Reading — 2026 Jan–Apr Recall Set 84

The modern scientific age in Antarctica really began with the introduction of aircraft in the 1920s. Aircraft transformed the possibilities of exploring the frozen continent around the South Pole, because before that Antarctic travel had been limited to the use of dog-teams pulling sledges. A plane could survey thousands of square kilometres an hour equivalent to a whole summer's work using previous techniques. However, the first planes in Antarctica, such as the Lockheed Vega and the Ford Trimotor, were unreliable in freezing conditions. This made polar flying particularly hazardous, since there was little chance of rescue if a plane was forced down in a remote region. It was in 1928 that Herbert Wilkins hoped to make the first flight in Antarctica, attempting to cross the continent. A further attempt in 1930 was also unsuccessful, but Wilkins' aerial photographs seemed to show that the Antarctic Peninsula was in fact an island, not part of the continent as had previously been thought. This new theory caused some excitement among geographers and cartographers. However, the British Grahamland Expedition of 1934-37 proved conclusively that the Antarctic Peninsula was attached to the rest of the continent. In 1929, the famous American pilot Richard Byrd flew over the South Pole, and another American, Lincoln Ellsworth, made a successful Antarctic flight in 1935. Although Ellsworth claimed a sector of the continent for the USA, the American government did not follow it up. In 1938, the German explorer, Alfred Ritscher, led an expedition south across the sea. Once Antarctica was reached, the aircraft that had been stored in pieces on the ship's deck was reconstructed. The aeroplane was then launched and used to stake a claim to one section of Antarctica by dropping thousands of tiny flags from the air. A significant motivation behind many Antarctic expeditions right up to the 1940s was simply the spirit of adventure. Many of these expeditions had a large measure of private funding, and often the subsequent book about the expedition was a means of clearing debts incurred. The vast majority of Antarctic expeditions since 1940 have been funded by governments, usually for political reasons and scientific research. The setting up of the Research and Development Committee in Britain was a significant development in the history of science in the Antarctic. The Committee's report, published in 1920, focused particularly on the sea that circles the Antarctic continent. The report proposed detailed scientific investigations of the physiology and behaviour of the whales inhabiting the region. As a result, a shore station at Grytviken on the island of South Georgia near Antarctica was occupied by scientists for six years. In addition, three research ships were commissioned. They travelled through the Southern Ocean all year, researching physical and chemical oceanography. The high quality of the specimens and data collected by scientists produced nearly 40 large volumes of reports. This entire project came to be known as the Discovery Investigations. The costs of the Discovery Investigations were completely covered by the proceeds of a tax that was placed on whaling businesses operating in the area. It was in 1875 that the idea of international scientific collaboration at the poles was first proposed, with the aim of collecting valuable data. The result was the first Polar Year in 1882-83. A second Polar Year was organised 50 years later, involving 44 nations and scientific bodies. Both of these Polar Years had been timed to coincide with a period when the sun was at its lowest level of activity, in order to monitor the impact this had. So much interest was aroused by this process that a third Polar Year was organised 25 years later. In 1951 it was decided that this scientific programme should be expanded to cover the globe. This new project was renamed the International Geophysical Year (IGY). Antarctica was chosen as an area for particular attention because of its important influence on global weather. Throughout this period, politics were kept firmly in the background. The IGY took place in 1957-58 and it was during this period that the last great Antarctic journey was accomplished. Dr Vivian Fuchs' privately-funded Trans Antarctic Expedition finally achieved what the explorer Ernest Shackleton had first set out to do in 1914. Driving modified tractors, Fuchs' team traversed Antarctica from coast to coast in 99 days and covered 2,180 miles or roughly 3,500 kilometres. But there were scientific objectives as well, because the expedition's measurements allowed the first estimates to be made of the volume of ice that existed across the whole continent. So successful was the IGY that it was extended for a further year in order to promote Antarctic science. It also led directly to the signing of a treaty by members of the international community to regulate human conduct in Antarctica over the years ahead.

A. Parrots are found across the tropic and in all southern hemisphere continents except Antarctica, but nowhere do they display such a richness of diversity and form as in Australia. One-sixth of the world’s 345 parrot species are found there, and Australia has long been renowned for the number and variety of its parrots. B. In the 16th century, the German cartographer Mercator made a world map that included a place, somewhere near present-day Australia, that he named Terra Psittacorum – the Land of Parrots – and the first European settlers in Australia often referred to the country as Parrot Land. In 1865, the celebrated British naturalist and wildlife artist John Gould said: “No group of birds gives Australia so tropical and benign an air as the numerous species of this great family by which it is tenanted.” C. Parrots are descendants of an ancient line. Due to their great diversity, and since most species inhabit Africa, Australia and South America, it seems almost certain that parrots originated millions of years ago on the ancient southern continent of Gondwana, before it broke up into the separate southern hemisphere continents we know today. Much of Gondwana comprised vast rainforests intersected by huge slow-flowing rivers and expansive lakes, but by eight million years ago, great changes were underway. The center of the continent of Australia had begun to dry out, and the rainforests that once covered it gradually contracted to the continental margins, where, to a limited extent, they still exist today. D. The creatures that remained in those shrinking rainforests had to adapt to the drier conditions or face extinction. Reacting to these desperate circumstances, the parrot family, typically found in jungles in other parts of the world, has populated some of Australia’s harshest environments. The parrots spread from ancestral forests through eucalypt woodlands to colonise the central deserts of Australia, and as a consequence they diversified into a wide range of species with adaptations that reflect the many changes animals and plants had to make to survive in these areas. E. These evolutionary pressures helped mould keratin, the substance from which beaks are made, into a range of tools capable of gathering the new food types favored by various species of parrot. The size of a parrot’s short, blunt beak and the length of that beak’s curved upper section are related to the type of food each species eats. Some have comparatively long beaks that are perfect for extracting seeds from fruit; others have broader and stronger beaks that are designed for cracking hard seeds. F. Differently shaped beaks are not the only adaptations that have been made during the developing relationship between parrots and their food plants. Like all of Australia’s many honey-eating birds, the rainbow-coloured lorikeets and the flowers on which they feed have long co-evolved with features such as the shape and colour of the flowers adapted to the bird’s particular needs, and physical example, red is the most attractive colour to birds, and thus flowers which depend on birds for pollination are more often red, and lorikeets’ tongues have bristles which help them to collect as much pollen as possible. G. Today, most of Australia’s parrots inhabit woodland and open forest, and their numbers decline towards both deserts and wetter areas. The majority are nomadic to some degree, moving around to take advantage of feeding and breeding places. Two of the dry country parrots, the pink and grey galah and the pink, white and yellow corella have expanded their ranges in recent years. They are among the species that have adapted well to the changes brought about by European settlement; forest felling created grasslands where galahs and corellas thrive. H. But other parrot species did not fare so well when their environments were altered. The clearing of large areas of rainforest is probably responsible for the disappearance of the double-eyed fig parrot, and numbers of ground parrots declined when a great part of their habitat was destroyed by the draining of coastal swamps. Even some parrot species that benefited from forest clearing at first are now confronted by a shortage of nesting sites due to further man-made changes. I. New conditions also sometimes favour an incoming species over one that originally inhabited the area. For example, after farmers cleared large areas of forest on Kangaroo Island off the coast of South Australia, the island was colonised by galahs. They were soon going down holes and destroying black cockatoo eggs in order to take the hole for their own use. Their success precipitated a partial collapse in the black cockatoo population when the latter lost the struggle for scarce nesting hollows.

All living languages undergo changes of various kinds, for which there are various reasons. The changes that have caused most dispute are those in pronunciation. We have various sources of evidence for the pronunciations of earlier times, like the evidence of spellings, the treatment of words borrowed from other languages or borrowed by them, the descriptions of contemporary grammarians, and the modern pronunciations in all the languages and dialects concerned. These, combined with a knowledge of the mechanism of speech production, can often give us a very good idea of the pronunciation of an earlier age, though absolute certainty is never possible. When we study the pronunciation of a language over any period of a few generations or more, we find that it is subject to change. Moreover, there are always large-scale regularities in the changes: for example, over a period of time, all the long a sounds in a language may change into long o sounds, or all the b sounds in a certain position (for example, at the end of a word) may change into p sounds. Such regular changes are often called sound laws. There are no universal sound laws, but simply particular sound laws for one given language at one given period. One cause of change is the influence of one language on another. We learn our mother tongue very thoroughly, and acquire a whole set of speech habits which become second nature to us. When later we learn a foreign language, we inevitably carry over some of these speech habits into it, and so do not speak it exactly like a native. Consequently, in bilingual situations the second language tends to be modified. Such modifications may not persist, of course: an isolated Polish or German immigrant to Britain will usually have grandchildren who speak English like natives because the influence of the general speech environment (playmates, school, work) is stronger than that of the home. But if a large and closely knit group of people adopt a new language, then the modifications they make in it may persist among their descendants, even if the latter no longer speak the original language that caused the changes. This can be seen in Wales, where the influence of Welsh has affected the pronunciation of English, and the very characteristic melody of Welsh English has been carried over from Welsh. It is also possible that fashion plays a part in the process of change. It certainly plays a part in the spread of change: one person imitates another, and people with the most prestige are most likely to be imitated, so that a change that takes place in one social group may be imitated (more or less accurately) by speakers in another group. When a social group goes up or down in the world, its pronunciation will gain or lose prestige. Some of the changes in accepted English pronunciation in the seventeenth and eighteenth centuries have been shown to consist of the replacement of one style of pronunciation by another style already existing, and it is likely that such substitutions were a result of the great social changes of the period: the increased power and wealth of the middle classes, and their steady infiltration upwards into the ranks of the landed gentry probably carried elements of middle class dialect into upper class speech. However, besides spreading changes that have already taken place, fashion may actually cause changes in pronunciation. In a stratified society, the important thing about a fashion is that it is exclusive: as soon as the fashion has penetrated to a lower social group, it’s time to move on. This can be seen in clothes: fashionable people may find it flattering to be imitated, but as soon as the new fashion has really caught on they must change to something else, to mark themselves off as different. It may be the same with language, for social groups use characteristic styles of language to mark themselves off from other groups. A group that has high prestige may find that its style of speech is being imitated by other groups, and then its members may (perhaps subconsciously) begin to change it, perhaps by exaggerating its distinguishing characteristics. However, while interaction between different languages, and between the dialects of a single language, can explain some changes in pronunciation, it cannot explain them all. Another cause that has been suggested is the fact that the imitation of children is imperfect: they copy their parents’ speech, but never reproduce it exactly. This seems to be true enough and it moreover seems to be true that even adults show a certain amount of random variation in their pronunciation. However, these facts cannot explain changes in pronunciation, unless it can be shown that there is some systematic trend in the failures in imitation. If they are merely random deviations they will cancel one another out and there will be no net change in the language. For some of these random variations to be selected at the expense of others, there must be further forces at work. One such force, which is often suggested, is known as the principle of ease. We are all naturally lazy, it is argued, and so we tend to take short cuts in the movements of our speech organs, to replace movements calling for great accuracy or energy by less demanding ones, to omit sounds if they are not essential for understanding, and so on. For example, the word scant was once skamt, but the m has been changed to n under the influence of the following t. An economy of effort has thereby been achieved, because n and t are articulated in the same place (with the tip of the tongue against the teeth-ridge), whereas m is articulated elsewhere (with the two lips). The change from skamt to scant would be an example of assimilation, which is a very common kind of change. Assimilation is the changing of a sound under the influence of a neighbouring sound. Assimilation is not the only way in which we change our pronunciation in order to reduce effort. A sound may come to be pronounced less energetically, wherever it occurs: the English r and h sounds are undoubtedly pronounced much less vigorously now than they were a thousand years ago. In some positions a sound may disappear altogether. At one time the t was pronounced in words like castle and Christmas, and the g in words like gnat and gnaw. Sometimes a whole syllable is dropped out if it occurs twice running. A modern example is temporary, which in Britain is pronounced as if it were tempory.