摘要:

AbstractThe phenetics of 12 genera of Afrotropical Cryptobiina have been analysed by multivariate statistics. Three analyses (principal component analysis, canonical discriminant analysis and cluster analysis) have been used to determine the relative positions of the taxa in a morphospace. These analyses have allowed us to confirm the generic divisions based on alpha‐systematic and phylogenetic grounds. While phenetic systematics and cladistic systematics have often been opposed, this study shows that both approaches are, in the end, complementary. Phenetical analysis allow, in addition to a quantitative definition of the genera, the isolation of ethological or ecological characters, while the cladistic approch gives to them precision and a phylogenetic sense.The three types of analyses point out the importance in Cryptobiina of the size, length of the scapus and width of the neck, all three characters which were also designated as significant characters by the phylogenetic analysi

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00194.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractPopulations ofAcanthoscelides obtectuswere maintained for 7 generations in either low‐ or high‐larval densities in order to examine whether weevils life‐history traits are modified in the direction predicted by r/K‐selection theory. We found that r‐selected population had a higher total fecundity, earlier age at first and last reproduction, and higher intrinsic rate of growth than K‐selected population. Contrary to the theory, we have no evidence that preadult developmental time and adult longevity have been molded by density‐dependent selection. The analysis of genetic variation of the weevils life‐history traits in responses to different larval densities in both r‐ and K‐selection populations indicates that different set of genes determining performance in two densities of analysed fecundity indices were accumulated during the course of the

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00195.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn the first half of the 20th century small founder groups of the Amur sleeper,Perccottus glenii, have been transferred from their native range in the Far East to some regions of the European part of Russia. In order to investigate the consequences of the introductions, 15 Far East populations and 11 European populations, that originated from two transfers, were studied for their variability on two enzyme loci (SodandOdh) using polyacrylamide gel electrophoresis. For both loci, divergence between populations and heterozygosity in the populations were higher in the colonized regions than in the native range. Heterozygote advantage in small founder populations seems to be a factor resisting genetic drift and determining the changes observed in the genetic structure of the introduced populations.

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00196.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractAfrican forest bulbuls of the genusBledaare usually placed into three separate species:B. syndactylaand B.eximiadistributed both in Upper and Lower Guinea forest blocks, and B. canicapilla restricted to the Upper Guinean one. Acoustic data lead to question traditional morphologically‐based species limits in this genus.Colouration patterns and measurements, particularly bill shape and length, wing and tail lengths, are reconsidered for all taxa. Multivariate (discriminant functions) analyses lead to separate nominateB. eximiaas an Upper Guinean species distinct from Lower GuineanB. notata. FurthermoreB. eximiaappears closer toB. syndactylathan to the other two species.Acoustically, by the physical traits of their calls and songs as well as the behaviour associated with their production,B. eximiaandB. syndactylaare very close and quite different from B. canicapilla and B. notata which constitute another pair of very close species.Obviously, in the frame of the biological species concept, the four taxa branched in two groups from a common ancestor,B. eximiaandB. syndactylarepresent a species‐pair whereasB. notataandB. canicapillaare allospecies of a single superspecies.Allopatric speciation patterns based on alternate fragmentations and unitings of forests can be drawn from present knowledge of African forest history in relation to Pleistocene‐Holocene events. However, a brief review of recent data on interspecific genetic differentiation in birds suggests an important discrepancy between biogeographical and molecular time calibrations. The development of molecular studies appears as a priority for the understanding of the evolution of African tropical forests

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00197.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractOn the evolution of basicranial articulations of birds, especially of fowl and waterfowl (Galloanseres)Basicranial articulations are among the most neglected structures of the avian feeding apparatus. Based on the presented ontogenetic evidence two nonhomologous types of basicranial articulations are distinguished in birds:1. A basipterygoid articulation developing from an early embryonic quadratopolar comissure, which is homologous to the basipterygoid articulation of other amniotes. This diarthrosis is present in all paleognathous as well as in many juvenile and some adult neognathous birds.2. A rostropterygoid articulation developing through apposition of the pterygoid on the parasphenoid. This secondary articulation is known from galliform and ansenform birds (Galloanseres).Based on ontogenetic evidence as well as functional analysis following hypothesis explaining the evolution of rostropterygoid articulations in the Galloanseres is proposed:1. In the groundplan of birds (Aves, sensu Gauthier 1986) a basipterygoid articulation was present continuously during ontogeny. It protected the pterygoid‐quadrate articulation against propalineal distortion by controlling the movement of the caudal end of the flexible, but undivided pterygopalatinal bar. This construction is preserved in recent paleognaths.2. In the groundplan of the Neognathae an intrapterygoid joint subdividing the pterygopalatinal bar was formed in juveniles. Consequently the basipterygoid articulation had lost its function in adults and was therefore developed only in embryonic and juvenile stages. This condition is present in many recent neognaths.3. In the stemline of the Galloanseres the intrapterygoid joint was already formed in embryos. Since an undivided pterygopalatinal bar is absent in any ontogenetic stage of the Galloanseres, no basipterygoid articulation is being formed. The recent Galloanseres retain this developmental pattern.4. In the groundplan of the Galloanseres a newly developed rostropterygoid articulation was present providing a support for the pterygopalatinal bar. This articulation could withstand not only pressure but also increasing tension occurring as a consequence of the development of a gliding jaw joint and a firm grip with beak tips, both consequences of increasing herbivory in the Galloanseres. Since the basipterygoid articulation was reduced, a new secondary joint had to be develope

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00198.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Gilbert, Francis (ed.): Insect Life Cycles. Genetics, Evolution and Co‐ordination. Berlin, Heidelberg, New York, London, Paris, Tokyo, Hong Kong:Kuschel, G.: Beetles in a suburban environment: a New Zealand case study. The identity and status of Coleoptera in the natural and modified habitats of Lynfield.Lewin, B.: Gene ‐ Lehrbuch der molekularen Genetik. 2. Aufl. Übersetzt von S. Vogel, M. Cramer, B. Grunemann, B. Kemper, M. Pohlmann und T. Vogel.Haumann, G.: Zur Phylogenie primitiver Oribatiden (Acari: Oribatida). (On the phytogeny of primitive oribat

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1993.tb00199.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY