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MEN AND IDEAS

The Faith of DarwinismBy Marjorie Grene

"Vainly did we philosophersand ~ritical theo-logians over and over again decree the extermina-tion o[ miracles,our ineffectual sentencedied away,becausewecould neither dispense with miraculousagency,nor point to anynatural[orce able to supplyit, where t hadseemedmost ndispensable.Darwinhas demonstratedhis [orce, this processo[ Nature;he has opened he door by which a happier comingrace will cast out miracles,never to return. Every-one who knowswhat miracles imply will praisehim, in consequence, s one o[ the greatest bene-]actors o[ the humanace."T r~ u s wrote he Biblical critic DavidStraussin The Old Faith and the New, publishedin English translation in ~873 and quoted byGertrude Himmelfarb in her Darwin and theDarwinianRevolution.* The sixties and seven-ties saw, not only the triumph of Darwinismover religion, but the rise of Darwinismasreligion: as a religion of humanity, mpelled bythe inhumanityof literal Christian belief. Dar-win, though himself only partly a Darwinian,yet set the tone for this aspect of the Darwiniancult in his autobiography--in a passage sup-pressed by his widowand included in the newcompleteedition:

I can indeed hardly see howanyoneought towishChristianity o be true; for, if so, the plainlanguageof the text seems o show hat the menwhodo not believe, and this would nclude myFather, Brother and almost all mybest friends,will be everlastingly punished. And his is adamnable octrine.

This ~damnabledoctrine" of Christianity hasbeen the target of evolutionary ethics from theearly T. H. Huxley to Julian Huxley, GeorgeGaylord Simpson, or Theodosius Dobzhanskyin the present generation. Sin, punishment, helast vestige of the jealous Hebrewgod, suchthinkers feel, have been vanquished under the* Chatto & Windus. 2s. 48

benevolent banner of purely naturalistic nature,unplanned and therefore unresentful. So wehave, for instance, Julian Huxleys"morality ofevolutionary direction":Anything which permits or promotes opendevelopments right, anything which estrictsor frustrates developments wrong.

SomeDarwinians, it is true, deny this ethicalimplication of Darwinism. T. H. Huxley, inhis later years, denied it; so does the Britishnaturalist David Lack in a recent book calledEvolutionary Theory and Christian Belie[: TheUnresolved Conflict. For such thinkers, Dar-winian nature, which scientific conscience com-pels them o accept, is the blind ongoingof factindifferent to value and incapable of generatingvalue. Morality must maintain itself, on thisview, not within, but against the evolutionarystream. But this is, on the whole, an exceptionalview; the humanitarian Leitmoti[ has been agenuine force in the origin and spread of Dar-winism.Yet this is only half the story, and the lesserhalf. It is as a religion o[ sciencethat Darwinismchiefly held, and holds mens minds. The deri-vation of life, of man, of mans deepest hopesand highest achievements,from the external andindirect determination of small chance errors,appears as the very keystone of the naturalisticuniverse. And he defence of natural selectionappears, therefore, as the defence of the in-tegrity, the independence,he dignity of scienceitself. In this spirit T. H. Huxley irst rose toits defence:

I have aid that the man f science s thesworn nterpreter of nature in the high court ofreason. Butof what vail is his honest peech, fignorance s the assessor of the judge, and preju-dice the foreman f the jury ?... To hose whoselife is spent, to use Newtons oble words, inpicking up here a pebble and there a pebble on

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The Faiththe shores of the great ocean of truth--whowatch, day by day, the slow but sure advanceofthat mighty fide, bearing on its bosom hethousand reasures wherewithmanennobles andbeautifies his life--it would e laughable, f itwerenot so sad, to see the little Canutes f thehour enthroned in solemn state, bidding thatgreat wave o stay, and threatening o check tsbeneficentprogress ... Surely, t is the duty ofthe public to discourageanythingof this kind,to discredit these foolish meddlerswho hinkthey do the Almighty service by preventing athoroughstudy of His works.

Thus, a century ago, Darwinism gainst Chris-tian orthodoxy.To-day he tables are turned. The modified,but still characteristically Darwinianheory hasitself becomean orthodoxy, preached by itsadherents with religious fervour, and doubted,they feel, only by a few muddlers mperfect inscientific faith. Sir Gavinde Beersgreat classicEmbryosand Ancestors, for example, presentsin brilliant array a host of embryologicaldatabearing on evolution, but with no apparentrelevance o the processof natural selection. Yethe concludes he third edition:It is now ecognised hat evolution s the resultof selection acting on heritable variation in theform of mutation and recombination of Men-delian genes. These processesmust have been atwork in all the evolutionary changes onsideredin this book. The morphologicalmodes escribeaspects of the coursewhich he changes ook, butit wasvariation andselection which aused hem.(mytalics)

And accordingly, in his centennial essay inEndeavour,Sir Gavin assures us that . . with the same confidence as it acceptsCopernicussdemonstrationsof the movementfthe Earth round the sun and Newtons ormula-tion of the laws of this movement,cience cannow elebrate the centenaryof the first generalprinciple to be discovered pplicable o the entirerealmof living beings.

Biology, thanks to Darwin with assistance, in-deed, from the rediscoverers of Mendel),has atlast matured into a proper science, "Lamarcknonsense" is disinherited, old metaphysicalfollies re-echoonly distantly in the ears of a fewfoolish mystics. Branchesof biology once dis-parate--paleontology, embryology, cology, tax-onomy, genetics--converge on the new, greatsynthesis. Matter becoming life (and mind)through natural selection of small chance muta-tions; life spreading in ever new directionsthrough opportunistic exploitation of the un-expected: of new niches in nature happening tofit a slightly newdeparture in the arrangement

of Darwinism 49of established genotypes, or slightly newgeno-types happening to tumble into hitherto un-exploited environments--this s the vision whichexperiment and mathematics, field observationand its statistical analysis combineo support.T HrRx was a time, about the turn of thecentury, when he concept of mutation--i.e.of a sudden change n the structure of the germplasm--appcared to contradict Darwins viewof a slow and gradual process in whichslightlyless fit variations wereeliminated in favour ofthe slighdy better adapted. But beginning withSir RonaldFishers Genetical Theoryo] NaturalSelection in ~93o there has arisen a most impos-ing synthesis of these two conceptions. Darwindid not knowwhether inheritance was blendingor particulate--whether variations once occur-ring were or were not assimilated in someun-knownway into the material of inheritance.Mendel, whose work lay buried till the early2oth century, had, in fact, in Darwins ifetimeproved the particulate basis. This seemedatfirst to mean hat variations, for the use ofevolution, are suddenand large, and not minuteand gradual as Darwin imagined. What Fishersaw, however, was (0 that particulate inheri-tance retains variations for selection to workon,as blending inheritance wouldnot, and (2) thatit is not the changes n individuals that matter,for the purposes of evolution, but the changesin populations--and these are gradual. For ifyou have an active interbreeding population,say, of a thousand fruit flies, and you get achangedgene, say, for eyeless, in one chromo-some n one of them, the proportion will nowbe 999 normal lies to one containing the muta-tion (and the correspondingchange in the geneswill be to r,999 of the normalallele and one ofthe mutated form); in the next generation youmayhave 998 to two (or x,998 normal genes totwo mutated ones) and so on. This kind ofchange in a population is usually, and can be,very gradual; and it is measurable y statisticalmethods. n fact this measurements said to bethe measure f selective intensity--the change nMendelian roportions in a population is naturalselection, or genetical selection, as it is moreproperly called, and Darwinisms vindicated.

Yet surely, one mayprotest, Darwins theoryhad to do with the "preservation of favouredraces," the survival of the fittest and all that.On the face of it, these changing Mendelianratios seem o have no connection with increas-ing adaptation, or the elimination of the unfit,or anything of the sort. Yet here, too, themodern heory is more Darwinian than Darwinhimself. "Evolution," Fisher says, "is progres-sive adal~tation and consists in nothing else."Andifeitselfis evolution: populations volving,




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5Ofitting in here and there, weeding themselvesout here and there, as changing opportunitiesappear and disappear. That is what selectiveintensity measures; for what else could it .con-ceivably be measuring? Darwin excepted somecharacters from this rule, seeing no reason toconsider them advantageous or otherwise. Butmodern ecological methods have greatly ampli-fied and codified the relevant data, and haveproved even some of Darwins exceptions--notably, for instance, colour polymorphism inthe commonand snail--to be in fact confirma-tions of his view. For modern Darwinians ~nlytrivial variations can be indifferent to selectionpressure. Whatever characters are stable musthave a reason, and the reason must be adaptive,otherwise natural selection could not control it.

The compelling power of the selection theory--that is, the view that all major trends inevolution are adaptive, and that the genesis ofadaptations is explained by the gradual andexternal control of chance variations throughselection pressure--is well illustrated, for ex-ample, by de Beers reasoning in the centennialessay quoted above. Attacking those who invokeagainst the selection theory its "mathematicalimprobability," he argues that they

can be refuted out of their own mouths.Muller has estimated that on the existing know-ledge of the percentage of mutations that arebeneficial, and a reasoned estimate of the numberof nautations that would be necessary to convertan amoeba into a horse, based on the averagemagnitude of the effects of mutations, the num-ber of mutations required on the basis of chancealone, if there were no natural selection, wouldbe of the order of one thousand raised to thepower of one million. This impossible andmeaningless figure serves to illustrate the powero] natural selection in collecting ]avourablemutations and minimising waste o] variation, [orhorses do exist and they have evolved. (my talics)In other words, if horses have evolved--andfew are those who would like to deny it--andif an explanation of this transformation throughrandom mutations alone is excessively unlikely--as indeed it seems to be, since the great majorityof mutations so far observed are adverse or even

lethal--then it must be the automatic selection,in each generation, of very slightly advantageousvariants that has built up the otherwise astonish-ing result. But how, one may ask, do we knowthis? If mutation alone cannot explain theevolutionary process--the origin of life, of sen-tient life, of intelligent life--why is natural selec-tion-the elimination of the worst mutations, anegative and external agency--the only con-ceivable alternative?And what does this selective process really

Marjorie Greneconsist in? Selection selects by definition thebetter adapted alternatives; yet adaptation oftenleads not to survival, let alone to the evolutionof new forms, but to extinction. In de Beerscentennial argument, however, this fact appearsas evidence against a belief in teleology or provi-dence, not against selection. So he argues, onthe very same page as the passage just quoted:It can be shown that the more detailed theadaptation, the more "improbable" it may appearas a product of "chance," the more likely itspossessor is to be doomed o extinction throughinability to become adapted to changed con-ditions. Structures may be developed which atfirst benefit individuals in their competition tosurvive; but by continued selection such struc-tures maybecomeexaggerated and lead to extinc-tion of the species. This seems to have been whathappened to the Huia-bird, where mated pairsconstantly remained in company together, andthe beaks of the male and female reached anextraordinary disparity of size in adaptation to

their very special feeding, but failed to enablethe birds to obtain ordinary food when theirspecial diet wasunavailable. Excess, even of adap-tation, is harmful, and the fossil record showsthat the vast majority of lines of evolution haveled to extinction, which is a grim commentonthe alleged powers of providential guidance andpurpose.So it is; and surely, thanks largely to Darwinsinfluence, few educated people believe literallyany more in "providential guidance and pur-pose" in nature. But is it not also a "grimcomment" on natural selection? Yet convincedneo-Darwinians apparently see no such implica-tion in the Huia-birds fate.IN s r~o R r, three concepts, evolution, in theminimal sense of "descent with modifica-tion" (no "emergence," no "higher and lower"allowed), variation, in the sense of Mendelianmicromutation, tiny changes in the structure orarrangement of the genes, the ultimate materialof heredity (no sweeping or sudden alterationsallowed), and natural selection, the decrease infrequency of those variants that happen in eachsuccessive generation to be less well adaptedthan others to their particular environment:these three form a tight circle within which, inhappy self-confirmation, neo-Darwinian think-ing moves. To those who believe in it, thiscircle is an ample intellectual dwelling place,roomy enough in fact to house all the immenseachievements of modern biological research. Tothose not so convinced, however, the circle seemsa strangely constricted one. They may evenagree with the Professor Emeritus of Zoology atCambridge that "no amount of argument, orclever epigram," can disguise the inherent ira-,,probability of orthodox (Darwinian) theory.




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The Faith ofAnd hough such non-believers maynot, as Dr.Himmelfarb uggests, include a "growing num-ber of scientists," neither are they so few or sofeeble as neo-Darwinian writers sometimessuggest.How oes this tight trio of concepts take sofirm a hold upon so manyand such able minds?If we are r~ot convinced by the neo-Darwiniandogmawe maywell ask this question; and ifwe do so, Dr. Himmelfarbsbook will give usimportant help on the road to an answer. True,she is dealing principally with ~9th-centuryDarwinism; he brings to life not only Darwinas a scientist but also his friends and contem-poraries, Lyell, Huxley,Hooker, nd the climateof opinion in which their ideas originated andflourished. But to do this as clearly and pains-takingly as she does is to makea significantcontribution also to our understanding of thenature of Darwinismn its present form. Threepoints in particular stand out very clearly fromher analysis.F~ R s r, it is one of the majorparadoxes f thehistory of science, that the Darwiniantheory, speculative as it must be by the verynature of its subject-matter, has been held up asa model of simple Baconian nduction throughthe patient accumulation of facts. Now o onedenies that Darwin did patiently accumulatefacts--but the facts he accumulatedduring thevoyage of the Beagle did not at the time leadhim to his species theory, and moreover, formany of the years during which the speciestheory was maturing in his mindhe was in factaccumulating acts not directly about evolutionbut for his extendedworkon barnacles. No, thespecies theory, like most great forwardsteps inscience, was a triumphof scientific imaginationrather than of fact-collecting. Dr. Himmelfarbshowsus plainly, the two leaps of imaginationthrough whlch Darwins theory took shape:first in the sketch of x837, wherehe speaks ofadaptationperpetuated through generatton, andsecondly in the notes of x842 and x844, whichfollow his reading of Malthus on population,the text whichby his ownaccount suggested tohim the concepts of struggle for existence andsurvival of the fittest, the essential agents ofnatural selection. These steps once made, thenew conceptual scheme ook over, and the taskof the Originwas to amplify he evidence in itssupport---evidence gleaned everyhow nd every-where--with he passion of genius, but not, asDr. Himmelfarb emarks, by unusually accurateor systematic collection of data--and toassimilate within its all-enclosing scope what-ever evidencemight appear at first sight to con-flict with it. The methods one of imagination,of extrapolation from a few facts to manymore

Darwinism 51inferred realities seen in terms of the imaginedscheme, and proof of these realities by the ex-clusion of other possibilities. Much he samemethod, Dr. Himmelfarb points out, was em-ployed by Darwin n his work on the origin ofcoral reefs: the subsidence heory, whichhe heldmust be true of all such formations because asa conceptual scheme t was so clearly superiorto the current alternative, the volcanic-cratertheory. And the other alternative being ex-cluded, this one is proved: "If, then," he writes,"the foundations of the manyatolls were notuplifted into the required position, they mustof necessity have subsided into it; and this atonce solves every difficulty." This style of argu-mentoccurs again and again in the Origin also--and it is also very like Sir Gavins argumentabout mutation, selection, and the horse.This is not to suggest that Darwinor Dar-winians, past or present, are."speculative" ratherthan "scientific" in their reasoning. Darwinhimself certainly was not of a philosophical urnof mind;and he certainly believed sincerely, ashis followers have done and do, that, as againstsuch day-dreamingevolutionists as his grand-father or such systematising evolutionists asHerbert Spencer, he was patiendy and empiric-ally and critically pursuingfacts and rejectinghypothesesnot confirmedby facts. Yet what thegenius of Darwinachieved, surely, was not todiscover a host of new facts unknown o hispredecessors that somehowadded up to thefurther fact of evolution throughnatural selec-tion; what he did was to see the facts in a newcontext--an imaginative context, the context ofan idea, but an idea whichseemedand seems omanymodernminds peculiarly factual, an ideaso convincing, o congenial, so satisfying that itfeels like fact.*Moreover, he circular structure which seemsso oddly llogical to the outsider is just what,seen from the inside, most firmly supports thetheory. "The genius--and the folly--of such atheory," Dr. Himmelfarb ays of the subsidencetheory, "is that it can explain anything andeverything," and she showshow his applies to

* Mr. G. F. Seddon as written in the ManchesterGuardianJuly x7th): "It musthavebeenat a fairlyearly age that I decided that Mr. Darwinhad abetter explanation of myexistence than God. Iforget whether his idea, once implanted, spreadlike a cancerous rowth o oust the other belief, orwhether t filled a vacuumeft by loss of belief.Howevert happened,t seemedatisfyingly right,and t still does."Dr. Gertrude Himmelfarb n Darwinand theDarwinianReuolution knocks holes in his dataand his logic, but even f she took the bottomoutof him altogether (which he does not, nor set outto do) I should till find himsatisfying even f notright."




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5 2 Marjoriethe argument f the Originas well. This, again,it seems to me, is an important point if onewants to understand the modernas well as theigth-century evolutionary iterature. Difficultiessuch as the want of intermediaries in the fossilrecord or the problem f explaining on a chance-plus-eliminationbasis .the slow cumulative volu-tion of organs like the eye, Darwinovercamesometimesby adding further hypotheses to sup-port his original hypothesis, sometimes y urg-ing us not to let our reason give in to a meredifficulty of imagination;and his very franknessin facing these difficulties as difficulties seemedto turn themfromdifficulties of the theory intoparts of its proof. How ould this be.; Dr.Himmelfarb suggests that Darwin moves be-tween wo senses of explanation: to explain andto explain away. That maybe what happens ineffect, but the root of the matter, I suspect, liesdeeper. It was he idea of natural selection thatconvinced the Victorians that evolution hap-pened: so much so that for many people theidea of evolution meansnatural selection still.Now he chief direct evidence for evolution isthe fossil record, but this, with its gaps, itsexplosive periods, its development f structurespast any apparent adaptive end, is not in themainevidence for the very gradual, adaptation-controlled process envisaged by Darwin. Yet ifit is evidence or evolution, and evolutionmeansnatural selection, then natural selection, by itsconvincingpower, assimilates to itself the veryevidence which would seem at first glance totell against it. Thus Darwinsargumenton theone hand proves that evolution happened bynatural selection, and on the other hand, con-ceiving evolution as the result of natural selec-tion, identifies all evidence for evolution withevidence or selection. It is not evolutionas suchbut evolutionby selection that defines the circle.Difficulties of selection theory, if they are proofsof evolution, must be in fact proo]sof selection--since that is what,essentially, evolution s.M O n E ~ r arguments work in much thesame way. Thus for example the recentwork of H. B. D. Kettlewell on industrialmelanismhas certainly confirmed he hypothesisthat natural selection takes place in nature. Thisis thestory of the black mutant of the commonpeppered moth which, as Ketdewell has shownwith beautiful precision, increases in numbersin the vicinity of industrial centres and de-creases, being moreeasily exposed o predators,in rural areas. Here, say the neo-Darwinians, snatural selection, that is, evolution, actuallygoing on. But to this we mayanswer: selection,yes; the colour of moths or snails or mice isclearly controlled by visibility topredators; but"evolution"? Do hese observations explain how

Grenei.a the first place there came o be any mothsorsnails or mice at all? By what right are we toextrapolate the pattern by whichcolour or othersuch superficial characters are governed o theorigin of species, let alone of classes, orders,phyla of living organisms? But, say the neo-Darwinians gain, natural selection is the onlymechanismwe observe in present-day nature.But again, if this wereso, we should still haveno right to say that the only mechanismwe seeat work now is the only one that has been atwork n all the long past of the living world.Nor, for that matter, is it the only "mechanism."What of the mechanisms of development? Whynot look at phylogeny s an ontogenywrit large,at the history of groups as expressing a funda-mental rhythm still, in its intimacy, unknownto us, but analogous o the rhythmof individualdevelopment? Because the chance-variation/natural-selection schema, which through Dar-wins work irst convinced he world that evolu-tion did in fact happen, still holds the mindentranced, absorbs into itself all evolutionarydata, and at the same ime rejects all data notso absorbable.To say that neo-Darwinian thinking moveswithin a circle of concepts s not, in itself, how-ever, to challenge its validity. For all compre-hensive theories, all fundamental heories thatthe mind eally dwells in--the corpuscular theoryof the Newtonians,he relativity theory of 2oth-century physicists--are similarly circular, sincethey rest in the last analysis on the self-satisfyingcharacter of their own remises. But in the caseof neo-Darwinism he circle seems so narrow,and the detours taken to maintain t in the teethof the evidence so circuitous and so many.Several years ago, for example, Professor C. H.Waddington ave a series of B.B.C. broadcastscalled "Is the Problem of Evolution Solved?"in which he described some experiments thatseemedat the time to shed somedoubt on someaspects of the current theory; nowhis findingsappear to have been happily assimilated and histitle forgotten. He produceda character called"crossveinless" in fruit flies by subjection tohigh temperature for a short period of time.Breeding crossveinless flies, he got a higherproportion of flies which eacted in this way othe heat treatment; but after a time he got arace of flies that werecrossveinless evenwithoutsubjection to heat. This looked ike a cousin, atleast, of the geneticists old enemy, nheritanceof acquired characters. But no, genes and selec-tion explain it all with ease. So P. M. Sheppardwrites in his recent book Natural Selection andHeredity:

In other words, selection had resulted in acharacter, usually only produced under excep




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The Faithtional environmental conditions, being producedunder normalconditions. Selection for those indi-viduals that produced the character only withheat-shock would give a phenotypically flexiblestock, whereas selection for those that producedit under both conditions would give a pheno-typically fixed one. This result explains howsome plants or animals can develop a gene-complexwhich produces a particular form fittedto a particular environment under most environ-mental conditions; that is to say, they are notphenotypically flexible, whereas in others theform is only produced under the appropriateenvironmental onditions (i.e. it is phenotypicallyflexible).

In short, the gene-complex, together with thetheory of polygenic inheritance, can do any-thing. For each character is controlled, not, asused to be thought, by one gene, but by manygenes, all balancing and buffering one another;and every change in the environment is balancedagainst the resulting balance. Thus in stableenvironments natural selection is conservative,preserving advantageous arrangements againstdisruption; but let the environment begin chang-ing ever so slighdy, natural selection causes--or rather is, by definition--the slight prepon-derance of a genotype slightly more favourableto the new conditions. Whatever might at firstsight appear as evidence against the theory isassimilated by redefinition into the theory.Finally, if evolution is axiomatically evolutionby natural selection, it is at the same timeevolution as progressive adaptation, since it isadaptive relationships that natural selection con-trois. This identity--the dependence of Dar-winian and neo-Darwinian thought on theaxiom that organic phenomena are explicableprimarily in terms of adaptation, of the useful-ness of particular structures and functions inparticular niches in nature--is also illuminated,in its x9th-century background, by Dr. Himmel-farbs work. Firstly, as she points out, the sketchof x837 argues plainly from adaptation as itsbasic datum. Secondly, adaptation" is a matterof means and ends; and the reception of theOrigin as Dr. Himmelfarb describes it showshow essential such means-end relations are toits argument. From he first the Origin, dispens-ing with a planner and with fixed ends for theprocesses of nature, seemed to many criticsmaterialistic and mechanistic in its inspiration,but, saturated as it is with the conception ofutility, fitness, and the like, appealed to othersas the triumphant vindication of teleologicalthinking. For the in-between teleology of utili-tarian thought is indeed the proper habitat, thenatural niche, of Darwinism. Darwin, Shawsaid, threw Paleys famous watch, the paradigmfor the argument from design, into the ocean.

of Darwinism 5 3It was not really, however, the watch he threwaway, but the watchmaker. Darwinism is tele-ology decapitated; everything in nature isexplained in terms of its purpose, but an un-planned purpose in which the organism is tool,tool user, and beneficiary all in one. And theartefact analogy is as basic to Darwinism, bothold and new, as it is to natural theology: notonly is the concept of natural selection groundedon the analogy with the great livestock breeders,but organisms themselves are conceived inPaleyan terms as contrivances, aggregates ofcharacters and functions good for--what? Forsurvival, that is, for going on being good for,going on being good for--and so an adinfinitum. For the summum bonum, like themaker, is dispensed with; yet the means-endrelation, the notion of "this as useful for that,"is fundamental still.

o R E o v E R, despite the attempt of someM of the leading neo-Darwinians to prove aselection theorem independendy of the fact ofadaptation, in purely mathematical terms, allthis, again, is equally true of neo-Darwinism.For again and again in the course of theirarguments the bare mathematics has to beswelled out to its full adaptive context in orderto make of it a theory of evolution--though itmay be drawn in again to statistical and mathe-matical form as scientific respectability demands.From this point of view by far the most honestand consistent statement of Darwinism n recentyears is the Pelican on evolution by MaynardSmith. He starts, for example, with an accountof Dices experiments proving that owls takemore mice against a contrasting than a similarbackground. This is to begin fairly and squarelywith the old Darwinian idea of adaptation forsurvival, and from here he argues ingeniouslybut openly to fit a ~vide variety of evidence intoa frankly utilitarian context. He uses, and citesothers who use, modern statistical methods inthe service of selection theory, but he does notpretend to deduce the equation of evolution withadaptive relationships from a mathematical base.Both the strength and the limitations of thetheory appear with much less ambiguity inthis form.

For it is precisely the insistence on the equa-tion of life with adaptation that defines thelimits of Darwinism, and it is doubt of the all-inclusiveness of adaptation as a concept defini-tive of life that motivates the most effectiveobjections to the Darwinian synthesis. As be-tween the Lamarckian and neo-Darwinian viewsof the origin of adaptations Darwinism appearsto have won out; and though many critics ofDarwinism still challenge it on the ground thatthe infinitely complex harmonies of mutual




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54adaptations could not have been producedsimply by a set of curious chances, the mostfundamental opposition comes, it seems to me,from a more sweeping challenge. One may in-deed ask whether all adaptations have arisenby Darwinian-Mendelian means; but one mayalso ask, as someeminentbiologists do, whetherevolution, on a large as well as on a small scale,is essentially a matter of adaptation at all. Tosuch biologists--such as A. M.Dalcq of Brussels,O. Schindewolf of Tiibingen, or A. Vandel ofToulouse--there appear in fact to be two diver-gent directions in the evolutionary story. Thereare, indeed, all the minute specialised diver-gences like those of the Galapagos inches whichso fascinated Darwin; t is their story that istold in the Originand elaborated by the selec-tionists to-day. But these are dead ends, lastminutia: of development; it is not from themthat the great massive novelties of evolutioncould have sprung. For this, such dissentersfeel, is the major evolutionary theme: great newinventions, new deas of living, which rise withstartling suddenness,proliferate in a variety ofdirections, yet persist with fundamental con-stancy--as in Darwinian terms they wouldhaveno reason in the world o do. Neither the originand persistence of great new modesof life--photosynthesis, breathing, thinking--nor all theintricate and co-ordinated changes needed tosupport them, are explained or even madecon-ceivable on the Darwinian view. And if onereturns to read the Originwith these criticismsin mind, one finds, indeed, that for all thebrilliance of its hypotheses iled on hypotheses,for all the splendid simplicity of the "mechan-ism" by which it "explains" so many and sovaried phenomena, t simply is not about theorigin of species, let alone of the great ordersand classes and phyla, at all. Its argumentmovesin a different direction altogether, in the direc-tion of minute specialised adaptations, whichlead, unless to extinction, nowhere. And hesame s true of the whole mmense nd infinitelyingenious mountain of work by present-dayDarwinians:cest magnifique, mais ce nest pasla guerre That the colour of mothsor snails orthe bloom on the castor bean stem are "ex-plained" by mutation and natural selection isvery likely; but how rom single-celled (and forthat matter from inanimate) ancestors therecame o be castor beans and moths and snails,and howfrom these there emerged llamas and.hedgehogs and lions and apes--and men--that~s a question which neo-Darwinian theorysimply leaves unasked. With nfinite ingenuityit elaborates the microscopic onditions for suchmacroscopic occurrences; but it provides noconceptual framework in terms of which theycan be admitted to exist, let alone an "expIana-

MarjorieGre,te:ion" of their descent from "lower" forms.*In short, reflections on someof the problemsof macroevolution may well lead to remarkslike that of Professor Waddington, ucked awayin the folds of his ingenious and "orthodox"z.rgument on The Strategy o] the Genes:

. . the unprejudicedtudent s likely to derivethe impressionhat the failure of present theoryto provide any plausible explanation for suchoccurrences has played a not unimportant partin weighting he scales against an acceptanceoftheir real existence. It would ertainly seem hatin this field . . . the adequacy f modernheorymaybe doubted.Moreover,evolutionists sceptical of the neo-Darwinian synthesis have themselves empiricalevidence to support their doubts. For despitethe neo-Darwiniansclaims, two great biologi-cal disciplines, paleontology and embryology,appear to lend their chief weight against the

selectionist dogma.p A~.~ONTOI~OCY, nce more, furnishesboth the most direct evidence lot the factof evolution, and the most imposing evidenceagainst the conception of evolution as a con-tinuous, gradual progression of adaptive rela-tionships. "Gaps in the fossil record" were aserious stumbling block in Darwins time, anddespite the discovery of manymissing links--for example the striking completion of horsefamily history, or the discovery of the birdancestor Archaeopteryx, with its reptilianfeatures--they still persist. Moreover,hey per-sist systematically: over and over, with sudden-ness termed "explosive," a bewildering varietyof new types appear: this is true, notably, forexample, of the origin of the major mammaliantypes. Thus, as G. G. Simpsonscalculations ofrates of evolution show, the bats wing, ifevolved by "normal" Mendelian mutation andselective pressure, would have had to begindevelopingwell before the origin of the earth l"

* Neo-Darwinians, f course, have heard thisquestion; hey say, "natural selection plus time willdo the trick." But in what ense is this an answerNatural selection as a mechanism bserved innature is a short-termbusiness, and to extrapolateit to the whole f macroevolutioneedsgreat faithindeed;natural selection in the statistical sense of"differential reproduction," on the other hand, issimplya formulaicexpression or the retrospectiveobservation hat evolutionhash.appened, ncludingall its aspects, thosenot conformings wellas thoseconformingo the micro-mutation-selectionheoryof its nature.~" This does not, however,we shouldadd, impairProfessor Simpsons confidence in the neo-Dar~vinianynthesis.




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The FaithOnce new types appear, moreover, they fre-quently continue, so some paleontologists atleast believe, in directions bearingno systematicrelation to adaptive needs: in fact, they oftenexceed the demandsof utility so grossly as tolead their species and genera and families to thecommonate of life: that is, to death. Again,of course, if one is convinced n advance hatall extinction must result not from any general"evolutionary trend," but from environmentalchange, one can interpret these cases too inaccordancewith selec-tionist principles: asT. S. Westoll has ~ .........done, for instance, ~with the oyster ances-tor Gryphaea, whichlooks as if it hadsecreted so muchlimestone that it leftitself no room o livein its own hell. Theseover-specialised crea-tures, Westollargues ........were probably agedindividuals of noevolutionary interestand their particularform of senility mayhave been associatedwith an actual re-productiv.e advantageearlier an their in ....dividual lives: so thatselection kept themgoing because of thisadvantage, which hap-pened to carry withit what looks to uslike a disadvantage;and in fact it mayhave been not this"disadvantage" but anenvironmental change(for which howeverwe have no evidence)that carried themoff.Thus we must inferboth an unknownad-vantage and an unknown environmentalchange in order to avoid making he muchmoreobvious nference that this kind of animal--thispattern of living--simply played itself out.But if the major hythmsof the history of lifein the past seem o some tudents to resist com-pression into the Darwinian-Mendelianmould,these stubborn paleontological data agree, onthe other hand, in the opinion of a numberofbiologists, with the evidence provided by ourknowledge f development, hat is, of the his-

of Darwinism 5 5tory of the living individual. There has beeninteresting speculation during the past thirtyyears, and even earlier--speculation based onincreasing knowledge of comparative embry-ology-on the rble of "heterochrony," or changein the temporal rhythms of development, ineffecting evolutionary change. Instead of beingtacked on, as evolutionists used to think, to theadult stage of early forms, it looks as if newdevelopmentsmayoccur at any stage in the lifecycle--the earlier, the morebasic: and, in termsof the fossil record,the more sudden.Sometimes such early........... changes appear, in-deed, to have consistedin a kind of inspiredinfantilism: the reten-.... tion of a larval stageinto adult life, per-mitting, as it were,

rejuvenation of therace. This would ex-plain the poverty ofthe fossil record attransitional stages, andthe relatively suddenbursts of evolutionaryenergy that so fre-quently occur. Thelate Professor Gar-stang of Leeds, one ofthe great originatorsof this kind of evolu-tionary thinking, firstpublished in x894 histheory that thechordates may havedeveloped from some-thing like an echino-derm (starfish orsea urchin) larva:freely swimmingform, which, beingdorsally exposed tolight, might be stimu-lated to develop thedorsal nervous systemcharacteristic of verte-brates. Or again, it has been pointed out that ahuman dult holds his head like an embryodog:presumably, the failure to grow up in thisrespect enabled our ancestors to adopt an up-right posture, and to achieve binocular vision.A host of arguments of this kind are substan-tiated and systematised in de Beers book, towhich have already referred. To biologists likeVandel or Schindewolf, however, the view ofevolution they suggest does not, as de Beerthinks, complement election theory, but runs




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56 Marjoriedirectly counter to it. Along with the grow-ing evidence from experimental embryology(stressed, for example,by Dalcq or by the lateR. S. Lillie of Chicago),conceptions ike thesesuggest, not that lifes history is a function oftwo variables, variation and selection, but thatit hides a much icher complexity,a spontaneity,an inventiveness, an orderliness which eludesexplanation in terms of such simple conceptions,howevermasterly the statistical edifice on whichthey are enthroned. Once more, if one mustreduce the macroscopic o the microscopic, onecan indeed say, there must have been "rategenes" to bring these changing rhythms about:but this is, once more, to postulate an unknownto explain awayan uncomfortable aspect of theknown.y ET, if all this is so, why is the net-Darwinian theory so confidently affirmed?Partly, in the centennial year, as a mark ofrespect for the Newtonof biology; but pardyalso, I believe, because net-Darwinism, likeDarwinism efore it, is more than a scientifictheory. It is a theory deeply embedded n ascientific faith: in the faith that science can andmust explain all the phenomena f nature interms of one hypothesis, and that an hypothesisof maximum implicity, of maximum mper-sonality and objectivity. Relatively speaking,net-Darwinisms logically simple: there are justtwo things happening, chance variations, andthe elimination of the worst ones among hem;and both these happeningsare just plain facts,things that do or dont happen, yes or no.Nature is like a vast computingmachine et upin binary digits; no mystery there. And--whatmanhas not yet achieved--the machine s self-programmed: t began by chance, it continuesautomatically, its master plan itself creeping upon itself, so to speak, by means of its ownautomatism. Again, no mystery there. LikeStrauss miracles, mystery is banished; man sat home n a simple rational world.As against this simplistic and reductive ex-planation, however, this cosmic behaviourism,the objections I have mentioned, such as theneed to recognise the harmony f adaptations orthe persistent structures and rhythms n phylo-genetic development, are complicating andhence mystifying matters. They introduce aneed for a morecomplex ogic, permitting levelsof emergence, for example; they introduce aneed for frank retrospective assessment of the

Greneevolutionary story, and hence for personalappraisal of our own ituation in evolution, asthe outcome of evolution. Thus, in a recentpaper, Professor Dalcq has warnedus that, evensFoould ife be synthesised in the laboratory, itwouldbe we ourselves, think~ing and continuingproducts of lifes long history, who ad achievedthis synthesis: and this fact would make anessential, logical, even a metaphysical ifferenceto the import of the achievement.From another perspective, David Lack, loyalDarwinian though he is, gives the game away.In the bookI have already mentioned, he refersto Darwins question: "Can the mind of man,descended,as I believe, from the lowest animal,be trusted when it draws such grand con-clusions?" and he comments:

Dar~vins horrid doubt" as to whether he con-victions of mans volvedmind ould be trustedapplies as mucho abstract truth as to ethics;and"evolutionary ruth" is at least as suspectasevolutionary thics. At this point, therefore, itwouldseem that the armies of science are indanger of destroying their ownbase. For thescientist mustbe able to trust the conclusions fhis reasoning.Hence e cannotaccept the theorythat mans mindwas evolved wholly by naturalselection if this means, s it would ppear o do,that the conclusions of the mind dependulti-mately on their survival value and not theirtruth, thus makingll scientific theories, includ-ing that of natural selection, untrustworthy.Lackconcludesfrom this that the old oppositionof science and religion is still, and must emain,an "unresolved conflict." But I think one mayconclude, on the contrary, that it is the con-ventional logic of science, and the view of mindimplied in it, that needs revision. For, as Platoargued long ago about Protagonas "man themeasure," there is surely something wrong ina theory which, at its very root, invalidatesitself.To help us to understand, and to overcomein our ownminds, this heritage of simplisticscientism is a signal service of Dr. Himmelfarbsbook. From he reductive, mechanistic point ofview, however, from the point of view of thefaith of Darwinism, all these arguments,biological as well as historical and philosophical,are muddled and mystical, unscientific, andtherefore incompetent objections, lying, evenwhen hey come rom competent cientists ratherthan historians or philosophers, beyond thebounds f rational discourse.




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encounter 1959nov

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