摘要:

Phylogenetic relationships within the Euro‐Mediterranean stock of theRana temporariaspecies group(R. temporaria, R. iberica, R. cameranoi, R. macrocnemis, R. holtzi, R. dalmatina, R. graeca, R. latastei)were studied by (1) morphometric analysis, (2) osteological study and (3) electrophoresis. The three data sets were analysed independently and phenograms and cladograms examined for congruent patterns. The tree resulting from electrophoretic analysis is the most clearly resolved (and being also compatible with the other two) is assumed to represent the most likely phylogeny of the Mediterranean brown frogs. Patterns indicated by electrophoretic data matched the molecular clock‐hypothesis. This suggests that the first split of the main stock of Mediterranean brown frogs separated ancestors ofRana temporariaandR. ibericafrom the others during the Late Pleistocene. A second split occurred separating the ancestors of what are currently the other big‐bodied and the small‐bodied brown frogs. The relationships between and within the three main stocks are discussed in the context of biogeographical and geologic

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1992.tb00925.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Data derived from studies of comparative anatomy, development, neuroanatomy, behaviour and the reconstruction of fossils are combined to evaluate the evolution of the oral‐pharyngeal region in mammals. An important event in the evolution of the mammalian feeding apparatus was the development of a novel neuromuscular apparatus, consisting of a large series of striated muscles. The most important of these muscles are the pharyngeal elevators and constrictors, which appear to be without homologues in other amniotes. In addition to considerable peripheral neural and muscular modifications, the motor nuclei of the brain stem in mammals exhibit significant differences from other amniotes. The morphological features characteristic of mammals are reflected in behavioural differences, most significantly during swallowing and suckling. The neuromuscular changes in the mammalian oral‐pharyngeal apparatus are at least as extensive as those involving the masticatory system, and have importance far beyond the separation of the airway and foodway, the foci of most previous studies. The hypothesis of neuromuscular conservativism in the evolution of the mammalian feeding mechanism is considered and it is concluded that few data exist to support this hypothe

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1992.tb00926.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The totally aquatic pipid frogXenopus borealisproduces long trains of click‐like sound at high sound pressure levels (>105 dB SPL) underwater at night. WhileX. borealisretains an essentially terrestrial respiratory tract, the larynx is highly modified in two ways. First, the cricoid cartilage is greatly expanded posteriorly to form a large ‘box’. Portions of this cricoid box are composed of an unusual elastic cartilage. Second, portions of the arytenoid cartilages are elaborated into calcified rods with disc‐like enlargements at their posterior ends. These discs are the only freely moveable components within the larynx–there are no vocal cords. Artificial stimulation of a pair of muscles controlling the discs and discrete lesions that impair their movement demonstrate that motion of the discs is both necessary and sufficient for click production. Unlike all other anurans, Xborealisdoes not use a moving air column in sound production. A possible mechanism of click production involves two steps: (1) at first, the discs are held tighdy apposed in the midline by fluid adhesive forces, and contraction of bipennate muscles is isometric; (2) when the muscle tension exceeds the adhesive force, the discs separate with very high acceleration leaving a vacuum between them. Air rushing into the space at high speed (an implosion) produces the click. The cricoid box shapes the frequency spectrum of the clicks, and opening the box broadens the power spectrum. The power spectrum of clicks produced by males after breathing helium is

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1992.tb00927.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Book reviewed in this article:Patterns of Injury and Illness in Great Apes, by N. C. LovellMoths of Australia, by I. F. B. CommonThe Scientific Names of the British Lepidoptera. Their History and Meaning, by A. Maitland EmmetPlant‐Animal Interactions: Evolutionary Ecology in Tropical and Temperate Regions, edited by P. W. Price, T. M. Lewinsohn, G. W. Fernandes and W. W. BensonSearching Behaviour: The behavioural ecology of finding resources, by William J. Be

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1992.tb00928.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY