Tuatara: Volume 24, Issue 2, August 1980
Essay Review: — How to Be a Good Biogeographer in 1979 *
How to Be a Good Biogeographer in 1979
‘… the “normal” scientist … is a person, one ought to be sorry for …, I believe, and so do many others, that all teaching on the university level … should be training and encouragement in critical thinking. The “normal” scientist … has been badly taught. He has been taught in a dogmatic spirit: he is a victim of indoctrination.’
— Popper (1970: 52-53)
‘The phrase, “the fossil record”, sounds impresive and authoritative. As used by some persons it becomes, as intended, intimidating, taking on the aura of esoteric truth as expounded by an elite class of specialists.’
— Nelson (1978: 329)
For the past thirty years, Sir Charles Fleming has wandered up and down the stratigraphic column, and he has woven a wondrous web of tales about the biogeography of New Zealand. It is to Fleming's credit that he has done more than anyone else to arouse interest in, and advance the study of New Zealand biogeography. The present book serves as a worthy testament to his many years of endeavour in this field. But it is not to the credit of other New Zealand biogeographers that they have been content to merely follow the Pied Piper into the Magic Mountain.
Believing, along with numerous others, that informed criticism is essential to the growth of scientific knowledge (see e.g. Lakatos and Musgrave, 1970) I am compelled to ask ‘Where in the New Zealand biogeographic literature is the critique one might expect of Fleming's work?’. We are forced to turn to our fellow Gondwanan, Leon Croizat of Coro, Venezuela, for commentary. Croizat (1968: 27-28) felt with regard to Fleming (1963):
‘Cet auteur (i.e. Fleming) est évidemment dans une complète ignorance des faits essentiels de la repartition… . Il envisage des “centres”, des “moyens de transport”, des “migrations” qui l'empêchent de raisonner par le bon sens les faits dont pourtant la Nouvelle Zelande abonde dans toute sa biogéographie. Sa “methode” est une épave ballottée par des relents darwiniens qu’ on lui a insufflé à ses heures d'ecole. Nous ne voudrions, évidemment, rien discuter avec lui, pas plus que nous voudrions analyser une question de mathématiques avec tel qui nous assurerait que si nous voulons nous entendre il es indispensable que nous croyons que deux et deux, font cinq… . En effet entre la biogéographie de Zimmerman, Fosberg, Darlington Jr., Mayr, Simpson, Van Steenis, Fleming, etc., et celle que nous allons exposer à nos lecteurs la difference est la même qu' entre la cosmogonie de Ptolemee et celle de Copernic.’1
Croizat (reviewed in Craw, 1978) has written extensively on problems of New Zealand biogeography, especially with emphasis on the avifauna (Croizat, 1958), an interest he shares with Fleming, yet Croizat merits scarely a mention in the present volume and that only in the following context (p. 12): ‘I do not class myself in any particular school of biogeographers but this does not mean I will not page 82 be so classified by others. I have consciously avoided adhering to any one master and have my reservations about the followers of W. D. Matthew and Leon Croizat alike.’ Apparently Fleming has changed his beliefs from his earlier stance (1958: 65, ‘… I am a thorough-going and unashamed Darwinian in my beliefs and in my approach to Natural History’) but there is no evidence of this in his latest book. Once again we are served up the stale Darwinian recipe for grappling with problems of the distribution of life (i.e. notions of centres of origin, means of dispersal, dispersal routes, etc.), that all sound so familiar to those who have read Chapters 12 and 13 of On the Origin of Species.
It is fair to ask ‘Is this important?’ Yes, of course it is, for Fleming would have us believe that he works in an intellectual vacuum, reading the history of life with complete objectivity from the fossil record:
‘Interpretation springs from the observational data of the fossil record and of living organisms. Paleontologists, who realise the extent of imperfection in the fossil record, are in a good position to appreciate the imperfection of the present distribution patterns of living plants and animals and the great changes that have occurred, in the geologically recent past, in the composition of biotas and the communities they comprise’ (p. 12) and:
‘Universal laws may be sought in the observed data but not imposed upon them’ (p. 13).
This is of course the inductivist view of science, first formulated in popular form by Lord Bacon, at the close of the Renaissance. But there is a problem with induction, with this supposed inferring directly from the fossil record. This is known, not surprisingly, as the problem of induction; our knowledge of which we attribute to David Hume, the famous Scots philosopher of the 18th century who first pointed out that it is impossible to justify a law by observation or experiment. Popper, a foremost philosopher of science, has this to say on the problem (1972: 27):
‘According to a widely accepted view … the empirical sciences can be characterized by the fact that they use “inductive methods”, as they are called… . It is usual to call an inference “inductive” if it passes from singular statements … such as accounts of the results of observations or experiments, to universal statements, such as hypotheses or theories.
Now it is far from obvious, from a logical point of view, that we are justified in inferring universal statements from singular ones, no matter how numerous; for any conclusion drawn in this way may always turn out to be false: no matter how many instances of white swans we may have observed, this does not justify the conclusion that all swans are white."
Now if I understand Popper correctly the scientific methodology and its application to biogeography espoused by Fleming is philosophically unsound. Popper's alternative is ‘the theory of the deductive method of testing or … the view that a hypothesis can only be empirically tested — and only after it has been advanced' (1972: 30). The criterion between science and non-science becomes whether or not a hypothesis is able to be falsified; not how ‘objectively’ or page 83 ‘impartially’ we marshal the ‘Facts’ free of the hindrance of theory. So whether Fleming likes it or not we do impose something on the data, be it Darwinian centres of origin/dispersal or Croizatian vicariance hypotheses. The question then arises ‘How do we choose between these different hypotheses rationally rather than on the basis of weight of consensus, personal authority, etc?’. It is by now, pretty well accepted that centres of origin/dispersal biogeographic hypotheses, such as those advanced by Fleming, are not scientifically resolvable as they are not able to be falsified (see McDowall, 1978, and Craw, 1979, for some discussion of this with reference to the New Zealand situation). Application of the hypothetico-deductive method to biogeography and the manner in which falsifiable biogeographic hypotheses can be constructed has been explored in some considerable depth and detail, and often with reference to problems of Southern Hemisphere biogeography, by (amongst others) Ball (1975) and Rosen (1975, 1978).
What this all means is that there is an alternative approach to Fleming's biogeography and that this alternative finds its immediate roots in the work of Leon Croizat published over the same time period as Fleming's work. Why then, one can fairly ask, has it been suppressed for so long in this country? Why then, as Croizat et al. (1974: 277) point out, why do we not ‘admit that ideas and beliefs have a history; and in the search for that history, … be candid with students so that they may not wander in a world of make-believe and pretense — however reputable and orthodox that world might seem.’ Why indeed!
The notion that organisms arise in a specific centre of origin is an important concept in Darwin/Wallace biogeography, and naturally enough in Fleming's application of that hallowed tradition to states of affairs in the New Zealand sector. The problem with this notion, as pointed out by Cain (1943), is that none of the criteria advanced for the recognition of a centre of origin are of any real value in biogeographic studies. Nowhere is this more apparent than in the controversy between on the one hand Fleming (1976, present book pp. 104-106) and Wardle (1978), and on the other hand, West and Raven (1977) over whether or not certain taxa had their centres of origin in New Zealand or Australia respectively. What it boils down to is ‘How do we choose between the alternatives?’ Do we accept Fleming's view because he is the foremost biogeographer in New Zealand or do we accept Raven's because he is an expert in the taxonomy of the taxa involved? Perhaps all these gentlemen would care to inform us on what grounds we should accept their authority and their divining of centres of origin.
In contrast to Croizat's view that the distributions of individual plant and animal taxa when compared yield patterns that are not random, and that taxa with the same disjunct distribution patterns have a common history being members of an ancestral biota that has page 84 fragmented (i.e. common patterns have common causes), Fleming appears to believe that any patterns in biogeography are an accident: ‘But what we know of the past history of our forests from the study of fossils … leads us to conclude that each member of a forest community, be it tree or shrub or herb, or bird or insect or earthworm, has had its own history …’ (1977: 249). The dangers of this approach are readily observable in Fleming's belief that, for instance, species of Hebe arose in a New Zealand centre of origin and dispersed outwards from this centre to Rapa Island, Fuegia and Falkland Islands. Such a method of biogeographic analysis ignores the pretty massive and fundamental ties between Rapa Island and New Zealand occurring in organisms, with diverse ‘means of dispersal’ ranging from numerous plants (Brown, 1935; Croizat, 1952) to an isopod (Jackson, 1938).
As Croizat (1964: 141) notes ‘it is not so that [species X] next after birth by a Darwinian, “origin of species” in, e.g. Florida decided one fine morning to “migrate” by “casual means” to Hawaii and Rapa’ but ‘much has been, and still is being written by “zoogeographers” and “phytogeographers” to prove that dispersal in and around the Pacific is due to “very gradual” transportation of seed, etc., by “casual means”, “coloizing flights” and the like’ (p. 153). It is interesting to note that on the basis of his biogeographic studies Croizat (1952: 180) was led to the following conclusion: ‘… we are bound to connect Stewart Island, the Kermadecs, Tahiti, Somoa, Fiji, New Hebrides and New Caledonia by a track also touching New Zealand… . It may be that Tahiti was not solidly connected within a single landmass with Stewart Island though good evidence is at hand that an “antarctic” shore ran all the way between New Zealand and the New World immediately interesting such modern islands as Rapa, Sala y Gomez Island and the Juan Fernandez.’ It is quite significant that Croizat's prediction about an ancient Pacific continent, where there is no ocean and supposedly ‘oceanic’ islands, is being independently corroborated at this very hour by workers in the geological sciences (e.g. Shields, 1976). And Nur and Avraham (1977) postulate a large, lost Pacifica continent that once existed next to Australasia and Antarctica. They conclude (p. 43) that ‘the evidence from geophysics, geology and biology makes a compelling case for a now extinct Pacific continent, whose fragmented remains are now embedded in the circum-Pacific, mountain belts.’ Further evidence is supplied by Cranwell's (1963) report of coal from Rapa Island. Hardly the sort of find one would expect on a recent volcanic, oceanic island. Where now Fleming's (p. 106) birds and plants that have ‘crossed the sea from New Zealand to some of the Pacific Islands’? Which brings me to my final point.
What is most noticeable to the discerning reader of Fleming's book is the tension that exists between his geological and his biogeographical page 85 history. This tension arises because, despite Fleming's adamant disavowal that he adheres to any particular school of biogeographers, the concepts and methodology that he uses do in fact originate in the extremely influential tradition of Darwin/Wallace/Matthew biogeography that ‘colonized’ New Zealand, via trans-oceanic dispersal, some time in the 1940's in the form of the works of Ernst Mayr (see Fleming, 1958). These concepts of Darwinian biogeography were formulated in the belief that the continents and oceans have always been, with minor changes, very much as they are today. Fleming accepts that there have been massive changes in the past in the geography of the globe but to this mobilist past geography he transfers dispersal routes tailored to fit a stabilist geography of the past (see especially his Figure 32). Fleming in this book is surprisingly avantgarde geology-wise but he does not extend the insights gained from geology to his biogeography. Matthew, writing in 1915, expressed the view that animal groups arose in centres of origin in the northern hemisphere and dispersed southwards through the main land masses. Fleming, in 1979, appears to believe likewise (p. 111): ‘Antarctica was closer to New Zealand, was not heavily glaciated, and was at least partly vegetated in the earlier Tertiary with Paleoaustral plants … and this undoubtedly contributed … to the dispersal of Paleoaustral elements, most of which had probably entered the area from the north down one of the southern land masses’ (my emphasis). It will come as no surprise to readers of this review to learn that I personally believe that concepts of continental drift/plate tectonics have somewhat different implications for the biogeography of New Zealand, than those attributed to them by Fleming, some of which have been explored by Nelson (1975) and Craw (1979).
My conclusion? Perhaps Fleming, as a paleontologist, has been preoccupied with stratigraphy, and ignored the implications of tectonics, to the detriment of his biogeography. And it is only fair that the last word go to Leon Croizat. Not because, as Fleming (1977, in. litt.) wrote that ‘it seems a national disease to ignore him’, but because Croizat's work will prove to be more of a guide to the future of biogeography than this present work of Fleming's: ‘Tectonics, not stratigraphy, are the proper standard … by which to dovetail geology and biogeography. Indeed a very new stratigraphy may harbour very ancient life …’ (Croizat. 1964: 259).
1 My translation, somewhat free, of the passage: ‘This author (i.e. Fleming) is evidently in complete ignorance of essential facts of distribution… . He considers ‘centres’, ‘means of dispersal’, ‘migration’, which prevent him from weighting in the best sense, the facts which however abound in New Zealand biogeography. His ‘method’ is a wreck of the Darwinian vapours that had been forced into him in his school hours. Obviously we would never discuss with him, no more than we would analyse a mathematical question with one who would assure us that if we wish to come to an understanding it is essential to page 86 believe that two and two make five… . In fact, between the biogeography of Zimmerman, Fosberg, Darlington Jr., Mayr, Simpson, Van Steenis, Fleming, etc,. and that which we are going to outline to our readers the difference is the same as between the cosmology of Ptolemy and that of Copernicus.’
Ball, I. R., 1975: Nature and formulation of biogeographical hypotheses. Syst. Zool. 24: 407-430.
Brown, F. B. H., 1935: Flora of S.E. Polynesia. Bernice P. Bishop Museum Bulletin 130: 1-386.
Cain, S. E., 1943: Criteria for the indication of centre of origin in plant geographical studies. Torreya 43: 132-154.
Cranwell, L. M., 1963: Rapa Island Coal and its Microfossils: a preliminary report, pp. 43-47 in L. M. Cranwell (Ed.) Ancient Pacific Floras: The Pollen Story, University of Hawaii Press.
Caw, R. C., 1978: Two biogeographical frameworks: implications for the biogeography of New Zealand. A review. Tuatara 23: 81-114.
——, 1979: Generalized tracks and dispersal in biogeography: a response to R. M. McDowall. Syst. Zool. 28: 99-107.
Croizat, L., 1952: Manual of Phytogeography. W. Junk, The Hague.
——, 1958: Panbiogeography Vols. 1, 2 a-b. Published by the author, Caracas.
——, 1964: Space, Time, Form: The Biological Synthesis. Published by the author, Caracas. (Title page has 1962.)
——, 1968: Introduction raisonee a la biogéographie de l'Afrique. Mem. Soc. Broteriana 20: 1-451.
Croizat, L., Nelson, G., and Rosen, D. E., 1974: Centers of origin and related concepts. Syst. Zool. 23: 265-287.
Fleming, C. A., 1958: Darwinism in New Zealand: Some Examples, Influences and Developments. Proc. Roy. Soc. N.Z. 86: 65-86.
——, 1963: Paleontology and southern biogeography. In J. L. Gressitt (ed.) Pacific Basin Biogeography, pp. 369-385. Bishop Museum Press, Honolulu.
——, 1976: New Zealand as a Minor Source of Terrestrial Plants and Animals in the Pacific. Tuatara 22: 30-37.
——, 1977: The History of Life in New Zealand Forests. N.Z. Jl. Forestry 22: 249-262.
Jackson, H. G., 1938: Terrestrial isopods of south-eastern Polynesia. Occ. Pap Bernice P. Bishop Mus. 14: 167-192.
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Nelson, G., 1975: Reviews, Biogeography, the vicariance paradigm and continental drift. Syst. Zool 24: 490-504.
——, 1978: Ontogeny, phylogeny, paleontology and the biogenetic law. Syst. Zool. 27: 324-345.
Nur, A., and Ben-Avraham, Z., 1977: Lost Pacifica continent. Nature 270: 41-43.
Popper, K., 1970: Normal Science and its Dangers. Pages 51-58 in Lakatos and Musgrave (Eds). 1970, Criticism and the Growth of Knowledge. Cambridge University Press.
——, 1972: The Logic of Scientific Discovery. Hutchinson, London. 6th Impression (Revised).
Rosen, D. E., 1975: A vicariance model of Caribbean biogeography. Syst. Zool. 24: 431-464.
——, 1978: Vicariant patterns and historical explanation in biogeography. Syst. Zool. 27: 159-188.
Shields, O., 1976: A summary of the oldest ages for the world's islands. Pap. Proc. Roy. Soc. Tas. 110: 35-61.
West, K. R., and Raven, P. H., 1977: Novelties in Australian Epilobium (Onagraceae). N.Z. Jl. Bot. 15: 503-509.
Wardle, P., 1978: Origin of the New Zealand mountain flora, with particular reference to trans-Tasman relationships. N.Z. Jl. Bot. 16: 535-550.
Victoria University of Wellington