Paleontological Society Systematics and Paleobiology Author(s): Niles Eldredge and Michael J. Novacek Source: Paleobiology, Vol. 11, No. 1 (Winter, 1985), pp. 65-74 Published by: Paleontological Society Stable URL: http://www.jstor.org/stable/2400424 Accessed: 04-01-2016 19:37 UTC Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://www.jstor.org/page/ info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Paleontological Society is collaborating with JSTOR to digitize, preserve and extend access to Paleobiology. http://www.jstor.org This content downloaded from 132.248.28.28 on Mon, 04 Jan 2016 19:37:58 UTC All use subject to JSTOR Terms and Conditions Paleobiology,11(l), 1985, pp. 65-74 Systematicsand paleobiology Niles Eldredgeand MichaelJ. Novacek Abstract.-Systematics,ostensibly the "old" paleontology,actually plays a centraland crucial role in modernpaleobiology. We argue that a revisedontology has recentlydarified the natureof species and has expresslyadded monophyleticgroups to the rosterof spatiotemporallybounded entities-"individ- uals -that are now seen as participantsin the evolutionaryprocess. Systematics is the studyof species and monophyletictaxa, and fossilsalone providethe data on the temporalboundedness of such taxa. Cladistics(phylogenetic systematics) is explicitlygeared to the recognitionof monophyletictaxa. We reviewaspects of the core problemof characteranalysis in systematics,particularly addressing the still contendedissue of the seeminglycompetitive claims of three methodologies:out-group comparison, comparativeontogeny, and the "paleontologicalmethod." We findthat these methodsoverlap in their basic assumptionsto a significantextent, yet each retainsa characteristicand distinctiveflavor. They are not all "the same," nor are theyalways "complementary"'-and no one methodis superiorto the others in all circumstances. Far frombeing the Victoriansymbol of a moribundscience, systematics lies at thevery heart of modern paleobiologicalresearch, providing the centraldata forpaleobiology's truly unique contribution,both real and potential,to evolutionarybiology in general. Niles Eldredgeand Michaelj. Novacek. Departmentsof Invertebrates and VertebratePaleontology, American Museumof Natural History,Central Park Westat 79thSt., New York,New York10024. Accepted: November5, 1984 Searchingfor the connectionbetween system- evolved or that eutherianmammals are mono- atics and paleobiologyis like asking why the phyletic. PaleontologicalSociety supports not one but two And so we ask, What is the data base of journals:Journal of Paleontology,heavily given paleobiology?Perusal of the firstdecade of Pa- over to the descriptionof taxa (predominantly leobiologyreveals the heavyimpact of ecological species),and Paleobiology,seemingly devoted to and functionalmorphological theory, relying re- just about everythingbut systematics.Paleobiol- spectivelyon analyzedoccurrences of various sorts ogyembodies the ideas that are half of any sci- of ecologicalunits and on the physicalanalysis ence's lifeblood.Here one findsout why fossils of organismalphenotypes as the data base. But are interestingat all, and what relevancethey therehave also been manydiscussions of "evo- may have to an understandingof life'spast and lution," particularlydiversity studies, and these perhapseven some of theforces that have shaped usually involve numbers of subunits within thathistory. In contrast,systematics often seems units--suchas familieswithin orders. Clearly a dull, atheoretical,and forevercommitted mind- large proportionof studiespublished in Paleo- lesslyto dustingoff, correcting, and adding to biologydepend directly on systematicsas a source the accomplishmentsof our forerunners. of data. Yet mostof us also realizethat the otherhalf This latterstate of affairsstrikes us as highly of any science'sessential fluids is information, appropriate.In themost direct discussion of sys- statementsabout the real world that are pur- tematics-how it is done and what its relevance portedto be true. Certainlytheory informs our trulymight be for paleobiology-that has yet data, even to the point of influencingheavily appeared in these pages, Cracraft(1981) em- what we thinkwe observeabout nature.Yet it phasized the need fordades (be they"real" or is the informationthat keeps the theoryhonest. "imagined") to be monophyletic:for monophy- That is how we reallymake progressin the his- letictaxa are literallybranches on thetree of life. tory of knowledge: ideas consistentlyverified More thanmetaphor is at workhere: life, we all eventuallyleave the realmof theoryand become agree,has had a history.There has been "descent "fact." There is no seriousdoubt that life has withmodification," and it is the generalaim of ? 1985 The PaleontologicalSociety. All rightsreserved. 0094-8373/85/1 101-0006/$1.00 This content downloaded from 132.248.28.28 on Mon, 04 Jan 2016 19:37:58 UTC All use subject to JSTOR Terms and Conditions 66 NILES ELDREDGE & MICHAEL J.NOVACEK systematicsto identifyall the integralrami on about Ghiselin's (1974a, b) "radical individu- that tree.' Thus is life's historyreconstructed, alism," we see immediatelythat contemporary and that, it seems clear, is the basic natureof biologicaltheory has not,in general,seen species the data base whichpaleontology (and system- and monophyletictaxa of rank higher than aticsin general)can giveto evolutionarybiology. species as "individuals,"that is, as spatiotem- Cracraft's(1981) paper should be consultedfor porallybounded entities. If one doeslook at such more detail on why monophylyis important- entitiesin thisway, the ontologyof evolutionary and why it is that systematicsis relevantfor biology,the list of "things"we thinkparticipate paleobiology. in someway in theevolutionary process, is some- We wish, here, to go a bit further.Specifi- what expandedfrom the conventionalgenes, or- cally, we are concernedwith what systematics ganisms,populations, and species (the latterin (includingsystematic paleontology) can contrib- a generallyahistorical sense) to include species ute to paleobiology-and herewe mean partic- and highertaxa as actual historicalunits. And ularlythe genealogicaland economicaspects of thisimplies that the data of systematicsare di- evolution.(See Eldredgeand Salthe119841, Vrba rectlyrelevant-really for the first time-to test- and Eldredgei19841, and Eldredge 119851for ing notionsof evolutionaryprocess. And paleon- discussionsof these twin aspects of the evolu- tologyis our primesource of informationon the tionaryprocess in explicitlyhierarchical terms.) temporalboundedness of individual taxa. We It seemsto us thatsystematics points the way to emerge,in short,holding the cards when it comes a deeper understandingof what paleobiology to decidingwhat the grosserpatterns of the his- holds as unique in its data base. To the query, toryof lifehave been,even though such patterns What is unique about thefossil record? the usual may not requirehigher-level processes for their responseis, of course,time. From the vantage explanation.Paleobiology is thusfreed to devise point of systematics,though, time is only part testabletheory, and to consultits own data base of the answer.Much moreto the point,we ap- to testits theory.And, of course,to some extent pear to be at the brink of adopting a revised thisis aleady going on. We need no longeras- ontologyof the biologicalrealm. Indeed, Hull cribeall aspectsof the anatomicalmodification (1980) has even claimed that no progressin betweenthe Warrawoona prokaryotes and Blan- evolutionarybiology is in prospectuntil we do can bisonsto the vagariesof shiftingallelic fre- revise our basic conceptionson the nature of quencies. biological entities,going beyond the obvious "commonsense"ontology and beginningto see Systematics:Seeing the Forest for the Trees that there are additional biological entitiesat The Modern Synthesis,according to some of play in theevolutionary game. Bettertheory and its more recentchroniclers, gave us a deep ap- laboratoryinstrumentation have now convinced preciationof variation.No two organisms,real- us of the existenceof codons,pseudogenes, and ly,are exactlyalike, and as Lewontin(e.g., 1974) transposons-and we even think we know has been pointingout foryears, an appreciation somethingof theirnature and how theyshape of variationwas one of the majorfacets of Dar- the courseof evolution.An enhancedontology win's revolution.Its reemphasisin the synthesis could also embracethe rethinkingof ecological had an immediateimpact on systematics;it was units, and here paleontologybecomes directly J. S. Huxleywho named boththe "modernsyn- relevant(Eldredge and Salthe 1984; Eldredge thesis" and the "new systematics"within the 1985; Salthe 1985). But our subjectis system- briefspan of two years.The reason forthe as- atics,and that leaves taxa. In short,if we think sociationbetween the two is obvious enough: interorganismicvariation within populations and I We are awarethat some dadists(see, e.g., Platnick1979) speciesis the raw stuffon whichselection works. maintainthat theirs is a searchsimply for "natural groups," Evolutionin the Darwiniantradition, of course, withno attendantnotion of evolutioninvolved.