科学家旨在在生物灭绝之前冻结其DNA

Scientists Aim to Freeze DNA¹ Before Creatures Die Off 科学家旨在在生物灭绝之前冻结其DNA

Earth is in the middle of its sixth mass extinction². The last such event took place 66 million years ago, when an asteroid³ – a huge space rock –- hit our planet. The asteroid strike killed off dinosaurs⁴ and almost everything else.

Now, scientists are in a race against time to classify -– organize into groups -– the estimated 11 million species alive today. Yet only about two million species are known to science. Researchers are worried many will disappear before they even have a name.

The United States Botanic Garden has launched a field project with a really big goal. Vicki Funk, a botanist⁵ with the Smithsonian Institution, explains.

"We are trying to get about half of the diversity of plant life on Earth at the genus level in two years."

The effort is part of what Smithsonian officials are calling the Global Genome Initiative. Its goal is to classify 50 percent of all plant species. Vicki Funk admits it seems like a huge project, but says the Botanic Garden is a great place to start.

"Because if you look around you, you see all kinds of plants from all over the world growing right next to one another. So instead of going to Madagascar to get a plant and Hawaii to get a plant, you can get them in rooms that are adjacent to one another."

Many of the species are already growing in botanic gardens – places known for their collections of rare or endangered plants. The aim is to set up a program to classify plants at 36 partner organizations in 17 countries.

One recent day in Washington, Vicki Funk performed a test-run on a long-stemmed pink flower called Sabatia. She took pictures of the plant. She then put one piece into silica gel, and dropped another piece into liquid nitrogen, where it is frozen. Next, she removed the flower and pressed it in a plant book for a museum collection.

"The plants are placed between these corrugates⁶ (corrugated cardboard) that have holes in them and when we get the press back we put it into a dryer⁷ that blows hot air through it and overnight it will turn it into a beautiful specimen⁸. Usually it saves the color. It looks very nice."

All the plants are numbered and linked in a computer database with the frozen pieces. These specimens⁹ are sent to the Smithsonian Institute's Genomics Laboratory for studies of their genetic¹⁰ material. Jonathan Coddington directs the Genome Initiative at the Smithsonian’s Museum of Natural History. He says the project is on target to gather samples from all 10,000 plant and animal families, and half the genera in those families, within five years.

"Just into our biorepository in the pipeline¹¹ I have over 2,000 families and close to 12,000 genera."

Jonathan Coddington says that biorepository is the largest such facility in the world. It collects, classifies and stores samples.

"What we want to do is organize it and get a lot of information evenly spaced out across all of life from bacteria to humans."

College student Kristen Van Neste is helping¹² with the project. 

"What we are doing is important because it is not just for our use, its for future use."

Scientists will use the information to identify species, solve environmental problems, study climate change and look for new cures for diseases.

Words in This Story

classify– v.  to organize or arrange (people or things) into groups based on ways that they are alike

species – n. a group of animals or plants that are similar

adjacent – adj. close or near

specimen – n. something collected (such as an animal or plant) collected as an example of a particular kind of thing

biorepository - n. a place that collects, catalogs and stores samples of materials

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 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。

3 asteroid   

n.小行星；海盘车(动物)

参考例句：

• Astronomers have yet to witness an asteroid impact with another planet.天文学家还没有目击过小行星撞击其它行星。
• It's very unlikely that an asteroid will crash into Earth but the danger exists.小行星撞地球的可能性很小，但这样的危险还是存在的。

4 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

5 botanist   

n.植物学家

参考例句：

• The botanist introduced a new species of plant to the region.那位植物学家向该地区引入了一种新植物。
• I had never talked with a botanist before,and I found him fascinating.我从没有接触过植物学那一类的学者，我觉得他说话极有吸引力。

6 corrugates   

v.（使某物）起皱褶，起皱纹，起波纹( corrugate的第三人称单数 )

参考例句：

• The wind corrugates the surface of the sea. 风吹海面起微波。 来自《现代英汉综合大词典》

7 dryer   

n.干衣机，干燥剂

参考例句：

• He bought a dryer yesterday.他昨天买了一台干燥机。
• There is a washer and a dryer in the basement.地下室里有洗衣机和烘干机。

8 specimen   

n.样本，标本

参考例句：

• You'll need tweezers to hold up the specimen.你要用镊子来夹这标本。
• This specimen is richly variegated in colour.这件标本上有很多颜色。

9 specimens   

n.样品( specimen的名词复数 )；范例；（化验的）抽样；某种类型的人

参考例句：

• Astronauts have brought back specimens of rock from the moon. 宇航员从月球带回了岩石标本。
• The traveler brought back some specimens of the rocks from the mountains. 那位旅行者从山上带回了一些岩石标本。 来自《简明英汉词典》

10 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。

11 pipeline   

n.管道，管线

参考例句：

• The pipeline supplies Jordan with 15 per cent of its crude oil.该管道供给约旦15%的原油。
• A single pipeline serves all the houses with water.一条单管路给所有的房子供水。

12 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。