ancient virus雅思閱讀真題機(jī)經(jīng)

Ancient viruses恐龍時(shí)期的病毒

一項(xiàng)研究結(jié)果顯示，遠(yuǎn)在恐龍時(shí)代出現(xiàn)的一些病毒仍然在活躍于當(dāng)代人類的遺傳基因里。

至今為止，科學(xué)界對(duì)基因組的了解仍然處于初級(jí)狀態(tài)，科學(xué)家們希望這項(xiàng)研究能夠提供有關(guān)人類基因淵源的線索。

With only a small part of our genetic material fully understood,scientists have been trying to unravel where most of our DNA came from and what it does.Now researchers from Oxford,New York and Belgium have investigated the genes of 38 mammals–including humans,mice,elephants and dolphins,and they've found that most of them share traces of the same ancient viruses.The work has established that at least one virus infected our common ancestors as long as one hundred million years ago.

The scientists found that these micro-organisms have adapted to stay within their host cell where they have thrived.So within the double helix of our DNA lies not only a legacy of past infections but also a miniature eco-system in which the viruses live on and evolve.

The researchers hope that further work will identify what role these genetic parasites might play.There's no evidence that they cause harm,indeed one ancient virus is known to help in the growth of the placenta.According to the senior author of the study,Dr Robert Belshaw of Oxford University,understanding these survivors from the distant past may provide clues to the early detection of cancers or infections.

Quiz聽力測(cè)試

How many mammals did the researchers study in their investigation?

38 species,including humans,mice,elephants and dolphins.

How long ago do the scientists think at least one of the viruses infected our ancestors?

100 million years ago.

Which two words are used in the report to mean a virus?

A parasite and a micro-organism.

Are these ancient viruses harmful to people today?

No.There's no evidence of them being harmful to people.

Glossary詞匯表

to unravel解開

genes基因

traces微量的

to establish確認(rèn)

micro-organism微生物

to thrive繁榮興旺

legacy遺留下來的資產(chǎn)

parasites寄生蟲

placenta胎盤

to provide clues提供線索

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