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SCIENCE IN THE NEWS - Digest

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SCIENCE IN THE NEWS -March 5, 2002: Digest


VOICE ONE:

This is Sarah Long.

VOICE TWO:

And this is Bob Doughty1 with Science in the News, a VOA Special English program about recent developments
in science. Today, we tell about the first genetic2 copy of a cat. We tell about scientists who are playing love songs
for sharks. And we tell about the deaths of hundreds of millions of butterflies in Mexico.

((THEME))

VOICE ONE:

American scientists in the state of Texas have produced a genetic copy of a cat for the first time. This cloned
baby cat was born in December. Its birth marks the first successful cloning of an animal commonly kept as a pet.
During the past few years, other researchers have cloned sheep, mice, pigs, cows and goats.

The scientific journal Nature reported the cloning of the cat last month. The kitten is called “c-c”
for “copy
cat”
or “carbon copy.

C-c was created at the College of Veterinary Medicine of Texas A-and-M University.
This school for doctors who treat animals is in College Station, Texas. Mark Westhusin (west-TOO-shin) led the
team that created the kitten.

VOICE TWO:

Scientists usually clone animals by placing a cell from an adult animal into a special egg
cell whose genetic material has been removed. The genes3 in the adult cell direct the
development of the embryo4. The process means that the newly born creature will be an
exact genetic copy of the adult.

Doctor Westhusin and his team first tried to create a male kitten. They took cells from a

male cat’s mouth and joined them with the specially5 treated egg cells. This produced
more than eighty cloned embryos6. The researchers then placed the embryos in seven
female cats. One of these cats became pregnant. However, the pregnancy7 ended too soon.

Doctor Westhusin and the other researchers tried again. They took cells from the ovaries of a female cat named
Rainbow and joined them with the special egg cells. They placed five cloned embryos into a female cat called
Allie. Allie became pregnant. Sixty-six days later, the doctors assisted in the birth of a normal, healthy kitten.

VOICE ONE:

C-c is now more than two months old. She has
continued to develop normally. She has exactly the
same genes as Rainbow. But she does not look exactly
like her. The cats have different colored markings. This
is because their colors are decided8 partly by genes and
partly by molecular9 changes during development.

Doctor Westhusin’s team has been trying to develop
a cloned dog for several years. However, they say cloning a dog is much more
difficult. They say scientists know more about cats because they have worked much more with cat eggs and

embryos. Cats produce eggs when they mate. Dogs, however, do not produce eggs at any special time.

Doctor Westhusin says research on cloning cats and dogs has provided important information about their


Rainbow
Allie

reproduction. He says this information could help develop new methods of preventing the birth of unwanted
animals. He also says cloning could be used to produce identical animals in research to find cures for diseases in
humans. Researchers also say information from cloning could help save large endangered cats, like the African
wild cat.

VOICE TWO:

A company called Genetic Savings10 and Clone of College Station, Texas, supported the research. The company
wants to offer cloning to owners of cats and dogs in the future. The company believes some people may want to
clone their pets when the animals die.

However, many groups that are concerned with the treatment of animals oppose cloning cats and dogs. They say
it serves no useful social purpose. And they say it would add to the problem of too many pets in the United
States. Each year, American animal shelters destroy millions of unwanted dogs and cats.Some people also fear
that the cloning of a cat means another step toward cloning humans. Some scientists already say they are working
toward that goal.

((MUSIC BRIDGE))

VOICE ONE:

Scientists at the National Sealife Center in Birmingham, England have a problem with their sharks. They want
the five male and five female sharks to mate. Yet none of the creatures has shown any interest in the opposite sex.
The center has had success in getting other sea creatures to reproduce. Some of those creatures live in the same
area with the sharks.


The British scientists seem willing to try almost anything to get the sharks to mate.
Recently, they started to play love songs near a large container of water where the
sharks live. The scientists hoped that the music would get the creatures ready for
mating.

VOICE TWO:

The scientists decided to play music after they heard about a study done by the Rowland Institute for Science in
Cambridge, Massachusetts. In the American study, scientists tested different sounds on koi carp fish. These
scientists found that the fish react to sounds in a way similar to humans. They showed that the koi are affected11 by
and can identify different kinds of music.

Sharks have excellent hearing. But it is limited to low -pitched sounds. The scientists in Birmingham started

playing music for the sharks just a few days before February fourteenth. That was Saint Valentine’s Day, the
yearly celebration for lovers. They played a number of popular love songs, including some by American singer
Barry White.

((MUSIC INSERT: "YOU ’RE THE FIRST, THE LAST, MY EVERYTHING")
)
VOICE ONE:
Scientists played the music in the room where the sharks live. The scientists say they


may consider an idea to play the music underwater.
The researchers say they are not sure how long it would be before the music has an


effect. How will the scientists know if their experiment is successful? They say that,
before mating, the male shark will chase the female and attempt to bite her on the back.
((MUSIC BRIDGE)
)
VOICE TWO:
Scientists say the loss of hundreds of millions of monarch12 butterflies in central Mexico is not expected to threaten


the species. The butterflies froze to death in January after a severe winter storm. Most of the butterflies in the

 


Rosario and Sierra Chincua colonies were killed in the storm. The colonies are in the mountains in the state of
Michoacan, west of Mexico City.


Researchers say the butterflies froze to death after heavy rain fell in the area, followed
by freezing temperatures. Scientists say the temperatures following the storm were
the lowest recorded in the area in the past twenty-five years.

VOICE ONE:

During the year, monarch butterflies fly long distances, or migrate. They are one of
the few kinds of insects that migrate. This has made the monarch popular among nature lovers.

The monarchs13 spend the winter in Mexico. Each spring, the butterflies fly north after they mate. The females stop
to lay their eggs in the southern United States. The adults die soon after. The monarchs that develop from those
eggs continue the flight. They return to the same areas in North America where their parents lived. By summer,
the butterflies can reach as far north as Canada.

During the autumn, the monarchs return to the same forests in the mountains of Mexico. They like the oyamel
tree the best. These tall trees are sometimes completely covered with butterflies.

VOICE TWO:

Some scientists have suggested that the loss of forests in the mountains of Mexico led to the die -off of monarchs.
They say the remaining forests may no longer provide enough protection to keep the butterflies warm and dry.
Every winter, millions of monarchs die in the high mountain forests.

However, scientists note that the species is not in danger of disappearing. That is because there are other, smaller
populations of monarchs in the United States that did not migrate to Mexico. Scientists say they will know after
more study if the monarch populations in Mexico will be able to recover from the die-off.

((THEME))

VOICE ONE:

This SCIENCE IN THE NEWS program was written by Jerilyn Watson, George Grow and Cynthia Kirk. It was
produced by Cynthia Kirk. This is Sarah Long.

VOICE TWO:

And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice
of America.


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点击收听单词发音收听单词发音  

1 doughty Jk5zg     
adj.勇猛的,坚强的
参考例句:
  • Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质:脾气倔强,性格刚强。
  • The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。
2 genetic PgIxp     
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。
3 genes 01914f8eac35d7e14afa065217edd8c0     
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 embryo upAxt     
n.胚胎,萌芽的事物
参考例句:
  • They are engaging in an embryo research.他们正在进行一项胚胎研究。
  • The project was barely in embryo.该计划只是个雏形。
5 specially Hviwq     
adv.特定地;特殊地;明确地
参考例句:
  • They are specially packaged so that they stack easily.它们经过特别包装以便于堆放。
  • The machine was designed specially for demolishing old buildings.这种机器是专为拆毁旧楼房而设计的。
6 embryos 0e62a67414ef42288b74539e591aa30a     
n.晶胚;胚,胚胎( embryo的名词复数 )
参考例句:
  • Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段,而且其行为象胚。 来自辞典例句
  • Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句
7 pregnancy lPwxP     
n.怀孕,怀孕期
参考例句:
  • Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
  • Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。
8 decided lvqzZd     
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。
9 molecular mE9xh     
adj.分子的;克分子的
参考例句:
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
10 savings ZjbzGu     
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。
11 affected TzUzg0     
adj.不自然的,假装的
参考例句:
  • She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
  • His manners are affected.他的态度不自然。
12 monarch l6lzj     
n.帝王,君主,最高统治者
参考例句:
  • The monarch's role is purely ceremonial.君主纯粹是个礼仪职位。
  • I think myself happier now than the greatest monarch upon earth.我觉得这个时候比世界上什么帝王都快乐。
13 monarchs aa0c84cc147684fb2cc83dc453b67686     
君主,帝王( monarch的名词复数 )
参考例句:
  • Monarchs ruled England for centuries. 世袭君主统治英格兰有许多世纪。
  • Serving six monarchs of his native Great Britain, he has served all men's freedom and dignity. 他在大不列颠本国为六位君王服务,也为全人类的自由和尊严服务。 来自演讲部分

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