TOEFL-Reading-Comprehension – Test of English as a Foreign Language - Reading Comprehension

In strongly territorial birds such as the indigo bunting, song is the main mechanism for securing g, defining, and defending an adequate breeding are. When population density is high, only the strongest males can retain a suitable are. The weakest males do not breed or are forced to nest on poor or marginal territories.

During the breeding season, the male indigo bunting sings in his territory; each song lasts two or three seconds with a very short pause between songs, Melodic and rhythmic characteristics are produced by rapid changes in sound frequency and some regularity of silent periods between sounds. These modulated sounds form recognizable units, called figures, each of which is reproduced again and again with remarkable consistency. Despite the large frequency range of these sounds and the rapid frequency changes that the birds makes, the n umber of figures is very limited. Further, although we found some unique figures in different geographical populations, more than 90 percent of all Indigo bunting figures are extremely stable on the geographic basis. In our studies of isolated buntings we found that male indigo buntings are capable of singing many more types of figures than they usually do. Thus, it would seem that they copy their figures from other buntings they hear signing.

Realizing that the ability to distinguish the songs of one species from those of another could be an important factor in the volition of the figures, we tested species recognition of a song. When we played a tape recording of a lazuli bunting or a painted bunting, male indigo bunting did not respond; Even when a dummy of male indigo bunting was placed near the tape recorder. Playing an indigo bunting song, however, usually brought an immediate response, making it clear that a male indigo bunting can readily distinguished songs of its own species from those of other species.

The role of the songs figures in interspecies recognition was then examined. We created experimental songs composed of new figures by playing a normal song backwards, which changed the detailed forms of the figures without altering frequency ranges or gross temporal features. Since the male indigos gave almost a full response to the backward song, we concluded that a wide range of figures shapes can evoke positive responses. It seems likely, therefore, that a specific configuration is not essential for interspecies recognition, but it is clear that song figures must confirm to a particular frequency range, must be within narrow limits of duration, and must be spaced at particular intervals.

There is evident that new figures may arise within a population through a slow process of change and selection. This variety is probably a valuable adaptation for survival: if every bird sang only a few types of figures, in dense woods or underbrush a female might have difficulty recognizing her mate’s song and a male might not be able to distinguished a neighbor from a stranger. Our studies led us to conclude that there must be a balance between song stability and conservatism, which lead to clear-cut species recognition, and song variation, which leads to individual recognition.

It can be inferred that a dummy of a male indigo bunting was placed near the tape recorder that played the songs of different species in order to try to

At the time Jane Austen’s novels were published – between 1811 and 1818 – English literature was not part of any academic curriculum. In addition, fiction was under strenuous attack. Certain religious and political groups felt novels had the power to make so called immoral characters so interesting young readers would identify with them; these groups also considered novels to be of little practical use. Even Cole-ridge, certainly no literary reactionary, spoke for many when he asserted that “novel-reading occasions the destruction of the mind’s power”.

These attitudes towards novels help explain why Austen received little attention from early nineteenth century literary critics. (In any case, a novelist published anonymously, as Austin was, would not be likely to receive much critical attention). The literary response that was accorded her, however, was often as incisive as twentieth century criticism. In his attack in 1816 on novelistic portrayals “outside of ordinary experience“, for example, Scott made insightful remarks about the merits of Austen’s fiction. Her novels, wrote Scott, “present to the reader an accurate and exact. picture of ordinary everyday people and places, reminiscent of seventeenth – century Flemish painting. “ Scott did not use the word “realistic probability in judging novels. The critic whitely did not use the word realism either, but he expressed agreement with Scott’s evaluation, and went on to suggest the possibilities for moral instruction in what we have called Austen’s realistic method. Her characters, wrote whitely, are persuasive agents for moral truth since they are ordinary persons “so clearly evoked that was feel an interest in their fate as if it were our own” Moral instruction, explained Whitely, is more likely to be effective when conveyed through recognizably human and interesting characters then when imparted by a sermonizing narrator. Whately especially praised Austen’s ability to create characters who “mingle goodness and villainy, weakness and virtue, as in life they are always mingled. “Whately concluded his remarks by comparing Austen’s art of characterization to Sicken’s, stating his preference for Austin’s. often anticipated the reservations of twentieth-century critics. An example of such a response was Lewes’ complaint in 1859 that Austen’s range of subjects and characters was too narrow. Praising her verisimilitude, Lewes added that nonetheless her focus was too often upon only the unlofty and the common place. (Twentieth-century Marxists, on the other hand, were to complain about what they saw as her exclusive emphasis on a lofty upper-middle class) in any case, having been rescued by some literary critics from neglect and indeed gradually lionized by them, Austen’s steadily reached, by the mid-nineteenth century, the enviable pinnacle of being considered controversial.

The passage supplies information to suggest that the religious and political groups mentioned and Whately might have agreed that a novel

The fossil remain of the first flying vertebrates, the pterosaurs, have intrigued paleontologists for more than two centuries. How such large creatures, which weighed in some cases as much as a piloted hangglider and had wingspans from 8 to 12 meters, solved the problems of powered flight, and exactly what these creatures were-reptiles or birds- are among the questions scientist have puzzled over.

Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skulls, pelvises, and hind feet are reptilian. The anatomy of their wings suggests that they did not evolve into the class of birds. In pterosaurs a greatly elongated fourth finger of each forelimb supported a wing like membrane. The other fingers were short and reptilian, with sharp claws, In birds the second finger is the principle strut of the wing, which consists primarily of features. If the pterosaur walked or remained stationary, the fourth finger, and with it the wing, could only turn upward in an extended inverted V-shape along side of the animal’s body.

The pterosaurs resembled both birds and bats in their overall structure and proportions. This is not surprising because the design of any flying vertebrate is subject to aerodynamic constraints. Both the pterosaurs and the birds have hollow bones, a feature that represents a saving in weight. In the birds, however, these bones are reinforced more massively by internal struts.

Although scales typically cover reptiles, the pterosaurs probably had hairy coats. T.H. Huxley reasoned that flying vertebrates must have been warm – blooded because flying implies a high internal temperature. Huxley speculated that a coat of hair would insulate against loss of body heat and might streamline the body to reduce drag in flight. The recent discovery of a pterosaur specimen covered in long, dense, and relatively thick hair like fossil material was the first clear evidenced that his reasoning was correct.

The authors views the idea that the pterosaurs became airborne by rising into light winds created by waves as