【英语时差8,16】小狗躺下前为什么要转圈圈？

 Why Dogs Turn In Circles Before Lying Down Ever wonder why dogs turn around in circles before lying down? Almost all domestic and wild dogs show this behavior as they prepare to curl up and lie down. There are many legends that claim to explain this stereotyped¹ behavior. But there are almost no experiments that actually test these claims–in part because such hypotheses would be difficult to verify experimentally. The most commonly repeated story is that the behavior is an evolutionary² hold-over from dogs’ wild ancestors. Circling may have been necessary to trample³ down tall vegetation and shoo away any pests hiding in the grass, making the ground more comfortable to lie on. Others theorize that dogs in the wild preferred to sleep with their nose into the wind. Circling allowed dogs to determine wind direction. The simplest explanation is that turning in circles is just a way to orient the body into a tight curled posture⁴ as the dog lies down. What scientists do know is that the behavior is an example of what has traditionally been called a “fixed⁵ action pattern.” Fixed action patterns are stereotyped behaviors that are exhibited by all members of a particular species. These behaviors are triggered by some external or internal stimulus⁶, and once triggered, the pattern usually continues to completion. Yawning is a good example. Yawns can be triggered by others yawning near you, or by an internal cue. Once started, a yawn is very difficult to stop. Most fixed action patterns are not as inflexible⁷ as the name suggests, and can often be modified subtly by experience or environment. For dogs turning in circles before lying down, factors such as age, surroundings, or other individual differences may change the exact behavioral pattern. But the basic action pattern is likely an inborn⁸ and hard-wired one.

 

1 stereotyped   

adj.(指形象、思想、人物等)模式化的

参考例句：

• There is a sameness about all these tales. They're so stereotyped -- all about talented scholars and lovely ladies. 这些书就是一套子，左不过是些才子佳人，最没趣儿。
• He is the stereotyped monster of the horror films and the adventure books, and an obvious (though not perhaps strictly scientific) link with our ancestral past. 它们是恐怖电影和惊险小说中的老一套的怪物，并且与我们的祖先有着明显的（虽然可能没有科学的）联系。

2 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

3 trample   

vt.踩，践踏；无视，伤害，侵犯

参考例句：

• Don't trample on the grass. 勿踏草地。
• Don't trample on the flowers when you play in the garden. 在花园里玩耍时,不要踩坏花。

4 posture   

n.姿势，姿态，心态，态度；v.作出某种姿势

参考例句：

• The government adopted an uncompromising posture on the issue of independence.政府在独立这一问题上采取了毫不妥协的态度。
• He tore off his coat and assumed a fighting posture.他脱掉上衣，摆出一副打架的架势。

5 fixed   

adj.固定的，不变的，准备好的；(计算机)固定的

参考例句：

• Have you two fixed on a date for the wedding yet?你们俩选定婚期了吗？
• Once the aim is fixed,we should not change it arbitrarily.目标一旦确定，我们就不应该随意改变。

6 stimulus   

n.刺激，刺激物，促进因素，引起兴奋的事物

参考例句：

• Regard each failure as a stimulus to further efforts.把每次失利看成对进一步努力的激励。
• Light is a stimulus to growth in plants.光是促进植物生长的一个因素。

7 inflexible   

adj.不可改变的，不受影响的，不屈服的

参考例句：

• Charles was a man of settled habits and inflexible routine.查尔斯是一个恪守习惯、生活规律不容打乱的人。
• The new plastic is completely inflexible.这种新塑料是完全不可弯曲的。

8 inborn   

adj.天生的，生来的，先天的

参考例句：

• He is a man with an inborn love of joke.他是一个生来就喜欢开玩笑的人。
• He had an inborn talent for languages.他有语言天分。