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黒いjagur was considered a different species, but is the same Panthera onca.
Melanistic Eastern Grey Squirrel, fauna of Toronto, Canada
Melanistic Guinea pigs are relatively rare, and considered especially effective in ritual use by Andean curanderos.[1]

　メラニズムは肌や毛などにおいて、黒色の色素であるメラニンの発達によっておこるものであり、アルビニズムの反対に位置する用語である。

また、メラニズムという用語はギリシア語: μελανός ("黒い色素"の意)から由来している。[2]

アバンディズムとも呼ばれている疑似メラニズムは、黒ぶち模様や縞模様拡大し、動物たちの体の大半を覆っていることで、メラニズムのように見えることが特徴である[3]

　反対に、メラニン色素が不足、もしくは完全に欠如していることをアメラニズムと呼ぶ。

他にも、ガンなどの病気によって起こる黒色の色素沈着はメラノシスと呼ばれている。 [4]

（メラニンの不調の説明のめに、メラニンと目に見えるメラノシスを見てみましょう。）

For a descriptio　

n of melanin-related disorders, see melanin and ocular melanosis.

順応

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A melanistic European adder (Vipera berus) compared to a normal-colored adder.

進化の過程と関連しているメラニズムのことをアダプティブと呼ぶ。最も一般的には、黒い固体はより生き残りやすく、より周りの環境に溶け込みやすいため、繁殖しやすい。このことは　彼らを捕食者から見つかりにくくする。反対に、黒ヒョウのような捕食者たちにとっては、それは夜間の狩りにおいて有利なものとなる。[5] 典型的には、順応メラ二ズムは遺伝性で, mela: A dominant allele, which is entirely or nearly entirely expressed in the phenotype, is responsible for the excessive amount of melanin.

順応的メラニズムは多くの猫科動物や犬科動物、リスやサンゴヘビのような様々な種類の動物の間に起こってきている。また、順応的メラニズムによって生き物たちは変態することができるようにもなる。最も分かりやすい例として、大霜降枝尺の存在がある。イギリスにおいての大霜降枝尺の進化歴は自然淘汰説を説明する古典的なツールとして提示されてきた。

産業的メラニズム

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産業的メラニズムは、業発展が大霜降枝尺のようなこ昆虫たちに与えた影響であり、イギリス内の大霜降枝尺は産業汚染が原因で生まれた。より黒く色素沈着した個体は、汚染されたという背景を持ちながらも、明らかに自身の身を隠しやすくなるため、自然淘汰において優位に立つ。n,aouflagendsWhen pollution was later reduced, lighter forms regained the advantage and melanism became less frequent.[6][7][8][9][10][11] Other explanations have been proposed, such as that the melanin pigment enhances function of immune defences,[12] or a thermal advantage from the darker coloration.[13][14][15]

猫科n

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Melanistic coat coloration occurs as a common polymorphism in 11 of 37 felid species and reaches high population frequency in some cases but never achieves complete fixation. The black panther, a melanic form of leopard, is common in the equatorial rainforest of Malaya and the tropical rainforest on the slopes of some African mountains, such as Mount Kenya. The serval also has melanic forms in certain areas of East Africa. In the jaguarundi, coloration varies from dark brown and gray to light reddish. Melanic forms of jaguar are common in certain parts of South America.[16] In 1938 and 1940, two melanistic bobcats were trapped alive in sub-tropical Florida.[17]

In 2003, the dominant mode of inheritance of melanism in jaguars was confirmed by performing phenotype-transmission analysis in a 116-individual captive pedigree. Melanistic animals were found to carry at least one copy of a mutant MC1R sequence allele, bearing a 15-base pair inframe deletion. Ten unrelated melanistic jaguars were either homozygous or heterozygous for this allele. A 24-base pair deletion causes the incompletely dominant allele for melanism in the jaguarundi. Sequencing of the agouti signalling peptide in the agouti gene coding region revealed a 2-base pair deletion in black domestic cats. These variants were absent in melanistic individuals of Geoffroy’s cat, oncilla, pampas cat and Asian golden cat, suggesting that melanism arose independently at least four times in the cat family.[18]

Melanism in leopards is inherited as a Mendelian, monogenic recessive trait relative to the spotted form. Pairings of black animals have a significantly smaller litter size than other possible pairings.[19] Between January 1996 and March 2009, leopards were photographed at sixteen sites in the Malay Peninsula in a sampling effort of more than 1000 trap nights. Of 445 photographs of melanistic leopards taken, 410 came from study sites south of the Kra Isthmus, where the non-melanistic morph was never photographed. These data suggest the near fixation of the dark allele in the region. The expected time to fixation of this recessive allele due to genetic drift alone ranged from about 1,100 years to about 100,000 years.[20]

Melanism in leopards has been hypothesized to be causally associated with a selective advantage for ambush.[21] Other theories are that genes for melanism in felines may provide resistance to viral infections, or a high-altitude adaptation, since black fur absorbs more heat.[22]

鳥類

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White Silkie rooster
Black Silkie rooster

主に烏骨鶏にこの特徴がみられる。2015年の４月、端にに珍しい黒フラミンゴが地中海の島、キプロス島で発見された。 Cyprus.[23]

脚注

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  1. ^ Morales, E. (1995). The Guinea Pig : Healing, Food, and Ritual in the Andes. University of Arizona Press. ISBN 0-8165-1558-1 
  2. ^ Liddell, H. G., Scott, R. (1940). μελα^νός. In: A Greek-English Lexicon, revised and augmented throughout by Sir Henry Stuart Jones, with the assistance of Roderick McKenzie. Clarendon Press, Oxford.
  3. ^ Osinga, N., Hart, P., van VoorstVaader, P. C. (2010). Albinistic common seals (Phoca vitulina) and melanistic grey seals (Halichoerus grypus) rehabilitated in the Netherlands. Animal Biology 60 (3): 273−281.
  4. ^ Webster's Revised Unabridged Dictionary (1913) Melanosis Archived 2013-07-29 at the Wayback Machine.. C. & G. Merriam Co. Springfield, Massachusetts. Page 910
  5. ^ King, R.C., Stansfield, W.D., Mulligan, P.K. (2006). A Dictionary of Genetics, 7th ed., Oxford University Press
  6. ^ Majerus, M. E. (2009). Industrial melanism in the peppered moth, Biston betularia: an excellent teaching example of Darwinian evolution in action. Evolution: Education and Outreach, 2(1), 63-74.
  7. ^ McIntyre, N. E. (2000). Ecology of urban arthropods: a review and a call to action. Annals of the Entomological Society of America, 93(4), 825-835.
  8. ^ Cook, L. M., Saccheri, I. J., 2013. The peppered moth and industrial melanism: evolution of a natural selection case study. Journal of Heredity 110:207-12
  9. ^ Grant, B. S., Wiseman L. L., 2002. Recent history of melanism in american peppered moths. Journal of Heredity 93:86-90.
  10. ^ Brakefield, P. M., Liebert, T. G., 2000. Evolutionary dynamics of declining melanism in the peppered moth in the Netherlands. Proceedings of the Royal Society of London Biology 267:1953-1957.
  11. ^ Grant, B. S., Cook, A. D., Clarke, C. A., & Owen, D. F. (1998). Geographic and temporal variation in the incidence of melanism in peppered moth populations in America and Britain. Journal of Heredity, 89(5), 465-471.
  12. ^ Mikkola, K., & Rantala, M. J. (2010). Immune defence, a possible nonvisual selective factor behind the industrial melanism of moths (Lepidoptera). Biological Journal of the Linnean Society, 99(4), 831-838.
  13. ^ Mikkola, K., Albrecht, A., 1988. The melanism of Adalia-bipunctata around the Gulf of Finland as an industrial phenomenon (Coleoptera, Coccinellidae). Annales Zoologici Fennici 25:177-85.
  14. ^ Muggleton, J., Lonsdale, D., Benham, B. R., 1975. Melanism in Adalia-bipunctata L (ColCoccinellidae) and its relationship to atmospheric pollution. Journal of Applied Ecology 2:451-464.
  15. ^ De Jong, P. W., Verhoog, M. D., Brakefield, P. M., 1992. Sperm competition and melanic polymorphism in the 2-spot ladybird, Adalla bipunctata (Coleoptera, Coccinellidae). Journal of Heredity 70:172-178.
  16. ^ Searle, A. G. (1968) Comparative Genetics of Coat Colour in Mammals. Logos Press, London
  17. ^ Ulmer, F. A. (1941) Melanism in the Felidae, with special reference to the Genus Lynx. Journal of Mammalogy 22 (3): 285–288.
  18. ^ Eizirik, E., Yuhki, N., Johnson, W. E., Menotti-Raymond, M., Hannah, S. S., O'Brien, S. J. (2003). “Molecular Genetics and Evolution of Melanism in the Cat Family”. Current Biology 13 (5): 448–453. doi:10.1016/S0960-9822(03)00128-3. PMID 12620197. オリジナルの2013-05-06時点におけるアーカイブ。. https://web.archive.org/web/20130506054200/http://www.pucrs.br/fabio/genomaenglish/index_arquivos/artigos_eduardo/Copy%20of%20Melanism_CB_reprint.pdf. 
  19. ^ Robinson, R. (1970). “Inheritance of black form of the leopard Panthera pardus”. Genetica 41: 190–197. doi:10.1007/BF00958904. PMID 5480762. 
  20. ^ Kawanishi, K., Sunquist, M. E., Eizirik, E., Lynam, A. J., Ngoprasert, D., Wan Shahruddin, W. N., Rayan, D. M., Sharma, D. S. K., Steinmetz, R. (2010) Near fixation of melanism in leopards of the Malay Peninsula. Journal of Zoology, Volume 282 (3): 201–206.
  21. ^ Majerus, M. E. N. (1998) Melanism: evolution in action. Oxford University Press, New York
  22. ^ Seidensticker, J., Lumpkin, S. (2006). Smithsonian Q & A: the ultimate question and answer book. Cats. Collins, New York
  23. ^ Krol, Charlotte (2015年4月9日). “Rare black flamingo spotted in Cyprus”. The Telegraph. オリジナルの2015年4月25日時点におけるアーカイブ。. https://web.archive.org/web/20150425102520/http://www.telegraph.co.uk/news/earth/wildlife/11526328/Rare-black-flamingo-spotted-in-Cyprus.html 2015年5月16日閲覧。 

参考文献

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ウィキメディア・コモンズには、れとりぃばぁ/sandboxに関連するカテゴリがあります。
  • David Attenborough (2002). The Life of Mammals (TV-Series and book). United Kingdom: BBC.
  • Kettlewell, Bernard (1973). The Evolution of Melanism. Clarendon Press. ISBN 0-19-857370-7 
  • Majerus, Michael (1998). Melanism: Evolution in Action. Oxford University Press. ISBN 0-19-854982-2 
  • Melanism and disease resistance in insects
  • Fryer, G. 2013. How should the history of industrial melanism in moths be interpreted? The Linnean. 29 (2): 15 - 22.
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