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Unit2
THE RETURN OF THE DINOSAURS?
恐龙的回归？
The possibility of cloning fierce and
extinct wild animals has always excited film
makers.
克隆凶猛和灭绝的野生动物的可能性一直使
电影制片商感到兴奋。
And they are not
the only ones!
然而他们并不是唯一对此感到兴奋的人。
The popularity of films such as
Jurassic Park, in which a scientist clones several
kinds of extinct
dinosaurs, proves how
the idea struck a mixture of fear and excitement
into people's hearts.
在《侏罗纪
公园》这部影片中，
有一位科学家克隆了好几种不同的绝种恐龙。类似这样的电
影很受欢迎，证明了这一想法使人们感到既兴奋又恐惧。
But in fact we are a long way from
being able to clone extinct animals.
但事实上，想要克隆绝种动物，我们还要很长的路程要走。
Scientists are still experimenting with
cloning mammals.
科学家们现在还在进行克隆哺乳动物实验，
This is because the cloning of mammals
is still a new science and its story only began
seriously in
the 1950s as this list
shows:
这是因为克隆哺乳动物仍然还是一门新的科学，
它是从
20
世纪
50
< br>年代才开始进行认真研究
的，如下表所示：
1950s cloning of frogs
1996 first clone of a mammal: Dolly the
sheep
20
世纪
50
年代：克隆青蛙
1966
年：首次克隆哺乳动物
(
多莉
)
1970s research using the embryos of
mice
2000 cow gave
birth to a bison
20
< br>世纪
70
年代：用老鼠胚胎进行研究
2000
年：母牛生野牛
1979 work on embryos of sheep and mice
2001 China's first cloned
twin calves
1979
年：对羊和老鼠的胚胎进行研究
2001
年：中国首次克隆出双胞胎小牛
1981 first experimental clones of mice
2002 first cloned cats
1981
年：首次对老鼠进行实验性的克隆
2002
年：首次克隆猫
1983 first experimental clones of cows
2005 first cloned dog
1983
年：首次对母牛进行实验性
的克隆
2001
年：首次克隆狗
……
From time to
time
people suggest that extinct
animals like dinosaurs, can possibly be brought
back to life through
cloning.
不时地会有人提议，克隆技术将有可能使
地球上已经消失的动物（如恐龙）复活。
Unfortunately, with what we know now,
this is either impossible or unsuitable. There are
many
reasons.
不幸的是，据我们现在所知这是
不可能的，也是不合适的。其原因有很多：
◎
The initial
requirement is that you need perfect DNA (which
gives information for how cells
are to
grow).
首先要求你有完好的
DNA
，以提供有关细胞将如何生长的信息。
◎
All efforts of
cloning an animal will be in vain if there is not
enough diversity in the group to
overcome illnesses.
如果某个动物群体没有足够的多样性以战胜疾病，那么克隆这种动物的
所有努力都将是无用的。
Diversity in a group means having
animals with their genes arranged in different
ways.
群体的多样性是指这群动物的基因要以不同的方式排列。
The
advantage
is
that
if
there
is
a
new
illness
some
of
these
animals
may
die,
but
others
will
survive and pass on the
ability to resist that disease to the next
generation.