought to be the oldest form of life, with early protocells possibly emerging 3.8–4.0 billion years ago. Although some prokaryotes live in colonies, they are not specialised cells with differing functions. These organisms live together, and each cell must carry out all life processes to survive. In contrast, even the simplest multicellular organisms have cells that depend on each other to survive. Most multicellular organisms have a unicellular life-cycle stage. Gametes, for example, are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Dallinger
William Henry Dallinger FRS (5 July 1839 – 7 November 1909) was a British minister in the Wesleyan Methodist Church. He was also an accomplished scientist, being the first to study the complete lifecycle of unicellular organisms under the microscope and studying the adaptation of such organisms to temperature. He made numerous contributions to microscopy, and was president of the Quekett Microscopical Club from 1889 to 1892. Dallinger was awarded three honorary doctorates, the Ll.D. from Victoria College, Toronto in 1884, the D.Sc. from Dublin in 1892, and the D.L.C. from Durham in 1896. Dallinger was married to Emma Ion Goldsmith (1842-1910). They had one child, son Percy Gough (1867-1930). Research into Darwin's theories Dallinger was one of the first to carry out a controlled evolution experiment. In the late 19th century, he cultivated small unicellular organisms in a custom-built incubator over a time period of seven years (1880–1886). Dallinger slowly increased ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dallinger Incubator J
Dallinger is a surname. Notable people with the surname include: * James Dallinger (1989-), New Zealand rower * William Dallinger (1839-1909), scientist and British minister in the Wesleyan Methodist Church * Frederick W. Dallinger (1871-1955), American Republican politician * Johann Dallinger von Dalling (1741-1806), Austrian painter ** Johann Baptist Dallinger von Dalling (1782-1868), his son, also an Austrian painter ** Alexander Johann Dallinger von Dalling (1783-1844), his second son, also an Austrian painter * Reinhard Dallinger (1950-), Austrian zoologist * Maximilian Dallinger Maximilian Dallinger (born 25 September 1996) is a German sport shooter. Part of the national team since 2014. Professional sport shooter since 2015. Completion of the apprenticeship to become police officer in 2020. He participated at the 2018 ... (1996-), German sport shooter {{surname, Dallinger English-language surnames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. published on 24 November 1859, is a work of scientific literature by Charles Darwin that is considered to be the foundation of evolutionary biology. Darwin's book introduced the scientific theory that populatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended from a common ancestor is now generally accepted and considered a fundamental concept in science. In a joint publication with Alfred Russel Wallace, he introduced his scientific theory that this branching pattern of evolution resulted from a process he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding. Darwin has been described as one of the most influential figures in human history and was honoured by burial in Westminster Abbey. Darwin's early interest in nature led him to neglect his medical education at the University of Edinburgh; instead, he helped to investigate marine invertebrates. His studies at the University of Cambridge's Christ's Col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The leafy stalk of the plant produces pollen inflorescences (or "tassels") and separate ovuliferous inflorescences called ears that when fertilized yield kernels or seeds, which are fruits. The term ''maize'' is preferred in formal, scientific, and international usage as a common name because it refers specifically to this one grain, unlike ''corn'', which has a complex variety of meanings that vary by context and geographic region. Maize has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat or rice. In addition to being consumed directly by humans (often in the form of masa), maize is also used for corn ethanol, animal feed and other maize products, such as corn starch and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cabbage
Cabbage, comprising several cultivars of ''Brassica oleracea'', is a leafy green, red (purple), or white (pale green) biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage ( ''B. oleracea'' var. ''oleracea''), and belongs to the "cole crops" or brassicas, meaning it is closely related to broccoli and cauliflower (var. ''botrytis''); Brussels sprouts (var. ''gemmifera''); and Savoy cabbage (var. ''sabauda''). A cabbage generally weighs between . Smooth-leafed, firm-headed green cabbages are the most common, with smooth-leafed purple cabbages and crinkle-leafed savoy cabbages of both colours being rarer. Under conditions of long sunny days, such as those found at high northern latitudes in summer, cabbages can grow quite large. , the heaviest cabbage was . Cabbage heads are generally picked during the first year of the plant's life cycle, but plants intended for seed are allowed to grow a second year and must be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selective Breeding
Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant males and females will sexually reproduce and have offspring together. Domesticated animals are known as breeds, normally bred by a professional breeder, while domesticated plants are known as varieties, cultigens, cultivars, or breeds. Two purebred animals of different breeds produce a crossbreed, and crossbred plants are called hybrids. Flowers, vegetables and fruit-trees may be bred by amateurs and commercial or non-commercial professionals: major crops are usually the provenance of the professionals. In animal breeding, techniques such as inbreeding, linebreeding, and outcrossing are utilized. In plant breeding, similar methods are used. Charles Darwin discussed how selective breeding had been successful in producing change over time in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domestication
Domestication is a sustained multi-generational relationship in which humans assume a significant degree of control over the reproduction and care of another group of organisms to secure a more predictable supply of resources from that group. A broader biological definition is that it is a coevolutionary process that arises from a mutualism, in which one species (the domesticator) constructs an environment where it actively manages both the survival and reproduction of another species (the domesticate) in order to provide the former with resources and/or services. The domestication of plants and animals by humans was a major cultural innovation ranked in importance with the conquest of fire, the manufacturing of tools, and the development of verbal language. Charles Darwin recognized the small number of traits that made domestic species different from their wild ancestors. He was also the first to recognize the difference between conscious selective breeding (i.e. artificial se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
