the.lost.world-第1部分

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To　Carolyn　Conger

〃What　really　interests　me　is　whether　God　had　any　choice　in　the　creation　of　the　world。〃

ALBERT　EINSTEIN


〃Deep　in　the　chaotic　regime；　slight　changes　in　structure　almost　always　cause　vast　changes　in　behavior。　plex　controllable　behavior　seems　precluded。〃

STUART　KAUFFMAN


〃Sequelae　are　inherently　unpredictable。〃
IAN　MALCOLM

Introduction：

〃Extinction　at　the　K…T　Boundary〃

The　late　twentieth　century　has　witnessed　a　remarkable　growth　in　scientific　interest　in　the　subject　of　extinction。
　　　　It　is　hardly　a　new　subject　…　Baron　Georges　Cuvier　had　first　demonstrated　that　species　became　extinct　back　in　1786；　not　long　after　the　American　Revolution。　Thus　the　fact　of　extinction　had　been　accepted　by　scientists　for　nearly　three…quarters　of　a　century　before　Darwin　put　forth　his　theory　of　evolution。　And　after　Darwin；　the　many　controversies　that　swirled　around　his　theory　did　not　often　concern　issues　of　extinction。
　　　　On　the　contrary；　extinction　was　generally　considered　as　unremarkable　as　a　car　running　out　of　gas。　Extinction　was　simply　proof　of　failure　to　adapt。　How　species　adapted　was　intensely　studied　and　fiercely　debated。　But　the　fact　that　some　species　failed　was　hardly　given　a　second　thought。　What　was　there　to　say　about　it？　However；　beginning　in　the　1970s；　two　developments　began　to　focus　attention　on　extinction　in　a　new　way。
　　　　The　first　was　the　recognition　that　human　beings　were　now　very　numerous；　and　were　altering　the　planet　at　a　very　rapid　rate…eliminating　traditional　habitats；　clearing　the　rain　forest；　polluting　air　and　water；　perhaps　even　changing　global　climate。　In　the　process；　many　animal　species　were　being　extinct。　Some　scientists　cried　out　in　alarm；　others　were　quietly　uneasy。　How　fragile　was　the　earth's　ecosystem？　Was　the　human　species　engaged　in　behavior　that　would　eventually　lead　to　its　own
extinction？
　　　　No　one　was　sure。　Since　nobody　had　ever　bothered　to　study　extinction　in　an　organized　way；　there　was　little　information　about　rates　of　extinction　in　other　geological　eras。　So　scientists　began　to　look　closely　at　extinction　in　the　past；　hoping　to　answer　anxieties　about　the　present。
　　　　The　second　development　concerned　new　knowledge　about　the　death　of　the　dinosaurs。　It　had　long　been　known　that　all　dinosaur　species　had　bee　extinct　in　a　relatively　short　time　at　the　end　of　the　Cretaceous　era；　approximately　sixty…five　million　years　ago。　Exactly　how　quickly　those　extinctions　occurred　was　a　subject　of　long…standing　debate：　some　paleontologists　believed　they　had　been　catastrophically　swift；　others　felt　the　dinosaurs　had　died　out　more　gradually；　over　a　period　of　ten　thousand　to　ten　million　years　…　hardly　a　rapid　event。
　　　　Then；　in　1980；　physicist　Luis　Alvarez　and　three　coworkers　discovered　high　concentrations　of　the　element　iridium　in　rocks　from　the　end　of　the　Cretaceous　and　the　start　of　the　Tertiary　…　the　so…called　K…T　boundary。　（The　Cretaceous　was　shorthanded　as　〃K〃　to　avoid　confusion　with　the　Cambrian　and　other　geological　periods。）　Iridium　is　rare　on　earth；　but　abundant　in　meteors。　Alvarez's　team　argued　that　the　presence　of　so　much　iridium　in　rocks　at　the　K…T　boundary　suggested　that　a　giant　meteorite；　many　miles　in　diameter；　had　collided　with　the　earth　at　that　time。　They　theorized　that　the　resulting　dust　and　debris　had　darkened　the　skies；　inhibited　photosynthesis；　killed　plants　and　animals；　and　ended　the　reign　of　the　dinosaurs。
　　　　This　dramatic　theory　captured　the　media　and　public　imagination。　It　began　a　controversy　which　continued　for　many　years。　Where　was　the　crater　from　this　meteor？　Various　candidates　were　proposed。　There　were　five　major　periods　of　extinction　in　the　past…had　meteors　caused　them　all？　Was　there　a　twenty…six…million…year　cycle　of　catastrophe？　Was　the　planet　even　now　awaiting　another　devastating　impact？
　　　　After　more　than　a　decade；　these　questions　remained　unanswered。　The　debate　raged　on　…　until　August　1993；　when；　at　a　weekly　seminar　of　the　Santa　Fe　Institute；　an　iconoclastic　mathematician　named　Ian　Malcolm　announced　that　none　of　these　questions　mattered；　and　that　the　debate　over　a　meteoric　impact　was　〃a　frivolous　and　irrelevant　speculation。〃

〃Consider　the　numbers；〃　Malcolm　said；　leaning　on　the　podium；　staring　forward　at　his　audience。　〃On　our　planet　there　are　currently　fifty　million　species　of　plants　and　animals。　We　think　that　is　a　remarkable　diversity；　yet　it　is　nothing　pared　to　what　has　existed　before。　We　estimate　that　there　have　been　fifty　billion　species　on　this　planet　since　life　began。　That　means　that　for　every　thousand　species　that　ever　existed　on　the　planet；　only　one　remains　today。　Thus　99。9　percent　of　all　species　that　ever　lived　are　extinct。　And　mass　killings　account　for　only　five　percent　of　that　total。　The　overwhelming　majority　of　species　died　one　at　a　time。〃
　　　　The　truth；　Malcolm　said；　was　that　life　on　earth　was　marked　by　a　continuous；　steady　rate　of　extinction。　By　and　large；　the　average　lifespan　of　a　species　was　four　million　years。　For　mammals；　it　was　a　million　years。　Then　the　species　vanished。　So　the　real　pattern　was　one　of　species　rising；　flourishing；　and　dying　out　in　a　few　million　years。　On　average；　one　species　a　day　had　bee　extinct　throughout　the　history　of　life　on　the　earth。
　　　　〃But　why？〃　he　asked。　〃What　leads　to　the　rise　and　decline　of　earth's　species　in　a　four…million…year　life　cycle？
　　　　〃One　answer　is　that　we　do　not　recognize　how　continuously　active　our　planet　is。　just　in　the　last　fifty　thousand　years　…　a　geological　blink　of　an　eye　…　the　rain　forests　have　severely　contracted；　then　expanded　again。　Rain　forests　aren't　an　ageless　feature　of　the　planet；　they're　actually　rather　new。　As　recently　as　ten　thousand　years　ago；　when　there　were　human　hunters　on　the　American　continent；　an　ice　pack　extended　as　far　down　as　New　York　City。　Many　animals　became　extinct　during　that　time。
　　　　〃So　most　of　earth's　history　shows　animals　living　and　dying　against　a　very　active　background。　That　probably　explains　90　percent　of　extinctions。　If　the　seas　dry　up；　or　bee　more　salty；　then　of　course　ocean　plankton　will　all　die。　But　plex　animals　like　dinosaurs　are　another　matter；　because　plex　animals　have　insulated　themselves　…　literally　and　figuratively　…　against　such　changes。　Why　do　plex　animals　die　out？　Why　don't　they　adjust？　Physically；　they　seem　to　have　the　capacity　to　survive。　There　appears　to　be　no　reason　why　they　should　die。　And　yet　they　do。
　　　　〃What　I　wish　to　propose　is　that　plex　animals　bee　extinct　not　because　of　a　change　in　their　physical　adaptation　to　their　environment；　but　because　of　their　behavior。　I　would　suggest　that　the　latest　thinking　ill　chaos　theory；　or　nonlinear　dynamics；　provides　tantalizing　hints　to　how　this　happens。
　　　　It　suggests　to　us　that　behavior　of　plex　animals　can　change　very　rapidly；　and　not　always　for　the　better。　It　suggests　that　behavior　can　cease　to　be　responsive　to　the　environment；　and　lead　to　decline　and　death。　It　suggests　that　animals　may　stop　adapting。　Is　this　what　happened　to　the　dinosaurs？　Is　this　the　true　cause　of　their　disappearance？　We　may　never　know。　But　it　is　no　accident　that　human　beings　are　so　interested　in　dinosaur　extinction。　The　decline　of　the　dinosaurs　allowed　mammals　…　including　us　…　to　flourish。　And　that　leads　us　to　wonder　whether　the　disappearance　of　the　dinosaurs　is　going　to　be　repeated；　sooner　or　later；　by　us　as　well。　Whether　at　the　deepest　level　the　fault　lies　not　in　blind　fate…in　some　fiery　meteor　from　the　skies　…　but　in　our　own　behavior。　At　the　moment；　we　have　no　answer。〃
　　　　And　then　he　smiled。
　　　　〃But　I　have　a　few　suggestions；〃　he　said。

THE　LOST　WORLD

Prologue：

〃Life　at　the　Edge　of　Chaos〃

The　Santa　Fe　Institute　was　housed　in　a　series　of　buildings　on　Canyon　Road　which　had　formerly　been　a　convent；　and　the　Institute's　seminars　were　held　in　a　room　which　had　served　as　a　chapel。　Now；　standing　at　the　podium；　with　a　shaft　of　sunlight　shining　down　on　him；　Ian　Malcolm　paused　dramatically　before　continuing　his　lecture。
　　　　Malcolm　was　forty　years　old；　and　a　familiar　figure　at　the　Institute。　He　had　been　one　of　the　early　pioneers　in　chaos　theory；　but　his　promising　career　had　been　disrupted　by　a　severe　injury　during　a　trip　to　Costa　Rica；　Malcolm　had；　in　fact；　been　reported　dead　in　several　newscasts。　〃I　was　sorry　to　cut　short　the　celebrations　in　mathematics　departments　around　the　country；〃　he　later　said；　〃but　it　turned　out　I　was　only　slightly　dead。　The　surgeons　have　done　wonders；　as　they　will　be　the　first　to　tell　you。　So　now　I　am　back　…　in　my　next　iteration；　you　might　say。〃
　　　　Dressed　entirely　in　black；　leaning　on　a　cane；　Malcolm　gave　the　impression　of　severity。　He　was　known　within　the　Institute　for　his　unconventional　analysis；　and　his　tendency　to　pessimism。　His　talk　that　August；　entitled　〃Life　at　the　Edge　of　Chaos；〃　was　typical　of　his　thinking。　In　it；　Malcolm　presented　his　analysis　of　chaos　theory　as　it　applied　to　evolution。
　　　　He　could　not　have　wished　for　a　more　knowledgeable　audience。　The　Santa　Fe　Institute　had　been　formed　in　the　mid…1980s　by　a　group　of　scientists　interested　in　the　implications　of　chaos　theory。　The　scientists　came　from　many　fields…physics；　economics；　biology；　puter　science。　What　they　had　in　mon　was　a　belief　that　the　plexity　of　the　world　concealed　an　underlying　order　which　had　previously　eluded　scien