【英语时差8,16】克隆恐龙

搜索关注在线英语听力室公众号：tingroom，领取免费英语资料大礼包。

Don and Yael give a movie review of sorts on this Moment of Science D: Welcome to another episode of A Moment of Science at the Movies. Y: Today we're reviewing Steven Spielberg's 1993 blockbuster Jurassic Park. D: As I'm sure you recall, Jurassic Park is about a scientist who clones dinosaurs² from DNA³ preserved in amber⁴. Y: Although I found the film entertaining and the special effects spectacular, I was disappointed by the scientific inaccuracies. Cloning dinosaurs might be an intriguing⁵ idea, but scientifically speaking it's not possible. D: Wait a sec. We can clone sheep and other animals, right? So why not dinosaurs? Y: Let me rephrase. Cloning a dinosaur¹ is theoretically possible. But it's not like cloning a sheep. D: Why not? Y: It has to do with how cloning works. In nuclear transfer cloning, a nucleus⁶ from the animal to be cloned is inserted into an egg with its nucleus removed. The nucleus contains most of the genetic⁷ material of eggs and other cells. If things go well, the egg with its new nucleus forms an embryo⁸ that starts to divide and mature. After a few days it's transferred to a surrogate mother. D: OK, so why not do that with dinosaurs or other extinct animals like wooly⁹ mammoths? Y: The problem is that we don't have well preserved DNA from dinosaurs and wooly mammoths. Millenia of freezing and thawing¹⁰ and other processes break up most of the DNA. And even if we did find useable dinosaur DNA, finding a surrogate mother similar in size and biology to a dinosaur would be difficult, to say the least. Crocodile or ostrich¹¹ eggs might be as close as we could come. D: So what you're saying is there's no way to resurrect dinosaurs. Y: Well, there is one place where it's possible. D: Where? Y: Hollywood.

 

分享到：