美国国家公共电台 NPR Scientists Get Down And Dirty With DNA To Track Wild Pigs

 

DAVID GREENE, HOST:

So biologists have invented a new way to track wild animals. They pick up on traces of their DNA¹. It's kind of like wildlife CSI. NPR's Rae Ellen Bichell tells us that this is helping² some states track down a destructive invader³.

RAE ELLEN BICHELL, BYLINE⁴: In the foothills of Colorado's Rocky Mountains, a gravel⁵ road leads to a 10-foot-tall metal fence. Type in a key code and one gate scrapes open. Behind that, another. The residents of this facility are wild pigs.

(SOUNDBITE OF PIG GRUNTING)

BICHELL: They're playing in the snow and asking for someone to scratch the bristles⁶ on their ridged backs. Biologist Morgan Wehtje studies these pigs, which were raised in captivity⁷ and now live at the National Wildlife Research Center in Fort Collins.

MORGAN WEHTJE: These are nice animals. They've been handled since they were piglets.

BICHELL: But make no mistake, these beasts can do real damage. The pig next to Wehtje weighs as much as an NFL tight end.

WEHTJE: Which is why if they were to run at you, they'd take you out.

BICHELL: Out in the wild, their less cuddly⁸ counterparts are an invasive species destroying the landscape in much of the U.S. They will eat anything from rows of corn to baby deer and goats. They've also been known to eat human corpses⁹ on occasion. In Texas, they're tearing up yards in the suburbs. In Louisiana, they damaged levees by digging for food.

WEHTJE: They just rototill the landscape and consume kind of everything in their path.

BICHELL: Though pigs arrived on this continent 500 years ago with early explorers, for some unknown reason, their populations have really exploded in the last 30 years or so. There are now at least 6 million pigs across the country. And they're hard to get rid of despite the money that state and federal legislators have funneled¹⁰ into controlling these animals. But wild pigs may have met their match - Kelly Williams. She's a genetics researcher with the National Center for Wildlife Research. And she and her colleagues have found the Achilles heel of hogs¹¹.

KELLY WILLIAMS: So pigs are attracted to intermittent¹², stagnant¹³, turbid¹⁴ water bodies.

BICHELL: Also known as mud and dirty water. When pigs drink, roll or wallow in it, they leave bits of themselves behind - drool, hair, skin cells, a wildlife crime scene of sorts. Williams figured out a way to pull the DNA from that evidence sometimes up to a month after a pig has visited a site. All she needs is a scoop¹⁵ of dirty water, like this one from Texas.

WILLIAMS: There's a lot of, like, junk floating around in there. Sometimes they look like chocolate milk, sometimes it looks like lemonade.

BICHELL: She spins down all the solids, isolates¹⁶ the DNA inside and compares it to pig DNA. At the end, she has an answer - yes, pigs were here or, no, they weren't and passes it along to people like Brian Archuleta. He's a wildlife biologist with the U.S. Department of Agriculture in New Mexico. And he has a goal for the New Year - pig annihilation.

BRIAN ARCHULETA: Total elimination¹⁷ by the last day of September of this year.

BICHELL: That is a big goal given the fact that he covers eastern New Mexico, thousands of square miles of desert, mountains and sand dunes¹⁸ right next to Texas, which is teeming¹⁹ with pigs.

ARCHULETA: Eastern side of New Mexico is a big place, lots of country. We are looking for a needle in a haystack.

BICHELL: Recently, he sent a few people to collect water and then shipped it to Kelly Williams. With her results, he was able to narrow the search down to about ten square miles. So Archuleta booked a helicopter, hired some sharpshooters and flew over the areas where pig DNA had been found. They shot eight hogs in one place, 13 in another. That, he says, is progress. Rae Ellen Bichell, NPR News.

1 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

2 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。

3 invader   

n.侵略者，侵犯者，入侵者

参考例句：

• They suffered a lot under the invader's heel.在侵略者的铁蹄下，他们受尽了奴役。
• A country must have the will to repel any invader.一个国家得有决心击退任何入侵者。

4 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

5 gravel   

n.砂跞；砂砾层；结石

参考例句：

• We bought six bags of gravel for the garden path.我们购买了六袋碎石用来铺花园的小路。
• More gravel is needed to fill the hollow in the drive.需要更多的砾石来填平车道上的坑洼。

6 bristles   

短而硬的毛发，刷子毛( bristle的名词复数 )

参考例句：

• the bristles on his chin 他下巴上的胡楂子
• This job bristles with difficulties. 这项工作困难重重。

7 captivity   

n.囚禁；被俘；束缚

参考例句：

• A zoo is a place where live animals are kept in captivity for the public to see.动物园是圈养动物以供公众观看的场所。
• He was held in captivity for three years.他被囚禁叁年。

8 cuddly   

adj.抱着很舒服的，可爱的

参考例句：

• The beautiful crib from Mom and Dad is so cuddly.爸爸妈妈送的漂亮婴儿床真舒服。
• You can't call a hedgehog cuddly.你不能说刺猬逗人喜爱。

9 corpses   

n.死尸，尸体( corpse的名词复数 )

参考例句：

• The living soldiers put corpses together and burned them. 活着的战士把尸体放在一起烧了。 来自《简明英汉词典》
• Overhead, grayish-white clouds covered the sky, piling up heavily like decaying corpses. 天上罩满了灰白的薄云，同腐烂的尸体似的沉沉的盖在那里。 来自汉英文学 - 中国现代小说

10 funneled   

漏斗状的

参考例句：

• The crowd funneled through the hall. 群众从走廊中鱼贯而过。
• The large crowd funneled out of the gates after the football match. 足球赛后大群人从各个门中涌出。

11 hogs   

n.（尤指喂肥供食用的）猪( hog的名词复数 )；（供食用的）阉公猪；彻底地做某事；自私的或贪婪的人

参考例句：

• 'sounds like -- like hogs grunting. “像——像是猪发出的声音。 来自英汉文学 - 汤姆历险
• I hate the way he hogs down his food. 我讨厌他那副狼吞虎咽的吃相。 来自辞典例句

12 intermittent   

adj.间歇的，断断续续的

参考例句：

• Did you hear the intermittent sound outside?你听见外面时断时续的声音了吗？
• In the daytime intermittent rains freshened all the earth.白天里，时断时续地下着雨，使整个大地都生气勃勃了。

13 stagnant   

adj.不流动的，停滞的，不景气的

参考例句：

• Due to low investment,industrial output has remained stagnant.由于投资少，工业生产一直停滞不前。
• Their national economy is stagnant.他们的国家经济停滞不前。

14 turbid   

adj.混浊的，泥水的，浓的

参考例句：

• He found himself content to watch idly the sluggish flow of the turbid stream.他心安理得地懒洋洋地望着混浊的河水缓缓流着。
• The lake's water is turbid.这个湖里的水混浊。

15 scoop   

n.铲子，舀取，独家新闻；v.汲取，舀取，抢先登出

参考例句：

• In the morning he must get his boy to scoop it out.早上一定得叫佣人把它剜出来。
• Uh,one scoop of coffee and one scoop of chocolate for me.我要一勺咖啡的和一勺巧克力的。

16 isolates   

v.使隔离( isolate的第三人称单数 )；将…剔出（以便看清和单独处理）；使（某物质、细胞等）分离；使离析

参考例句：

• The transformer isolates the transistors with regard to d-c bias voltage. 变压器可在两个晶体管之间隔离直流偏压。 来自辞典例句
• In regions with certain isolates of TRV, spraining is more prominent. 在具有TRV某些分离物的地区，坏死是比较显著的。 来自辞典例句

17 elimination   

n.排除，消除，消灭

参考例句：

• Their elimination from the competition was a great surprise.他们在比赛中遭到淘汰是个很大的意外。
• I was eliminated from the 400 metres in the semi-finals.我在400米半决赛中被淘汰。

18 dunes   

沙丘( dune的名词复数 )

参考例句：

• The boy galloped over the dunes barefoot. 那男孩光着脚在沙丘间飞跑。
• Dragging the fully laden boat across the sand dunes was no mean feat. 将满载货物的船拖过沙丘是一件了不起的事。

19 teeming   

adj.丰富的v.充满( teem的现在分词 )；到处都是；（指水、雨等）暴降；倾注

参考例句：

• The rain was teeming down. 大雨倾盆而下。
• the teeming streets of the city 熙熙攘攘的城市街道