进化生态学.docx

进化生态学.docx

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进化生态学

AnIntroductionofEvolutionaryEcology

Outline

1.Introduction........................................................................................................1

2.Treeoflife…………………………………………………………………………………………………………2

3.Biogeography…………………………………………………………………………………………………….4

4.Theforcesofevolutionarychanges…………………………………………………………………..7

5.Speciesandspeciation………………………………………………………………………………………9

Introduction：

Evolutionaryecologyliesattheintersection（交叉）ofecology（生态学）andevolutionarybiology.Itapproachesthestudyofecologyinawaythatexplicitly（明确的）considerstheevolutionaryhistoriesofspeciesandtheinteractionsbetweenthem.Conversely,itcanbeseenasanapproachtothestudyofevolutionthatincorporates（并入）anunderstandingoftheinteractions（互动）betweenthespeciesunderconsideration.Themainsubfields（分支）ofevolutionaryecologyarelifehistoryevolution,sociobiology（theevolutionofsocialbehavior）,theevolutionofinterspecificrelations（cooperation,predator-preyinteractions,parasitism,mutualism）andtheevolutionofbiodiversityandofcommunities.

Pristine,naturalenvironmentsthathavebeenrelativelyunaltered（未被改变的）byhumansareofparticularimportanceinevolutionaryecologybecausetheyconstitute（构成）theenvironmentstowhichanyparticularorganismhasbecomeadaptedtoovertime.

Darwin’stheoriesofevolution（Mayr,2001inWhatEvolutionIs）

1.Thenonconstancyofspecies

2.Thedescent（由来）ofallorganisms（生物）fromcommonancestors（branchingevolution;treeoflife）

3.Thegradualness（逐渐）ofevolution（nosaltations跳跃,nodiscontinuities中断，不连续）

4.Themultiplication（增加）ofspecies（theoriginofdiversity）

5.Naturalselection

Whatisevolution

1.Evolutionasaprocessinsteadofanentity

2.Evolutionbiologyasascientificdisciplinestudyingtheevolutionaryprocessanditsoutcomes,andapplicationsfrommoleculestoecosystems

3.Evolutionasaworldview

a）“Nothinginbiologymakessenseexceptinthelightofevolution”

4.Thetriumph（成功）ofaconcept

Evolutionischangeintheheritabletraitsofbiologicalpopulationsoversuccessivegenerations.Evolutionaryprocessesgiverisetodiversityateverylevelofbiologicalorganisation,includingthelevelsofspecies,individualorganisms,andmolecules.

AlllifeonEarthsharesacommonancestorknownasthelastuniversalancestor,whichlivedapproximately3.5–3.8billionyearsago,althoughastudyin2015found"remainsofbioticlife"from4.1billionyearsagoinancientrocksinWesternAustralia.Accordingtooneoftheresearchers,"IflifearoserelativelyquicklyonEarth...thenitcouldbecommonintheuniverse."

Repeatedformationofnewspecies（speciation）,changewithinspecies,andlossofspecies（extinction）throughouttheevolutionaryhistoryoflifeonEartharedemonstratedbysharedsetsofmorphologicalandbiochemicaltraits,includingsharedDNAsequences.Thesesharedtraitsaremoresimilaramongspeciesthatshareamorerecentcommonancestor,andcanbeusedtoreconstructabiological"treeoflife"basedonevolutionaryrelationships,usingbothexistingspeciesandfossils.Thefossilrecordincludesaprogressionfromearlybiogenicgraphite,[10]tomicrobialmatfossils,tofossilizedmulticellularorganisms.Existingpatternsofbiodiversityhavebeenshapedbothbyspeciationandbyextinction.Morethan99percentofallspeciesthateverlivedonEarthareestimatedtobeextinct.EstimatesofEarth'scurrentspeciesrangefrom10to14million,ofwhichabout1.2millionhavebeendocumented.

Inthemid-19thcentury,CharlesDarwinformulatedthescientifictheoryofevolutionbynaturalselection,publishedinhisbookOntheOriginofSpecies（1859）.Evolutionbynaturalselectionisaprocessdemonstratedbytheobservationthatmoreoffspringareproducedthancanpossiblysurvive,alongwiththreefactsaboutpopulations:

1）traitsvaryamongindividualswithrespecttomorphology,physiology,andbehaviour（phenotypicvariation）,2）differenttraitsconferdifferentratesofsurvivalandreproduction（differentialfitness）,and3）traitscanbepassedfromgenerationtogeneration（heritabilityoffitness）.Thus,insuccessivegenerationsmembersofapopulationarereplacedbyprogenyofparentsbetteradaptedtosurviveandreproduceinthebiophysicalenvironmentinwhichnaturalselectiontakesplace.Thisteleonomyisthequalitywherebytheprocessofnaturalselectioncreatesandpreservestraitsthatareseeminglyfittedforthefunctionalrolestheyperform.Naturalselectionistheonlyknowncauseofadaptationbutnottheonlyknowncauseofevolution.Other,nonadaptivecausesofmicroevolutionincludemutationandgeneticdrift.

Intheearly20thcenturythemodernevolutionarysynthesisintegratedclassicalgeneticswithDarwin'stheoryofevolutionbynaturalselectionthroughthedisciplineofpopulationgenetics.Theimportanceofnaturalselectionasacauseofevolutionwasacceptedintootherbranchesofbiology.Moreover,previouslyheldnotionsaboutevolution,suchasorthogenesis,evolutionism,andotherbeliefsaboutinnate"progress"withinthelargest-scaletrendsinevolution,becameobsoletescientifictheories.Scientistscontinuetostudyvariousaspectsofevolutionarybiologybyformingandtestinghypotheses,constructingmathematicalmodelsoftheoreticalbiologyandbiologicaltheories,usingobservationaldata,andperformingexperimentsinboththefieldandthelaboratory.

Evolutionisacornerstoneofmodernscience,acceptedasoneofthemostreliablyestablishedofallfactsandtheoriesofscience,basedonevidencenotjustfromthebiologicalsciencesbutalsofromanthropology,psychology,astrophysics,chemistry,geology,physics,mathematics,andotherscientificdisciplines,aswellasbehavioralandsocialsciences.Understandingofevolutionhasmadesignificantcontributionstohumanity,includingthepreventionandtreatmentofhumandisease,newagriculturalproducts,industrialinnovations,asubfieldofcomputerscience,andrapidadvancesinlifesciences.Discoveriesinevolutionarybiologyhavemadeasignificantimpactnotjustinthetraditionalbranchesofbiologybutalsoinotheracademicdisciplines（e.g.,biologicalanthropologyandevolutionarypsychology）andinsocietyatlarge.

EvolutionaryBiology:

anadaptationist’sview

EvolutionarybiologyisasubfieldofbiologyconcernedwiththestudyoftheevolutionaryprocessesthatproducedthediversityoflifeonEarth.Someonewhostudiesevolutionarybiologyisknownasanevolutionarybiologist.Evolutionarybiologistsstudythedescentofspecies,andtheoriginofnewspecies.

Treeoflife

Howtheseorganismsareorganized?

1.Taxonomy（alphataxonomy）:

finding,describing,andnamingtaxa

2.Classification（betataxonomy）:

thesortingofspeciesintogroupsofrelatives（"taxa"）andtheirarrangementinahierarchyofhighercategories

3.Systematics

Whatsystematicbiologyis

Systematicbiologyisthescientificstudyofthediversityoforganismsandofanyandallrelationshipsamongthem.

1.Phylogeneticanalysistoproduceortesthypothesesofgenealogicalrelationshipamonggroupsoforganisms（evolutionarytaxonomy）

2.Usingthosehypothesestodiscoverpatternsofstructural,developmental,ormolecularevolution

3.Learnaboutprocessesthatunderlietheoriginandmaintenanceoftaxonomicdiversity

4.Conductstudiesofbiogeographical,co-evolutionary,andpaleobiologicalpatternstolearnaboutthediversification,distribution,andextinctionoftaxa.

5.Learnaboutthetempoandmodeofevolutionarychange.

6.Conductstudiesleadingtoimprovedclassifications,bettermethodsoftaxonomicidentificationandnomenclaturalreform.

Aphylogenetictree系统发育树

atree-likediagramtodepict（描绘）thegenealogicalrelationship（谱系关系）amongorganismsandtheirhypotheticalancestors

Aphylogenetictreeorevolutionarytreeisabranchingdiagramor"tree"showingtheinferredevolutionaryrelationshipsamongvariousbiologicalspeciesorotherentities—theirphylogeny—baseduponsimilaritiesanddifferencesintheirphysicalorgeneticcharacteristics.Thetaxajoinedtogetherinthetreeareimpliedtohavedescendedfromacommonancestor.Phylogenetictreesarecentraltothefieldofphylogenetics.

Rootedtree[edit]

Arootedphylogenetictree（seetwographicsattop）isadirectedtreewithauniquenodecorrespondingtothe（usuallyimputed）mostrecentcommonancestorofalltheentitiesattheleavesofthetree.Themostcommonmethodforrootingtreesistheuseofanuncontroversialoutgroup—closeenoughtoallowinferencefromtraitdataormolecularsequencing,butfarenoughtobeaclearoutgroup.

Unrootedtree

Anunrootedphylogenetictreeformyosin,asuperfamilyofproteins.[1]

Unrootedtreesillustratetherelatednessoftheleafnodeswithoutmakingassumptionsaboutancestry.Theydonotrequiretheancestralroottobeknownorinferred.[2]Unrootedtreescanalwaysbegeneratedfromrootedonesbysimplyomittingtheroot.Bycontrast,inferringtherootofanunrootedtreerequiressomemeansofidentifyingancestry.Thisisnormallydonebyincludinganoutgroupintheinputdatasothattherootisnecessarilybetweentheoutgroupandtherestofthetaxainthetree,orbyintroducingadditionalassumptionsabouttherelativeratesofevolutiononeachbranch,suchasanapplicationofthemolecularclockhypothesis.[3]

Bifurcatingtree[edit]

Bothrootedandunrootedphylogenetictreescanbeeitherbifurcatingormultifurcating,andeitherlabeledorunlabeled.Arootedbifurcatingtreehasexactlytwodescendantsarisingfromeachinteriornode（thatis,itformsabinarytree）,andanunrootedbifurcatingtreeta