A Short History of Nearly Everything-第80章

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millipedes；　three　representing　new　genera；　and　one　newspecies　of　tree。　“big　tree；”　he　added；　and　shaped　his　arms　as　if　about　to　dance　with　a　verylarge　partner。　cloud　forests　are　found　on　the　tops　of　plateaus　and　have　sometimes　beenisolated　for　millions　of　years。　“they　provide　the　ideal　climate　for　biology　and　they　havehardly　been　studied；”　he　said。

overall；　tropical　rain　forests　cover　only　about　6　percent　of　earth’s　surface；　but　harbor　morethan　half　of　its　animal　life　and　about　two…thirds　of　its　flowering　plants；　and　most　of　this　liferemains　unknown　to　us　because　too　few　researchers　spend　time　in　them。　not　incidentally；much　of　this　could　be　quite　valuable。　at　least　99　percent　of　flowering　plants　have　never　beentested　for　their　medicinal　properties。　because　they　can’t　flee　from　predators；　plants　have　hadto　contrive　chemical　defenses；　and　so　are　particularly　enriched　in　intriguing　pounds。　evennow　nearly　a　quarter　of　all　prescribed　medicines　are　derived　from　just　forty　plants；　withanother　16　percent　ing　from　animals　or　microbes；　so　there　is　a　serious　risk　with　everyhectare　of　forest　felled　of　losing　medically　vital　possibilities。　using　a　method　calledbinatorial　chemistry；　chemists　can　generate　forty　thousand　pounds　at　a　time　in　labs；but　these　products　are　random　and　not　unmonly　useless；　whereas　any　natural　moleculewill　have　already　passed　what　the　economist　calls　“the　ultimate　screening　programme：　overthree　and　a　half　billion　years　of　evolution。”

looking　for　the　unknown　isn’t　simply　a　matter　of　traveling　to　remote　or　distant　places；however。　in　his　book　life：　an　unauthorised　biography；　richard　fortey　notes　how　oneancient　bacterium　was　found　on　the　wall　of　a　country　pub　“where　men　had　urinated　forgenerations”—a　discovery　that　would　seem　to　involve　rare　amounts　of　luckand　devotion　andpossibly　some　other　quality　not　specified。

there　aren’t　enough　specialists。the　stock　of　things　to　be　found；　examined；　and　recordedvery　much　outruns　the　supply　of　scientists　available　to　do　it。　take　the　hardy　and　little…knownorganisms　known　as　bdelloid　rotifers。　these　are　microscopic　animals　that　can　survive　almostanything。　when　conditions　are　tough；　they　curl　up　into　a　pact　shape；　switch　off　theirmetabolism；　and　wait　for　better　times。　in　this　state；　you　can　drop　them　into　boiling　water　orfreeze　them　almost　to　absolute　zero—that　is　the　level　where　even　atoms　give　up—and；　whenthis　torment　has　finished　and　they　are　returned　to　a　more　pleasing　environment；　they　willuncurl　and　move　on　as　if　nothing　has　happened。　so　far；　about　500　species　have　been　identified（though　other　sources　say　360）；　but　nobody　has　any　idea；　even　remotely；　how　many　there　maybe　altogether。　for　years　almost　all　that　was　known　about　them　was　thanks　to　the　work　of　adevoted　amateur；　a　london　clerical　worker　named　david　bryce　who　studied　them　in　his　sparetime。　they　can　be　found　all　over　the　world；　but　you　could　have　all　the　bdelloid　rotifer　expertsin　the　world　to　dinner　and　not　have　to　borrow　plates　from　the　neighbors。

even　something　as　important　and　ubiquitous　as　fungi—and　fungi　are　both—attractsparatively　little　notice。　fungi　are　everywhere　and　e　in　many　forms—as　mushrooms；molds；　mildews；　yeasts；　and　puffballs；　to　name　but　a　sampling—and　they　exist　in　volumesthat　most　of　us　little　suspect。　gather　together　all　the　fungi　found　in　a　typical　acre　of　meadowand　you　would　have　2；500　pounds　of　the　stuff。　these　are　not　marginal　organisms。　withoutfungi　there　would　be　no　potato　blights；　dutch　elm　disease；　jock　itch；　or　athlete’s　foot；　but　alsono　yogurts　or　beers　or　cheeses。　altogether　about　70；000　species　of　fungi　have　been　identified；but　it　is　thought　the　number　could　be　as　high　as　1。8　million。　a　lot　of　mycologists　work　inindustry；　making　cheeses　and　yogurts　and　the　like；　so　it　is　hard　to　say　how　many　are　activelyinvolved　in　research；　but　we　can　safely　take　it　that　there　are　more　species　of　fungi　to　be　foundthan　there　are　people　to　find　them。

the　world　is　a　really　big　place。we　have　been　gulled　by　the　ease　of　air　travel　and　otherforms　of　munication　into　thinking　that　the　world　is　not　all　that　big；　but　at　ground　level；where　researchers　must　work；　it　is　actually　enormous—enormous　enough　to　be　full　ofsurprises。　the　okapi；　the　nearest　living　relative　of　the　giraffe；　is　now　known　to　exist　insubstantial　numbers　in　the　rain　forests　of　zaire—the　total　population　is　estimated　at　perhapsthirty　thousand—yet　its　existence　wasn’t　even　suspected　until　the　twentieth　century。　the　largeflightless　new　zealand　bird　called　the　takahe　had　been　presumed　extinct　for　two　hundredyears　before　being　found　living　in　a　rugged　area　of　the　country’s　south　island。　in　1995　a　teamof　french　and　british　scientists　in　tibet；　who　were　lost　in　a　snowstorm　in　a　remote　valley；came　across　a　breed　of　horse；　called　the　riwoche；　that　had　previously　been　known　only　fromprehistoric　cave　drawings。　the　valley’s　inhabitants　were　astonished　to　learn　that　the　horse　wasconsidered　a　rarity　in　the　wider　world。

some　　people　　think　　even　　greater　　surprises　may　await　us。　“a　leading　british　ethno…biologist；”　wrote　the　economist　in　1995；　“thinks　a　megatherium；　a　sort　of　giant　ground　slothwhich　may　stand　as　high　as　a　giraffe　。　。　。　may　lurk　in　the　fastnesses　of　the　amazon　basin。”

perhaps　significantly；　the　ethnobiologist　wasn’t　named；　perhaps　even　more　significantly；nothing　more　has　been　heard　of　him　or　his　giant　sloth。　no　one；　however；　can　categorically　saythat　no　such　thing　is　there　until　every　jungly　glade　has　been　investigated；　and　we　are　a　longway　from　achieving　that。

but　even　if　we　groomed　thousands　of　fieldworkers　and　dispatched　them　to　the　farthestcorners　of　the　world；　it　would　not　be　effort　enough；　for　wherever　life　can　be；　it　is。　life’sextraordinary　fecundity　is　amazing；　even　gratifying；　but　also　problematic。　to　survey　it　all；　youwould　have　to　turn　over　every　rock；　sift　through　the　litter　on　every　forest　floor；　sieveunimaginable　quantities　of　sand　and　dirt；　climb　into　every　forest　canopy；　and　devise　muchmore　efficient　ways　to　examine　the　seas。　even　then　you　would　overlook　whole　ecosystems。　inthe　1980s；　spelunkers　entered　a　deep　cave　in　romania　that　had　been　sealed　off　from　theoutside　world　for　a　long　but　unknown　period　and　found　thirty…three　species　of　insects　andother　small　creatures—spiders；　centipedes；　lice—all　blind；　colorless；　and　new　to　science。

they　were　living　off　the　microbes　in　the　surface　scum　of　pools；　which　in　turn　were　feeding　onhydrogen　sulfide　from　hot　springs。

our　instinct　may　be　to　see　the　impossibility　of　tracking　everything　down　as　frustrating；dispiriting；　perhaps　even　appalling；　but　it　can　just　as　well　be　viewed　as　almost　unbearablyexciting。　we　live　on　a　planet　that　has　a　more　or　less　infinite　capacity　to　surprise。　whatreasoning　person　could　possibly　want　it　any　other　way？

what　is　nearly　always　most　arresting　in　any　ramble　through　the　scattered　disciplines　ofmodern　science　is　realizing　how　many　people　have　been　willing　to　devote　lifetimes　to　themost　sumptuously　esoteric　lines　of　inquiry。　in　one　of　his　essays；　stephen　jay　gould　notes　howa　hero　of　his　named　henry　edward　crampton　spent　fifty　years；　from　1906　to　his　death　in1956；　quietly　studying　a　genus　of　land　snails　in　polynesia　called　partula。　over　and　over；　yearafter　year；　crampton　measured　to　the　tiniest　degree—to　eight　decimal　places—the　whorls　andarcs　and　gentle　curves　of　numberless　partula；　piling　the　results　into　fastidiously　detailedtables。　a　single　line　of　text　in　a　crampton　table　could　represent　weeks　of　measurement　andcalculation。

only　slightly　less　devoted；　and　certainly　more　unexpected；　was　alfred　c。　kinsey；　whobecame　famous　for　his　studies　of　human　sexuality　in　the　1940s　and　1950s。　but　before　hismind　became　filled　with　sex；　so　to　speak；　kinsey　was　an　entomologist；　and　a　dogged　one　atthat。　in　one　expedition　lasting　two　years；　he　hiked　2；500　miles　to　assemble　a　collection　of300；000　wasps。　how　many　stings　he　collected　along　the　way　is　not；　alas；　recorded。

something　that　had　been　puzzling　me　was　the　question　of　how　you　assured　a　chain　ofsuccession　in　these　arcane　fields。　clearly　there　cannot　be　many　institutions　in　the　world　thatrequire　or　are　prepared　to　support　specialists　in　barnacles　or　pacific　snails。　as　we　parted　at　thenatural　history　museum　in　london；　i　asked　richard　fortey　how　science　ensures　that　whenone　person　goes　there’s　someone　ready　to　take　his　place。

he　chuckled　rather　heartily　at　my　naiveté。　“i’m　afraid　it’s　not　as　if　we　have　substitutessitting　on　the　bench　somewhere　waiting　to　be　called　in　to　play。　when　a　specialist　retires　or；even　more　unfortunately；　dies；　that　can　bring　a　stop　to　things　in　that　field；　sometimes　for　avery　long　while。”

“and　i　suppose　that’s　why　you　value　someone　who　spends　forty…two　years　studying　asingle　species　of　plant；　even　if　it　doesn’t　produce　anything　terribly　new？”

“precisely；”　he　said；　“precisely。”　and　he　really　seemed　to　mean　it。

。。。！



24CELLS

^生。网！
it　starts　with　a　single　cell。　the　first　cell　splits　to　bee　two　and　the　two　bee　fourand　so　on。　after　just　forty…seven　doublings；　you　have　ten　thousand　trillion（10；000；000；000；000；000）　cells　in　your　body　and　are　ready　to　spring　forth　as　a　human　being。

1and　every　one　of　those　cel