摘要:

AbstractThe importance of the species concept in biology has led to a continuing debate about the definition of species. This paper summarizes the recent literature in relation to the ‘biological species concept’ (MAYR 1942). Among the general attributes demanded, possible limitations of the universality and applicability of a species definition are discussed. Three different areas of criticism of the biological species concept are considered: 1. The impracticability of the criterion of reproductive isolation. The demand for more practical criteria is rejected, because reproductive isolation is seen as the factor that produces and maintains species as discrete entities in nature. 2. The inapplicability to non‐bisexual organisms. A brief survey of modes of uniparental reproduction and their relative importance suggests that obligatory apomicts are of little evolutionary significance. 3. The inapplicability to multidimensional situations. Despite practical difficulties, the biological species concept is held to apply to organisms separated in space. The impossibility to delimit species in time by reproductive isolation is recognized. Out of two ways to divide continuous evolutionary lineages in time, the phylogenetic approach, which considers only speciation events (cladogenesis), is preferred as it is more objective. A list of recently published alternative definitions of species, none of which is found acceptable, is given. It is concluded that the biological species concept needs not be changed or dismissed on the basis of the discussed criti

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00607.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper presents a new phylogenetic estimate of isopod crustaceans of the suborder Asellota with the aim of clarifying the evolution of the superfamily Janiroidea, a large and diverse group inhabiting all aqueous habitats. The phylogenetic analysis is based on a morphological evaluation of characters used in past classifications, as well as several new characters. The evolutionary polarity of the characters was determined by outgroup analysis. The characters employed were from the pleopods, the copulatory organs, the first walking legs, and the cephalon. The resulting character data set was analyzed with numerical phylogenetic computer programs to find one most parsimonious clado‐gram, which is translated into a classification using the sequencing convention. The new phylogenetic estimate is significantly more parsimonious than previous trees from the literature, and several of its monophyletic groups have robust confidence limits. The superfamily Stenetrioidea belongs to the clade including the Janiroidea, not with the Aselloidea as previously suggested. The sister group of the Janiroidea is the family Pseudojaniridae, which is elevated to superfamily rank. The clade including the families Gnathostenetroididae and Protojaniridae is not the sister group of the Janiroidea, and is derived earlier in janiroidean evolution than the Stenetrioidea. Within the Janiroidea, the family Janiridae is not the most primitive taxon as previously believed. The clade including the families Munnidae and Pleurocopidae contains the earliest derived janiroideans. The data also indicate that the unusual sexual morphology of the Janiroidea did not appear suddenly but developed as a series of independent steps within the Asellot

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00608.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractProtein variations and taxonomy of seed‐eating oscinesThe variability of 21 proteins coded by 24 geneloci has been analysed among 99 oscines, 93 of them seed‐eaters, out of a total of 40 species. Based on the ascertained allel‐frequencies genetic distances were calculated according to ROGERS (1972) and NEI (1972). Dendrograms have been constructed with the “unweighted pair‐group arithmetic average clustering‐method” (UPGMA) (SOKAL and SNEATH 1963). A new procedure is proposed in order to verify the reliability of these results. Published argumentations on the taxonomy of seed‐eating oscines are collected and evaluated all together. With due regard to all results the following conclusions are drawn: 1. Ploceidae and Viduidae are closely related sistergroups. 2. The Estrildidae stand opposite to Ploceidae, Viduidae, Sporopipidae and Passeridae. 3. Together with Motacillidae and Prunellidae the above mentioned groups probably form the Passerioidea. 4. Carduelidae and Fringillidae are sister‐groups as well as Emberizidae and Thraupidae. 5. These four families and other not analysed ones form the Fringil‐lioidea and stand opposite

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00609.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractTwenty five specimens of the brown hare and fourteen specimens of the wild rabbit were examined for genetic differentiation and polymorphism in 28 enzyme systems by means of horizontal starch gel electrophoresis and isoelectric focusing in polyacrylamide gels. Indices of genetic variation show values similar to those averaged over numerous mammalian species. A D‐value of 0, 0288 between wild and domestic rabbits suggests a high amount of gene frequency changes at enzyme loci during domestication. Evolutionary time of divergence between the rabbit and the hare (about 2430000 years) calculated from electrophoretic data is in good agreement with palaeontological finding

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00610.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Book reviewed in this article:Population Genetics and Molecular Evolution. Hrsg. von T. OHTA und K. AOKI.ECHELLE, A. A.; KORNFIELD, I. (eds.): Evolution of Fish Species Flocks.GRZIMEK, B. (Ed.): Grzimeks Enzyklopadie der Saugetiere.GRANT, P. R.: Ecology and Evolution of Darwin's Finches.ZAHRADNIK, J.: Kafer Mittel‐ und Nordwesteuropas. Ein Bestimmungsbuch fur Biolo‐gen und Naturfreunde. Translated from the Czech language by MARTIN ROSCH.RULCKER, J.; STALFELT, F.: Das Elchwild. Naturgeschichte, OkologieNACHTIGALL, W. (Hrsg.): Biona Report 5 Bat flight ‐ Fledermausflug. Mit Bei

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00611.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY