时差N小时 计划生育 蚜虫的风格

If you keep a garden and have never been bothered by aphids, you are lucky. But one day you may find your rose bushes or bean plants covered--almost overnight--with these green, greedy sap-suckers. What allows aphids--and thousands of other species--to appear so fast is a trick these insects have developed for circumventing¹ the old rule about the birds and the bees.

如果你有个花园，却从来没被蚜虫侵扰过，那你就很幸运了。但是你有可能发现园子里的玫瑰丛和豌豆叶上，几乎一夜之间爬满了绿幽幽，贪婪狂吃的蚜虫。是什么让这些蚜虫以及其它成千上万种虫子如此迅速地出现，这是虫子为规避鸟类和蜜蜂旧的食物链规则发展而来的诀窍。

During the summer months when aphid-food is plentiful², aphids reproduce through a process called "parthenogenesis," from the Latin words "virgin⁴ birth." What that means is that female aphids give birth to more female aphids without ever seeing a male. As soon as those daughters mature, they produce their own offspring, and so on.

在夏季的几个月期间，蚜虫的食物充足，它们会通过单性生殖方式繁殖后代，"parthenogenesis"这一词来源于拉丁语“virgin birth（圣灵感孕）”，意思就是雌性蚜虫不与雄性交配而生出许多雌性蚜虫。雌性蚜虫的女儿们一成熟，就立即繁衍自己的后代，如此以往。

Without the search for mates or the ensuing courtship rituals, parthenogenesis means big savings⁵ in time and energy: in just one season, a single aphid can give rise to billions of descendants.

单性生殖不需要蚜虫去寻找雄性配偶，更省略了随之而来的求爱仪式，因此十分节省时间和精力：在一个季节里，一只蚜虫会繁衍出十多亿后代。

But in the fall, fresh food gets harder to find and there'd no longer be any reason for producing so many offspring. So now a generation of aphids is born that includes males as well as females. And what happens next between the males and females is just what you might expect.

但是到了秋天新鲜食物很难找，这时就没必要去生产那么多子孙了。在新生一代蚜虫里既有雌性也有雄性。你可能会想到在雌雄性蚜虫之间接下来会发生什么。

Why aphids would turn from parthenogenesis to something as messy and inefficient⁶ as sex is another story, but in short, sexual reproduction is nature's way of shuffling⁷ the genes³ to create variety. Each of the offspring inherits a random⁸ mix of the parents' genes. And variety is what enables species to adapt and evolve as the environment changes.

为什么蚜虫会从单性生殖转为即紊乱又效率低下的有性生殖，这又是另一个故事了。简而言之，有性生殖是自然的基因重组方式，以创造多样的个体。每一个后代都遗传了父母随机组合的基因。多样性则是为了物种进化以适应环境的变化。

But when summer returns and the living is easy, the aphids give up on variety and reproduce once again in the fastest way they know how.

但是在下一个夏季，生存又变得容易起来，蚜虫就会放弃多样性，以它们掌握的最快的方式重新生殖。

1 circumventing   

v.设法克服或避免（某事物），回避( circumvent的现在分词 )；绕过，绕行，绕道旅行

参考例句：

• They found a way of circumventing the law. 他们找到了规避法律的途径。
• This viewpoint sees the Multinational Corporation as capable of circumventing or subverting national objectives and policies. 这种观点认为，跨国公司能够遏制和破坏国家的目标和政策。 来自辞典例句

2 plentiful   

adj.富裕的，丰富的

参考例句：

• Their family has a plentiful harvest this year.他们家今年又丰收了。
• Rainfall is plentiful in the area.这个地区雨量充足。

3 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

4 virgin   

n.处女，未婚女子；adj.未经使用的；未经开发的

参考例句：

• Have you ever been to a virgin forest?你去过原始森林吗？
• There are vast expanses of virgin land in the remote regions.在边远地区有大片大片未开垦的土地。

5 savings   

n.存款，储蓄

参考例句：

• I can't afford the vacation,for it would eat up my savings.我度不起假，那样会把我的积蓄用光的。
• By this time he had used up all his savings.到这时，他的存款已全部用完。

6 inefficient   

adj.效率低的，无效的

参考例句：

• The inefficient operation cost the firm a lot of money.低效率的运作使该公司损失了许多钱。
• Their communication systems are inefficient in the extreme.他们的通讯系统效率非常差。

7 shuffling   

adj. 慢慢移动的, 滑移的 动词shuffle的现在分词形式

参考例句：

• Don't go shuffling along as if you were dead. 别像个死人似地拖着脚走。 来自英汉文学 - 嘉莉妹妹
• Some one was shuffling by on the sidewalk. 外面的人行道上有人拖着脚走过。 来自英汉文学 - 嘉莉妹妹

8 random   

adj.随机的；任意的；n.偶然的(或随便的)行动

参考例句：

• The list is arranged in a random order.名单排列不分先后。
• On random inspection the meat was found to be bad.经抽查，发现肉变质了。