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  • nomos XIX
    absence of the discoidal cell M4 either branches off from the chief stem of the media M or from Cu1 Figure 25 A and B Many examples of which we find in the Nematocera In the case of the presence of the discoidal cell the free branch M4 is always connected with this cell either directly or by a cross vein Figure 25 C and D This we find in a part of Tipulomorpha Anisopodomorpha Asilomorpha USSATCHOV 1968 p 625 In the new family Eremochaetidae see the two Figures further above in contrast we encounter the interesting combination of these two mentioned situations In the presence of the discoidal cell the vein M4 independently branches off from the chief stem of M having no connection whatsoever with the discoidal cell and not taking part in its structure Figure 25 E This fact legitimates us to agree with the point of view of Tillyard 1919 according to whom the vein lying between M3 and Cu1 in Diptera represents the last branch of the medial system of veins that is the true M4 and consequently is not the product of coalescence of M4 and Cu1 as is supposed by Hennig 1954 see the groundplan of dipterous wing venation as conceived by HENNIG USSATCHOV 1968 p 625 It might be interesting to compare the above wings of three Jurassic diptera asserted to belong to the Suborder Brachycera orthorrapha to those of recent relatively primitive members of this suborder In the next Figure we show the wing venation of one of them Figure 26 Wing venation of Rhagio scolopaceus LW Order Diptera Suborder Brachycera orthorrapha Family Rhagionidae After HENNIG 1954 Although with Rhagio we find ourselves well within the next suborder the first one being the Nematocera the wing venation can nevertheless be very archaic as can be seen in the above Figure This indicates that at least some groups of Brachycera orthorrapha must have had their origin deep down in the Nematocera perhaps somewhere close to the Rhyphidae The origin of the order Diptera cannot be read off solely from the wing venation of certain Mecoptera and archaic Diptera But insofar as we have to rely on fossils wing venation is the only thing we have And wing venation is in this case the origin of Diptera very significant because it comprises structural features of the wings and thus expresses different types of flight regimes And it is precisely the diversifying of flight regimes which seems to be the chief characteristic of the further evolution of the Diptera Probably a prerequisite for being able to evolutionarily evolve a vast array of different flight regimes is the two winged condition together with the formation of halteres at the sites of the former hindwings So once having evolutionarily achieved this two winged condition a radiation of flight regimes among other things expressed by the wing venation will we can expect necessarily follow What is not so clear however is how and why a two winged

    Original URL path: http://www.metafysica.nl/nature/insect/nomos_19.html (2016-02-01)
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  • nomos XX
    consisting of only one vein Cross vein between M3 and M1 2 absent therefore discoidal cell opened and thus absent 1A and 2A still long Wing still elongate This concludes our discussion of the wing venation in the family Limoniidae In this family there is no tendency for R2 to become strongly recurrent as we will see it in the family Cylindrotomidae Tipulidae Especially in the family Tipulidae we see in the wing venation a strong tendency to having all the forks shifted towards the apical part of the wing As in Limoniidae but in the present family apparently even more so the wings are markedly elongate R2 tends to be a recurrent vein but apparently by far not so much as in the family Cylindrotomidae The venational groundplan of the family Tipulidae can be represented by Pales dorsalis FABR except that the origin of Rs must be situated in this groundplan a little more proximally as we see it in for example Idiotipula confluens ALEX See for the latter Figure 17 Figure 15 Wing venation of Pales dorsalis FABR After HENNIG 1954 Capture of R4 by the vein R2 3 R2 recurrent and ending up in R1 R3 short ending up at wing margin M1 M2 fork present that is the veins M1 and M2 present M is 4 branched M1 M2 M3 M4 1A and 2A long and reaching the wing margin Figure 16 Distal part of wing venation of Xiphura atra L After HENNIG 1954 Same as in previous Figure but with Rs branching off more proximally So also this species can at least as to the part of it that is depicted its distal half represent the venational groundplan of the family Tipulidae Figure 17 Wing venation of Idiotipula confluens ALEX After ALEXANDER 1921 from HENNIG 1954 Capture of R4 by the vein R2 3 as in the two previous Figures but R3 absent Fork of M1 M2 absent meaning that the media is 3 branched Figure 18 Distal part of wing venation of Tanypremna sp After HENNIG 1954 Still capture of R4 by the vein R2 3 as in the previous Figure but R2 more clearly recurrent and R3 still present albeit very short and on the verge of vanishing altogether Fork of M1 M2 present The media is 4 branched So relative to the wing in Figure 17 Idiotipula this wing is primitive plesiomorph as to R3 and as to M But it is advanced apomorph as to the recurrent course of R2 and especially as to the point where Rs branches off from R which point lies very distally and still more so in Dolichopeza next Figure Figure 19 Distal part of wing venation of Dolichopeza albipes STRÖM After HENNIG 1954 Follows upon Tanypremna previous Figure with the complete disappearance of R3 Basal piece of M3 vanished so that the discoidal cell is absent The fork M1 M2 still present M still 4 branched Rs branches off from R still more distally Judging from the recent Tipulidae the capture of R4 by R2 3 that is shift of R2 3 towards the apical part of the wing along R4 is at least already present in the groundplan of the family The fact that this situation is already very old is suggested by fossils such as Architipula clara HANDL probably belonging to the Limoniidae see Figure 7 and also by Architipula radiata ROHD from the lower Jurassic of central Asia Figure 20 Wing of Architipula radiata ROHD from the lower Jurassic of Issic Kul central Asia PIN No 371 403 The age of the Issic Kul fauna originally was held as being upper Triassic Later however it was held as being Lower Jurassic Length of wing 5 9 mm After ROHDENDORF 1962 from ROHDENDORF 1964 We clearly see in this fossil Architipula radiata that the Radial Sector first splits into two branches R5 and R4 Shifted onto R4 we see R2 3 which latter in turn gives two branches R3 which ends up at the wing margin and R2 which folds back and ends up in R1 Radius To express this same situation differently Originally in more primitive forms Rs splits into R2 3 and R4 5 Later in evolution R2 3 shifts distally along R4 thus resulting in the capture of R4 by vein R2 3 During this shift R2 keeps its connection with R1 and thus becomes recurrent M is 4 branched The cross vein tp between M4 and M3 is present implying that the discoidal cell is present Between R5 and M there is the cross vein ta rm connecting R5 with the discoidal cell Between CuA and M there is the cross vein tb mcu it connects CuA with the discoidal cell CuP thin not reaching the wing margin 1A long reaching the wing margin 2A probably also long and also reaching the wing margin With R2 strongly recurrent this fossil leads us structurally to the Family Cylindrotomidae with which we will deal next The tipuloid venational scheme including in it the described capture of R4 by vein R2 3 can undoubtedly be evolutionarily accomplished in different ways that is along different pathways for instance certain parts of the overall process taking place in a different order This means that among other things in evolutionarily accomplishing the pattern as we see it in Tipulidae as well as in many Limoniidae and also in the other families of the superfamily the historical process does not necessarily need to pass through the tanyderid phase see Figure 1 in all cases If the development origin of the first Tipulidea from a non dipterous stock starts from Mecoptera with a reduced venation such as representatives of the suborder Paratrichoptera see Figure 1 in previous document or of some true Mecoptera such as ancestors of the family Nannochoristidae see Figure 13 in previous document it that is the development will probably go its way through the tanyderid stage 4 free branches of Rs as well

    Original URL path: http://www.metafysica.nl/nature/insect/nomos_20.html (2016-02-01)
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  • nomos XXI
    it is true more primitive than in any other Dipteron including the tipuloids This means that the mentioned differentiation into wing base and wing blade might be only seemingly so In the Ptychopteridae on the other hand there is with respect to wing structure more similarity with the tipuloids The wing is narrow but this is also the case in Eutanyderus Figure 12 and there is no incision into the hind margin separating wing base from wing blade see Figure 1 and Figure 2 That this is the result of a secondary development is shown by the fact that the second anal vein is absent and that a phragma is present see Figure 9 and Figure 10 However as can be seen especially in Figure 9 a phragma is only weakly present if present at all It is perhaps instructive to compare with the wing base in Pachyneura Figure 13 Pachyneura fasciata ZETT Pachyneuridae Wing base basiala Schematic Abbreviations as usual Here we have an example of a weakly developed basiala that is lots of elements are missing After ROHDENDORF 1946 and with Petaurista Tipulidea Trichoceridae Figure 14 Petaurista maculipennis MEIG Petauristidae Trichoceridae Base of right wing of male Topview Specimen Nr 2534 Length of wing 7 35 mm Length of part starting from the level of the base of the costal vein to that of the humeral cross vein the cross vein between Costa and Subcosta supposedly delineating the basiala 0 94 mm For the abbreviations see Figure 1a in Part II of Evolution of Insects The brace in upper part of figure with the sign Ba indicates the extent of the supposed basiala After ROHDENDORF 1951 Apparently the wing structure in Ptychopteridae has secondarily changed markedly The development here has been partially resulted in a re appearance of some original features of the tipuloids pseudoplesiomorphy of the Ptychopterids undoing of the differentiation between wing stalk and wing blade at least with respect to the wing s outline As to other features the narrowing of the wing has resulted both in the tipuloids and in Ptychopteridae in a correspondence of derived apomorphous characters the ending up of R2 in R1 So in at least one character the development in both groups was such that while starting from the same initial condition free ending of R2 into the wing margin it went into different directions but it nevertheless finally resulted in the same derived condition R2 ending up in R1 In other characters on the other hand the one group the tipuloids had retained the original condition smooth contour of the posterior wing margin while the other the Ptychopteridae developed from a deviating starting condition incision into the posterior wing margin separating wing stalk and wing blade at last the original condition as it is in the tipuloids smooth contour of the posterior wing margin HENNIG 1968 p 13 So it indeed seems that the groundplan of the wing and its venation or at least the starting condition in the evolution of the Ptychopteridae must be different from what we originally set out it to be that is different from the wing and its venation of Liriope as depicted in Figure 1 above And certainly it seems the venational starting condition is different from those of the other tipuloids But although such non tipuloids which later gave rise to the tipuloid like Ptychopteridae might have existed in Jurassic or Triassic times fossils of them not found we cannot find descendants of them among recent Diptera Because the Radial Sector Rs in Ptychopteridae is 4 branched see Figure 1 we cannot find a non tipuloid having at least 4 branches of its Rs among the Bibionomorpha they all have a Radial Sector that is at most 3 branched So from types like these the Ptychopteridae cannot have evolved unless we allow a turning back having taken place in the evolution of the Radial Sector They cannot be found even among the Rhyphidea which are also Bibionomorphs with primitive venation but with Rs having at most 3 branches neither in Blephariceridae The only non tipuloids by which we here mean not belonging to the superfamily Tipulidea having a venation from which that of the Ptychopteridae can formally be derived which here means that Rs must have at least 4 branches and in addition these forms possessing no characters that are in a derived apomorphous state with respect to those characters in Ptychopteridae are representatives of the family Nemopalpidae of the superfamily Psychodidea such as Nemopalpus zelandiae ALEX Figure 15 Wing of Nemopalpus zelandiae ALEX Order Diptera Family Nemopalpidae Superfamily Psychodidea After ALEXANDER 1927 from HENNIG 1954 In Nemopalpus Rs has four branches all of them still ending up in the wing margin The media has 4 branches M1 M2 M3 M4 and the second anal vein is lacking Indeed from such a venation that of the Ptychopteridae can at least formally be derived by letting R2 end up in R1 by losing M3 The problem seems to be that we then have to assume that the specialized condition in the cubito anal area of the wing in Nemopalpus has as it were when changing so to say into Ptychopteridae evolutionarily turned back to the more original condition Cubitus and first anal vein long and strong as we see it for example in Tipulidae see Figure 4 but here the second anal vein is still present However we have no right to a priori call the cubito anal area as it is in Nemopalpus a specialized condition although it probably is The only real specialization is the loss of the second anal vein and this vein is also absent in Ptychopteridae Anyway the derivation of the venation of the latter from that of Nemopalpus is not without problems If we look to the basal part of the wing of Liriope Ptychoteridae Figure 9 we see that the evolution of the Ptychopteridae did not necessarily start from flies having as HENNIG supposed wings with

    Original URL path: http://www.metafysica.nl/nature/insect/nomos_21.html (2016-02-01)
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  • nomos XXII
    Ulomyia fuliginosa MEIG Order Diptera Family Psychodidae Superfamily Psychodidea After HENNIG 1954 All bifurcation points markedly shifted toward the wing base resulting in the forks themselves being very long and their stalks short Wing broad and pointed Radial Sector Rs 4 branched R2 3 branches off from main stem of Rs Media 4 branched depending on interpretation see Figure 3 CuA Cu1b is not shortened and not bended toward the hindmargin but almost straight First anal vein very short depending on interpretation see Figure 3 Discoidal cell absent Figure 5 Wing venation of Trichomyia urbica CURT Order Diptera Family probably Psychodidae Superfamily Psychodidea After HENNIG 1954 Also here all bifurcation points markedly shifted toward the wing base and thus the forks themselves very long Radial Sector Rs 3 branched R2 3 branches off from R4 not forked The venation of Phlebotomus see Figure 2 shows or suggests that it is indeed the fork R2 R3 that has disappeared M is 4 branched CuA Cu1b is long almost straight First anal vein 1a short Discoidal cell absent Wing moderately broad less pointed than in Ulomyia Phlebotomus and Psychoda The main evolutionary trend in the history of the wing venation of the Psychodidea is a shift of the main bifurcations toward the wing base whereas in the Tipuloids this shift was toward the wing apex and a broadenig of the wing In the venational groundplan of the Psychodidea Figure 1 this shift of the main bifurcation points toward the wing base is not yet apparent although it is so in the cubito anal region Like the tipuloids we believe that the first Psychodeans have evolved from Mecoptera whose wings possessed a fairly large number of veins like we see it in the Permian Agetopanorpa Figure 6 Fore wing of Agetopanorpa maculata CARP Length 9 0 mm Lower Permian of Kansas U S A After CARPENTER 1930 By a reduction in size and a slight reduction in the venation such a wing could give rise to one that resembles that of the recent Nemopalpus see Figure 1 Of course like in the case of the tipuloids we cannot definitely indicate a particular fossil mecopteron representing a species that has given rise to the first psychodideans Fossils are sparce as compared to the actual number of corresponding insects that actually lived at the time Moreover it seems that the transitions from mecopterons to dipterons were relatively fast resulting in there having been only few transitional forms Culicidea The superfamily Culicidea includes three families Dixidae Chaoboridae and Culicidae of which the latter comprises the well known mosquitoes According to ROHDENDORF 1964 these families are divided among two superfamilies the Culicidea Culicidae Chaoboridae and Dixidea Dixidae For the present purpose it is perhaps better to unite these three families into a single superfamily Of the Chaoboridae we have no precise venational data at our disposal but its seems certain that their wings do not significanly differ from those of the Culicidae The venational groundplan of the

    Original URL path: http://www.metafysica.nl/nature/insect/nomos_22.html (2016-02-01)
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  • nomos XXIII
    such as the permian or triassic ancestors of the Nannochoristidae Figure 8 Nannochorista dipteroides TILL male ca x 12 Order Mecoptera Family Nannochoristidae Recent After TILLYARD 1917 2 The venational groundplan of the family Ceratopogonidae can be represented by the wing venation as it is in Atrichopogon rostratus WINN Figure 9 Wing venation of Atrichopogon rostratus WINN Order Diptera Family Ceratopogonidae Heleidae Superfamily Chironomidea After HENNIG 1954 R5 and R4 coalesced resulting in one single vein R4 5 Endpoints of R1 and Radial Sector shifted toward the wing base R2 3 branches off from R4 5 it is very short and ends up in R1 The fork M1 M2 is present and deep that is its bifurcation point has shifted toward the wing base M4 present The cross vein tb that is its anterior part has been shifted all the way into the wing base First anal vein 1a present but shortened not reaching the wing margin Wing moderately elongate in fact relatively broad H ENNIG 1954 p 283 4 discusses the status of the fork lying between R4 5 and M1 as we see it in Atrichopogon rostratus figure 9 The main lines of this discussion we now give The proper identification of a fork lying between the Radial Sector and M1 in many Heleidae has caused headaches in many authors Here we have not to do with simply the formation of creases or grooves in the wing membrane but as coloration and growth of hair indicate with a true vein like stiffening of it Interpreting this fork and its arms as R4 and R5 or MA 2 VIGNON SÉGUY would ask for big problems because it would then be incomprehensible why these veins precisely in Heleidae have been preserved while they evidently have been lost in all their close relatives also in those that are apart from it much more primitive What is meant here evidently is the f o r k R4 R5 two veins not R4 5 itself one vein The interpretation as R4 and R5 lets the venational groundplan of the Heleidae have a 4 branched Radial Sector Against such an interpretation we can also bring up the following The mentioned fork especially occurs in forms that are otherwise relatively apomorph derived advanced According to me all these problems are solved easily by the following considerations Often we have already found out that the structure of the wing surface the formation of creases and grooves has it is true original connections with the course of true veins but that these veins can free themselves relatively easily from their creases while after such things have happened the original structure of the wing surface is being retained relatively tenaciously Apparently when needed things can lead to a re activation of the old wing surface structures without having to assume the reappearance or preservation of veins that have been lost or shifted long ago while they have been lost in all close relatives In Heleidae the development of

    Original URL path: http://www.metafysica.nl/nature/insect/nomos_23.html (2016-02-01)
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  • nomos XXIV
    1929 from HENNIG 1954 In this form the Radial Sector Rs is 3 branched M1 2 M3 and M4 present Wing moderately elongate The wing venation in the genus Paulianina represents a deviation from the main evolutionary path of venational transformation in Blephariceridae Figure 2 Wing venation of Paulianina hova ALEX Order Diptera Family Blephariceridae Infraorder Blephariceromorpha After ALEXANDER 1952 from HENNIG 1954 Capture of R4 by R2 3 shift of R2 3 distad over and along R4 As in Edwardsina previous Figure R2 3 not forked and not ending up in R1 The main evolutionary path starting with the venation of Edwardsina Figure 1 is picked up again by Bibiocephala grandis O S Figure 3 Wing venation of Bibiocephala grandis O S Order Diptera Family Blephariceridae Infraorder Blephariceromorpha After HENNIG 1954 Distal end piece of R2 3 moves basad i e shifts toward the wing base over and along R1 Basal piece of M3 reduced This main path is further followed by Bibiocephala doanei KELL Figure 4 Wing venation of Bibiocephala doanei KELL Order Diptera Family Blephariceridae Infraorder Blephariceromorpha After KELLOGG 1907 from HENNIG 1954 The process indicated in Bibiocephala grandis Figure 3 has now progressed very far The basal piece of R2 3 has climbed up along the stem of Rs This process comes to a conclusion in Blepharicera fasciata WESTW Figure 5 Wing venation of Blepharicera fasciata WESTW Order Diptera Family Blephariceridae Infraorder Blephariceromorpha After HENNIG 1954 The process indicated in Bibiocephala grandis Figure 3 has now come to its conclusion R2 3 disappeared leaving Rs only 2 branched The same can be seen in Liponeura Figure 6 Wing of Liponeura bilobata LOEW Blephariceridae After HENNIG 1968 Figure 7 Wing venation of Hapalothrix lugubris LW Order Diptera Family Blephariceridae Infraorder Blephariceromorpha After HENNIG 1954 R4 R5 fork

    Original URL path: http://www.metafysica.nl/nature/insect/nomos_24.html (2016-02-01)
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  • nomos XXV
    is the basal section of M2 while the posterior part is the cross vein tp intermedial cross vein In wings where this cell is lost this usually has come about by the loss of this cross vein The Anterior Cubitus CuA Cu1b arches down to the wing margin and reaches it The First Anal Vein 1a 1A is long and well developed it reaches the wing margin not far from the endpoint of CuA Later in evolution CuA and 1A meet before reaching the wing margin their common stalk reaching the wing margin The space then enclosed between CuA and 1A is called the Anal Cell See next diagram The next Figures depict wings of fossil flies middle Jurassic that have been assigned to the suborder Brachycera orthorrapha Figure 8 Wing of Archirhagio obscurus ROHD Middle Jurassic of Karatau southern Kazachstan Length of wing 13 mm After ROHDENDORF 1938 from HENNIG 1954 The venation of this wing totally complies with that of the Protorhyphidae Apart from a small extra cross vein the next wing also so complies Figure 9 Wing of Protorhagio capitatus ROHD Middle Jurassic of Karatau southern Kazachstan Length of wing 5 0 mm After ROHDENDORF 1938 from HENNIG 1954 And insofar as preserved also the next wing complies with those of Protorhyphidae Perhaps here M4 is not separated from the Discoidal Cell forming its posterior boundary Figure 10 Wing of Rhagionempis tabanicornis ROHD Middle Jurassic of Karatau southern Kazachstan Length of wing 3 5 mm After ROHDENDORF 1938 from HENNIG 1954 In the next wing this is clearly the case that is M4 forms the posterior boundary of the Discoidal Cell Figure 11 Wing of Palaeostratiomyia pygmaea ROHD Middle Jurassic of Karatau southern Kazachstan Length of wing 2 5 mm After ROHDENDORF 1938 from HENNIG 1954 We can compare these fossils together with those of the Protorhyphidae with the wings of recent representatives of the order Brachycera orthorrapha Figure 12 Wing venation of Rhagio Asilomorpha Rhagionidae Diptera Recent 1A first anal vein often denoted as A1 or An 1 or 1a 2A second anal vein often denoted as A2 or An 2 or 2a R radial system of veins M medial system of veins Cu 1 often denoted as CuA or Cu1 or Cu1b anterior branch of cubital system of veins the posterior branch Cu 2 CuP is in Diptera either a fold or is absent altogether After RICHARDS DAVIES 1977 Imms General Textbook of Entomology Figure 13 Wing venation of Coenomyia ferruginea SCOP Recent Order Diptera Family Erinnidae Suborder Brachycera orthorrapha After HENNIG 1954 Here Figure 13 M4 forms part of the posterior boundary of the Discoidal Cell Anterior part of tb tb1 lost Further the ends of CuA and 1A have come closer together Anal Cell almost closed CuA Cu1b 1A 1a In the next wing also tb1 is lost Figure 14 Wing venation of Leptogaster cylindrica DEG Recent Order Diptera Family Asilidae Suborder Brachycera orthorrapha After HENNIG 1954 The next wing is the first one of a series of wings of recent Empididae still Brachycera orthorrapha The venation in this family is well under way to become the venation as we shall see it in all Brachycera cyclorrapha such as fruit flies blowflies and the house fly Figure 15 Wing of Homalocnemis nigripennis PHIL Recent Order Diptera Family Empididae subfamily Brachystomatinae Suborder Brachycera orthorrapha Length of wing approximately 5 mm After COLLIN from ROHDENDORF 1951 The venation of this wing Figure 15 is the most primitive within the Family Empididae that is most primitive with respect to the morphological ascent that eventually leads to the muscoid wing venation as we see it in most Brachycera cyclorrapha In it the Radial Sector is still 3 branched like in Protorhyphidae and Rhagionidae The Discoidal Cell is still present as it will be in most Brachycera cyclorrapha M3 has already vanished as a result of the coalescence of M3 and M4 M4 instead of M3 now forms the posterior boundary of the Discoidal Cell The anal cell in fact more properly called the cubital cell as ROHDENDORF 1951 does is closed and its contraction has just begun the stalk CuA 1A still very short With this form as a point of departure we see the venation in Empididae successively be transformed along a number of independent lines morphoklines The Radial Sector becomes 2 branched as it is in all Brachycera cyclorrapha the anal cell further contracts as a result of the shift of the endpoint of CuA along 1A toward the wing base at last resulting in a very short cell Figure 16 Wing venation of Dolichocephala irrorata FALL Recent Order Diptera Family Empididae Suborder Brachycera orthorrapha After HENNIG 1954 Here Figure 16 the Anal Cell has already become very small that is CuA has shifted its endpoint up along 1A all the way to the wing base a transitional stage of this can be seen in Figure 15 In addition the common end stalk of CuA and 1A has retreated from the wing margin Further the Radial Sector Rs seems to have here four branches instead of three of which one does not end at the wing margin but in R2 instead This reminds one of the 4 branched Rs in Tanyderidae Suborder Nematocera but here all ending up at the wing margin However in the Suborder Brachycera such a 4 branched Rs only occurs in Dolichocephala irrorata that is in the species depicted here Figure 16 We consider the veinlet connecting R4 and R2 not to represent R3 but to be just an extra cross vein or a re activation of an old bed and thus consider this species to have simply a 3 branched Rs like in Protorhyphidae and most other Brachycera orthorrapha M4 forms the posterior boundary of the Discoidal Cell and that means that in this form M3 has vanished Apart from a small extra cross vein the next wing is similar to the previous one except that it has the normal

    Original URL path: http://www.metafysica.nl/nature/insect/nomos_25.html (2016-02-01)
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  • nomos XXVI
    example suffice According to the above considerations the vertical lines in our diagram not only represent morphoklines but also true genealogical lines And they are parallel and genealogically independent of each other even within smaller sections of the order Diptera Even within the single family Empididae we find three such independent genealogical lines Supposing such a polyphyletic development is forced upon us by the phenomenon of cross specialization which is not only found here but almost everywhere in the system of organisms If we do not believe in the occurrence of reversed evolution Dollow s Law respected by all evolutionists a given feature cannot have evolved from a formally more advanced state of it It must have been either as such inherited from some ancestral species or it must have been developed from a more primitive state of it as still present in some ancestral species Consider two species A and B which are thought to have a common ancestor somewhere in the past Now it is very common that the species A has a mix of formally primitive and advanced features primitive and advanced relative to the states of the corresponding features in the species B A little reflection reveals that depending on the degree of primitiveness of characters in A and in B one has to locate the common ancestor of A and B very deeply back into history And as characters in A and B are discovered of a still higher degree of formal primitiveness then one must project the common ancestor still further into the depths of history As a result the supposed ancestral species becomes more and more hypothetical and more and more ancient The two lines originating from this supposed ancestral species then run for longer and longer times independently of each other A natural conclusion or at least a reasonable assumption might be that following these lines from recent times into the depths of history they never meet at some common ancestor The same can be said in cases involving three or more of such parallel lines And this consideration of course also holds for our present case of fly evolution The morphologies and other characters at least suggest the type of evolution that is polyphyletic evolution as expressed by our above diagram of morphoklines Evolution chiefly driven by random genetic mutations natural selection or by non random genetic mutations The generally accepted framework of factors in organic evolution consists of random genetic mutations of which some that turn out to be beneficial in a particular biological context are favored by natural selection resulting in such a mutation to become dominant in that context while locally weeding out the original state of that part of the genome in which the mutation had taken place This is standard Darwinian theory that is it is the theory of Darwin 1859 now updated with the many findings in cell biology and genetics that came after him The theory first of all was designed to give a natural explanation not only of the fact of organic evolution but also of the factors driving it These factors are supposed to be un intelligent agents And in fact the only way to figure this out is to assume randomness and natural selection that is organisms are supposed to constantly diversify themselves into intraspecific varieties in random ways and in this way gives natural selection something to go on The resulting accumulation of selected small beneficial changes ultimately leads to the evolutionary emergence of complex organic systems and sophisticated and subtle adaptations so goes the theory Indeed any theory insisting in providing a material or purely physical explanation of the emergence of truly novel structures and patterns as we see it in organic evolution must come up with some sort of existing stochastic system that is a system in which elements of the same sort are nevertheless naturally scattered over a certain range of variation and such a system then existing together with some selecting mechanism And in order for the explanation to be purely physical the selecting mechanism should not be some extrinsic agent like it is for instance in the breeding and selecting of canine races but be intrinsic to the system and its immediate conditions that is the selecting agent must reside within that system its natural external conditions determined by that system itself Said differently such an explanation should not use the model of structured things selected or made by man because in such a model man is taken to be the extrinsic intelligent selector or designer In the Darwinian theory of evolution the selecting agent is indeed not some extrinsic entity but just a logical principle residing everywhere because it is no more than a tautology it always holds survival of the fittest which in fact merely means survival of the survivors Such a selection agent will be active in all cases where there are entities whose enduring existence depends on the degree of their intrinsic robustness and resistance against detrimental conditions The variations to which natural selection can fasten upon are the phenotypical expressions of genetic variations that originated as a result of random genetic mutations Most genetic mutations are either not phenotypically expressed or when expressed harmful but some of them in their phenotypical expression happen to be beneficial to its carriers in a given biological context And because they are genetic they will be passed on to the next generation and so on During the course of successive generations these mutants that is the individuals carrying the beneficial genetic mutation are going to represent the majority of individuals in the population in which the mutants appeared for the first time and intially in small numbers This is supposed to be followed by other random genetic mutations among which there are some that carry the initial beneficial phenotypic effect further until at last a new functional phenotypic structure has been formed giving the organism new ecological opportunities This Darwinian way of explaining organic evolution an explanation that is to say in terms of random genetic mutations and natural selection as the chief driving forces of evolution plausible as it seems to be is often challenged by alternative ways to explain the historical transformation and development of organisms We do not discuss here the silly attempts to deny the fact itself of evolution on religious grounds However every genuinely physical explanation using exclusively unintelligent factors of the appearance of true novelty must bring in random variation and natural selection Random variation indeed creates novelty without being led by purpose design and foresight which cannot of course figure in any physical explanation But because it is random novelty it can be of all sorts beneficial detrimental insignificant or irrelevant So the presence of a selection mechanism must be assumed And thus every physical explanation of the appearance of novelty must assume the enduring presence of random variation and consequently all alternative explanations of the factors of evolution must involve non physical factors Such an explanation is then in fact no explanation at all because every genuine explanation of some given complex not understood phenomenon reduces it to a more simple familiar and understood phenomenon and such a phenomenon is always some material entity or process But although random genetic mutation and natural selection as chief factors of organic evolution remain to represent the only genuine physical explanation that is an explanation in terms of physics and chemistry of the fact and course of evolution because no alternative physical explantion can be given it has seemed to me and to some others already for a long time highly improbable that random genetic mutation and natural selection of fittest mutants are the leading factors of organic evolution It is not denied that they exist and play a role in evolution it is only denied that they represent the main driving force of evolution Some reasons for this denial are the following three points 1 It has turned out that there does not exist a straightforward and always holding one to one correspondence between genes and visible morphological physiological ethological features in organisms Genes code for proteins which are biochemical catalysts building materials or regulating entities regulating the switching on or off of genes but we don t know much about the supposed long chain that leads from genes or even proteins to macroscopic features of the organism Most of these features certainly depend on certain genes and on the proteins the latter code for but it is by far not certain that there are no other factors involved than genes and proteins in the determination of these macroscopic features We know of organisms having the same genome but which are structurally very different There may be factors lying outside the organism that co determine many of its macroscopic and constant features or even determine many of them without any genetic control whatsoever In such cases genetic mutations random or non random are simply irrelevant 2 All morphological physiological behavioral novelties that are associated with the evolutionary emergence of new types of organisms are the result of highly complex and seemingly designed transformations of initial more or less simple states of organs or of the very beginnings of them To let this happen exclusively as a result of a series of successive random genetic mutations and selection of the beneficial mutants would take too much time that is would take much more time than is actually available in organic evolution on our planet On its way to the creation of the more or less final useful morphological physiological or behavioral structure of some given organ evolution will often get stuck in dead ends i e ending up on local fitness peaks in the evolutionary fitness landscape long before the mentiond structure situated on the global fitness peak of the fitness landscape would have been evolutionarily developed And it will take unique mutations and thus much time for the organisms meant here as evolutionary entities species to leave the local fitness peak and continue their evolution toward the global fitness peak 3 Contrary to general and wide spread opinion it is my belief that evolution is not about the creation of more and more fitted organisms The fact that many so called very primitive organisms are thriving extremely well still today as they did in the past think of bacteria coelenterates many primitive worms insects etc supports this belief Of course fitness in the sense of being well adapted to the environment everywhere and always will constitute the final decisive factor in evolutionary changes but that is not some sort of general multi purpose fitness for life as such but an appropriate and stable adaptation to a given particular environment in which a specific type of organism lives while another type is living in another particular enviropnment Indeed it is the fitness to live in a newly colonized environment that counts And here we must concentrate our attempts to understand the nature of organic evolution not on this fitness to live in because this is evident and tautological but on the newly colonized Only here we find the general fitness being created that is the fitness of life to be life at all The surface of our planet has suffered many changes climatological and geological Many of such changes have wiped out whole populations species or even types of organisms But the fact that life still flourishes almost everywhere on earth demonstrates that its general nature is such that it as a whole can survive even almost global catastrophes such as significant climatic changes drought freezing conditions heat in extensive areas of the globe big changes in land sea relations meteor impacts etc And this it does by being extremely diverse that is by having colonized virtually every kind of environment in the large and in the small and thus by splitting itself up into a myriad of different groups each specially adapted to a particular corner of the overall environment So life at least in the form as we know it from our earth must be such that it intrinsically seeks to diversify itself as much as possible which here means not to create merely better organisms but to colonize as great a diversity of environmental types as possible by creating a corresponding diversity in life itself To become different is more important than to become more fitted to an existing environment But of course successfully colonizing a new environment or a new corner of an existing environment implies a developed fitness to live in this environment Nevertheless we can say that Darwinian evolutionary theory is too one sidedly engaged with the fitness of organisms and neglects the evolutionary importance of their diversity When on the other hand the latter is seen as the most significant phenomenon of evolution the notion of natural selection becomes less significant So these three points always had convinced us that random mutation in combination with natural selection Darwinian evolution cannot constitute the essence of organic evolution as it has taken place on our planet But be these points as they are they could nevertheless be valuated as constituting no more than merely qualitative and speculative objections against Darwinian evolution However they could have been so evaluated only until recently Genetic mutation is a change in the genome of some given organism a change passed on to its descendants and depending on the phenotypic effect it has in the life of its carriers being selected in favor of the original structure of the genome in some given biological context Such a mutation can consist in the replacement or deletion of a single nucleotide by another in an animal s DNA or in the replacement or deletion of two three or a complete series of nucleotides or of a whole genetic unit a gene This is first of all reflected in a chemical change in the corresponding protein coded for by that segment of the changed genome And because proteins are 1 either enzymes catalysts for important biochemical reactions or 2 are specific building materials of the organisms or 3 are often in conjunction with some other proteins specific cellular machines performing certain fundamental operations in the cell such genetic mutations can have profound effects in the working of an organism i e effects on its fundamental machinery Most genetic mutations are supposed to be random mutations having taken place somewhere in the genome of a given organism and they i e random mutations where they are not noxious or even lethal are supposed to provide for a store of potential novelty eventually to be expressed in evolution But despite the fact that explaining the evolutionary appearance of organic novelty needs randomness and selection the chief role being allegedly played by random mutation natural selection in organic evolution has been recently emphatically denied not simply by considering merely the above three points but by precise statistic reasonings concerning the detailed features of the genome and the proteins coded by it including all the uncovered molecular control systems responsible for the correct working of the organic cell It has turned out that the limits of Darwinian explanation of evolution explanation by random genetic mutation natural selection lie already in the molecular processes of the living cell and not solely in macroscopic features of organisms Random mutation and subsequent natural selection cannot account for the origin and transformation of even these molecular processes only for a very few of them when they are sufficiently simple The odds are too much against such origins and transformations to ever take place Without going into molecular details we note that the arguments for this contention can be read in the book The edge of Evolution meant is the edge of Darwinian evolution 2007 by Michael BEHE who evidently is an expert on molecular and genetic processes in organic cells BEHE argues not against the fact itself of organic evolution but against the widely accepted notion that the genuine driving force of organic evolution is constituted by random genetic mutation and natural selection while not denying the frequent occurrence of random genetic mutations and the presence of natural selection of mutants Random genetic mutations and subsequent natural selection of certain mutants can only bring about some minor evolutionary changes and because of this randomness the accumulation of appropriate mutations eventually leading to significant evolutionary changes is out of the question BEHE therefore argues that the genetic mutations responsible for most of evolution must be non random genetic mutations This case is in the book well argued and certainly convincing But then BEHE goes on to determine what it exactly means to say that evolution is driven by non random genetic mutation He holds that the concept of change by way of non random mutation is equivalent to intellegent design without explaining however what this latter should mean Have we to do here with a scientist who has become desperate during his long quest for the true factors of organic evolution and finally falls into the trap of religion which tries to explain things away by simply having people to believe in the existence of a transcendent creator and ruler a of the World or have we to do with a scientist who on the basis of his findings and those of many others should think once again about the very nature of Reality as a whole but lacking the philosophical power and knowledge of ontology and metaphysics isn t able to do so I don t know BEHE sticks with the conclusion intelligent design and doesn t add anything to that except a little hint that the intellegent designer is not necessarily the benevolent God of most religions because he also created biological entities like the parasite causing malaria in humans including innocent children and the AIDS causing virus And moreover the argument leading from the existence of highly complicated and functional machinery or grand pieces of art for that matter as we indeed find them in living organisms to the existence of some intelligent designer a God is an old one In the eighteenth century it was given by Paley It s true the argument leading to non random mutations instead of random mutations responsible for the origin and transformation of structure already at the cellular level of life is sound quantitative and therefore convincing But the conceptual transition from non random changes to intelligent design is not I thought that using the analogy with man made machines to explain the organic world had been rightly so abandoned already for a long long time especially since Darwin So we must continue where BEHE left sound reasoning that is we must try to understand what non random in non random mutation should actually and truly mean Of course in a specifically human context a non random change is a change performed on the basis of intelligent decision or design so here it has acquired a special meaning To answer this question we must first know what random genetic mutation is Here that is in the present context the term random is not supposed to express that there is no knowledge of the cause of that what is random that is that we don t know what the cause of the mutation is The term also is not intended to express that there is no cause The term random in the expression random genetic mutation expresses the very uniqueness of the cause of the mutation Not every cause is necessarily unique but some are Such a unique cause is probably tied up with the total collocation of things and events in the whole world or in a large part of it at a single given point in time At another even at the next or previous point in time in the history of the Universe this total collocation is different And such a collocation how it precisely is at a given point of time itself is undoubtedly unique And a unique collocation generates unique causes among which the cause of a given genetic mutation Such a mutation is then called a random mutation Having said this what then is a non random genetic mutation Let s try to answer this question Like a random mutation also a non random mutation has a definite cause But the general nature of the cause is different from that of the random mutation It is not unique And this here means that it is such that it can in principle be repeated that is take place again because it is not dependent on the unique total collocation of things and events in the whole world at a given point in time And when the cause is not unique so is its effect the genetic mutation not unique which means that we can expect such a mutation to take place more than once in the course of time In a human context a mutation which here is of course not a genetic mutation but just some change of a given initial state of some limited and definite collocation of things into a different collocation for example when something is purposefully designed and constructed can be repeated by re creating the determining conditions And only here the result of non random change can be equated with the result of intelligent design In a natural and general context however we should equate the result of non random change genetic or otherwise with the effect of a non unique cause And the effect is then also non unique Only an uncritical look at such an effect tempts us to invoke intelligent design and lets us forget that the correspondency between 1 purposeful design and construction of machines by humans and 2 the generation and transformation of biological devices and structures in organic evolution is no more than an analogy until it is proved to be otherwise However the problem is far from solved It cannot be denied that the nature of almost all organic structures and processes is very functional indeed And of course only such structures have a chance to survive in the course of time But how were they evolutionarily generated in the first place We now know that the answer random mutation is wrong precisely because of this very functionality and specifity of such structures and processes that is because of the narrow range for them to be functional in a given specific biological context To rely on pure chance would demand too much time than there is actually available for such a structure ever to appear in the right organism at the right time Before we will adress this problem and its solution we will first turn to the implications of our discovery of the genetic mutations being non unique A genetic mutation being non unique means that its cause is non unique Such a cause could be for instance the presence of short wave radiation We do not think that is the right place to find such causes because the genetic mutations in which we are interested here take part in specific evolutionary transformations in organisms resulting in the diversification of functions among organisms This means that the non random genetic mutations playing a part in evolution are very specific And indeed only then they can be functional So the cause of a given genetic non random mutation must be non unique but nevertheless biologically functional Well a cause that can present itself on several different occasions which might mean that it is present as a spatially and temporally extensive factor and a cause that is at the same time functional i e a cause that can take part in the creation or transformation of certain organic functions what could that be Expressed in general terms it could be the environment of the organisms in question The environment of a given organic species S living in it is itself specific and at the same time not necessarily unique Like the individuals of the species S are not unique but nevertheless specific the environment insofar as it is the environment of the species S is delimited by this species Said differently while the environment simply as being the external world is a broad segment of the bio and abiosphere the organic species S narrows it down to a very specific sector of it which is precisely its environment The rest of the outside world contains some general necessary conditions not only for the species S but for all organic species So the precise qualitative content of a given organic species S the latter s very essence or nature delimits its specific environment or ecological niche It collects from the complete set of environmental elements precisely and only those qualitative elements of the existing outside world that in some way constitute a qualitative extension of it that is an extension of the nature of the species S Said differently the nature of the species S picks out only those elements of its external world that are relevant to it or form some sort of qualitative extension of it The total collection of these chosen elements then constitutes the specific environment or equivalently the ecological niche of the species S In the same way in which the actual specific environment or ecological niche of a given organic species is delimited by the qualitative nature of that species also a p o t e n t i a l ecological niche of this same species is so delimited A potential ecological niche of a given species is like its actual niche also an extended qualitative sector of the external world in which however the species cannot as such live but could live after having acquired one or two additional adaptations As long as such a qualitative sector of the external world does not exist the species does not have a potential ecological niche but only an actual one namely the one in which it resides and to which it is fully adapted And like the actual ecological niche of a given species is a spatially and temporally extended qualitative sector of the existing external world so also the potential ecological niche is such a sector And if we assume the potential ecological niche of a given organic species to harbour in some way a possible cause of genetic mutations in individuals of this species then we have our sought for non unique cause taking part in the formation of adaptations to new environments How precisely a potential ecological niche can cause a genetic mutation will be discussed later on the basis of our metaphysical theory established earlier where we discuss the functionality of the mutations Here we will concentrate on the non uniqueness of the cause of the genetic mutations where this cause is the potential ecological niche The point is that wherever and whenever this potential niche of a given species happens to exist the potential cause of a particular genetic mutation or a set of sequential causes of respective mutations is present And such a genetic mutation could spread among the members of the population and is then partaking in the development of an adaptation to the potential niche And in this way the potential ecological niche of a given species changes into the actual ecological niche of a new species And because of the fact that a potential ecological niche is a spatially and temporally extended section of the general environment the external world it can be a cause repeatedly on several different occasions that is causing the same or at least similar genetic change independently in several different geographic locations or at several points in history Like an organic species an ecological niche as such is a more or less abstract entity but it can occur concretely in the form of several individual instances throughout the overall environment Let us diagrammize all this If necessary increase the brightness of your monitor in order to obtain well distinct colors in the diagrams that follow Of course it is possible that one or more individual instances of a given ecological niche happen not yet to be colonized by its corresponding organic species but they can in principle become so colonized at any time The next diagram expresses the supposed fact that species S has in addition to its actual ecological niche green a potential ecological niche individual instances orange of which might be scattered throughout the overall environment This potential ecological niche can become the actual ecological niche of a new species S1 that is new as a result of the transformation acquisition of an adaptation to this new niche of the invading species S But this will only happen when individual instances of this new niche are accessible at all by individuals of the species S In the diagram this accessibility is indicated by the patches orange of the overall environment patches representing the potential ecological niche to actually being adjacent to the actual ecological niche of the species In places where this is not the case the relevant individuals of the species are not supposed to be able to invade the potential niche The other species depicted in the diagram the species T and U also have their respective actual ecological niches but are supposed each to have such a nature that some of the many environmental elements demanded by this nature to be elements of the species potential ecological niche do not happen to exist in the overall environment We here are describing things occupation of new ecological niches the appearance of adaptations to these niches etc as we see them happening in the Explicate Order the Order that is where things are unfolded along the space and time dimensions And for the time being we will continue to do so Earlier Part IV of the Nomological Theory we have argued that these things we see observe are in fact the result of projections of immaterial noëtic that is thought like reactions and their products from the Implicate Order where they originally take place into the Explicate Order By having this noëtic reactions Implicate Order projection and injection in the back of our mind we can allow ourselves happily to speak about factors of the new ecological niche evolutionarily causing an adaptive change in the members of the species which is invading this new ecological niche We can say this without us having to worry about the problematic issue of the change of parts of the genome by the action of non random environmental factors because our ultimate description will be in terms of noëtic reactions and the Implicate Order Let s now apply all this to the evolution of muscoid flies as it was depicted in the above diagram of morphoklines This is supposed to have been an evolution along parallel lines where each line started off from some different member of the family Protorhyphidae and where some lines got stuck being not able to evolutionarily further develop while other lines continued finally producing the muscoid stock We can reproduce this supposed evolution by setting up a consecutive series of diagrams in terms of species invading their potential niches The green zone in the above diagram is the actual ecological niche so to speak for a moment of the Protorhyphidae We can call it the actual ecological zone of them In fact this zone is subdivided into a number of slightly different subzones which we call ecological niches each corresponding to a different species of Protorhyphidae that is because these species differ a little from each other their respective ecological niches also differ In addition to the actual ecological niche each species also delimits a potential ecological niche which is different from the actual niche These potential niches one for every species collectively form the potential ecological zone of the Protorhyphidae orange zone in the diagram In the case of the Protorhyphidae we do not here consider cases of certain existing species that cannot delimit a potential ecological niche Such species do of course each for themselves d e f i n e a potential niche but because one or more elements of this defined niche are lacking in the existing overall environment it is impossible for such a species to d e l i m i t a potential niche In the course of evolution this potential ecological zone orange is invaded by members of the at the time existing Protorhyphidae For a number of individuals of certain such species of Protorhyphidae no individual instances of their potential ecological niche can actually be reached by them because of say geographical barriers So these individuals will not participate in the invasion and colonization of individual instances of this potential ecological niche and consequently will not develop an adaptation to this niche At least at this point in history they remain unchanged that is they keep belonging to the original species Other individuals of such a species do manage to reach and gradually colonize one or more individual instances of the species potential ecological niche They will evolutionarily develop the necessary and initially lacking adaptations to the potential ecological niche They thus change and become a new species The potential ecological niche of the original species becomes the actual ecological niche of the new species Based on such considerations we can assume that in many cases of such a transgression into a new ecological niche this transgression does not only result in the appearance of a new species but also in the preservation of the original species represented by those individuals that have not been able to reach any individual instance of the potential niche We do not however consider the latter phenomenon any further in our exposition So as has been said in the course of evolution the potential ecological zone orange consisting of the slightly different individual potential ecological niches of the respective species is invaded by members of the Protorhyphidae See diagram above The latter thereby develop the necessary adaptations to this ecological zone causing each one of them to become a new species These new species are supposed not to belong anymore to the morphologically and ecologically defined protorhyphoid type but to the morphologically and ecologically defined rhagionid type see next diagram and compare it with the previous situation depicted earlier in the diagram above We call it rhagionid type because all these new species have identical or similar wing venation a wing venation as we see it for example in Rhagio see Figure 2 above As soon as the new species have been formed and live in their respective actual ecological niches and all of them taken together as the rhagionid type which type strictly is only about the wing venation living in the common actual ecological zone green they delimit each for themselves a potential ecological niche and as a collective a potential ecological zone orange The species indicated at the extreme left is supposed to be a rhagionid species that cannot delimit a potential ecological niche Consequently this particular species remains the same while the other rhagionid species will change in the course of evolution as soon as they have successfully invaded their respective potential ecological niches and as a whole the potential ecological zone and have acquired the necessary adaptational changes As soon as the new ecological zone is conquered which means adapted to by the rhagionid invaders having those invaders changed into empidoids they each for themselves or most of them delimit a new potential ecological niche while collectively delimiting a new potential ecological zone orange The line having resulted in Homalocnemis is such that it cannot delimit a potential ecological niche because some necessary environmental factors are absent Invasion and successful adaptation of the new ecological zone next diagram results in representatives of the genera Rhamphomyia and Hybos both still belonging to the family Empididae which do not delimit a potential ecological niche

    Original URL path: http://www.metafysica.nl/nature/insect/nomos_26.html (2016-02-01)
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