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Coloration Evidence For Natural Selection
Animal coloration provided important early Evidence of common descent, evidence for evolution by natural selection, at a time when little direct evidence was available. Three major functions of coloration were discovered in the second half of the 19th century, and subsequently used as scientific evidence, evidence of selection: camouflage (protective coloration); mimicry, both Batesian and Müllerian mimicry, Müllerian; and aposematism. Charles Darwin's ''On the Origin of Species'' was published in 1859, arguing from circumstantial evidence that selection by human breeders could produce change, and that since there was clearly a struggle for existence, that natural selection must be taking place. But he lacked an explanation either for genetic variation or for heredity, both essential to the theory. Many alternatives to natural selection, alternative theories were accordingly considered by biologists, threatening to undermine Darwinian evolution. Some of the first evidence wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock Ptarmigan (Lagopus Muta)
The rock ptarmigan (''Lagopus muta'') is a medium-sized game bird in the grouse family. It is known simply as the ptarmigan in the UK. It is the official bird for the Canadian territory of Nunavut, where it is known as the ''aqiggiq'' (ᐊᕿᒡᒋᖅ), and the official game bird for the province of Newfoundland and Labrador. In Japan, it is known as the ''raichō'' (雷鳥), which means "thunder bird". It is the official bird of Gifu, Nagano, and Toyama Prefectures and is a protected species nationwide. Unlike many arctic bird species, ptarmigan do not gain substantial mass to hibernate over winter. Etymology The ptarmigan's genus name, ''Lagopus'', is derived from Ancient Greek ''lagos'' (λαγώς ''lagṓs''), meaning "hare", + ''pous'' (πούς ''poús''), "foot", in reference to the bird's feathered legs. The species name, ''muta'', comes from New Latin and means "mute", referring to the simple croaking song of the male. It was for a long time misspelt ''mutus'', in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fritz Müller
Johann Friedrich Theodor Müller (31 March 1822 – 21 May 1897), better known as Fritz Müller, and also as Müller-Desterro, was a German biologist who emigrated to southern Brazil, where he lived in and near the German community of Blumenau, Santa Catarina. There he studied the natural history of the Atlantic forest south of São Paulo, and was an early advocate of Darwinism. He lived in Brazil for the rest of his life. ''Müllerian mimicry'' is named after him.West, David A. 2003. ''Fritz Müller: a naturalist in Brazil''. Blacksburg: Pocahontas Press. Life Müller was born in the village of Windischholzhausen, near Erfurt in Thuringia, Germany, the son of a minister. Müller had what would be seen today as a normal scientific education at the universities of Berlin (earning a BSc in Botany) and Greifswald, culminating in a doctoral degree in Biology. He subsequently decided to study medicine. As a medical student, he began to question religion and in 1846 became an ath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domestic Animal
This page gives a list of domesticated animals, also including a list of domestication of animals, animals which are or may be currently undergoing the process of domestication and animals that have an extensive relationship with humans beyond simple predation. This includes species which are semi-domesticated, undomesticated but Captive breeding, captive-bred on a commercial scale, or commonly wild-caught, at least occasionally captive-bred, and Tame animal, tameable. In order to be considered fully domesticated, most species have undergone significant Heredity, genetic, Behavior, behavioural and Morphology (biology), morphological changes from their wild ancestors, while others have changed very little from their wild ancestors despite hundreds or thousands of years of potential selective breeding. A number of factors determine how quickly any changes may occur in a species, but there is not always a desire to improve a species from its wild form. Domestication is a gradual process ... [...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 evolut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Murray (publishing House)
John Murray is a British publisher, known for the authors it has published in its long history including, Jane Austen, Sir Arthur Conan Doyle, Lord Byron, Charles Lyell, Johann Wolfgang von Goethe, Herman Melville, Edward Whymper, Thomas Malthus, David Ricardo, and Charles Darwin. Since 2004, it has been owned by conglomerate Lagardère under the Hachette UK brand. Business publisher Nicholas Brealey became an imprint of John Murray in 2015. History The business was founded in London in 1768 by John Murray (1737–1793), an Edinburgh-born Royal Marines officer, who built up a list of authors including Isaac D'Israeli and published the ''English Review''. John Murray the elder was one of the founding sponsors of the London evening newspaper ''The Star'' in 1788. He was succeeded by his son John Murray II, who made the publishing house important and influential. He was a friend of many leading writers of the day and launched the '' Quarterly Review'' in 1809. He was the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Melanism
Industrial melanism is an evolutionary effect prominent in several arthropods, where dark pigmentation ( melanism) has evolved in an environment affected by industrial pollution, including sulphur dioxide gas and dark soot deposits. Sulphur dioxide kills lichens, leaving tree bark bare where in clean areas it is boldly patterned, while soot darkens bark and other surfaces. Darker pigmented individuals have a higher fitness in those areas as their camouflage matches the polluted background better; they are thus favoured by natural selection. This change, extensively studied by Bernard Kettlewell, is a popular teaching example in Darwinian evolution, providing evidence for natural selection. Kettlewell's results have been challenged by zoologists, creationists and the journalist Judith Hooper, but later researchers have upheld Kettlewell's findings. Industrial melanism is widespread in the Lepidoptera (butterflies and moths), involving over 70 species such as '' Odontopera b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peppered Moth Evolution
The evolution of the peppered moth is an evolutionary instance of directional colour change in the moth population as a consequence of air pollution during the Industrial Revolution. The frequency of dark-coloured moths increased at that time, an example of industrial melanism. Later, when pollution was reduced, the light-coloured form again predominated. Industrial melanism in the peppered moth was an early test of Charles Darwin's natural selection in action, and it remains a classic example in the teaching of evolution. In 1978, Sewall Wright described it as "the clearest case in which a conspicuous evolutionary process has actually been observed." The dark-coloured or ''melanic'' form of the peppered moth (var. ''carbonaria'') was rare, though a specimen had been collected by 1811. After field collection in 1848 from Manchester, an industrial city in England, the frequency of the variety was found to have increased drastically. By the end of the 19th century it almost com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disruptive Coloration
Disruptive coloration (also known as disruptive camouflage or disruptive patterning) is a form of camouflage that works by breaking up the outlines of an animal, soldier or military vehicle with a strongly contrasting pattern. It is often combined with other methods of crypsis including background colour matching and countershading; special cases are coincident disruptive coloration and the disruptive eye mask seen in some fishes, amphibians, and reptiles. It appears paradoxical as a way of not being seen, since disruption of outlines depends on high contrast, so the patches of colour are themselves conspicuous. The importance of high-contrast patterns for successful disruption was predicted in general terms by the artist Abbott Thayer in 1909 and explicitly by the zoologist Hugh Cott in 1940. Later experimental research has started to confirm these predictions. Disruptive patterns work best when all their components match the background. While background matching works b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclipse Of Darwinism
Julian Huxley used the phrase "the eclipse of Darwinism" to describe the state of affairs prior to what he called the "modern synthesis". During the "eclipse", evolution was widely accepted in scientific circles but relatively few biologists believed that natural selection was its primary mechanism. Historians of science such as Peter J. Bowler have used the same phrase as a label for the period within the history of evolutionary thought from the 1880s to around 1920, when alternatives to natural selection were developed and explored—as many biologists considered natural selection to have been a wrong guess on Charles Darwin's part, or at least to be of relatively minor importance. Four major alternatives to natural selection were in play in the 19th century: * Theistic evolution, the belief that God directly guided evolution * Neo-Lamarckism, the idea that evolution was driven by the inheritance of characteristics acquired during the life of the organism * Orthogenesis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Colours Of Animals
''The Colours of Animals'' is a zoology book written in 1890 by Sir Edward Bagnall Poulton (1856–1943). It was the first substantial textbook to argue the case for Darwinian selection applying to all aspects of animal coloration. The book also pioneered the concept of frequency-dependent selection and introduced the term " aposematism". The book begins with a brief account of the physical causes of animal coloration. The second chapter gives an overview of the book, describing the various uses of colour in terms of the advantages it can bring through natural selection. The next seven chapters describe camouflage, both in predators and in prey. Methods of camouflage covered include background matching, resemblance to specific objects such as bird droppings, self-decoration with materials from the environment, and the seasonal colour change of arctic animals. Two chapters cover warning colours, including both Batesian mimicry, where the mimic is edible, and Mullerian mimicr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snow Camouflage
Snow camouflage is the use of a coloration or pattern for effective camouflage in winter, often combined with a different summer camouflage. Summer patterns are typically disruptively patterned combinations of shades of browns and greys, up to black, while winter patterns are dominated by white to match snowy landscapes. Among animals, variable snow camouflage is a type of seasonal polyphenism with a distinct winter plumage or pelage. It is found in birds such as the rock ptarmigan, lagomorphs such as the Arctic hare, mustelids such as the stoat, and one canid, the Arctic fox. Since these have evolved separately, the similar appearance is due to convergent evolution. This was used as early evidence for natural selection. Some high Arctic species like the snowy owl and polar bear however remain white all year round. In military usage, soldiers often either exchange their disruptively-patterned summer uniforms for thicker snow camouflage uniforms printed with mainly-white ver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernard Kettlewell
Henry Bernard Davis Kettlewell (24 February 1907 – 11 May 1979) was a British geneticist, lepidopterist and medical doctor, who performed research on the influence of industrial melanism on peppered moth (''Biston betularia'') coloration, showing why moths are darker in polluted areas. This experiment is cited as a classic demonstration of natural selection in action. After live video record of the experiment with Niko Tinbergen, Sewall Wright called the study as "the clearest case in which a conspicuous evolutionary process has actually been observed." Early life Kettlewell was born in Howden, Yorkshire, and educated at Charterhouse School. During 1926 he studied medicine and zoology at Gonville and Caius College, Cambridge. During 1929 he began clinical training at St Bartholomew's Hospital, London, then during 1935 joined a general medical practice in Cranleigh, Surrey. He also worked as an anaesthetist at St. Luke's Hospital, Guildford. During World War II, from 1939 to 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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