沙漠生存，巧度“魚”生

王玲秀

人們普遍認為沙漠是所有生命的禁區(qū)，然而，研究人員發(fā)現(xiàn)，在干燥的沙漠地帶，竟然還生存著魚類……

1?How?life?manages?to?continue?in?unpredictable?and?extreme?environments?is?a?major?question?in?evolution.?For?aquatic?（水生的）?animals，?extreme?environments?include?those?with?little?water，?such?as?the?deserts?of?Central?Australia.

2?Researchers?believe?that?the?ability?to?adapt?the?environment?can?ensure?the?populations?of?desert?fish?survive?in?difficult?conditions.?They?focused?on?populations?of?Desert?Rainbowfish?collected?from?across?the?Australian?desert?and?found?that?populations?from?drier?regions?of?the?desert?are?more?isolated?（隔絕的）?and?smaller，?but?also?show?stronger?capacity?to?adapt?to?tough?and?dry?environments.?This?turns?on?its?head?traditional?thinking?that?small?populations?are?evolutionary?dead?ends.?Life?finds?a?way，?even?in?the?most?extreme?and?unpredictable?environments?on?the?Earth.

3?Genetic?diversity?helps?populations?evolve?in?response?to?environmental?changes，?so?maintaining?a?large?gene?pool?is?very?important，?but?understanding?how?small?populations?of?desert?fish?survive，?especially?when?located?in?isolated?pockets?of?water，?has?remained?a?mystery.

4?Generally?speaking，?a?small?gene?pool?can?lead?to?inbreeding?and?poor?health，?which?is?sometimes?seen?in?endangered?species.?However，?researchers?have?found?that?desert?fish?in?Australia?can?hold?on?to?life?through?adapting?to?tough?environments，?breeding?and?spreading?during?rare?flooding?events.

5?The?genes?adapted?to?the?drought?can?spread?when?the?fish?migrate?along?temporary?streams?and?floodwaters.?These?fish?and?their?adapted?genetic?makeup?are?then?ready?for?the?next?drought.?The?most?attractive?difference?is?in?a?gene?coding?for?the?proteins?that?are?used?in?fish?for?taste?and?smell.?They?can?be?used?to?find?out?water?flow?and?control?light?sensitivity?for?vision.?The?different?protein?in?fish?from?the?western?parts?of?drought?areas?may?improve?their?environmental?sensors.

6?Genes?adapted?to?drought?may?allow?species?to?keep?existing?as?dry?regions?expand?and?have?more?extreme?environmental?changes?under?future?climate?change.?The?results?of?the?recent?study?suggest?that?adaptations?of?genetic?diversity?can?take?place?even?in?small?populations，?as?long?as?natural?connectivity?during?floods?takes?place.?The?findings?that?small?populations?can?evolve?in?extreme?environments?have?some?influence?on

studies?of?adaptation?to?climate?change?and?conservation?science.

Detail? 1.?What?is?the?common?belief?about?small?populations？

A.?They?often?exist?in?the?deserted?areas.

B.?They?are?small?in?size?and?various?in?shape.

C.?They?don？蒺t?adjust?to?the?environment?easily.

D.?They?are?able?to?survive?the?extreme?conditions.

Detail ? 2.?What?plays?a?key?role?in?making?a?species?survive？

A.?A?large?gene?pool.

B.?The?number?of?its?population.

C.?The?environment?where?it?lives.

D.?Abundant?water?resources.

Detail 3.?What?effect?does?the?recent?study?have？

A.?It?can?contribute?to?protecting?rare?species.

B.?It?can?develop?a?kind?of?protein?for?gene?codes.

C.?It?helps?research?the?adaptation?to?climate?change.

D.?It?may?provide?evidence?for?genetic?diversity?study.

Inference 4.?Where?is?the?text?probably?from？

A.?A?medical?paper. B.?A?survival?guide.

C.?A?biology?textbook.? D.?A?science?magazine.

Ⅰ.?Difficult?sentence?in?the?text

However，?researchers?have?found?that?desert?fish?in?Australia?can?hold?on?to?life?through?adapting?to?tough?environments，?breeding?and?spreading?during?rare?flooding?events.?然而，研究人員發(fā)現(xiàn)，澳大利亞的沙漠魚可以通過適應(yīng)惡劣環(huán)境來維持生命，在罕見的洪水暴發(fā)期繁殖和擴散。

【點石成金】本句中，that引導(dǎo)賓語從句;through?adapting?to?tough?environments為

介詞短語作狀語;breeding?and?spreading?during?rare?flooding?events為非謂語動詞作結(jié)果狀語。

Ⅱ.?Textcentered?chunks

adapt?to?適應(yīng)

turn?sth?on?its?head?使人完全改變思路;使人從反面思考

in?response?to?對……做出反應(yīng)

generally?speaking?一般說來

lead?to?導(dǎo)致

as?long?as?只要

take?place?發(fā)生

have?some?influence?on?對……有一些影響