Skip to main content

Axiomatic Panbiogeography

offers an application of incidence geometry to historical biogeography by defining collection localities as points, tracks as lines and generalized tracks as planes.
Home
About Us
Contact Us
Site Map
Member Login
Incidence Geometry
Composite Construction
Orthogenesis
Quaternion Algebraic Geom
Vicariance
Primate Vicariances
Individual Track Construc
Generalized Tracks
Taxogeny
Nodes
Edges
Distributions
Propositions
CREADer
Areas
Main Massings
Geology
Track Analysis and MetaCo
Martitrack Panbiogeograph
Applications
Work
Replies to Criticism
Multimodel Selection
Search Encounter
Cenomanian
TinkerPopPanbiogeography
Track Analysis beyond Pan




 
 
 
CReader - an application to assist in reading Croizat's writings.
Mauro Cavalcanti has agreed to post up large parts of Croizat's corpus on-line faciliting more easily, for me, the CReader idea. I am begining just by typing up the pdf chapter on the West Indies that John Grehan has already uploaded. I am looking into various means to apply semantic markup to the text and create software agents that can assist the reader wend a way through the "corpus of Croizat".


. One reason to develop an aid to reading Croizat is so that the reasons for varying interpretations of panbiogeography might be made apparent.  One might like to understand how   came up with the following:

Keywords and summary of the lecture

Animal Geography

Peter Nagel

Summer Term 2006

5 Reconstruction of the distribution history (complex genesis)

5.5 Panbiogeographie

The panbiogeographische approach goes back to Croizat (1958). CROIZAT and its

Successor (since 1978 NELSON, ROSE, Platnick) stressed that the

permanent search for propagation centers and land bridges wrong approach

would follow, as the taxa had already differentiated before they spread. In

Reality had already spread the ancestral species and was then only the

Splitting occurs (by disjunction). They build it on a long time completely

rejected theory ("Hologenese") of the Italian zoologist PINK (1918) on the one

original cosmopolitanism postulated with polytopic subsequent speciation.

An important basis of Panbiogeographie is the assumption that mainly geological

Changes in the course of history the causal factors for the course of

Phylogeny and the complex genesis of entire biota. Individual taxonomic

Developments are of secondary importance at most.

Developed the foundation and the central point of the CROIZAT (1958)

Panbiogeographie is the track analysis. A "track" (distribution line) is the

two-dimensional

Verification

the

complete

Distribution area

one

Monophyletic group (= a monophyletic taxon). Originally this

Expression of CAMP (1947). A track includes both continuous and disjoint

Areas in their entirety.

Because of these individual tracks are then "generalized tracks" (distribution channel)

formed by the combination of two or more congruent tracks, so that the

Distribution area of ​​two or more different clades

represent. The overlapping areas of generalized tracks are called "nodes" (nodes)

referred to and interpreted as zones of tectonic convergence

 

Rekonstruktion der Verbreitungsgeschichte (Arealgenese)

5.5 Panbiogeographie

Der panbiogeographische Ansatz geht auf Croizat (1958) zurück. CROIZAT und seine

Nachfolger (seit 1978 NELSON, ROSEN, PLATNICK) betonten, dass man mit der

permanenten Suche nach Ausbreitungszentren und Landbrücken einen falschen Ansatz

verfolgen würde, da sich die Taxa bereits vor ihrer Ausbreitung differenziert hätten. In

Wirklichkeit hätte sich bereits die Stammart ausgebreitet und anschliessend sei erst die

Aufspaltung (durch Disjunktion) erfolgt. Sie bauen damit auf einer lange Zeit völlig

abgelehnten Theorie ("Hologenese") des italienischen Zoologen ROSA (1918) auf, der einen

ursprünglichen Kosmopolitismus postulierte mit anschliessender polytoper Artentstehung.

Eine wichtige Grundlage der Panbiogeographie ist die Annahme, dass vor allem geologische

Veränderungen im Verlauf der Erdgeschichte die ursächlichen Faktoren für den Ablauf der

Phylogenese und der Arealgenese ganzer Biota sind. Individuelle taxonomische

Entwicklungen sind von höchstens untergeordneter Bedeutung.

Die Grundlage und der zentrale Punkt der von CROIZAT (1958) entwickelten

Panbiogeographie ist die track-Analyse. Ein "track" (Verbreitungslinie) ist die

zweidimensionale

Verifizierung

des

kompletten

Verbreitungsgebietes

einer

Abstammungsgemeinschaft (= eines monophyletischen Taxons). Ursprünglich stammt dieser

Ausdruck von CAMP (1947). Ein track umfasst sowohl kontinuierliche als auch disjunkte

Areale in ihrer Gesamtheit.

Aufgrund dieser einzelnen tracks werden dann "generalized tracks" (Verbreitungskanal)

gebildet durch die Kombination von zwei oder mehr kongruenten tracks, die also das

Verbreitungsgebiet von zwei oder mehr verschiedenen Abstammungsgemeinschaften

darstellen. Die Überlappungsgebiete der generalized tracks werden als „nodes“ (Knoten)

bezeichnet und als Zonen tektonischer Konvergenz interpretiert





 CHAPTER VII

 

Dispersal in and around The West Indies




 

Patterns of dispersal geographically restricted only to the Antilles are well known to the student of distribution, but it nees be the biogeographer's viewpoint that in no case may even patterns of the kind be handled without regard to the rest of the world.  Patterns of the kind belong to the whole of the Americas in the first place, which means to the earth by implication, and as such - the biogeographer can only maintain - they must be approached.

 

The principle - right fundamental for a sequential appreciation of dispersal in all its phases - that everything interlocks with everything else consequently applies to the biogeography of the sector in and around the Caribbeans, and holds good even in cases when differential formmaking was established in the Antilles and/or on the continent nearby in ages so far remote as to preclude the possibility of retracing today the details of the "tracks" responsible for the original exchanges between the mainland and the Antillean islands;  and it might accordingly seem possible to handle the dispersal in the latter without regard of dispersal elsewhere.  This case is verified for example, when the picumnine genus Nesoctites turns up in Hispaniola away from the rest of the subfamily on the mainland, and the "track" that put it there ca no more be pinpointed step by step today than can the channel responsible for Picumnus' turning up simultaneously in Brazil and Indochina.  Even more striking in this same connection is the dispersal of two related avial living familites, Todidae all in Greater Antilles, and Momotidae all in Latin America 1.

 

 

Trusting the most conservative estimates of time demanded for the differential segregation of groups in this taxonomic rank, we cannot accept a date much later than Late Cretaceous/Palaeocene (age of fossilization![1]), which is to conclude that a critical study of the dispersal of archetypal todid/momotid stock necessarily brings into play palaeogeographic factors that lie by now wholly out of our grasp 1.  All we know is that we face in these "modern" families chips out of the same ancestral block which - strewn in origin jointly over sectors of the world which we today severally understand as Caribeans and Tropical America - eventually "ripened" (cf. Ameiva and Cnemidophorus) into the "modern" families.  These being the elements in our hands as regards the "todid/momotid problem" it seems rather reasonable that: i) What is "caribbean" or "continental" of these two "families" is at bottom a single "proble" for the competent student of distribution; and not to become the subject ever of aprioristic speculation on the ground that some of these birds are today "insular", but others not.  For all that we may reasonably accept, the birds that are today "insular" had sires that were "continental", and the oher way around; ii) It is wholly out of the question - this plainly being the case - that constructive inquiry may be made to rest on academic discussions of "lanbdbridges", "winds", "causal transportation", and the like; or on assumptions beforehand that the Todidae became Momotidae at the result of "colonizing flights" out of the Antilles into continental America; or that the Momotidae were turned into Todidae by "jumps" out of continental America into the Antilles.  Discussions and assumptions of the kind are necessarily very wide of the mark of nature, which is here unreservedly to affirm that their results are not genuine part of sceince.  Science is concerned on the contrary with ancestors of joint todid/ momotid genetic, and distributional, potential as the starting point of constructive inquiry; iii) Naturally, Todidae and Momotidae are to be studied together if we intend to understand either, and both throughout their history in time, space and form.  This can only mean, finally, that there is no biogeographic problem with the Antilles that is not also a problem with the rest of the world.

 

I should think these conclusions only embody truisms, and I am reasonably sure that these truisms are safe beyond a range of "zoogeographic" artillery.  This is my own opinion, but having had far better opportunities  of hearing the "zoogeographic" contrary the reader may perhaps not be inclined to accept these truisms as plausible.  Anticipating this possibility, I venture to state that to draw the line beteen, e.g. Mayr's understanding [3} of Antillean dispersal, and what I understand of it myself is easy.  To discriminate quickly and finally we no more than to take due account of concrete examples out of the records of life.  If the "zoogeographer" is right, the facts in the record shall bear him out; if not, no one will have permanent reasonh of bemoaning his eventual dismissal from the halls of knowledge.

 

Vast is indeed the arrary of instances useful to test the issue here pointedly beforfe us, the difficulty being now - as ever - in selecting for immediate use only a strict minimum of evidence of the sort nevertheless that drives clear to the jugular of the matter.  Freely using my own judgemnet - which may not be the best, I am afraid - still it seems to me that the plant-family Magnoliaceae offers excellent material as the test-case we here need.  This group turns up among the earlies angiospermous fossils which is to say that it dates (age of fossilization!) from Early Cretaceous, i.e., some 150,000,000 years back.  That this family was in existence by age of being at a much earlier age goes without saying.  Additionally to a factor of great age, the Magnoliaceae are of major interest for us right here because we have of them reliable data from the West Indies [4], nor are plants of the kind trashy ubiquists with active "means of dispersal", come today and gone tomorrow. They belong to the landscape, as we might say, and the land is perforce old there, where they are at home.  The record of Magnoliaceae in the sector of our present interest stands in these terms:

 

I) Magnolia (West Indies only)

 

1) M. cubensis - Cuba (higlands of Oriente: Pico Turquino, Sierra de Nipe; also Trinidad Mts. in Las Villas); 2) M. domingensis - Hispaniola (hills of Haiti); 3) M. pallescens - Hispaniola (Dominican Repubvlic: Cordillera Central at ca. 2100m. (7000 ft.)); 4) M. hamori - Hispaniola (Southwestern Dominican Republic: highlands of Barahona Province at ca 1350 m. (4500 ft.)); 5) M. emarginata - Hispaniola (Haiti: northern and central highlands at 900 - 1300 m. (ca. 3000 - 4300 ft. )); 6) M. ekmanii - Hispaniola (Haiti: southwestern peninsula, on Massif de la Hotte at 1200 m. (ca. 4000 ft.)); 7) M. splendens - Portorico (Sierra de Luquillo, El Yunque, etc. at ca. 1000 m. (ca. 3300 ft.)); 8) M. portoricensis - Portorico ( Mt. Bajaza, Cerro Gordo, etc., at about 1000 m. (ca. 3300 ft.)).

 

II) Talauma (West Indies only)

 

1) T. minor(T. truncata) - Cuba (highlands of Oriente: Pico Turquino, Sierra de Nipe, Sierra de Moa); 2) T. dodecapetala - Lessar Antilles (highlands of Guadeloupe, Dominica, St. Vincent).

 

Thisa is the record authenticated by recent reliable work 1 and I venture categorically to affirm in its light: 1) The localities stressed by these ten species are uniformly well known centers of relictural endemism and form-making.  No naturalist at all familiar with life in the West Indies, whether botanist or zoologist, can be found to maintain that these are "casual" records; ii) The form-making in Hispaniola, Portorico and Cuba cannot be explained having reference to secondary factors of chance-dissemination, ecology, climate, etc.  It represents the ultimate meeting of already ancient cores of survival following an history that can certainly not be later than late Cretaceous/Very Early Tertiary at the latest; iii) To match centers of this notable kind in the Greater Antilles, T. dode capetala delivers into our hands also a record out of the hoary cores of life extant in the Lesser Antilles, particularly the islands of Guadeloupe, Dominica and St. Vincent.  This record is worth underscoring because it alone promptly disposes of the oft-heard "zoogeographic" claim that if some of the Greater Antilles might, perhaps, have had former connections with the mainland, still the Lesser Antilles are themselves assuredly "oceanic".  Talauma  does plainly show that this is false, because one of the best known centers of relictual endemism in Cuba (the highlands of Oriente) does actually interplay in its ranks with Guadeloupe, Dominica and St. Vincent. 2

 

Of course, vouched for by one shred of Talauma evidence, the antiquity as a biogeographic center of Guadeloupe, Dominica, St. Vincent, and, subsidiarily, St. Lucia and Martinica, is none the less verified by the sizeable list of endemisms belonging to these islands in general, and in particular.  I note here, but to implement the data from Magnolia and Talauma, that the lesser Antillean Core, generally represented by the islands just mentioned, harbours endemic bird-species and genera, as follows: 1) Guadeloupe - Dendroica plumbea, Melanerpes lherminieri; 2) Dominica - Amazona arausiaca, A. imperialis, Cyanophaia bicolor (this last common to Martinica)'; 3) St. Vincent -Amazona guildingi, Catharopeza bishopi. Jointly shared by these islands and St. Lucia/Martinica are three local avian genera, Cinclocerthia, Ramphocinclus, and Cichlherminia (this one extending to Montserrat); and St. Lucia has for its own two monotypes, Leucopeza semperi and Melanospiza richardsoni.  Even discounting records unsuppported by actual specimens to the utmost, still it seems sure (2:p176) that these islands harboured to within rather recent hisorical times between four and siz endemic parrots.

 

Some of the forms mentioned (e.g. Cinclocerthia/Ramphocinclus, Melanospiza) have notable significance, and unquestinable position as relics.  Adding to this old avian stock and endemisms peculiar to these islands in point of plant-life, insects, onychophores, herpetofauna, etc., the total score is an imposing one, vouching for the sector of the map later become the Lesser Antilles having received its normal quota of "modern" life neither much earlier, nor much later, than the rest of the New World at large.  Cuba that up to the Mid-Miocene was not the single island it is today, only a galaxy of lesser discrete islands; Panama and Costarica that throughout the Tertiary repeadtely had insular status to match the Antilles as of today; Java, an island far remote from the Caribbeans but in many respects of its making (marked recent volcanism excepted) suggestive of Cuba; etc; do furnish a background of reasonable biogeographic comparison with the Lesser Antillean Core and the Antilles generally.

 

 

 

The 3-d nature mentioned in discussion of Comparative Biogeography can be tested fully (no matter the temporal discord) with C(AB) areas above:

 

What the Lesser Antilles are today, Panama/Costrica were in the past, and may well be tomorrow and so Cuba and Java again;  telling evidence how utterly futile is the "zoogeographic" approach that begins buzzing around for honey with the question: Is this today an island? Or is this not today an island?  And where could the "raft" or the "colonizing flight" themselves land to the exclusion of the "landbridge"?  I do not scruple affirming that this approach, and all it entails, is strictly nonsense.  It rests on streams of turbid compilation dissociated from a sufficient knowledge of the records of life: and having thus stated my own side of the question I suggest that dissenters - for the good of science - do prove making precise reference to the records of life that their own side of the question is better supported than mine.

 

Of course, the ancient bonds between Lesser and Greater Antilles displayed by Talauma, and handsomely confirmed by the endemisms peculiar to the Lesser Antillean Core, are not the exclusive property of the one magnoliaceous plant.  Connections of the very same scope also turn up in the rank of the following turdid species: Myadestes genibarbis - Highlands of Jamacia, solitarius; highlands of Hispaniola (local on the lowlands of Samana Peninsula; cf. Todus angustirostris), montanus; highlands of Dominica, dominicanus; higlands of Martinica, genibarbis s.s.; highlands of St. Lucia, sanctae-luciae; highlands of St. Vincent, sibilans

 

This record is precise and full, nor does it mean anything at all (cf Chapter V) that it is pinpointed with "races" rather than with "species". Faced by it, the innocent "zoogeographer" risks rushing along to claim that, oh!.... yes .... by all means! .... this is because "hurricanes" promoted "colonizing flights" and "jumps", but to keep him out of danger ere he steps headlong into it, I here observe: 1) Nothing can be claimed for the dispersal of Myadestes that fails to answer also for that of Talauma, and the whole of the endemisms belonging to the Antilles.  All or nothing is the slogan, so please refrain trying for only something.  That will never do; ii) Talauma rings the North Pacific from New Guinea and the Philippines to Mexico, the Lesser Antilles and beyond into South America.  The stations it has in Cuba and the Lesser Antillean Core are accordingly but function of a massive intercontinental dispersal, and the whole of this dispersal stands or falls together. What is true of Talauma on the Arfak Mountains of New Guinea must also be true by dispersal (i.e., by essentials of time and space) of Talauma on the mountains of Dominica; iii) Myadestes, currently accepted as an ally of the Hawaiian Phaeornis, ranges from Alaska to the Bolivian yungas, and the lone form reported from Venezuela, M. ralloides venezuelensis, has for its range: Colombia (Meta: La Macarena, Cudinamarca, Norte de Santander) and Venezuela (Andes of Tachira, Merida, Trujillo, Lara; cordilleras of the Distrito Federal).  Obviously, not being prepared to underwrite as good and true a "zoogeographic" claim to the effect that La Macarena and Norte de Santander (see Chapter IV, V) were colonized by "hurricanes" et. similia - considering said claim to be misplaced in essence and by origin (i.e., strictly stemming from disregard of elementary facts of nature) - I am even less prepared to accept a claim of the sort as vaild in regard of the Antilles; iv) Indications are generally not wanting for still other connections between the Greater and Lesser Antilles more or less in Myadestes genibarbis'  style.  For example: Bonds' accurate records [2} vouch for the finch Loxigilla portoricensis having ranged within 50 years ago both on Portorico (portoricensis s.s.) and beyond Anegada Channel on St. Chrisopher (or, St. Kitts; grandis extinct only after 1880); for the woodpecker Melanerpes lherminieri (Guadeloupe) being close to M. portoricensis (Portorico, Vieques); for the hummingbird Cyanophaia bicolor (Dominica, Martinica) suggesting direct alliance to Chlorostilbon (Portorico, Hispaniola, the Bahamas, Cuba and  Isle of Pines); for the hawk Buteo platypterus freely ranging with different races from Cuba and the Isle of Pines to Hispaniola, Portorico, Antigua, Dominica, Martinica, St. Lucia, St. Vincent, Grenada, Tobago; for another hummingbird Orthorhynchus being distributed from St. Vincent to the islands off Portorico (Vieques, Culebra,, Virign); etc.

 

 "Moralizing" and "preaching" (or what sounds like it, anyhow) is currently looked upon with disfavour in the best of scientific circles on the ground that the lanugage of science consists of "facts".  Well knowing how facts are on occasioin distorted to mean quite the contrary of their intrinsic message (see Chapter III), and how wholly brittle may prove the "statements of fact" even in the pages of "authoritative literarture" (see end of Chapter III in particular), I do strongly believe that the language of science does consist of carefully, sequential discussions of pertinent evidence, or - in other words - of reason and common sense jointly mustered to reach ever deeper -via the facts, or course - into the vitals of nature.  This discussion can happily be kept free from "moralizing" and "preaching" if there is no need for it, but not otherwise.  Knowledge is not an abstraction, but a psychological and historical phenomenon rising and ebbinbg with the tides of times, and it is strictly legitimate that the argument be conducgted with this also well in sight, accepting "moralizing" and "preaching" as connatural to the ultimate diffusion of better understanding.  Here accordingly "moralizing" and "preaching" a step farther still, I venture to invite the reader to consider how easy it proves to shatter ageold "zoogeographic" tales using but the club of a few assorted records, and how, starting with one record, it is easy to find others quite as telling.  The conclusion to present "moralizing" and "preaching" needs of course be, that if old "zoogeographic" tales still persist this can only be because the average naturalist is rather too supine before "authority" for his own, and the common good.

 

This being the seventh chapter of this book, it is my distinct feeling that whatever I am to deal with - inside and outside the Antilles - can hardly return anything at all that the reader has not seen, if in a different aspect, many a time before.  The zoogeographic score does not alter, and some new form of life comes in, but the biogeographic shop always does its business at the old sign, and the moment Myadestes or Talauma have gotten  manicured and shaved, the next customer can only take the chair for the same kind of service.  Here, for example, is with us a customer that, seemingly of the oddest, is in rfeality but the ordinary run of the millo, as follows: Aratinga pertinax (Psittacidae) - Panama (Chiriqui to the Canal Zone, islands in the Gulf of Panama),  ocularis; Colombia (Cordoba: Sinu Valley, eastward to Northern Magdalena, southward to Santander), Venezuela (Zulia to Territorio Amazonas), aeruginosa; Colombia (the eastern llanos from Arauca and Meta to the Orinoco), lehmanni; Venezuela throughout to the exception of Eastern Bolivar and Delta Amacuro, venezuelae; Venezuela (Bolivar: Mt. Roraima district), British Guiana, chrysophrys; Venezuela (Monagas:Barrancas to Delta Amacuro) eastward to French Guiana, surinama; Northern Brazil (upper Rio Negro), chrysogenys; Dutch Leeward Islands (Curacao; allegedly introduced in the Virgin Islands; St. Thomas), pertinax s.s.Venezuela (island of Tortuga, west of Margarita), tortugensis; Venezuela (Margarita and adjacent islets of Los Frailes; Anzoategui, Northern Bolivar, Sucre), margaritensis; Dutch Leeward Islands (Bonaire), xanthogenia.

 

Although records are extant in the literature [5] to the effect that the Virgin Island population of pertinax s.s.  is not quite true to the birds of Curacao, still it has been constantly maintained in the pages of standard referneces that this parrot occurs in the Virgin Islands only because of "introduction".  I do not know how this has gotten universal credence when those who affirm it have no proof of the "introduction" alleged 1,

and surely do know, somehow, of records such as these, for example:

1) Elaenia martinica (Tyrannidae) -...

2) Margarops fuscatus (Mimidae) - ...

3) Caprimulgus otiosus (Caprimulgidae) - ...

If one know casts a glance at the map (Fig. 80) displaying the distribution of these birds jointly,


 he will of course feel that there is nothing miraculous or unusual in A. pertinax associating as one in range Curacao and the Virgin Islands.  The range of this parrot may be spectacular on account of its thus exhibiting a marked disconnection, but it is clear out of the map that this disconnection has place within a distributional norm of major interest to a circum-caribbean circuit.  Accordingly, this disconnection oversea is neither more nor less wondrous than the breaks we have studied in previous pages, this time of interest to continental  South America overland. Concluding, the subject of what A. p. pertinax did, or did not, between Curacao and St. Thomas cannot be a major consideration with the informed student; we will accordingly drop it here, well understanding that it is by no means sure that this parrot was "introduced" to the island of St. Thomas. The contrary is most certainly true.

 

Hardly inclined to waste time on aspects of dispersal that are, yes, spectacular but nothing more at bottom, the inquistive student will be impressed on the contrary (see Fig. 80) by the manner in which dispersal disports itself along the whole of the insular chains fronting latin America (Cozumel - Grenada) into the Antilles proper, not only, but does interplay on occassion (cf. Aratinga pertinax, Caprimulgus otiosus) with the mainland.  The interplay that thus takes palce seems commonplace in regard of A. pertinax, but is right challenging as concerns C. otiosus.  Here is "something" that does not agree at all with the geography now extant.

 

Dispersal that clings to an insular chain offshore, zigzagging - on occasion - in and out the continent, eventually freely to stream - on occassion - tyo reach genuine archipelagoes at sea is, of course, no longer new to us. This is the dispersal we have identified already (see p. 492, 493) as parian or horstian.  It highlights the suture, as it were, of a land "in back" and islands "infront", true in its course to a fundamental aspect of geosynclinal activity.  The islands "in front" are one entity, as such, and so is one entity, as such, the land "in back"; but the two entites do stand within a single one geological bond. Because of this bond dispersal highlights, also necessarily, as essentially distinct the insular chain "in front" at one hand; and the land "in backf" at the other hand.  However, the two also act as one in endless degrees of possible combination "in front" as well as "in back" the like the attached diagram (Fig 81) generally indicates.


In thus stressing - and so forcefully - an essential interplay in horstian (or, parian) distribution of flesh and rocks it is not my intention to imply that the whole of the islands between Cozumel and Grenada, and Grenada into the Antilles proper is necessarily to be viewed as a single geologic feature (i.e. one geosyncline).  Geologists would not approve of too broad a generalization, for, quite as we are particular in matters of detail and proper terminology, so are they.  However, and so  by far this time, dispersal of the type we have seen - and we are yet abundantly to see - could not be were it not for an essential interplay, to repeat, between one system of islands "in front" and land "in back"; which interplay is characteristic in general of geosynclinal activity, and thus a powerful molder of dispersal on the rebound.  It matters not whether, technically speaking, we deal with one geosyncline or a whole system of geosync lines.  The point is that flesh and rocks here act in unison in answer to a generality common to geology and dispersal, as one. Whether this genearlity has yielded in the Colombian range high mountains or in the Caribbean sector only insular galaxies - as of today, for in the geological future the situatioin may easily be reversed -  is a secondary consideration, spectaular as its effects may be for us today1. (1 Many of the readers, and the North American ones in particular, have surely heard...)

 

Summing up, the patterns of dispersal we have seen displayed above do not belong to the geography of today otherwise than in point of record. They do belong to the palaeogeographies of the Caribbeans,


 and becasue of this they play havoc with (the geographic) set of land and sea that happens to rule today.  Had not a now vanished foreland of Parialand once held sway; had not the Antillean chains once been underwater; etc; we would not have today under the eye patterns of distribution we have sween and will yet see.  This is the fundamental consideration in Caribbean and Antillean dispersal; and I do suggest that those who may intend to deny that had better critically and carefully digest the records of life in preparation to their going to print.  Details to discuss and to settle remain plentiful; the main outlines seem rather clear right now.

 

Parian dispersal has not gone undectected by naturalists other than myself, nor can it be missed by anyone at all familiar with American distribution.  In one of his contributions on the herpetofauna of British Honduras [7] Schmidt speaks for example of a certain type of fauna "Peculiar to the keys" offshore, which is a qualification transparent enough.  Bond does not fail to comment in his study of the avifauana of the Bay Islands off Caribbean Honduras [8] as follows: "The Bay Islands are evidently the tops of a submerged mountain range, which, through isolation from the mainland, have retained a number of Central American species, which have entirely or most disappeared from Central America proper and which appear as relicts, not only on the Bay Islands, but also on islands off the coast of Yucatan". Thus very well informed in general, Bond does not fail to follow the statement just quoted with examples exhibiting distribution far-flung along the "tops of a submerged mountain range", including, e.g. Myiarchus tyrannulus insularum of the Bay Island but "Remarkably similar" to M.t.nugator of the Southern Lesser Antilles (Grenada, Grenadines, St. Vincvent); a close repetition of the "similarites" between races of Troglodytes musculus on Cozumel off Yucatan and the Southern Lesser Antilles again (St. Vincent/St. Lucia); etc.

 

Hardly credible, but nevertheless quite true, Bond's work as a professed "zoogeographer" [e.g.,9] actively spreads the creed of "zoogeography" by winds, hurricanes, causal agencies and the like, supinely toeing the Matthewian line1.  It is a curious question how a naturalist who had of life in the Caribbeans matchless knowledge; who knew that dispersal there made much better sense if - wholly against current geography - the islands of San Anres and Providencia were associated on score together with the true Antilles; who had clear perception  of distribution: "Along the tops of a submerged mountain range" generally to parallel the shore of the main, and understood these "tops" as relic-stations; who had, in sum, faithful, exact understanding of masses of details - some of relevant potential scope - and returned in every cases excellent analyses of affinites, "similarities", etc., from the very standpoint of rigorous biogeography;