摘要:

The Arthropoda form a natural phylum. The polyphyletic theories on the origin of Arthropods are rejected. The Palaeozoic Arthropods form a very complex assemblage and traditional taxonomic arrangement is inadequate to express their relationships.

ISSN:0373-4137    

DOI:10.1080/11250008009438701

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

This paper is a critical review of the principal problems in the taxonomy of the Chelicerata at higher levels.

ISSN:0373-4137    

DOI:10.1080/11250008009438702

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

From a critical reading of S. M. Manton's “The Arthropoda” (1977) and D.T. Anderson's “Embryology and phylogeny in Annelids and Arthropods” (1973) it is shown that the “functional morphology” of these authors used in phylogenetical sense is old fashioned “Lamarckism” and thus unsuited for phylogenetical considerations. A comparison of Mayr-Simpson's evolutionary systematics and Hennig's phylogenetical (cladistical) systematics is to the advantage of the latter. It is concluded that a final decision on the phylogeny of Apterygota—as on any other phylogeny—must be based on an evaluation of the plesiomorphous or the apomorphous state of the characters.

ISSN:0373-4137    

DOI:10.1080/11250008009438703

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

It is commonly believed that the Apterygota show signs of the transition from some hypothetical ancestor of the Insects to the Pterygota.

ISSN:0373-4137    

DOI:10.1080/11250008009438704

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Nearly all current hypotheses on the phylogeny of pterygote insects are unsatisfactory because they do not take into account the constraints resulting from the palaeozoic environments where the first steps of this evolutionary history were accomplished. Present knowledge about freshwater and terrestrial environments in the Middle and Upper Palaezoic suggests that the evolutionary history of insects is quite like that of vertebrates. Therefore, we agree with Handlirsch in maintaining that the pterygote insects came direct from aquatic ancestors; the transition from a truly aquatic to a truly terrestrial life being represented by amphibiotic habitants, as in mayflies, or dragonflies. Our hypothesis is supported by many arguments, mostly concerning (a) strategies for protecting eggs and juveniles from desiccation, (b) structural and functional traits of the sense organs, (c) mechanisms of sperm transfer, and (d) mechanisms for breathing.

ISSN:0373-4137    

DOI:10.1080/11250008009438705

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The acquisition of wings is recognized as the main cause of the evolution of the Pterygota. Evidence is brought to support the paranotal derivation of wings from thysanuroid insects since the theory that insect wings originate from tracheal gills is felt to be untenable. Evolution of wings is examined in regard to: 1) the origin and evolution of flight muscles and the cytological adaptations (both ultrastructural and physiological) of muscle fibres; 2) the articular region of the wings, the origin of axillary sclerites from tergal edges and vein bases. A monophyletic origin of wings is rejected since they must have originated independently in two distinct evolutionary lines: the first leading to Palaeodictyoptera and Odonata and the second to the other Pterygota. The former line derives from thysanuroid insects living on swamp grasses and using paranotal lobes as parachutes, and the latter from thysanuroid insects living in crevices of the soil and using paranotal lobes as sails in the wind.

ISSN:0373-4137    

DOI:10.1080/11250008009438706

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Speciation is discussed with special reference to the Orthoptera. Some species instatu nascendibelonging to this order are examined taking into account many biological characters, and it is concluded that the general picture of speciation in grasshoppers is rather different from that known inDrosophila.

ISSN:0373-4137    

DOI:10.1080/11250008009438707

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Electrophoretic studies of gene-enzyme systems: microevolutionary processes and phylogenetic inference

ISSN:0373-4137    

DOI:10.1080/11250008009438708

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The karyological characters differentiating the Amphibia from most other Vertebrates are the tendency toward genome hypertrophy, the occurrence of wide interspecific differences in nuclear DNA amounts and - in contrast - the relative conservativeness in karyotype morphology exhibited by the ‘higher’ families from the three orders. On examination of the more advanced Urodeles (Plethodontids and Salamandrids) these characters seem to represent the outcome of selective pressures tending on the one hand to favour the accumulation and speedy divergence of new DNA fractions, specifically the middle repetitive ones, and on the other to maintain or reduce the number of adaptive linkage-groups acquired through evolution. The primitive Urodela (Cryptobranchoidea) display only the first two of the above three characters. Their karyotypes are in fact widely variable in chromosome number and shape at the intergeneric and occasionally interspecific levels; the most prominent trend, from the karyological viewpoint, seems to be towards a progressive reduction in number of acrocentrics and microchromosomes. Evidence so far is lacking as to the presence of peculiar fractions of genomic DNA in the microchromosomes from these Urodeles.

ISSN:0373-4137    

DOI:10.1080/11250008009438709

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The most recent anatomical, neurochemical and experimental data on the hypothalamo-hypophysial system in vertebrates suggest that (a) the basic mechanism of regulation dates back very early in vertebrate phylogeny; (b) the fundamental plan of organization for tetrapods is present in amphibians; (c) the interactions between neurohormones and neurotransmitters in neuroendocrine regulation are extremely complex; and (d) a comprehensive explanation of the evolutionary role of neuroendocrine regulation is still lacking.

ISSN:0373-4137    

DOI:10.1080/11250008009438710

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor