物种起源导论04-自然条件下的变异课件

IntroductiontoTheOriginofSpeciesWANGYuguo (School of Life Sciences,Fudan University)复旦大学生命科学学院王玉国物 种 起 源 导 论VARIATION UNDER NATURE自然状态下的变异CHAPTER IIVariability Individual Differences Doubtful species Wide ranging,much diffused,and common species vary most Species of the larger genera in any country vary more than the species of the smaller generaMany of the species of the larger genera resemble varieties in being very closely,but unequally,related to each other,and in having restricted ranges.个体间的差异物种界定的尴尬环境对物种变异的影响大属和小属物种变异的频率Whetherorganicbeingsinastateofnaturearesubjecttoanyvariation？NorshallIherediscussthevariousdefinitionswhichhavebeengivenofthetermspecies.SpeciesGenerallythetermincludestheunknownelementofadistinctactofcreation.Varietiesherecommunityofdescentisalmostuniversallyimplied,thoughitcanrarelybeproved.Monstrositiessomeconsiderabledeviationofstructureinonepart,eitherinjurioustoornotusefultothespecies,andnotgenerallypropagated.VariabilityDarwin:pigshaveoccasionallybeenbornwithasortofproboscisLabukBayProboscisMonkeySanctuarySandakan,Sabah,Malaysia Ifmonstrousformsofthiskindeverdoappearinastateofnatureandarecapableofreproduction(whichisnotalwaysthecase),astheyoccurrarelyandsingly,theirpreservationwoulddependonunusuallyfavourablecircumstances.IndividualDifferencesThemanyslightdifferenceswhichappearintheoffspringfromthesameparents.Noonesupposesthatalltheindividualsofthesamespeciesarecastinthesameactualmould.Theseindividualdifferencesareofthehighestimportanceforus,fortheyareofteninherited,asmustbefamiliartoeveryone;andtheythusaffordmaterialsfornaturalselectiontoactonandaccumulate,inthesamemannerasmanaccumulatesinanygivendirectionindividualdifferencesinhisdomesticatedproductions.个体间的差异Theseindividualdifferencesgenerallyaffectwhatnaturalistsconsiderunimportantparts.Authorssometimesargueinacirclewhentheystatethatimportantorgansnevervary.Itwouldneverhavebeenexpectedthatthebranchingofthemainnervesclosetothegreatcentralganglionofaninsectwouldhavebeenvariableinthesamespecies;itmighthavebeenthoughtthatchangesofthisnaturecouldhavebeeneffectedonlybyslowdegrees;yetSirJ.LubbockhasshownadegreeofvariabilityinthesemainnervesinCoccus(介壳虫),whichmayalmostbecomparedtotheirregularbranchingofthestemofatree.Polymorphicspeciesorvarieties?Hieracium(山柳菊属)Rubus(悬钩子属)Rosa(蔷薇属)Cicindelaaurulenta(金斑虎甲)Brachiopodshells(腕足类)Thesefactsareveryperplexing,fortheyseemtoshowthatthiskindofvariabilityisindependentoftheconditionsoflife.Iaminclinedtosuspectthatwesee,atleastinsomeofthesepolymorphicgenera,variationswhichareofnoserviceordisservicetothespecies,andwhichconsequentlyhavenotbeenseizedonandrendereddefinitebynaturalselection,ashereaftertobeexplained.这些事实令人困惑，因为它们表现出的这些变异，似乎和生活条件无关。我猜想，因为这些变异，至少在某些多型属内对物种本身并无利害关系，所以自然选择既没有对它们起作用，也没有使这些特征固定下来。对此，我将在后文再做解释。Greatdifferencesofstructure,independentlyofvariationDoubtfulSpeciesTaxonomyAiluropodamelanoleuca1868年，法国传教士佩雷阿曼德戴维，在中国看到黑腿白熊毛皮1929年，美国西奥多和克米特罗斯福射杀了一只正在树上睡觉的大熊猫Panda可疑物种Somalibutcherbird?DiversityofMusselsDarwinwasmuchstruckhowentirelyvagueandarbitraryisthedistinctionbetweenspeciesandvarieties.Speciesorvarieties？TheQuercusrobur(夏栎)hastwenty-eightvarieties,allofwhich,exceptingsix,areclusteredroundthreesub-species,namely,Q.pedunculata(有柄栎),sessiliflora(无柄花栎),andpubescens(毛栎).Cycas micholitzii叉叶苏铁叉叶苏铁Cycas siamensis云南苏铁云南苏铁Cycas panzhihuaensis攀枝花苏铁攀枝花苏铁Cycasrumphii华南苏铁Cycasszechuanensis四川苏铁/南盘江苏铁Cycashainanensis海南苏铁Cycas angulata角苏铁Cycas guizhouensis贵州苏铁Cycas segmentifida叉孢苏铁石山苏铁Cycas miquelii台湾苏铁Cycas taiwaniana蓖齿苏铁CycaspectinataCycascouttsianaCycasmachonieCycascincinalis 西米苏铁Cycas revoluta苏铁Ceratozamia robusta粗壮苏铁(墨西哥)长籽苏铁(津巴布韦)Encephalartus manikensisZamia integrifolia全缘大苏铁苏铁科，裸子植物,11属，约110种Microcycas calocoma小苏铁Macrozamia moorei摩耳大苏铁Lepidozamia peroffskyana东澳苏铁大头苏铁Encephalartos gratus可爱苏铁Encephalartos friderici-guilielmiiDioonspinulosum 刺苏铁Stangeria eriopusBoweniaspectabilisCrowdedNoahsArk美国DigitalGlobe公司“快鸟”2003年拍摄到的“亚拉腊山异物”卫星照片Mt.Ararat“诺亚方舟”长300英尺、宽50英尺，高30英尺，分为上、中、下三层。这个尺寸是长133.29米、宽22.22米、高13.33米。方舟每层甲板的面积有3000多平方米，约为泰坦尼克号的一半。它的总重量为1.4万吨，完全由木头构成。宾西法尼亚州艺术家爱德华-希金斯的画作诺亚方舟有人认为多乌巴亚泽特是诺亚方舟的所在地Tigers:PastandPresent123虎8个变种，3个已经绝灭巴厘虎巴厘虎(Balinese Tiger)分布于印尼巴里岛分布于印尼巴里岛二十世纪二十世纪40年代灭绝年代灭绝爪哇虎爪哇虎(Javan Tiger)分布于印尼爪哇岛分布于印尼爪哇岛二十世纪二十世纪80年代灭绝年代灭绝里海虎里海虎(Caspian Tiger)分布于土耳其至亚洲中部以及西部分布于土耳其至亚洲中部以及西部二十世纪二十世纪70年代灭绝年代灭绝123苏门达腊虎(SumatranTiger)东北虎(SiberianTiger)华南虎(SouthChinaTiger)印支虎(Indo-chineseTiger)孟加拉虎(Pantheratigristigris)甲虫33万种向热带森林喷洒杀虫剂上千种新甲虫已经记录的真菌7万专家估计尚未发现的还有100万种全世界哺乳动物5000个类型还可能发现3000个新类型一把海底淤泥可能有100个类型的线虫海洋养育的动物类型可能多达50-1000万saolaHyemoschusaquaticusMoschiolameminnaTragulus美洲豹蛙(Ranapipiens)northernleopardfrog-渐变群群(cline)的经典例子的经典例子如果种群很大，或者同一物种的多个种群散布在大片地理区域中，邻近的种群虽然仍可杂交，但位于极端的种群，彼此相隔很远，已不能杂交，它们只能和相邻的种群杂交，而这一相邻的种群又可和它周围的种群杂交。MouseslegendItallstartedwithamouse.小小 鼠鼠(Mus musculus musculus)家家 鼠鼠(Mus musculus domesticus)Subfamily Murinae(Old World rats and mice)Genus Mus(Old World mice)SpeciesMus baoulei(Baoulesmouse)SpeciesMus booduga(littleIndianfieldmouse)SpeciesMus bufo(toadmouse)SpeciesMus callewaerti(Callewaertsmouse)SpeciesMus caroli(Ryukyumouse)SpeciesMus cervicolor(fawn-coloredmouse)SpeciesMus cookii(Cooksmouse)SpeciesMus crociduroides(Sumatranshrewlikemouse)SpeciesMus famulus(servantmouse)SpeciesMus fernandoni(Ceylonspinymouse)SpeciesMus fragilicauda(sheath-tailedmouse)SpeciesMus goundae(Goundamouse)SpeciesMus haussa(Hausamouse)SpeciesMus indutus(desertpygmymouse)SpeciesMus macedonicus(Macedonianmouse)SpeciesMus mahomet(Mahometmouse)SpeciesMus mattheyi(Mattheysmouse)SpeciesMus mayori(Mayorsmouse)SpeciesMus minutoides(pygmymouse)SpeciesMus musculoides(Kasaimouse)SpeciesMus musculus(house mouse)SpeciesMus neavei(Neavesmouse)SpeciesMus orangiae(orangemouse)SpeciesMus oubanguii(Oubanguimouse)SpeciesMus pahari(Gairdnersshrewmouse)SpeciesMus phillipsi(Phillipssmouse)SpeciesMus platythrix(flat-hairedmouse)SpeciesMus saxicola(rock-lovingmouse)SpeciesMus setulosus(Petersmouse)SpeciesMus setzeri(Setzerspygmymouse)SpeciesMus shortridgei(Shortridgesmouse)SpeciesMus sorella(Thomasspygmymouse)SpeciesMus spicilegus(mound-buildingmouse)SpeciesMus spretus(Algerianmouse)SpeciesMus tenellus(delicatemouse)SpeciesMus terricolor(earth-coloredmouse)SpeciesMus triton(gray-belliedpygmymouse)SpeciesMus vulcani(volcanomouse)Species of the Larger Genera in each Country Vary more frequently than the Species of the Smaller Genera.Many of the Species included within the Larger Genera resemble Varieties in being very closely,but unequally,related to each other,and in having restricted ranges.Wide-ranging,much diffused,and common Species vary most.分布广、扩散大的常见物种极易发生变异各地区较大属内的物种比较小属内的物种更容易发生变异与物种内各变种间的情况相似，一个大属内的许多物种也都彼此程度不等地密切相关，而且在分布上都有局限性Inga edulisInga veraInga laurinaInga punctataInga印加豆属(豆科-含羞草亚科Leguminosae-Mimosoideae)SummaryFinally,varietiescannotbedistinguishedfromspecies,except,first,bythediscoveryofintermediatelinkingforms;and,secondly,byacertainindefiniteamountofdifferencebetweenthem.-Ingenerahavingmorethantheaveragenumberofspeciesinanycountry,thespeciesofthesegenerahavemorethantheaveragenumberofvarieties.-Inlargegenerathespeciesareapttobeclosely,butunequally,alliedtogether,forminglittleclustersroundotherspecies.-Speciesverycloselyalliedtootherspeciesapparentlyhaverestrictedranges.Whatarevarietiesbutgroupsofforms,unequallyrelatedtoeachother,andclusteredroundcertainformsthatis,roundtheirparent-species?Inalltheserespectsthespeciesoflargegenerapresentastronganalogywithvarieties.Andwecanclearlyunderstandtheseanalogies,ifspeciesonceexistedasvarieties,andthusoriginated;whereas,theseanalogiesareutterlyinexplicableifspeciesareindependentcreations.Wehave,also,seenthatitisthemostflourishingordominantspeciesofthelargergenerawithineachclasswhichonanaverageyieldthegreatestnumberofvarieties;andvarieties,asweshallhereaftersee,tendtobecomeconvertedintonewanddistinctspecies.Thusthelargergeneratendtobecomelarger;andthroughoutnaturetheformsoflifewhicharenowdominanttendtobecomestillmoredominantbyleavingmanymodifiedanddominantdescendants.Butbystepshereaftertobeexplained,thelargergeneraalsotendtobreakupintosmallergenera.Andthus,theformsoflifethroughouttheuniversebecomedividedintogroupssubordinatetogroups.Biologicalspeciesconcept(BSC)SpeciesConcept“Speciesaregroupsofinterbreedingnaturalpopulationsthatarereproductivelyisolatedfromothersuchgroups.ErnstMayrAspeciesisasetoforganismsadaptedtoaparticularsetofresources,calledaniche,intheenvironment.EcologicalspeciesconceptSupplementary materialsPhylogenetic Species Concept(PSC)Speciesaredefinedasthesmallestdiagnosablemonophyleticgroup.Biologistshavenotbeenabletoagreeonexactlywhataspeciesis,orhowspeciesshouldbeabstractlydefine.Morphospecies Concept/Morphological Species ConceptSpeciesaregroupsofindividualsthataremorphologicallysimilarandclearlydistinguishablefromindividualsofothergroups.Phenetic Species ConceptPheneticspeciesconceptdefinesaspeciesasasetoforganismsthatlooksimilartoeachotheranddistinctfromothersetsThe Recognition Species Concept-AccordingtoPatterson(1993),specieshaveaspecific mate recognition system（SMRS，特异配偶识别系统）.-Speciescanbedefinedasasetoforganismswithacommonmethodofrecognizingmates物种是由种群组成的生殖单元，它与其他单元在生殖上互相隔离，并在自然界占有一定的生态位，在宗谱线上代表一定的分支。