VOA慢速英语2014 蚂蚁是如何生存和选择蚁后

 

AS IT IS 2014-06-26 How Ants Survive and Choose Their Leader 蚂蚁是如何生存和选择蚁后

Scientists have always been interested in the high level of organization in ant societies.  American researchers have watched ants build life-saving rafts to keep afloat during floods.  They also have documented how ant colonies choose their next queen – the female whose job is to produce eggs.                                                   

New technology is helping¹ to improve researchers’ understanding of the insects.  But there is still a lot to be learned.

Fire ants living in Brazilian forests are perfectly³ at home in an environment where flooding is common.  To save themselves, the insects connect their legs together and create floating rafts.  Some ant rafts can be up to 20 centimeters wide.

David Hu is a mechanical engineer with the Georgia Institute of Technology, also known as Georgia Tech.  He says ants know how to join together tightly.

“If you have 100 ants, which means 600 legs, 99 percent of those legs will be connected to a neighbor.  So they’re very, very good at maintaining this network.”

David Hu and other Georgia Tech researchers wanted to study ants and the secret of their engineering.  They froze ant rafts and then look at them with the help of computed⁴ technology, or CT, images.            

The pictures showed that larger ants serve in central positions to which smaller ants hold.  The larger ants form pockets of air that keep the insects afloat.                                       

Scientists say small robots or materials that can change shape could be programmed in a similar way, working towards a shared goal.

Researchers at North Carolina State University are also studying ants.  They examined how Indian jumping ants choose the leader of the colony when they lose their top female or queen.

Researcher Clint Penick says all the worker ants in the colony are females.  His team found that the work ants start a series of competitions or battles.  The team found that some workers became physically⁵ larger and that led to the release of chemicals in the insects.

“Within a matter of days, we see changes in dopamine in the brain that we think are linked to the reproduction that starts in these workers.”

Soon, the winning ant starts developing ovaries, the organs required to produce eggs, while its brain decreases in size.  The winning ant also begins standing² taller and generally lives three times as long as the other ants.                          

Scientists say this behavior and the release of neural⁶ hormones⁷ are the result of genetic⁸ orders.  Scientists say the new findings may help researchers better understand the link between hormones and genes⁹ in human beings.          

1 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

2 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

3 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

4 computed   

adj.[医]计算的，使用计算机的v.计算，估算( compute的过去式和过去分词 )

参考例句：

• He computed that the project would take seven years to complete. 他估计这项计划要花七年才能完成。 来自《简明英汉词典》
• Resolving kernels and standard errors can also be computed for each block. 还可以计算每个块体的分辨核和标准误差。 来自辞典例句

5 physically   

adj.物质上，体格上，身体上，按自然规律

参考例句：

• He was out of sorts physically,as well as disordered mentally.他浑身不舒服，心绪也很乱。
• Every time I think about it I feel physically sick.一想起那件事我就感到极恶心。

6 neural   

adj.神经的，神经系统的

参考例句：

• The neural network can preferably solve the non- linear problem.利用神经网络建模可以较好地解决非线性问题。
• The information transmission in neural system depends on neurotransmitters.信息传递的神经途径有赖于神经递质。

7 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

8 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

9 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