A Short History of Nearly Everything-第78章

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reat　joseph　banks　took　a　keen　and　believing　interestin　a　series　of　reported　sightings　of　mermaids　off　the　scottish　coast　at　the　end　of　the　eighteenthcentury。　for　the　most　part；　however；　linnaeus’s　lapses　were　offset　by　sound　and　oftenbrilliant　taxonomy。　among　other　acplishments；　he　saw　that　whales　belonged　with　cows；mice；　and　other　mon　terrestrial　animals　in　the　order　quadrupedia　（later　changed　tomammalia）；　which　no　one　had　done　before。

in　the　beginning；　linnaeus　intended　only　to　give　each　plant　a　genus　name　and　a　number—convolvulus　1；　convolvulus　2；and　so　on—but　soon　realized　that　that　was　unsatisfactory　andhit　on　the　binomial　arrangement　that　remains　at　the　heart　of　the　system　to　this　day。　theintention　originally　was　to　use　the　binomial　system　for　everything—rocks；　minerals；　diseases；winds；　whatever　existed　in　nature。　not　everyone　embraced　the　system　warmly。　many　weredisturbed　by　its　tendency　toward　indelicacy；　which　was　slightly　ironic　as　before　linnaeus　themon　names　of　many　plants　and　animals　had　been　heartily　vulgar。　the　dandelion　was　longpopularly　known　as　the　“pissabed”　because　of　its　supposed　diuretic　properties；　and　othernames　in　everyday　use　included　mare’s　fart；　naked　ladies；　twitch…ballock；　hound’s　piss；　openarse；　and　bum…towel。　one　or　two　of　these　earthy　appellations　may　unwittingly　survive　inenglish　yet。　the　“maidenhair”　in　maidenhair　moss；　for　instance；　does　not　refer　to　the　hair　onthe　maiden’s　head。　at　all　events；　it　had　long　been　felt　that　the　natural　sciences　would　beappreciably　dignified　by　a　dose　of　classical　renaming；　so　there　was　a　certain　dismay　indiscovering　that　the　self…appointed　prince　of　botany　had　sprinkled　his　texts　with　suchdesignations　asclitoria；　fornicata；　andvulva。

over　the　years　many　of　these　were　quietly　dropped　（though　not　all：　the　mon　slipperlimpet　still　answers　on　formal　occasions　to　crepidula　fornicata）　and　many　other　refinementsintroduced　as　the　needs　of　the　natural　sciences　grew　more　specialized。　in　particular　the　systemwas　bolstered　by　the　gradual　introduction　of　additional　hierarchies。genus　（pluralgenera）　andspecies　had　been　employed　by　naturalists　for　over　a　hundred　years　before　linnaeus；　andorder；　class；　and　family　in　their　biological　senses　all　came　into　use　in　the　1750s　and　1760s。

but　phylum　wasn’t　coined　until　1876　（by　the　german　ernst　haeckel）；　and　family　and　orderwere　treated　as　interchangeable　until　early　in　the　twentieth　century。　for　a　time　zoologists　usedfamily　where　botanists　placed　order；　to　the　occasional　confusion　of　nearly　everyone。

1linnaeus　had　divided　the　animal　world　into　six　categories：　mammals；　reptiles；　birds；　fishes；insects；　and　“vermes；”　or　worms；　for　everything　that　didn’t　fit　into　the　first　five。　from　theoutset　it　was　evident　that　putting　lobsters　and　shrimp　into　the　same　category　as　worms　wasunsatisfactory；　and　various　new　categories　such　as　mollusca　and　crustacea　were　created。

unfortunately　these　new　classifications　were　not　uniformly　applied　from　nation　to　nation。　inan　attempt　to　reestablish　order；　the　british　in　1842　proclaimed　a　new　set　of　rules　called　thestricklandian　code；　but　the　french　saw　this　as　highhanded；　and　the　société　zoologiquecountered　with　its　own　conflicting　code。　meanwhile；　the　american　ornithological　society；　forobscure　reasons；　decided　to　use　the　1758　edition　of　systema　naturae　as　the　basis　for　all　itsnaming；　rather　than　the　1766　edition　used　elsewhere；　which　meant　that　many　american　birdsspent　the　nineteenth　century　logged　in　different　genera　from　their　avian　cousins　in　europe。

not　until　1902；　at　an　early　meeting　of　the　international　congress　of　zoology；　did　naturalistsbegin　at　last　to　show　a　spirit　of　promise　and　adopt　a　universal　code。

taxonomy　is　described　sometimes　as　a　science　and　sometimes　as　an　art；　but　really　it’s　abattleground。　even　today　there　is　more　disorder　in　the　system　than　most　people　realize。　takethe　category　of　the　phylum；　the　division　that　describes　the　basic　body　plans　of　all　organisms。

a　few　phyla　are　generally　well　known；　such　as　mollusks　（the　home　of　clams　and　snails）；arthropods　（insects　and　crustaceans）；　and　chordates　（us　and　all　other　animals　with　a　backboneor　protobackbone）；　though　things　then　move　swiftly　in　the　direction　of　obscurity。　among　thelatter　we　might　list　gnathostomulida　（marine　worms）；　cnidaria　（jellyfish；　medusae；anemones；　and　corals）；　and　the　delicate　priapulida　（or　little　“penis　worms”）。　familiar　or　not；these　are　elemental　divisions。　yet　there　is　surprisingly　little　agreement　on　how　many　phylathere　are　or　ought　to　be。　most　biologists　fix　the　total　at　about　thirty；　but　some　opt　for　a　numberin　the　low　twenties；　while　edward　o。　wilson　in　the　diversity　of　life　puts　the　number　at　asurprisingly　robust　eighty…nine。　it　depends　on　where　you　decide　to　make　your　divisions—whether　you　are　a　“lumper”　or　a　“splitter；”　as　they　say　in　the　biological　world。

at　the　more　workaday　level　of　species；　the　possibilities　for　disagreements　are　even　greater。

whether　a　species　of　grass　should　be　called　aegilops　incurva；　aegilops　incurvata；　or　aegilopsovata　may　not　be　a　matter　that　would　stir　many　nonbotanists　to　passion；　but　it　can　be　a　sourceof　very　lively　heat　in　the　right　quarters。　the　problem　is　that　there　are　five　thousand　species　ofgrass　and　many　of　them　look　awfully　alike　even　to　people　who　know　grass。　in　consequence；some　species　have　been　found　and　named　at　least　twenty　times；　and　there　are　hardly　any；　itappears；　that　haven’t　been　independently　identified　at　least　twice。　the　two…volume　manual　ofthe　grasses　of　the　united　states　devotes　two　hundred　closely　typeset　pages　to　sorting　out　allthe　synonymies；　as　the　biological　world　refers　to　its　inadvertent　but　quite　monduplications。　and　that　is　just　for　the　grasses　of　a　single　country。

to　deal　with　disagreements　on　the　global　stage；　a　body　known　as　the　internationalassociation　for　plant　taxonomy　arbitrates　on　questions　of　priority　and　duplication。　at1to　illustrate；　humans　are　in　the　domain　eucarya；　in　the　kingdom　animalia；　in　the　phylum　chordata；　in　thesubphylum　vertebrata；　in　the　class　mammalia；　in　the　order　primates；　in　the　family　hominidae；　in　the　genus　homo；in　the　species　sapiens。　（the　convention；　im　informed；　is　to　italicize　genus　and　species　names；　but　not　those　ofhigher　divisions。）　some　taxonomists　employ　further　subdivisions：　tribe；　suborder；　infraorder；　parvorder；　andmore。

intervals　it　hands　down　decrees；　declaring　that　zauschneria　californica　（a　mon　plant　inrock　gardens）　is　to　be　known　henceforth　as　epilobium　canum　or　that　aglaothamniontenuissimum　may　now　be　regarded　as　conspecific　with　aglaothamnion　byssoides；　but　notwithaglaothamnion　pseudobyssoides。　normally　these　are　small　matters　of　tidying　up　thatattract　little　notice；　but　when　they　touch　on　beloved　garden　plants；　as　they　sometimes　do；shrieks　of　outrage　inevitably　follow。　in　the　late　1980s　the　mon　chrysanthemum　wasbanished　（on　apparently　sound　scientific　principles）　from　the　genus　of　the　same　name　andrelegated　to　the　paratively　drab　and　undesirable　world　of　the　genus　dendranthema。

chrysanthemum　breeders　are　a　proud　and　numerous　lot；　and　they　protested　to　the　real　ifimprobable…sounding　mittee　on　spermatophyta。　（there　are　also　mittees　forpteridophyta；　bryophyta；　and　fungi；　among　others；　all　reporting　to　an　executive　called　therapporteur…général；　this　is　truly　an　institution　to　cherish。）　although　the　rules　of　nomenclatureare　supposed　to　be　rigidly　applied；　botanists　are　not　indifferent　to　sentiment；　and　in　1995　thedecision　was　reversed。　similar　adjudications　have　saved　petunias；　euonymus；　and　a　popularspecies　of　amaryllis　from　demotion；　but　not　many　species　of　geraniums；　which　some　yearsago　were　transferred；　amid　howls；　to　the　genus　pelargonium。　the　disputes　are　entertaininglysurveyed　in　charles　elliott’s　the　potting…shed　papers。

disputes　and　reorderings　of　much　the　same　type　can　be　found　in　all　the　other　realms　of　theliving；　so　keeping　an　overall　tally　is　not　nearly　as　straightforward　a　matter　as　you　mightsuppose。　in　consequence；　the　rather　amazing　fact　is　that　we　don’t　have　the　faintest　idea—“noteven　to　the　nearest　order　of　magnitude；”　in　the　words　of　edward　o。　wilson—of　the　number　ofthings　that　live　on　our　planet。　estimates　range　from　3　million　to　200　million。　moreextraordinary　still；　according　to　a　report　in　the　economist；　as　much　as　97　percent　of　theworld’s　plant　and　animal　species　may　still　await　discovery。

of　the　organisms　that　we　do　know　about；　more　than　99　in　100　are　only　sketchilydescribed—“a　scientific　name；　a　handful　of　specimens　in　a　museum；　and　a　few　scraps　ofdescription　in　scientific　journals”　is　how　wilson　describes　the　state　of　our　knowledge。　in　thediversity　of　life；　he　estimated　the　number　of　known　species　of　all　types—plants；　insects；microbes；　algae；　everything—at　1。4　million；　but　added　that　that　was　just　a　guess。　otherauthorities　have　put　the　number　of　known　species　slightly　higher；　at　around　1。5　million　to　1。8million；　but　there　is　no　central　registry　of　these　things；　so　nowhere　to　check　numbers。　in　short；the　remarkable　position　we　find　ourselves　in　is　that　we　don’t　actually　know　what　we　actuallyknow。

in　principle　you　ought　to　be　able　to　go　to　experts　in　each　area　of　specialization；　ask　howmany　species　there　a