Ivan Aleksic, Jelka Crnobrnja-Isailovic and Davor Bejakovic
We examined degree of between-sides difference in number of femoral pores (fluctuating asymmetry, FA) in Podarcis muralis populations, distributed on islands and in coastal area of Lake Skadar (Southern Montenegro). The aim of this study was to test sensitivity of fluctuating asymmetry of chosen trait to isolation effect in the absence of anthropogenic impacts. The results indicate that FA in the number of femoral pores do not vary significantly between insular populations of P. muralis. Generally, there is negative but non-significant correlation between island size and FA level. Also, overdominance hypothesis of enhanced developmental homeostasis at higher levels of heterozygosity was not confirmed in this study. The results support earlier conclusions obtained from electrophoretic studies, that analyzed insular populations from Lake Skadar archipelago still do not suffer deleterious effects as a result of isolation.
Ivan Aleksić, Miloš Kalezić and Ana Ivanović
The patterns of ontogenetic and interspecific variation of morphological integration (the relationships and correlation patterns of functionally and developmentally related morphological traits) in facultative paedomorphic species of two European newts (Triturus vulgaris and T. alpestris) were examined. The degree of morphological integration differed among ontogenetic stages. Variation in the level of morphological integration of cranium and postcranial skeleton during ontogeny of paedomorphic newts had the same pattern in both analysed species. The lowest level of cranium morphological integration characterises the larvae and the juveniles. Individuals that follow alternative life-history path (paedomorphs) remain at a relatively low level of morphological integration, while integration highly increased in metamorphosed adult individuals. Limb skeleton also showed a lower level of integration in paedomorphs in comparison with metamorphosed individuals. The hypothesis of morphological integration was confirmed for all stages of T. vulgaris, while the same hypothesis was confirmed only for larval and paedomorphic stages of T. alpestris. In T. vulgaris, metamorphosis changes the pattern of correlation among the cranial traits, while in T. alpestris, the patterns of phenotypic correlation among the cranial traits remain substantially similar for all analysed ontogenetic stages.