小樽商科大学 過去問 2018(H30)年02月25実施 第３問
第３問 Read the text below and answer the questions in English. (30点)
How many different species are there on our planet? Nobody really knows, but estimates vary from 7 to 100 million, of which only about 1.4 million have so far been identified. Most of these exist only in tropical rainforests, wetlands and coral reefs, and many are in danger of becoming extinct as their habitats are destroyed by humans. Forests are burned by migrant farmers, and cut down by loggers. Wetlands are drained to create farmland. Coral reefs are blasted by fishermen using dynamite, and by workers constructing new harbors. In addition, global warming threatens to wipe out vast numbers of species which are unable to adapt to changing climate and conditions.
Under normal circumstances, we could expect up to ten species a year to become extinct. Yet the actual rate of extinctions is now thought to be more like ten species per day. Is this a problem? For the species concerned, it is. The last bear in Switzerland probably led a very lonely life until she was shot in September 1904. Other species have just as much right to exist as we do. However, the loss of biodiversity is a problem for humans too.
Among the thousands of species that will become extinct over the next few years will be medicinal plants that could cure diseases for which no cure currently exists, or with fewer of the side effects that current drugs have. Quinine, used to treat malaria, and the rosy periwinkle, the source of a cure for child leukemia, both originated in tropical rainforests.
Wild species of food plants are also threatened. Many of these contain genes that could protect crops from the effects of global warming and from outbreaks of insect infestations. The world’s population currently depends on just three crops – rice, wheat and corn – for about half of its food supply. A crisis affecting any one of them could lead to widespread famine, as could the loss of the many insects that help the farmer, such as the bees that enable the reproduction of the crops and the worms that enrich the soil.
We depend not only on these countless species, but also on the fragile ecosystems in which they live. Rainforests help store carbon, the biggest cause of global warming. Wetlands help purify our polluted rivers. Coral reefs provide us with rich fishing resources. Without these natural assets, we would be in serious trouble. Indeed, we would probably be headed for extinction ourselves.
coral reefs: ‘coral’ is a hard substance formed from the bones of very small sea animals. So coral reefs are long lines of corals.
infestations: troublesome invasions (of insects or animals)
Questions
(1) Where do most of the world’s species live?
(2) How fast are species dying out?
(3) Why is the writer worried about the loss of plants like the rosy periwinkle?
(4) Why are wild species of food plants so important?
(5) How do insects contribute to our food supply?
(6) How would the loss of rainforests affect our climate?
解答
(1) They live in tropical rainforests, wetlands and coral reefs.
(2) About ten species are thought to be dying out per day.
別解 They are dying out at the rate of ten a day.
(3) Because they are medicinal plants that could cure diseases for which no cure currently exists, or with fewer of the side effects that current drugs have.
別解 It’s because such plants could cure diseases that don’t have cures or produce drugs with fewer side effects than those of current ones.
(4) Because many of them contain genes that could protect crops from the effects of global warming and from outbreaks of insect infestations.
別解 It’s because they contain genes that could protect crops from global warming and insect infestations
(5) They help the farmer by enabling the reproduction of the crops and enriching the soil.
別解 Some enables the reproduction of the crops, and others enrich the soil.
(6) Less carbon would be stored in rainforests, leading to global warming.
別解 It would worsen global warming.
解説 [数えきれない種の生き物とその存在意義]
(1) 「世界の種のほとんどはどこに生息しているか」。第1段落第３文前半参照。「熱帯雨林や湿地、サンゴ礁にいる」。
(2) 「どれくらいの速度で種が存在しなくなっているか」。第２段落第２文参照。「実際の絶滅の率は１日につき10種に近いと考えられている」。
(3) 「日日草のような植物の絶滅をなぜ筆者は心配しているのか」。第３段落第１文参照。「それらは薬用植物であり、治療法が現在見つかっていない病気を治療したり、現在の薬よりも少ない副作用で治療したりする可能性があるから」。periwinkle 日日草、leukemia 白血病。
(4) 「食用植物の野生種はなぜそんなに重要なのか」。第４段落第１、２文参照。「それらの多くが含遺伝子は、地球温暖化の影響や昆虫来襲から作物を守る可能性があるから」。
(5) 「昆虫は私たちの食料供給にどのように役立っているか」。第４段落最終文参照。「農作物を増やしたり、土壌を豊かにして、農家を支援している」。bees ハチ、worms ミミズ。
(6) 熱帯雨林がなくなると地球の気候にどのような影響を与えるか」。最終段落第２文参照。「熱帯雨林は、地球温暖化の主な原因である炭素を蓄える手助けとなる」。
