原文朗读+词汇复习【自私的基因：The Selfish Gene 01B】

Blackheaded gulls nest in large colonies, the nests being only a few feet apart. When the chicks first hatch out they are small and defenceless and easy to swallow. It is quite common for a gull to wait until a neighbour's back is turned, perhaps while it is away fishing, and then pounce on one of the neighbour's chicks and swallow it whole. It thereby obtains a good nutritious meal, without having to go to the trouble of catching a fish, and without having to leave its own nest unprotected. More well known is the macabre cannibalism of female praying mantises. Mantises are large carnivorous insects. They normally eat smaller insects such as flies, but they will attack almost anything that moves. When they mate, the male cautiously creeps up on the female, mounts her, and copulates.If the female gets the chance, she will eat him, beginning by biting his head off, either as the male is approaching, or immediately after he mounts, or after they separate. It might seem most sensible for her to wait until copulation is over before she starts to eat him. But the loss of the head does not seem to throw the rest of the male's body off its sexual stride. In deed, since the insect head is the seat of some inhibitory nerve centres, it is possible that the female improves the male's sexual performance by eating his head. If so, this is an added benefit. The primary one is that she obtains a good meal.

The word ‘selfish' may seem an understatement for such extreme cases as cannibalism, although these fit well with our definition. Perhaps we can sympathize more directly with the reported cowardly behaviour of emperor penguins in the Antarctic. They have been seen standing on the brink of the water, hesitating before diving in, because of the danger of being eaten by seals. If only one of them would dive in, the rest would know whether there was a seal there or not. Naturally nobody wants to be the guinea pig, so they wait, and sometimes even try to push each other in.

Key Words & Phrases

1)blackheaded gulls n. 黑头鸥
2) colony n. (鸟、昆虫或动物的) 群体，集群，殖民地
3) hatch out 破壳而出，孵化出
e.g. When will the baby chickens hatch out? 小鸡什么时候孵出
4) swallow v. 吞下，咽下
5) pounce v. move down on as if in an attack 猛扑，突袭
e.g. …like a tiger pouncing on its prey... 像老虎猛扑向猎物一样
6) macabre adj. 可怕的，令人毛骨悚然的
7) cannibalism n. 同类相食，自相残杀
8) praying mantis n. 螳螂
9) carnivorous adj. 食肉的
10) cautiously adv. 小心翼翼; 小心地
11) creep v. 爬行，匍匐
12) copulate v. 交配
e.g. Whales take twenty-four hours to copulate. 鲸交配需要24小时。
13) mount v. climb 登上，骑上，攀升
14) stride n. 步伐，进展
15) inhibitory adj. 禁止的，抑制的
16) understatement n. 轻描淡写; 保守的陈述
e.g. To say I'm disappointed is an understatement. 说我失望那是说得太轻了。
17) sympathize with v. 同情，怜悯，理解
18) emperor penguins n. 帝企鹅
19) Antarctic n. 南极洲
20) guinea pig v. 试验品，实验对象；[动]豚鼠