外刊 莱弗赵亮.doc

赵亮考研外刊文章 请关注@莱弗赵亮 @赵亮考研 【】Animal?behaviour:?A?stilted?story? 　　IF?THERE?were?a?Royal?Society?for?the?Prevention?of?Cruelty?to?Ants,?Matthias?Wittlinger?of?the?University?of?Ulm,?in?Germany,?would?probably?be?top?of?its?hate?list.?The?reason?is?that?Dr?Wittlinger?and?his?colleagues?have,?as?they?report?in?this?week’s?Science,?been?chopping?the?feet?off?ants.?And?not?only?that.?They?have?been?making?other?ants?walk?around?on?stilts. 　　Saharan?desert?ants?of?the?genus?Cataglyphis?have?to?travel?long?distances?to?discover?food?in?their?impoverished,?sandy?environment.?How?they?find?their?way?home?once?they?have?done?so?is?a?mystery.?Ants?in?more?temperate?climates?often?lay?down?chemical?trails,?but?Cataglyphis,?apparently,?does?not.?Like?honeybees?and?ancient?mariners,?they?can?navigate?by?the?sun,?so?they?know?the?general?direction?in?which?to?travel.?But,?also?like?ancient?mariners?(who?knew?their?latitude,?but?not?their?longitude),?such?solar?reckoning?cannot?tell?them?when?to?stop. 　　Dr?Wittlinger,?therefore,?decided?to?investigate?a?century-old?hypothesis?that?desert?ants?have?internal?pedometers—in?other?words,?they?count?their?steps?out,?and?they?count?them?back.?When?one?total?matches?the?other,?they?are?home.?To?test?this?idea?he?trained?his?ants?to?walk?from?their?nests?to?a?feeding?station?through?a?ten-metre-long?channel.?When?they?had?picked?up?the?food,?he?caught?them?and?made?them?return?through?a?different?channel,?which?also?led?to?the?nest.?When?they?made?this?return?journey,?they?began?their?characteristic?nest-searching?behaviour,?quartering?the?ground?in?detail?looking?for?the?entrance,?after?travelling?about?ten?metres. 　　Once?the?ants?had?mastered?this?trick,?the?experiment?proper?began.?Some?ants,?when?they?arrived?at?the?feeding?station,?had?the?ends?of?their?legs?amputated,?to?shorten?their?stride?length.?Others?were?fitted?with?stilts?in?the?form?of?pig-bristles?glued?to?their?feet.?Both?lots?were?then?returned?to?the?feeding?station,?to