首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Cryptic Coloring Cryptic coloring is the commonest use of color in the struggle for existence. Ⅰ Cryptic coloring, may be ei
Cryptic Coloring Cryptic coloring is the commonest use of color in the struggle for existence. Ⅰ Cryptic coloring, may be ei
admin
2013-06-12
58
问题
Cryptic Coloring
Cryptic coloring is the commonest use of color in the struggle for existence.
Ⅰ Cryptic coloring, may be either general or special.
General
1) In general resemblance the animal through its coloring, produces the same
effect as its environment, but no special adaptation of shape and【1】______ 【1】______
is required.
2) General resemblance is commonly employed by the animal inhabiting some
uniformly colored expanse of the earth’ s surface, such as【2】______. The 【2】______
effect of a uniform appearance may be produced by a combination of tints in
startling【3】______. 【3】______
Special
Special resemblance is far commoner than the general one and is the form usually met with on the diversified surface【4】______, as well as on the floating masses of algae 【4】______
on the surface of the ocean. In these environments the cryptic coloring of animals is
usually aided by special modifications of shape, and by the instinct which leads them to
assume particular【5】______. 【5】______
Accordingly we can note that the animal tries to be
hidden from view by becoming【6】______ from its background in case of 【6】______
general resemblance while the animal tries to
be mistaken for some well-known object in case of special resemblance.
Ⅱ People have tried to explain these adaptations in two ways.
1) The first suggestion that the effect is a result of the direct influence of the
environment on the【7】______ breaks down when the complex nature of 【7】______
numerous special resemblances is【8】______ 【8】______
2) The second believes that natural selection produced the result and afterwards
maintained it by the survival of the best concealed in【9】______. The 【9】______
cryptic effect is due to the exact cooperation of many factors; and in the present state of science, the only possible hole of an interpretation lies in【10】______. 【10】______
【5】
Cryptic coloring is by far the commonest use of color in the struggle for existence. It is employed for the purpose of attack (aggressive resemblance or anticryptic coloring) as well as of defense (protective resemblance or procryptic coloring ). The fact that the same method concealment, may be used both for attack and defense has been well explained by T. Belt who suggests as an illustration the rapidity of movement which is also made use of by both pursuer and pursued, which is similarly raised to a maximum in both by the gradual dying out of the slowest through a series of generations. Cryptic coloring is commonly associated with other aids in the struggle for life. Thus well-concealed mammals and birds, when discovered, will generally endeavor to escape by speed and will often attempt to defend themselves actively. On the other hand, small animals which have no means of active defense, such as large, numbers of insects, frequently depend upon concealment alone. Protective resemblance is far commoner among animals than aggressive resemblance, in correspondence with the fact that predaceous forms are as a rule much larger and much less numerous than their prey. In the case of insectivorous Vertebrata and their prey such differences exist in an exaggerated form. Cryptic coloring, whether used for defense of attack, may be either general or special. In general resemblance the animal, in consequence of its coloring, produces the same effect as its environment, but the conditions do not require any special adaptation of shape and outline. General resemblance is especially common among the animal inhabiting some uniformly colored expanse of the earth’s surface, such as an ocean or a desert. In the former, animals of all shapes are frequently protected by their transparent blue color, on the latter, equally diverse forms are defended by their sandy appearance. The effect of a uniform appearance may be produced by a combination of tints in startling contrast. Thus the black and white stripes of the zebra blend together at a little distance, and "their proportion is such as exactly to match the pale tint which arid ground possesses when seen by moonlight." Special resemblance is far commoner than general and is the form which is usually met with on the diversified surface of the earth, on the shores, and in shallow water, as Well as on the floating masses of algae on the surface of the ocean, such as the Sargasso Sea. In these environments the cryptic coloring of animals is usually aided by special modifications of shape, and by the instinct which leads them to assume particular attitudes. Complete stillness and the assumption of a certain attitude play an essential part in general resemblance on land; but in special resemblance the attitude is often highly specialized, and perhaps more important than any other element in the complex method by which concealment is effected. In special resemblance the combination of coloring, shape, and attitude is such as to produce a more or less exact resemblance to some one of the objects in the environment, such as a leaf of twig, a patch of lichen, a flake of bark. In all cases the resemblance is to some object which is of no interest to the enemy or prey respectively. The animal is not hidden from View by becoming indistinguishable from its background as in the case of general resemblance, but it is mistaken for some well-know object.
In seeking the interpretation of these most interesting and elaborate adaptations, attempts have been made along two lines. The first seeks to explain the effect as a result of the direct influence of the environment upon the individual (G.L.L.Buffon), or by the inherited effects of efforts and the use and disuse of parts (J.B.P.Lamarck). The second believes that natural selection produced the result and afterwards maintained it by the survival of the best concealed in each generation. The former suggestion breaks down when the complex nature of numerous special resemblances is appreciated. Thus the arrangement of colors of many kinds into an appropriate pattern requires the cooperation of a suitable shape and the rigidly exact adoption of a certain elaborate attitude. The latter is instinctive and thus depends on the central nervous system. The cryptic effect is due to the exact cooperation of all these factors; and in the present state of science, the only possible hole of an interpretation lies in the theory of natural selection, which can accumulate any and every variation which tends toward survival. A few of the chief types of methods by which concealment is effected may be briefly described. The colors of large numbers of vertebrate animals are darkest on the back and become gradually lighter on the sides, passing into white on the belly. Abbot H. Thayer has suggested that this gradation obliterates the appearance of solidity, which is due to shadow. The color harmony, which is also essential to concealment, is produced because the back is of the same lint as the environment (e. g. earth), bathed in the cold blue-white of the sky, while the belly, being cold blue-white and bathed in shadow and yellow earth reflections produces the same effects. This method of neutralizing shadow for the purpose of concealment by increased lightness of tint was first suggested by E.B.Poulton in the case of a larva and a pupa, but he did not appreciate the great importance of the principle. In an analogous method an animal in front of a background of dark shadow may have part of its body obliterated by the existence of a dark tint, the remainder resembling, e.g., a pan of a leaf. This method of rendering invisible any pan which would interfere with the resemblance is well know in mimicry.
选项
答案
attitudes
解析
转载请注明原文地址:https://kaotiyun.com/show/Sr4O777K
0
专业英语八级
相关试题推荐
______meansthatlanguagecanbeusedtorefertothecontextsthatareremovedfromtheimmediatesituationofthespeaker,esp
Ifitwereonlynecessarytodecidewhethertoteachelementarysciencetoeveryoneonamassbasisorfindthegiftedfewandt
______meansthatlanguagecanbeusedtorefertothecontextsthatareremovedfromtheimmediatesituationofthespeaker,esp
______takesLondonasthesettinginmostofhisnovels.
Literatureisameansbywhichweknowourselves.Byitwe(1)______meetfutureselves,andrecognizepastselves;againstitw
在洛杉矶,一位美国朋友开车带我去看富人区。富人区就是有钱人的聚居地。美国人喜欢陪客人看富人区,好似观光。在我面前是千姿百态的房子和庭院,优雅、宁静、舒适,真如人间天堂。我忽然有个问题问他:“你们看到富人们住在这么漂亮的房子里,会不会嫉妒?”我这位
谎言三叶草人总是要说谎的,谁要是说自己不说谎,这就是一个彻头彻尾的谎言。有的人一生都在说谎,他的存在就是一个谎言。有的人偶尔说谎,除了他自己,没有人知道这是一个谎言。谎言在某些时候只是说话人的善良愿望,只要不害人,说说也无妨。在我心灵深
HowtoConquerPublicSpeakingFear?I.IntroductionA.Publicspeaking—acommonsourceofstressforeveryoneB.Thetruthabo
CrypticColoringCrypticcoloringisthecommonestuseofcolorinthestruggleforexistence.ⅠCrypticcoloring,maybeei
Peopletendtostrugglewhenlearninganotherlanguage,especiallyiftheyareexposedonlyitwhileattendingclasses.【M1】_____
随机试题
无形资产损耗不包括()
在运用调值公式进行工程价款价差调整时,要注意()。,
民主职能是指我国公安机关对危害国家安全的敌对势力、敌对分子和严重危害社会治安秩序的犯罪分子进行镇压、制裁、改造和监督的社会效能。()
下列电视剧中的情景符合史实的是()。
图书馆里有一批读者,以下判断中只有一项是假的。(1)图书馆里的读者中有的是女性(2)图书馆里的读者中,正在阅读文学作品的不是女性(3)图书馆里的读者中没有不是男性的(4)图书馆里的读者中,有的女性正在阅读科普作品。下列哪项说法是正确的?
青年:壮年()
《马赛曲》《国际歌》和《义勇军进行曲》等歌曲在革命斗争和抵御外敌入侵的战争中都显现出难以估量的()功能。
在一表单中,如果一个命令按钮Coml的方法程序中要引用文本框Textl中的Value属性值,下列中的______是正确的。
ChangesofWomen’sRoleTheroleofwomeninBritainhaschangedalotinthiscentury,(51)inthelasttwentyyears.Them
Accordingtothepassage,by1935theskepticismofBlackworkerstowardunionswas______Thepassagesuggestswhichofthefol
最新回复
(
0
)