摘要:

The evolution of close vertebrate associations has occurred in seven orders of insects, resulting in a great diversity of interactions which range from commensalism to true parasitism. The evolution of each taxon of vertebrate associates is discussed in turn, some new ideas on the development of certain groups are presented and, on a broader scale, a general model for the evolution of ectoparasitic insects is proposed. It argues that all vertebrate associates have evolved along one of two macroevolutionary pathways which differ only in the sequencing of adaptations facilitating host association and host feeding. These pathways lead to parasite types which differ greatly in their life history and intimacy of host association.Some microevolutionary processes influencing the diversification of ectoparasites are discussed, in particular the process of insect/vertebrate coevolution and the forms this may take. Host specificity, one consequence of coevolution, is recognised as an important factor influencing the structure of ectoparasite communities, and a hypothesis is presented that competition between ectoparasite species, mediated by host defensive responses, is also important in determining community structure.

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1979.tb00055.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

To understand the ecological significance of diversity in the buccal pump morphology of anuran larvae we have developed a descriptive geometric model of the tadpole buccal pump. The model allows comparison of the buccal puinping mechanism of different species.The reliability of the model was established by comparing buccal volumes predicted by the model with buccal volumes reported in the literature forRana sylvaticaandRana catesbeianaas well as those obtained from our own feeding experiments withXenopus laevislarvae.The model was used to examine the following features for the larvae of 40 species from 11 anuran families: (1) the amount of deflection inthebuccal floor with each stroke of the buccal pump (angle of rotation of the ceratohyal); (2) the mechanical advantage of the pump (the relative length of the lever arm on the ceratohyal); and (3) buccal volume. We identify patterns in diese three features that correlate with the feeding ecology of a variety of tadpoles. Macrophagous larvae tend to have a long lateral lever arm on the ceratohyal (high mechanical advantage), and produce a large buccal volume by deflecting a large buccal floor area through a shallow arc (i.e. a large bore, short stroke system). Midwater, microphagous larvae tend to have poor mechanical advantage, but nevertheless achieve a large buccal volume; in these forms the large buccal volume is obtained by deflecting a smaller buccal floor area through a larger arc (i.e. a small bore, long stroke system). Benthic larvae, such as stream tbrms with suctorial mouths, tend to have high mechanical advantage, but only modest buccal volume.Larvae can regulate their feeding rate by varying either the p umping rate (frequency modulation) or the buccal floor displacement (amplitude modulation). The anatomy of the buccal pump may determine not only the feeding ecology of a larva, but the predominant behavioral pattern it uses to regulate its feeding rate.Buccal volume has a negative allometric relationship to body length both intraspecifically and interspecihcally.

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1979.tb00056.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Pigments leached fromSinapis alba L.seeds and extracted from dark‐grown seedlings are described and investigated by spectrophotometry and chromatography and their functions examined. Evidence is given that they are quinonoid, and it is suggested that they form part of a complex which absorbs ultraviolet light and utilizes it to produce growth energy at stages before visible light becomes available to the plant, and that this process may be the means by which mutations are introduced into specie

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1979.tb00057.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The associations of the butterfly fauna of the Japanese islands of Hokkaido, Honshu, Kyushu, Shikoku and Ryukyu Rett are analysed with respect to one another and to the fauna of the far‐east U.S.S.R. A faunal discontinuity exists between the fauna of Ryukyu Rett and all other areas. The fauna of Ryukyu Rett can be considered as being of the Oriental region, the faunas ofthe otherJapanese islands as being of the Palaearctic region. This view was reinforced with conclusions drawn from MacArthus&Wilson's theory of island biogeography (1963, 1967). The divergence of die faunas of the Japanese islands is dependent on their isolation ‐ the further the distance between islands, the greater the isolation and the greater the faunal divergence. Thus the fauna of all silands of Japan, except of the Ryukyu Rett, have a close association with the far‐east Russian fauna. There is a greater similarity between these faunas than between the fauna of the islands of Hokkaido, Honshu, Kyushu and Shikoku with respect to that of Ryukyu

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1979.tb00058.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Book reviewed in this article:The Voyage of Charles Darwin: His Autobiographical writings, selected and arranged by Christopher Railing.Penguin Nature Guides: Fungi of Northern Europe, Vols I&II, by S. Nilsson&; O. Persson; illustrated by B. MossbergPenguin Nature Guides: Plant Communities, by Anned Biilow‐Olsen, illustrated by Susanne Larsen; translated from the Danish by Joan Tate; edited and adapted by Francis Rose.Penguin Nature Guides: Fishes of the British and Northern European Seas, by J. Moller Christensen; illustrated by Bente Nystrom; translated from the Danish by Gwynne Vevers; edited and adapted by Gwynne Vevers and Philip Orkin.Birds of Wood, Park and Garden, text and illustrations by Lars Jonsson; translated from the Swedish by Roger TannerBirds of Sea and Coast, text and illustrations by Lars Jonsson; translated from the Swedish by Roger Tann

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1979.tb00059.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY