摘要:

The extant Acari occurring on the inland mountain ranges and nunataks of Continental Antarctica comprise only pre‐Pleistocene endemic Prostigmata and Cryptostigmata of which the Prostigmata are the probable earlier colonists. The inland acarofauna of Continental Antarctica has a different origin from that of Maritime Antarctica, though both are the relict descendants of a Mesozoic acarofauna, which has been radically depleted by one or more Mesozoic and/or Cenozoic glacial event

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb00221.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

We reanalysed Yang&Pattern's allozyme data, published inAukin 1981, of Darwin's finches with a variety of distance and cladistic methods to estimate the phylogeny of the group. Different methods yielded different results, nevertheless there was widespread agreement among the distance methods on several groupings. First, the two species ofCamarhynchusgrouped near one another, but not always as a monophyletic group. Second,Cactospiza pallidaandPlatyspiza crassirostrisformed a monophyletic group. Finally, all the methods (including parsimony) supported the monophyly of the ground finches. The three distance methods also found close relationships generally between each of two populations ofGeospiza scandens, G. difficilisandG. conirostris.There is evidence for inconstancy of evolutionary rates among species. Results from distance methods allowing for rate variation among lineages suggest three conclusions which differ from Yang and Patton's findings. First, the monophyletic ground finches arose from the paraphyletic tree finches. Yang and Patton found that the ground finches and tree finches were sister monophyletic taxa. Second,Geospiza scandensappears to be a recently derived species, and not the most basal ground finch. Third,G. fuliginosais not a recently derived species of ground finch, but was derived from an older split from the remaining ground finches. Most of these conclusions should be considered tentative both because the parsimony trees disagreed sharply with the distance trees and because no clades were strongly supported by the results of bootstrapping and statistical tests of alternative hypotheses. Absence of strong support for clades was probably due to insufficient data. Future phylogenetic studies, preferably using DNA sequence data from several unlinked loci, should sample several populations of each species, and should attempt to assess the importance of hybridization in species phylogeny.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb00222.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Previous studies have shown there to be considerable inter‐specific variation in the cardiovascular anatomy of five of the six families of caecilians. Observations on the previously unstudied Rhinatrematidae reveal this family to be characterized by a number of cardiovascular features that are unique within the Gymnophiona. These include a poorly developed sinus venosus sinistra, a short truncus arteriosus, separate carotid and systemic arches and the right atrium larger than the left. Character analysis indicates that these unique features are primitive within the Gymnophiona and they provide considerable additional support for the hypothesis that the Rhinatrematidae are the sister‐group to all other caecilians. This hypothesis appears to be among the best supported hypotheses of relationships within the Gymnophiona. Caecilian cardiovascular variation provides a useful source of evidence for phylogeny reconstruction that should be integrated into phylogenetic studies of the gr

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb00223.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

The presence of cranial retia mirabilia in rays of the genusMobulais well established. Although previously regarded as consisting exclusively of arteries, the presence of veins has now been established in gross dissections of the rete in the mobulid,Manta birostris.Histological examination of the retia inManta birostrisandMobula tarapacanaconfirms the presence of veins. These findings suggest the presence of a counter‐current heat‐exchanger that warms the br

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb00224.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

The systematic status of the family Calappidae and the phylogenetic relationships of its four component subfamilies are re‐evaluated based on a cladistic analysis of 78 adult morphological characters. A single tree was produced (CI = 0.654). The monophyly of the Calappidaesensu latois rejected. The data suggest that the Calappinae and Hepatinae form a single lineage which is closer to some xanthids than to the Matutinae or Orithyiinae. A close link between the Matutinae and some leucosiids and between the Orithyiinae. and some dorippids is also apparent, with a suggestion that these four taxa all belong to a single lineage. A revised classification of the Oxystomataemend, and Calappidae is propose

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb00225.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb00225a.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY