物种分化速率

物种分化速率第1页，课件共19页，创作于2023年2月ThreeAssumptionsinNeutralCommunityEcologyNeutralityassumption

Zero-SumassumptionPointmutuationassumptionHubbell,S.P.2001.Theunifiedneutraltheoryofbiodiversityandbiogeography.-PrincetonUniversityPress.第2页，课件共19页，创作于2023年2月Relaxzero-sumassumptionEtienneetal.(2007):zero-sum

andnon-zero-sumformulationsofneutraltheoryhaveexactlythesame

samplingformulawhenthecommunityisinequilibrium.Conlisketal.(2010):asimplecolonizationrulecanyieldHubbell’slocalabundancedistributionwithweekerassumption(relaxingzero-sumassumption).EtienneRS,AlonsoD,McKaneAJ(2007a)Thezero-sumassumptioninneutralbiodiversitytheory.JTheorBiol248:522–536.ConliskJ,ConliskE,HarteJ(2010)Hubbell’slocalabundancedistribution:insightsfromasimplecolonizationrule.Oikos119:379–383.第3页，课件共19页，创作于2023年2月Relaxpointmutuationassumption

---randomfissionspeciationHubbell(2001)statedthattheequilibriummetacommunitySADresultingfromrandomfissionspeciationisazero-summultinomial.Ricklefs(2003)providedsomeapproximateformulasforthetotalspeciesrichnessinthemetacommunityunderrandomfissionspeciation.EtienneandHaegeman(2010)deriveanalyticalexpressionsforthedistributionofabundancesaccordingtotheneutralmodelwithrecruitment(i.e.,dispersalandestablishment)limitationandrandomfissionspeciation.第4页，课件共19页，创作于2023年2月Relaxpointmutuationassumption

---randomfissionspeciationEtienne,R.S.andBart,Haegeman,2010.Theneutraltheorybiodiversitywithrandomfissionspeciation.TheorEcolFigure5showstheabundancedistributionswiththefittedmodels.Clearlythemodelwithrandomfissionspeciationneverperformssignificantlybetterthanthepointmutationmodel.第5页，课件共19页，创作于2023年2月Relaxpointmutuationassumption

---randomfissionspeciationThemetacommunityabundancedistributionunderrandomfissionisidenticaltothebroken-stickabundancedistribution,andthusprovidesadynamicalexplanationforthisgrandoldladyofabundancedistributions.Themetacommunityabundancedistributionunderrandomfission:第6页，课件共19页，创作于2023年2月Relaxpointmutuationassumption

---speciationrateproportionaltoabundance

EtienneRS,ApolMEF,OlffH,WeissingFJ(2007b)Modesofspeciationandtheneutraltheoryofbiodiversity.Oikos116:241–258.第7页，课件共19页，创作于2023年2月Relaxpointmutuationassumption

---ProtractedspeciationProtractedspeciation:

bymodelingspeciationasagradual,protracted,processratherthananinstantaneousevent.Speciationrate:,whereuisgeneralspeciation-initiationrate.Protractedspeciation:

bymodelingspeciationasagradual,protracted,processratherthananinstantaneousevent.Speciationrate:,whereuisgeneralspeciation-initiationrate.第8页，课件共19页，创作于2023年2月Relaxpointmutuationassumption

---ProtractedspeciationRosindelletal.,2010.Protractedspeciationrevitalizestheneutraltheoryofbiodiversity.Ecol.Lett.13:716-727.第9页，课件共19页，创作于2023年2月Relaxpointmutuationassumption

---ProtractedspeciationRosindelletal.,2010.Protractedspeciationrevitalizestheneutraltheoryofbiodiversity.Ecol.Lett.13:716-727.第10页，课件共19页，创作于2023年2月ThreeAssumptionsinNeutralCommunityEcology

Whiletheneutralityassumptionistheheartoftheneutraltheory,theothertwoassumptionsareassumptionsofparticularmodelimplementationsofthetheory,allowingforanalyticalexpressionsfordiversitymeasures,ratherthanthefundamentalassumptionofthetheoryitself.Amismatchbetweenobservesandtheoreticalpredictionscan,beduetotheseadditionalassumptionsandthereforecannotbeimmediatelyinterpretedascallingforarejectionoftheneutraltheoryasawhole.RampalEtienneEtienne,R.S.andBart,Haegeman,2010.Theneutraltheorybiodiversitywithrandomfissionspeciation.TheorEcol第11页，课件共19页，创作于2023年2月Furtherstudy–niche-ovlappedHowever,thedegreetowhichrealecologicalcommunitesareacttuallyneutralisamoreopenquestion(GotelliandMcGill,2006).Thatis,whatisadistributionofecologicalcommunitiesalongacontinuumformpurelyneutral,througthweeklynich-structured,tostronglyniche-structured(Adler,HilleRisLambers&Levine2007)?---Differentbutequal:theimplausibleassumptionattheheartofneutraltheory,2011.Inthepresentcase,ourquestionis:whenisthelimitedcomplexityoftheneutralmodelsufficienttoprovideausefulapproximationtoamodelofbiodiversitywithsimplenichestructure?---Theorypredictsarapidtransitionfromniche-structuredtoneutralbiodiversitypatternsacrossaspeciation-rategradient,2011.第12页，课件共19页，创作于2023年2月Furtherstudy–niche-ovlappedChishomandPalaca(2010)presentananalyticalproofthat,inthelimitasdiversitybecomeslarge,astrongnichemodelgiverisestoexactlythesameasymptoticformofSADastheneutralmodel.HaegemanandEtienne(2011)arguethattheirresultisanartefactbecausetheirmodelforhighdiversityisequivalenttoanindependent-speciesmodel.theyanalysethisindependent-speciesmodel,andshowthatitsSADsareidenticaltoneutralpredictionsforalllevelsofdiversity.第13页，课件共19页，创作于2023年2月Furtherstudy–niche-ovlappedChishomandPalaca(2011):Asthespeciationrateinthehybridmodelincreases,weobserveasurprisinglyrapidtransitionfromanecosysteminwhichdiversityisalmostentirelygovernedbynichestructuretooneinwhichdiversityisstatisticallyindistinguishablefromthatoftheneutralmodel.Posteriorprobabilitythatanobservedspeciesabundancedistributionfromthehybridmodelcomesfromaneutralmodel,givenanuninformativedichotomouspriorthatspecifiesequalprobabilitiesfortheneutralmodelandthepure(broken-stick)nichemodel(P(neutral)=P(brokenstick)=0.5),fordifferentvaluesofthespeciationrate.Otherparametersarem=0.1,J=20,000,JM=1012,K=16.Seetextformodeldetails.Dashedlinesshow95%confidenceintervals(estimatedfrom20simulations)第14页，课件共19页，创作于2023年2月Furtherstudy–RelaxneutralityassumptionZhouandZhang(2008):Theneutraltheorycanbeextendedtoexplaintheseobservationsbyallowingspeciestodifferslightlyintheircompetitiveability(fitness).第15页，课件共19页，创作于2023年2月Furtherstudy–RelaxneutralityassumptionZhangetal.(2011)demonstratehowsuchaweakerformofsymmetrycangeneratesignificantmacroecologicaldiversitypatterns,leadingtoaverydifferentinterpretationoftherelationbetweenFisher’saandHubbell’sfundamentalbiodiv