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Melanistic
The term melanism refers to black pigment and is derived from the gr, μελανός. Melanism is the increased development of the dark-colored pigment melanin in the skin or hair. Pseudomelanism, also called abundism, is another variant of pigmentation, identifiable by dark spots or enlarged stripes, which cover a large part of the body of the animal, making it appear melanistic. The morbid deposition of black matter, often of a malignant character causing pigmented tumors, is called melanosis. Adaptation Melanism related to the process of adaptation is called adaptive. Most commonly, dark individuals become fitter to survive and reproduce in their environment as they are better camouflaged. This makes some species less conspicuous to predators, while others, such as leopards, use it as a foraging advantage during night hunting. Typically, adaptive melanism is heritable: A dominant allele, which is entirely or nearly entirely expressed in the phenotype, is responsible f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanism In Panthera Onca
The term melanism refers to black pigment and is derived from the gr, μελανός. Melanism is the increased development of the dark-colored pigment melanin in the skin or hair. Pseudomelanism, also called abundism, is another variant of pigmentation, identifiable by dark spots or enlarged stripes, which cover a large part of the body of the animal, making it appear melanistic. The morbid deposition of black matter, often of a malignant character causing pigmented tumors, is called melanosis. Adaptation Melanism related to the process of adaptation is called adaptive. Most commonly, dark individuals become Fitness (biology), fitter to survive and reproduce in their environment as they are better camouflaged. This makes some species less conspicuous to predators, while others, such as leopards, use it as a foraging advantage during night hunting. Typically, adaptive melanism is Heritability, heritable: A Dominance (genetics), dominant allele, which is entirely or nearly ent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Panther
A black panther is the melanistic colour variant of the leopard (''Panthera pardus'') and the jaguar (''Panthera onca''). Black panthers of both species have excess black pigments, but their typical rosettes are also present. They have been documented mostly in tropical forests, with black leopards in Kenya, India, Sri Lanka, Nepal, Thailand, Peninsular Malaysia and Java, and black jaguars of the Americas in Mexico, Panama, Costa Rica, Brazil and Paraguay. Melanism is caused by a recessive allele in the leopard, and by a dominant allele in the jaguar. Leopard In 1788, Jean-Claude Delamétherie described a black leopard that was kept in the Tower of London and had been brought from Bengal. In 1794, Friedrich Albrecht Anton Meyer proposed the scientific name ''Felis fusca'' for this cat, the Indian leopard (''P. p. fusca''). In 1809, Georges Cuvier described a black leopard kept in the Ménagerie du Jardin des plantes that had been brought from Java. Cuvier proposed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leopard
The leopard (''Panthera pardus'') is one of the five extant species in the genus '' Panthera'', a member of the cat family, Felidae. It occurs in a wide range in sub-Saharan Africa, in some parts of Western and Central Asia, Southern Russia, and on the Indian subcontinent to Southeast and East Asia. It is listed as Vulnerable on the IUCN Red List because leopard populations are threatened by habitat loss and fragmentation, and are declining in large parts of the global range. The leopard is considered locally extinct in Hong Kong, Singapore, South Korea, Jordan, Morocco, Togo, the United Arab Emirates, Uzbekistan, Lebanon, Mauritania, Kuwait, Syria, Libya, Tunisia and most likely in North Korea, Gambia, Laos, Lesotho, Tajikistan, Vietnam and Israel. Contemporary records suggest that the leopard occurs in only 25% of its historical global range. Compared to other wild cats, the leopard has relatively short legs and a long body with a large skull. Its fur is marked with ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leopards
The leopard (''Panthera pardus'') is one of the five extant species in the genus ''Panthera'', a member of the cat family, Felidae. It occurs in a wide range in sub-Saharan Africa, in some parts of Western and Central Asia, Southern Russia, and on the Indian subcontinent to Southeast and East Asia. It is listed as Vulnerable on the IUCN Red List because leopard populations are threatened by habitat loss and fragmentation, and are declining in large parts of the global range. The leopard is considered locally extinct in Hong Kong, Singapore, South Korea, Jordan, Morocco, Togo, the United Arab Emirates, Uzbekistan, Lebanon, Mauritania, Kuwait, Syria, Libya, Tunisia and most likely in North Korea, Gambia, Laos, Lesotho, Tajikistan, Vietnam and Israel. Contemporary records suggest that the leopard occurs in only 25% of its historical global range. Compared to other wild cats, the leopard has relatively short legs and a long body with a large skull. Its fur is marked with rosette ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biston Betularia
The peppered moth (''Biston betularia'') is a temperate species of night-flying moth. It is mostly found in the northern hemisphere in places like Asia, Europe and North America. Peppered moth evolution is an example of population genetics and natural selection. The caterpillars of the peppered moth not only mimic the form but also the colour of a twig. Recent research indicates that the caterpillars can sense the twig's colour with their skin and match their body colour to the background to protect themselves from predators. Description The wingspan ranges from 45 mm to 62 mm (median 55 mm). It is relatively stout-bodied, with forewings relatively narrow-elongate. The wings are white, "peppered" with black, and with more-or-less distinct cross lines, also black. These transverse wing lines and "peppered" maculation (spotting) can also, in rare instances, be gray or brown; the spotting pattern, in particularly very rare cases, is sometimes a combination of b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peppered Moth
The peppered moth (''Biston betularia'') is a temperate species of night-flying moth. It is mostly found in the northern hemisphere in places like Asia, Europe and North America. Peppered moth evolution is an example of population genetics and natural selection. The caterpillars of the peppered moth not only mimic the form but also the colour of a twig. Recent research indicates that the caterpillars can sense the twig's colour with their skin and match their body colour to the background to protect themselves from predators. Description The wingspan ranges from 45 mm to 62 mm (median 55 mm). It is relatively stout-bodied, with forewings relatively narrow-elongate. The wings are white, "peppered" with black, and with more-or-less distinct cross lines, also black. These transverse wing lines and "peppered" maculation (spotting) can also, in rare instances, be gray or brown; the spotting pattern, in particularly very rare cases, is sometimes a combination of b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphism (biology)
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Ford E.B. 1965. ''Genetic polymorphism''. Faber & Faber, London. Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canid
Canidae (; from Latin, '' canis'', " dog") is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid (). There are three subfamilies found within the canid family, which are the extinct Borophaginae and Hesperocyoninae, and the extant Caninae. The Caninae are known as canines, and include domestic dogs, wolves, coyotes, foxes, jackals and other extant and extinct species. Canids are found on all continents except Antarctica, having arrived independently or accompanied human beings over extended periods of time. Canids vary in size from the gray wolf to the fennec fox. The body forms of canids are similar, typically having long muzzles, upright ears, teeth adapted for cracking bones and slicing flesh, long legs, and bushy tails. They are mostly social animals, living together in family units or small groups and behaving cooperatively. Typically, only the dominant pair in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixation (population Genetics)
In population genetics, fixation is the change in a gene pool from a situation where there exists at least two variants of a particular gene (allele) in a given population to a situation where only one of the alleles remains. In the absence of mutation or heterozygote advantage, any allele must eventually be lost completely from the population or fixed (permanently established at 100% frequency in the population). Whether a gene will ultimately be lost or fixed is dependent on selection coefficients and chance fluctuations in allelic proportions. Fixation can refer to a gene in general or particular nucleotide position in the DNA chain ( locus). In the process of substitution, a previously non-existent allele arises by mutation and undergoes fixation by spreading through the population by random genetic drift or positive selection. Once the frequency of the allele is at 100%, i.e. being the only gene variant present in any member, it is said to be "fixed" in the population. Sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felid
Felidae () is the family of mammals in the order Carnivora colloquially referred to as cats, and constitutes a clade. A member of this family is also called a felid (). The term "cat" refers both to felids in general and specifically to the domestic cat ('' Felis catus''). Felidae species exhibit the most diverse fur pattern of all terrestrial carnivores. Cats have retractile claws, slender muscular bodies and strong flexible forelimbs. Their teeth and facial muscles allow for a powerful bite. They are all obligate carnivores, and most are solitary predators ambushing or stalking their prey. Wild cats occur in Africa, Europe, Asia and the Americas. Some wild cat species are adapted to forest habitats, some to arid environments, and a few also to wetlands and mountainous terrain. Their activity patterns range from nocturnal and crepuscular to diurnal, depending on their preferred prey species. Reginald Innes Pocock divided the extant Felidae into three subfamilies: the Panth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the battledress of a modern soldier, and the leaf-mimic katydid's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate, as well as making general aiming easier. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In the open ocean, where there is no background, the principal methods of camouflage are transparency, silvering, and countershading, while the bioluminescence, ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid. Some animals, such as chamel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Although environmental pollution can be caused by natural events, the word pollution generally implies that the contaminants have an anthropogenic source – that is, a source created by human activities. Pollution is often classed as point source or nonpoint source pollution. In 2015, pollution killed nine million people worldwide (one in six deaths). This remained unchanged in 2019, with little real progress against pollution being identifiable. Air pollution accounted for of these earlier deaths. Major forms of pollution include air pollution, light pollution, litter, noise pollution, plastic pollution, soil contamination, radioacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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