《A Short History of Nearly Everything》第155章

and。　as　strickland　wistfully　observed；　we　have　more　physical　evidenceof　some　ancient　sea　monsters　and　lumbering　saurapods　than　we　do　of　a　bird　that　lived　intomodern　times　and　required　nothing　of　us　to　survive　except　our　absence。
so　what　is　known　of　the　dodo　is　this：　it　lived　on　mauritius；　was　plump　but　not　tasty；　andwas　the　biggest…ever　member　of　the　pigeon　family；　though　by　quite　what　margin　is　unknownas　its　weight　was　never　accurately　recorded。　extrapolations　from　strickland’s　“osseousfragments”　and　the　ashmolean’s　modest　remains　show　that　it　was　a　little　over　two　and　a　halffeet　tall　and　about　the　same　distance　from　beak　tip　to　backside。　being　flightless；　it　nested　onthe　ground；　leaving　its　eggs　and　chicks　tragically　easy　prey　for　pigs；　dogs；　and　monkeysbrought　to　the　island　by　outsiders。　it　was　probably　extinct　by　1683　and　was　most　certainlygone　by　1693。　beyond　that　we　know　almost　nothing　except　of　course　that　we　will　not　see　itslike　again。　we　know　nothing　of　its　reproductive　habits　and　diet；　where　it　ranged；　what　soundsit　made　in　tranquility　or　alarm。　we　don’t　possess　a　single　dodo　egg。
from　beginning　to　end　our　acquaintance　with　animate　dodos　lasted　just　seventy　years。　thatis　a　breathtakingly　scanty　period—though　it　must　be　said　that　by　this　point　in　our　history　wedid　have　thousands　of　years　of　practice　behind　us　in　the　matter　of　irreversible　eliminations。
nobody　knows　quite　how　destructive　human　beings　are；　but　it　is　a　fact　that　over　the　last　fiftythousand　years　or　so　wherever　we　have　gone　animals　have　tended　to　vanish；　in　oftenastonishingly　large　numbers。
in america； thirty genera of large animals—some　very　large　indeed—disappearedpractically　at　a　stroke　after　the　arrival　of　modern　humans　on　the　continent　between　ten　andtwenty　thousand　years　ago。　altogether　north　and　south　america　between　them　lost　aboutthree　quarters　of　their　big　animals　once　man　the　hunter　arrived　with　his　flint…headed　spearsand　keen　organizational　capabilities。　europe　and　asia；　where　the　animals　had　had　longer　toevolve　a　useful　wariness　of　humans；　lost　between　a　third　and　a　half　of　their　big　creatures。
australia；　for　exactly　the　opposite　reasons；　lost　no　less　than　95　percent。
because　the　early　hunter　populations　were　paratively　small　and　the　animal　populationstruly　monumental—as　many　as　ten　million　mammoth　carcasses　are　thought　to　lie　frozen　in　thetundra　of　northern　siberia　alone—some　authorities　think　there　must　be　other　explanations；possibly　involving　climate　change　or　some　kind　of　pandemic。　as　ross　macphee　of　theamerican　museum　of　natural　history　put　it：　“there’s　no　material　benefit　to　huntingdangerous　animals　more　often　than　you　need　to—there　are　only　so　many　mammoth　steaksyou　can　eat。”　others　believe　it　may　have　been　almost　criminally　easy　to　catch　and　clobberprey。　“in　australia　and　the　americas；”　says　tim　flannery；　“the　animals　probably　didn’t　knowenough　to　run　away。”
some　of　the　creatures　that　were　lost　were　singularly　spectacular　and　would　take　a　littlemanaging　if　they　were　still　around。　imagine　ground　sloths　that　could　look　into　an　upstairswindow；　tortoises　nearly　the　size　of　a　small　fiat；　monitor　lizards　twenty　feet　long　baskingbeside　desert　highways　in　western　australia。　alas；　they　are　gone　and　we　live　on　a　muchdiminished　planet。　today；　across　the　whole　world；　only　four　types　of　really　hefty　（a　metric　tonor　more）　land　animals　survive：　elephants；　rhinos；　hippos；　and　giraffes。　not　for　tens　of　millionsof　years　has　life　on　earth　been　so　diminutive　and　tame。
the　question　that　arises　is　whether　the　disappearances　of　the　stone　age　and　disappearancesof　more　recent　times　are　in　effect　part　of　a　single　extinction　event—whether；　in　short；　humansare　inherently　bad　news　for　other　living　things。　the　sad　likelihood　is　that　we　may　well　be。
according　to　the　university　of　chicago　paleontologist　david　raup；　the　background　rate　ofextinction　on　earth　throughout　biological　history　has　been　one　species　lost　every　four　yearson　average。　according　to　one　recent　calculation；　human…caused　extinction　now　may　berunning　as　much　as　120；000　times　that　level。
in　the　mid…1990s；　the　australian　naturalist　tim　flannery；　now　head　of　the　south　australianmuseum　in　adelaide；　became　struck　by　how　little　we　seemed　to　know　about　manyextinctions；　including　relatively　recent　ones。　“wherever　you　looked；　there　seemed　to　be　gapsin　the　records—pieces　missing；　as　with　the　dodo；　or　not　recorded　at　all；”　he　told　me　when　imet　him　in　melbourne　a　year　or　so　ago。
flannery　recruited　his　friend　peter　schouten；　an　artist　and　fellow　australian；　and　togetherthey　embarked　on　a　slightly　obsessive　quest　to　scour　the　world’s　major　collections　to　find　outwhat　was　lost；　what　was　left；　and　what　had　never　been　known　at　all。　they　spent　four　yearspicking　through　old　skins；　musty　specimens；　old　drawings；　and　written　descriptions—whatever　was　available。　schouten　made　life…sized　paintings　of　every　animal　they　couldreasonably　re…create；　and　flannery　wrote　the　words。　the　result　was　an　extraordinary　bookcalled　a　gap　in　nature；　constituting　the　most　plete—and；　it　must　be　said；　moving—catalog　of　animal　extinctions　from　the　last　three　hundred　years。
for　some　animals；　records　were　good；　but　nobody　had　done　anything　much　with　them；sometimes　for　years；　sometimes　forever。　steller’s　sea　cow；　a　walrus…like　creature　related　tothe　dugong；　was　one　of　the　last　really　big　animals　to　go　extinct。　it　was　truly　enormous—anadult　could　reach　lengths　of　nearly　thirty　feet　and　weigh　ten　tons—but　we　are　acquainted　withit　only　because　in　1741　a　russian　expedition　happened　to　be　shipwrecked　on　the　only　placewhere　the　creatures　still　survived　in　any　numbers；　the　remote　and　foggy　mander　islandsin　the　bering　sea。
happily；　the　expedition　had　a　naturalist；　georg　steller；　who　was　fascinated　by　the　animal。
“he　took　the　most　copious　notes；”　says　flannery。　“he　even　measured　the　diameter　of　itswhiskers。　the　only　thing　he　wouldn’t　describe　was　the　male　genitals—though；　for　somereason；　he　was　happy　enough　to　do　the　female’s。　he　even　saved　a　piece　of　skin；　so　we　had　agood　idea　of　its　texture。　we　weren’t　always　so　lucky。”
the　one　thing　steller　couldn’t　do　was　save