ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1994.tb00480.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe electrophoretic variation at 26 presumptive gene loci was investigated in populations of the closely related speciesPodarcis sicula, P. wagleriana, P. raffonei, andP. filfolensis. Low values of proportion of polymorphic loci (P) and mean observed heterozygosity (Ho) were found inP. sicula(P= 0.10; Ho= 0.016),P. wagleriana(P= 0.13;Ho= 0.029), andP. raffonei(P= 0.08;Ho= 0.017), while higher levels of genetic variability were observed inP. filfolensis(P= 0.17;Ho= 0.054). In the latter species, a multiple regression analysis was carried out in order to analyse the geographic correlates ofPandHo. The results of this analysis were consistent with the predictions of the time‐divergence theory of variation, supporting the conclusion that directional selection is the main force eroding genetic variation on small islands. Intraspecific values of Nei's (1972) standard genetic distance were relatively low inP. sicula(averageD= 0.024),P. wagleriana(averageD= 0.004), andP. filfolensis(averageD= 0.012), while higher inP. raffonei(D= 0.040). The lizards from Pantellena Island, which were considered by BISCHOFF (1986) to be very similar toP. filfolensisfrom Malta on the basis of a superficial analysis of the coloration pattern, were shown to actually belong toP. sicula. This confirms that the range ofP. filfolensisonly includes the Maltese Archipelago, Linosa Island, and the islet of Lampione. Surprisingly, the samples ofP. filfolensisfrom the Pelagie Islands (Linosa and Lampione) were very similar to those from the Maltese Archipelago (averageD= 0.016). This could be explained by rafting or anthropogenic introduction ofP. filfolensison Linosa and Lampione.Podarcis waglerianaandP. raffoneiwere genetically related (averageD= 0.152), confirming the results of previous electrophoretic investigations.Podarcis filfolensis, though showing some morphological affinity withP. wagleriana, was genetically highly differentiated from this latter species (averageD= 0.526), while being more similar toP. sicula(averageD= 0.306). This indicates a close relationship betweenP. siculaandP. filfolensis, suggesting thatP. siculaandP. filfolensisprobably diverged from a common ancestor, and that the apparent similarity betweenP. filfolensisandP. waglerianacould be merely due to morphological convergenc

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1994.tb00481.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe population specific variability of diploid and triploidR. kl. esculentaindividuals was investigated by means of morphometric methods (canonical discriminant analysis, UPGMA cluster analysis) and DNA fingerprinting. As a result of the morphometric investigations, as well as of the DNA investigations, a clear separation of single populations was possible. However, no correlations between the morphometry and different population systems could be recognized. Clear morphometric differences could be seen between diploid ♀♀ and ♂♂ and triploid ♀♀ on the one hand, and triploid ♂♂ on the other. While the diploid ♀♀ and ♂♂ and the triploid ♀♀ were located in the intermediate area between the parental speciesR. lessonaeandR. ridibundaaccording to their morphometric parameters, the triploid ♂♂ showed a great overlap withR. lessonae. Up to now, this phenomenon has not been explained.The first results of the DNA investigations provided further hints at the high inter‐individual and population‐specific variability ofR. kl. esculenta. R. kl. esculentaindividuals of theR. lessonae/esculentapopulation Toter See could be distinguished from conspecific individuals of theR. ridibunda/esculenta‐♀♀ population Alte Oder according to their fingerprint patterns. Moreover, in theR. lessonae / esculentapopulation, the fingerprints or the diploidR. kl. esculenta‐♀♀ and the investigatedR. lessonae‐♀ were very similar. Furthermore, in this population, manyR. kl. esculentagenotypes resembleR. lessonaein their morphometric features. This finding suggests the occurrence of recombination inR. kl. esculenta.In general, every population seems to have its own genetic background. A classification of water‐frog populations according to populat

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1994.tb00482.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThis study concerns the contribution of directional asymmetry (DA) and fluctuating asymmetry (FA) as a characterization of variation in six sexual (diploid) and two asexual (triploid and tetraploid) populations of the weevilOtiorhynchus alpicola. It is shown that DA in sexual populations is about 1 % of the mean length of each of the seven bilateral traits and the average contribution of DA to trait variation is even lower in asexual populations (about 0.85 in triploids and 0.65 in tetraploids forms). The average contribution of FA to the total phenotypic variance is about 23 %, 12 % and 19 % in diploid, triploid and tetraploid populations, respectively. Since FA is generally regarded as a measure of developmental stability, our data indicate that triploid forms ofO. alpicolaare developmentally more stable than diploid and tetraploid forms. The relationship between the level of ploidy and FA is discussed.

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1994.tb00483.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractNiche occupation by 5 goby species (Teleostei, Gobiidae) in the Baltic Sea and its interpretation by means of the theory of pre‐adaptationThe habitats and prey of five goby species were investigated near the shore of the Lübeck Bight (SW Baltic) during the period 1989–1991. Observations showed thatGobius nigeris a macrobenthos feeder,Pomatoschistus micropsa meiobenthos feeder;Pomatoschistus pictusprefers meiobenthos as well as plankton whilePomatoschistus minutusfeeds on benthos of every size, as well as planktonic cope‐pods when offered in surplus;Gobiusculus flavescensis generally a plankton feeder but, when this component is in short supply in the summer, changes to macrobenthos.P. pictusandP. micropsexisted at different depths;G. flavescensandP. minutuspresented countercurrent densities in shallow habitats during the course of a year. This adaptability of behaviour in habitat and prey choice can be explained by the modification ability of pre‐adaptional genes in the goby genomes. After having invaded species‐poor habitats such as the brackish Baltic Sea, wide niche dimensions are initially occupied. The niche is here considered to be an attribute of the species as well as of the habitat according to GÜNTHER (1950). Hence, innidation is defined as a process which implies specialization by loss of most preadaptations and leads to the optimal use of the ecosystem by the species. This process of a single species corresponds to the maturation of successions of whole

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1994.tb00484.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Walossek, D. The Upper Cambrian Rehbachiella and the phylogeny of Branchiopoda and Crustacea.Sudhaus, W., Rehfeld, K.: Einführung in die Phylogenetik und Systematik.Miller, B. J.; Anderson, St. H.: Ethology of the Endangered Black‐footed Ferret (Mustela nigripes).SCHASSBURGER, R. M.: Vocal Communication in the Timber Wolf, Canis Lupus.SMITH, J. MAYNARD: Evolutionsgenetik. Übers. von K. WÖHRMANN und J. TO

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1994.tb00485.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY