高级英语 第四单元

The Domestication of Animals动物的驯化The domestication of wild species led directly to denser human populations by yielding more food than the hunter-gatherer lifestyle could provide. In societies that possessed domestic animals, livestock helped to feed more people by providing meat, milk and fertilizer, and by pulling plows. Large domestic animals became the societies’ main source of animal protein, replacing wild game, and they also furnished wool, leather, and land transport. Humans have domesticated only a few species of large animals, with “large” defined as those weighing over 100 pounds (45 kilograms). Fourteen such species were domesticated before the twentieth century, all of them terrestrial mammals and herbivores. The five most import of these are sheep, goats, pigs, horses, and cattle or oxen.野生物种的驯化直接导致了人类种群密度的增加，比狩猎采集者的生活方式提供了更多的食物。

在拥有家畜的社会里，牲畜通过提供肉类、牛奶和化肥，以及拉犁来养活更多的人。

大型家畜成为了社会动物蛋白的主要来源，取代了野生动物，他们还提供羊毛、皮革和陆地运输。

人类只驯养了一些大型动物，其中“大”被定义为体重超过100磅(45公斤)的大型动物。

在二十世纪之前驯养了十四种这样的动物，它们都是陆地哺乳动物和食草动物。

其中最重要的五个是绵羊、山羊、猪、马、牛或牛。

Small animals such as ducks, geese, rabbits, dogs, cats, mink, bees, and silkworms have also been domesticated. Many of these small animals provided food, clothing, or warmth. However, none of them pulled plows or wagons, none carried riders, and none except dogs pulled sleds. Furthermore, no small domestic animals have been as important for food as have large domestic animals.鸭子、鹅、兔子、狗、猫、鼬、蜜蜂和蚕等小型动物也被驯养。

许多小动物提供食物、衣服或温暖。

然而，没有一个人拉犁或马车，没有一个人带着骑手，只有狗拉雪橇。

此外，与大型家畜一样，小型家畜对食物的重要性也不高。

Early herding societies quickly domesticated all large mammal species that were suitable for domestication. There is archaeological evidence that these species were domesticated between 10,000 and 4,500 years ago, within the first few thousand years of the origins of farming-herding societies after the last Ice Age. The continent of Eurasia has been the primary site of large mammal domestication. Having the most species of wild mammals to begin with, and losing the fewest to extinction in the last 40,000 years, Eurasia has generated the most candidates for domestication.早期的放牧社会很快驯养了所有适合驯养的大型哺乳动物。

有考古证据表明，这些物种是在1万到4500年前被驯化的，这是在上一个冰河时代之后的农牧社会起源的最初几千年里。

欧亚大陆是大型哺乳动物驯化的主要场所。

在过去的4万年里，欧亚大陆拥有最多的野生哺乳动物，并在灭绝的过程中失去了最少的数量，因此成为了最适合驯化的物种。

Domestication involves transforming wild animals into something more useful to humans. Truly domesticated animals differ in many ways from their wild ancestors. These differences result from two processes: human selection of individual animals that are more useful to humans than other individuals of the same species, and evolutionary responses of animals to the forces of natural selection operating in human environments rather than in wild environments.驯化包括将野生动物转化为对人类更有用的东西。

真正的驯养动物在许多方面与它们的祖先不同。

这些差异是由两个过程产生的:个体动物的人类选择比其他个体对人类更有用，动物对自然选择的力量的进化反应在人类环境中而不是在野生环境中。

To be domesticated, a wild species must possess several characteristics. A candidate for domestication must be primarily a herbivore because it takes less plant biomass to feed a plant eater than it does to feed a carnivore that consumes plant eaters. No carnivorous mammal has ever been domesticated for food simply because it would be too costly. A candidate must not only weigh an average of over 100 pounds but also grow quickly. That eliminates gorillas and elephants, even though they are herbivores. Moreover, candidates for domestication must be able to breed successfully in captivity.要被驯化，野生物种必须具备几个特征。

一个驯养的候选人必须主要是食草动物，因为饲养食草动物所需的植物生物量要比消耗食草动物的食肉动物少。

没有食肉哺乳动物因为太昂贵而被驯养。

一个候选人不仅要平均体重超过100磅，而且要快速成长。

这就消除了大猩猩和大象，即使它们是食草动物。

此外，驯养的候选人必须能够在囚禁中成功繁殖。

Since almost any sufficiently large mammal species is capable of killing a human, certain qualities disqualify a wild animal for domestication. The animal cannot have a disposition that is nasty, dangerous, or unpredictable –characteristics that eliminate bears, African buffaloes, and some species of wild horses. The animal cannot be so nervous that it panics around humans. Large herbivores mammal species react to danger from predators or humans in different ways. Some species are nervous, fast and programmed for instant flight when they perceive danger. Others are less nervous, seek protection in herds, and do not run until necessary. Most species of deer and antelope are of the former type, while sheep and goats are of the latter.由于几乎任何足够大型的哺乳动物都能杀死人类，某些品质使野生动物丧失驯养能力。

这种动物不可能有一种令人讨厌、危险或不可预知的特性，这种特性可以消灭熊、非洲水牛和一些野马。

动物不可能如此紧张以至于它在人类周围恐慌。