早稲田文化構想2010 大問Ⅲ

Choose the most appropriate sentences from the following list ( a ~ h) for the gaps in the text (25―31). Mark your answers on the separate answer sheet.


(a) A third of the Earth's land surface was covered with ice, and ice covered half of the surface area of the oceans as well.

(b) However, these environmental problems were of a much smaller scale than the social and political crises which have occurred in recent years.

(c) In effect, the size of the population in many areas began to exceed the carrying capacity of the land, leading to competition for available resources.

(d) Populations of animals extended their range and as the period of global warming continued, humans extended their activities to areas that were once entirely uninhabitable.

(e) Species that had extended their range across the continent were forced back to isolated refuges where they could survive.

(f) The Sahara Desert itself moved southward across its entire length some 500 kilometers.

(g) This date approximates the greatest extension of the ice cover of the last major ice age.

(h) Where trees and plants had once provided sufficient food, the need to kill and process animals became just as important.


One of the fundamental human characteristics is the ability to adapt to changing circumstances, and while we are constantly confronted with the dangers of global warming, there is a degree of encouragement to be gained from looking at a reverse phenomenon that occurred around 16,000 BC. ( 25 ) While debate continues regarding precisely how low temperatures dropped, the calculations range from 8 to 11 °C below that of recent centuries.


Ice extended over much of North America and Europe, while glaciers flowed from the mountains not only of Asia and South America but also of Africa. Continental ice sheets 1.5 kilometers thick pressed down on the Earth's surface. ( 26 ) With all of this water locked up in ice, the levels of the planet's seas fell dramatically, as much as 130 meters in all.


With declines in temperatures and decreases in rainfall, the African continent was greatly affected, from the rainforests to the deserts. High winds struck the Sahara, generating sandstorms that dumped clouds of sand into the Atlantic Ocean. ( 27 ) In southern Africa, in the already dry Kalahari region, rainfall was reduced to half of the modern average, bringing intense dryness.


The maximum expansion of the glaciers brought hard times to both vegetation and animals, reducing populations to minimums in greatly restricted areas. ( 28 ) The human population was no different. It is believed that the equatorial and tropical regions of Africa are the cradle of human evolution, and although temperatures fell and the landscape turned drier even in these regions, conditions remained within the ranges that humans could endure. During warmer times, of course, groups of humans had migrated out of these regions as the human population grew. When conditions worsened, those who remained within the "cradle" areas were able to adapt, while the migrants found conditions elsewhere too difficult to survive.


Due to the fact that humans had originated in the tropics, they were physiologically adapted to cope with hot temperatures, but they were not prepared for the cold conditions that extended into the subtropical areas of Africa during the glacial period. Fire offered some relief from the cold, but it was the making of clothing that ensured long-term survival. The manufacture of clothing placed a premium on success in hunting animals, both for protein and for skins. ( 29 ) Additional skills were required for preparing the skins to make clothing and using other animal parts for utensils.


Once the climatic cycle turned and conditions in Africa improved, the dry landscape turned to lush savanna, grassland, and forest. When the rains returned, deserts were covered with vegetation within several hundred years. ( 30 ) With the extension of agriculture under more favorable climatic conditions, the human population increased rapidly. In attempting to increase food production, formerly uninhabited areas came to be used extensively. ( 31 ) While competition for diamonds, precious stones, and minerals often makes the news today, it is in fact the competition for more fundamental resources such as safe drinking water, grains, materials for clothing, and occasional meat that affects the future of the entire continent.







 氷は北アメリカとヨーロッパの多くの地域に広がる一方,氷河はアジアと南アメリカの山脈だけでなくアフリカの山脈からも流れ出した。 1.5キロメートルの厚さがある大陸の氷床は地球の表面を押し下げた。地表の3分の1が氷で覆われて,そして氷は海の表面の半分をも覆っていた。これらの水のすべてが,氷の中に閉じ込められたので,地球の海面の水位は全体で130メートルも劇的に低下した。