英语听力文摘 English Digest 585、不同年龄的蜜蜂有不同的分工！

 　　Bees Have Different Jobs According To Their Age

 

　　Bees take on different jobs in a bee hive according to their age. Many become food scouts¹ when older, but not all scouts are the same. Some search for new flowers, while others fly to and from established nectar sources.

 

　　A team of scientists wondering if some bees might be natural risk takers decided² to put that question to the test. They placed a hive in an enclosure³ with a feeder of sugar water and marked each bee that visited the feeder.

 

　　A few days later, they added second feeder and marked the bees that found that one. Challenging the bees again, they moved the second feeder to a new location and marked the bees that discovered that location too.

 

　　Bees that found new feeders both times were called scouts, while bees that only gathered nectar at the old feeder were called non scouts. Nest scouts, who search for new hive locations, were three times more likely to be nectar scouts when older.

 

　　To determine if there are differences between scouts and non scouts, researchers examined their brains to see which genes⁴ were active. What they found was surprising. There were large differences in over one thousand genes. Some of those genes are very similar to ones associated with human novelty⁵ seeking behavior.

 

　　Scientists examined genes controlling dopamine signaling, which reinforces pleasure in humans. In bees it works just the opposite; high dopamine reinforces aversion. Bees with genes that made more dopamine receptors were non scouts, while those with low receptors tended to be scouts.

 

 

 

　　不同年龄的蜜蜂有不同的分工

 

　　不同年龄的蜜蜂在蜂群中有不同的分工。许多蜜蜂在年老时会充当“食物侦察兵”。但不是所有的“侦察兵”均如此。一些会去寻找新的花朵，其他的则往返于筑好的蜜源和蜂巢之间。

 

　　一组科学家想知道一些蜜蜂是否天生就担当承担风险的角色，于是决定通过实验来找出答案。他们把蜂巢移到一个栅栏中，栅栏边放置装满糖水的喂食器，然后把每个去过喂食器的蜜蜂都做上标记。

 

　　几天过后，科学家们又安置了第二个喂食器，并标记出拜访过的蜜蜂。为了给蜜蜂增加点难度，他们把第二个喂食器移动到一个新的位置，然后标记上发现新位置的蜜蜂。

 

　　两次都能找到喂食器的叫做寻蜜蜂，而只在原先喂食器取蜜的蜜蜂称之为保育蜂。寻找新蜂巢的筑巢蜂在年老时有三倍的可能性会成为寻蜜蜂。

 

　　为了确定寻蜜蜂和保育蜂之间是否存在不同，研究人员通过观察它们的大脑来找出活跃的基因。他们的发现令人出乎意料。蜜蜂的上千种基因各不相同。有些基因与人类寻找新奇事物行为相关的基因十分相似。

 

　　科学家检查了控制多巴胺信号的基因，这种基因会增强人类的愉悦感。但是在蜜蜂中该基因的作用却恰恰相反；多巴胺含量高会增加蜜蜂的嫌恶感。携带这种能够产生较多多巴胺感受器基因的蜜蜂叫做保育蜂，而那些产生较少感受器的蜜蜂就成为了寻蜜蜂。

1 scouts   

侦察员[机，舰]( scout的名词复数 )； 童子军； 搜索； 童子军成员

参考例句：

• to join the Scouts 参加童子军
• The scouts paired off and began to patrol the area. 巡逻人员两个一组，然后开始巡逻这个地区。

2 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

3 enclosure   

n.围绕，圈地，围场，围墙，附件，封入物

参考例句：

• We were led to a fenced enclosure.我们被带到一处用篱笆围住的场地。
• I received your enclosure with gratitude.附件收到，十分感谢。

4 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

5 novelty   

n.新奇事物，新奇（感），新颖廉价的物品

参考例句：

• My mother bought a novelty pen for me.我妈给我买了一支新颖的笔。
• At first I enjoyed all the parties,but the novelty soon wore off.起初我喜欢参加一切聚会，但这种新奇感很快就消失了。