A Short History of Nearly Everything-第70章

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t　embroidered—walcott　makes　nomention　of　a　slipping　horse　or　falling　snow—but　there　is　no　disputing　that　it　was　anextraordinary　find。

it　is　almost　impossible　for　us　whose　time　on　earth　is　limited　to　a　breezy　few　decades　toappreciate　how　remote　in　time　from　us　the　cambrian　outburst　was。　if　you　could　fly　backwardsinto　the　past　at　the　rate　of　one　year　per　second；　it　would　take　you　about　half　an　hour　to　reachthe　time　of　christ；　and　a　little　over　three　weeks　to　get　back　to　the　beginnings　of　human　life。

but　it　would　take　you　twenty　years　to　reach　the　dawn　of　the　cambrian　period。　it　was；　in　otherwords；　an　extremely　long　time　ago；　and　the　world　was　a　very　different　place。

for　one　thing；　500…million…plus　years　ago　when　the　burgess　shale　was　formed　it　wasn’t　atthe　top　of　a　mountain　but　at　the　foot　of　one。　specifically　it　was　a　shallow　ocean　basin　at　thebottom　of　a　steep　cliff。　the　seas　of　that　time　teemed　with　life；　but　normally　the　animals　left　norecord　because　they　were　soft…bodied　and　decayed　upon　dying。　but　at　burgess　the　cliffcollapsed；　and　the　creatures　below；　entombed　in　a　mudslide；　were　pressed　like　flowers　in　abook；　their　features　preserved　in　wondrous　detail。

in　annual　summer　trips　from　1910　to　1925　（by　which　time　he　was　seventy…five　years　old）；walcott　excavated　tens　of　thousands　of　specimens　（gould　says　80；000；　the　normallyunimpeachable　fact　checkers　of　national　georgraphic　say　60；000）；　which　he　brought　back　towashington　for　further　study。　in　both　sheer　numbers　and　diversity　the　collection　wasunparalleled。　some　of　the　burgess　fossils　had　shells；　many　others　did　not。　some　were　sighted；others　blind。　the　variety　was　enormous；　consisting　of　140　species　by　one　count。　“the　burgessshale　included　a　range　of　disparity　in　anatomical　designs　never　again　equaled；　and　notmatched　today　by　all　the　creatures　in　the　world’s　oceans；”　gould　wrote。

unfortunately；　according　to　gould；　walcott　failed　to　discern　the　significance　of　what　hehad　found。　“snatching　defeat　from　the　jaws　of　victory；”　gould　wrote　in　another　work；　eightlittle　piggies；　“walcott　then　proceeded　to　misinterpret　these　magnificent　fossils　in　the　deepestpossible　way。”　he　placed　them　into　modern　groups；　making　them　ancestral　to　today’s　worms；jellyfish；　and　other　creatures；　and　thus　failed　to　appreciate　their　distinctness。　“under　such　aninterpretation；”　gould　sighed；　“life　began　in　primordial　simplicity　and　moved　inexorably；predictably　onward　to　more　and　better。”

walcott　died　in　1927　and　the　burgess　fossils　were　largely　forgotten。　for　nearly　half　acentury　they　stayed　shut　away　in　drawers　in　the　american　museum　of　natural　history　inwashington；　seldom　consulted　and　never　questioned。　then　in　1973　a　graduate　student　fromcambridge　university　named　simon　conway　morris　paid　a　visit　to　the　collection。　he　wasastonished　by　what　he　found。　the　fossils　were　far　more　varied　and　magnificent　than　walcotthad　indicated　in　his　writings。　in　taxonomy　the　category　that　describes　the　basic　body　plans　ofall　organisms　is　the　phylum；　and　here；　conway　morris　concluded；　were　drawer　after　drawer　ofsuch　anatomical　singularities—all　amazingly　and　unaccountably　unrecognized　by　the　manwho　had　found　them。

with　his　supervisor；　harry　whittington；　and　fellow　graduate　student　derek　briggs；　conwaymorris　spent　the　next　several　years　making　a　systematic　revision　of　the　entire　collection；　andcranking　out　one　exciting　monograph　after　another　as　discovery　piled　upon　discovery。　manyof　the　creatures　employed　body　plans　that　were　not　simply　unlike　anything　seen　before　orsince；　but　were　bizarrely　different。　one；　opabinia；　had　five　eyes　and　a　nozzle…like　snout　withclaws　on　the　end。　another；　a　disc…shaped　being　called　peytoia；　looked　almost　ically　like　apineapple　slice。　a　third　had　evidently　tottered　about　on　rows　of　stilt…like　legs；　and　was　so　oddthat　they　named　it　hallucigenia。　there　was　so　much　unrecognized　novelty　in　the　collectionthat　at　one　point　upon　opening　a　new　drawer　conway　morris　famously　was　heard　to　mutter；“oh　fuck；　not　another　phylum。”

the　english　team’s　revisions　showed　that　the　cambrian　had　been　a　time　of　unparalleledinnovation　and　experimentation　in　body　designs。　for　almost　four　billion　years　life　haddawdled　along　without　any　detectable　ambitions　in　the　direction　of　plexity；　and　thensuddenly；　in　the　space　of　just　five　or　ten　million　years；　it　had　created　all　the　basic　bodydesigns　still　in　use　today。　name　a　creature；　from　a　nematode　worm　to　cameron　diaz；　and　theyall　use　architecture　first　created　in　the　cambrian　party。

what　was　most　surprising；　however；　was　that　there　were　so　many　body　designs　that　hadfailed　to　make　the　cut；　so　to　speak；　and　left　no　descendants。　altogether；　according　to　gould；　atleast　fifteen　and　perhaps　as　many　as　twenty　of　the　burgess　animals　belonged　to　no　recognizedphylum。　（the　number　soon　grew　in　some　popular　accounts　to　as　many　as　one　hundred—farmore　than　the　cambridge　scientists　ever　actually　claimed。）　“the　history　of　life；”　wrote　gould；“is　a　story　of　massive　removal　followed　by　differentiation　within　a　few　surviving　stocks；　notthe　conventional　tale　of　steadily　increasing　excellence；　plexity；　and　diversity。”

evolutionary　success；　it　appeared；　was　a　lottery。

one　creature　thatdid　manage　to　slip　through；　a　small　wormlike　being　called　pikaiagracilens；　was　found　to　have　a　primitive　spinal　column；　making　it　the　earliest　known　ancestorof　all　later　vertebrates；　including　us。pikaia　were　by　no　means　abundant　among　the　burgessfossils；　so　goodness　knows　how　close　they　may　have　e　to　extinction。　gould；　in　a　famousquotation；　leaves　no　doubt　that　he　sees　our　lineal　success　as　a　fortunate　fluke：　“wind　back　thetape　of　life　to　the　early　days　of　the　burgess　shale；　let　it　play　again　from　an　identical　startingpoint；　and　the　chance　bees　vanishingly　small　that　anything　like　human　intelligence　wouldgrace　the　replay。”

gould’s　book　was　published　in　1989　to　general　critical　acclaim　and　was　a　great　mercialsuccess。　what　wasn’t　generally　known　was　that　many　scientists　didn’t　agree　with　gould’sconclusions　at　all；　and　that　it　was　all　soon　to　get　very　ugly。　in　the　context　of　the　cambrian；“explosion”　would　soon　have　more　to　do　with　modern　tempers　than　ancient　physiologicalfacts。

in　fact；　we　now　know；　plex　organisms　existed　at　least　a　hundred　million　years　beforethe　cambrian。　we　should　have　known　a　whole　lot　sooner。　nearly　forty　years　after　walcottmade　his　discovery　in　canada；　on　the　other　side　of　the　planet　in　australia；　a　young　geologistnamed　reginald　sprigg　found　something　even　older　and　in　its　way　just　as　remarkable。

in　1946　sprigg　was　a　young　assistant　government　geologist　for　the　state　of　south　australiawhen　he　was　sent　to　make　a　survey　of　abandoned　mines　in　the　ediacaran　hills　of　the　flindersrange；　an　expanse　of　baking　outback　some　three　hundred　miles　north　of　adelaide。　the　ideawas　to　see　if　there　were　any　old　mines　that　might　be　profitably　reworked　using　newertechnologies；　so　he　wasn’t　studying　surface　rocks　at　all；　still　less　fossils。　but　one　day　whileeating　his　lunch；　sprigg　idly　overturned　a　hunk　of　sandstone　and　was　surprised—to　put　itmildly—to　see　that　the　rock’s　surface　was　covered　in　delicate　fossils；　rather　like　theimpressions　leaves　make　in　mud。　these　rocks　predated　the　cambrian　explosion。　he　waslooking　at　the　dawn　of　visible　life。

sprigg　submitted　a　paper　to　nature　；　but　it　was　turned　down。　he　read　it　instead　at　the　nextannual　meeting　of　the　australian　and　new　zealand　association　for　the　advancement　ofscience；　but　it　failed　to　find　favor　with　the　association’s　head；　who　said　the　ediacaranimprints　were　merely　“fortuitous　inorganic　markings”—patterns　made　by　wind　or　rain　ortides；　but　not　living　beings。　his　hopes　not　yet　entirely　crushed；　sprigg　traveled　to　london　andpresented　his　findings　to　the　1948　international　geological　congress；　but　failed　to　exciteeither　interest　or　belief。　finally；　for　want　of　a　better　outlet；　he　published　his　findings　in　thetransactions　of　the　royal　society　of　south　australia。　then　he　quit　his　government　job　andtook　up　oil　exploration。

nine　　years　　later；　　in　　1957；　　a　　schoolboy　　named　john　mason；　while　walking　throughcharnwood　forest　in　the　english　midlands；　found　a　rock　with　a　strange　fossil　in　it；　similar　toa　modern　sea　pen　and　exactly　like　some　of　the　specimens　sprigg　had　found　and　been　trying　totell　everyone　about　ever　since。　the　schoolboy　turned　it　in　to　a　paleontologist　at　the　universityof　leicester；　who　identified　it　at　once　as　precambrian。　young　mason　got　his　picture　in　thepapers　and　was　treated　as　a　precocious　hero；　he　still　is　in　many　books。　the　specimen　wasnamed　in　his　honor　chamia　masoni。

today　some　of　sprigg’s　original　ediacaran　specimens；　along　with　many　of　the　other　fifteenhundred　specimens　that　have　been　found　throughout　the　flinders　range　since　that　time；　canbe　seen　in　a　glass　case　in　an　upstairs　room　of　the　stout　and　lovely　south　australian　museumin　adelaide；　but　they　don’t　attract　a　great　deal　of　attention。　the　delicately　etched　patterns　arerather　faint　and　not　terribly　arresting　to　the　untrained　eye。　they　are　mostly　small　and　disc…shaped；　with　occasional；　vague　trailing　ribbons。　fortey　has　described　them　as　“soft…bodiedoddities。”

there　is　still　very　little　agreement　about　what　th