MBA联考英语精彩文章推荐之中级篇(十三)

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Cryptic Coloring

  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 tint 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 part of a leaf. This method of rendering invisible any part which would interfere with the resemblance is well know in mimicry.

  1.The black and white stripes of the zebra are most useful form

  A.hunters

  B.nocturnal predators

  C.lions and tigers

  C.insectivorous  Vertrbrata

  2.Aggressive resemblance occurs when

  A.a predaceous attitude is assumed

  B.special resemblance is utilized

  C.an animal relies on speed

  D.an animal blends in with its background

  3.Special resemblance differs from general resemblance in that the animal relies on

  A.its ability to frighten its adversary

  B.speed

  C.its ability to assume an attitude

  D.mistaken identify

  4.The title below that best expresses the ides of this passage is

  A.Cryptic coloration for Protection

  B.How Animals Survive

  C.The uses of Mimicry in Nature

  D.Resemblances of Animals

  5.Of the following which is the least common?

  A.protective resemblance

  B.General resemblance

  C.Aggressive resemblance

  D.Special resemblance

  难句译注

  1.…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.

  译文:追捕动物和被追的动物也利用快速的动作。这种快速的运动同样是通过几代更迭,逐渐消除了慢速,而发展到快速顶峰。

  2.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.

  译文:保护性模仿远比侵犯行模仿要普遍得多,这是和下述的情况想配合的:食肉的(形式)动物,按惯律总是比他们捕食的对象要大而且多得多。

  3.The effect of a uniform appearance may be produced by a combination of tints in startling contrast.

  译文:在惊人的对比中,色泽的综合可能产生外形一致的效果。

  4.…their proportion is such as exactly to match the pale tint which arid ground possesses when seen by moonlight.

  译文:(这里指斑马的黑白条)比例正好和在月光下观看贫瘠土地所具有的苍白色泽相吻合。

  5.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.

  译文:在这些环境中,动物的保护色常常得到特定的形状变化和本能的协作,这种本能会使动物采取特定的姿势。

  6.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…

  译文:绝对静态和采取一般姿势在陆地的一般模仿中起很大作用,而在专门模仿中,姿势常常是高度专门化的。

  7.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.

  译文:因此许多类颜色排列成恰当的模式/形式,要求把合适的外形和严格的采用一定的精心设计的姿势相结合。

  8.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.

  译文:保护效果是由于所以这些因素确切合作而形成。根据目前科学水平,唯一的解释(此种现象)就是自然选择理论,它可以累积要生存的各种变异/变种。

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