发布时间 : 星期六 文章2019年北京东城中考英语一模阅读C篇译文 - 图文更新完毕开始阅读0e85a256f71fb7360b4c2e3f5727a5e9856a27b7
2019年北京东城中考英语一模阅读C篇译文
Most groups of plants and animals are richer in species and more plentiful near the equator. In the ocean, that holds true for cold-blooded predators. But warm-blooded predators are more diverse toward the poles and noticeably missing from several warm hot spots. Why?
赤道附近物种丰富，数目繁多，那里尤其适合于生存在海洋里的冷血捕食动物。但是对于温血捕食动物来说，极地种类繁多，温热带地区却明显减少。
John Grady, an ecologist, and his team considered the possibility—warm-blooded animals need a lot to fuel their metabolism. Perhaps colder waters are just richer in small fish? But they found that at higher, colder places, there isn’t actually much more food around. It’s more that warm-blooded animals are eating a much bigger share of it than their cold-blooded competitors.
一位生态学家约翰﹒杰瑞德及其团队这样认为——可能温血动物维持新陈代谢需要猎取大量食物。或许水越是寒凉就越盛产小鱼吧？但是他们发现越是高寒地带的猎物并不充足。所谓的多只是体现在温血动物捕食占比多于与之争雄的冷血动物罢了。
The real explanation is simple. An animal’s speed, swiftness, and intelligence depend on its metabolism, which in turn depends on its temperature. Since birds and mammals can keep heating
their bodies in icy conditions, they remain fast and attentive. By contrast, the fish they hunt become slower and duller. At some tipping point of temperature, seals, dolphins, and penguins start outswimming their prey. They become more likely to come upon targets and outpace the cold-blooded predators of their own.
其实这理解起来并不难。动物的速度、敏捷与智力活动都有赖于通过新陈代谢补充能量，反过来新陈代谢也要需要动物的体温做后盾。既然鸟类和哺乳动物能够在寒冷条件下维持体温，他们的速度和注意力就可以得到保障。相对来说它们捕猎的鱼就显得动作迟缓。到了一定温度，海豹、海豚和企鹅的游泳速度就可以超过它们猎物的速度。而且一旦发现猎物，它们还能抢先赶在冷血掠食动物的前面。
In Grady’s words, “Warm-bodied predators are favored where preys are slow, stupid and cold.” That’s why sharks and other predatory fish dominate near the equator, but colder waters are the kingdom of whales and seals. By keeping food to themselves in the poles, these creatures can then specialize on specific types of prey, which makes them more likely to split into separate species. The killer whales of the North Pacific, for example, include mammal-eating transients and fish-eating, year-round residents.
用杰瑞德的话说，“越是在猎物行动迟缓、笨拙、寒凉的地带，温血动物越占优势。这也正说明了鲨鱼和其它食肉鱼类堪称赤道水域的霸主，而寒带水域便成了鲸鱼和海豹的王国。这些生物独享极地的猎物，然后就可以专门捕食它们喜好的猎物，这样更有利于物种的分化。比如说北太平洋的虎鲸就分以哺乳动物为食的迁徙鲸群，还有以鱼类为食的常住鲸群。”
But the world is changing. It’s likely that the surface of the oceans will warm by 2 to 3℃ within this century. Grady’s team estimates that every time the ocean’s surface warms by 1℃, populations of sea mammals will fall by 12%, and populations of seals and sea lions will fall by 24%.
不过，这个世界的变化是永恒的。本世纪洋表温度可能会上升2-3摄氏度。杰瑞德研究团队估算洋表温度每上升1摄氏度，海洋哺乳动物的数量将会减少12%，同时海豹和海狮数量减少24%。
But“predictions are hard,” Donna Hauser from the University of Alaska Fairbanks notes.“Polar bears are losers of a warming world, but some populations are still doing well. Some groups of whales have changed the timing of their migrations; others are hunting in deeper, colder waters. These changes might make sea mammals more adaptable to changing climates. Maybe they just need to find the places where fish remain slow, stupid and cold.”
不过“预言的过于绝对。”阿拉斯加费尔班克斯大学的多纳﹒豪斯尔解释说。“北极熊虽然从气温变暖地带消失，但有些群落在这些地区生存得还是蛮好的。有一些鲸鱼种群调整了迁徙时间，其它种群换到更深更冷的水域捕食。这样就会令海洋的哺乳动物更加适应日益变换的气候。也许它们正想另寻他地，那里的鱼仍旧迟缓、笨拙、寒凉。”