In this study, we explored the interspecific variation of body size and shape changes during postembryonic development (from the mid-larval period up to the end of metamorphosis) of four crested newt species. We analysed ontogenetic changes in the body size and shape, growth rate and the dynamics of shape variance patterns. We found a consistent pattern of changes in variance across the Selleckchem GSK1120212 species studied, with the mid-larval and juvenile stages being highly constrained and canalized and the period of metamorphosis as the most variable
stage. The ontogenetic trajectories of larval shape diverge in both the direction and the rate of shape changes along species-specific trajectories. These divergences are concordant with interspecific differences in adult body form and species-specific ecological preferences. However, crested newt species reach the juvenile stage at similar size and shape, indicating that metamorphosis, which is a key point between aquatic and terrestrial morphs, ‘resets’ the ontogenetic trajectories of larvae. Thus, metamorphosis interrupts the pattern of interspecific divergence, causing species to converge in body form. We speculate that such a pattern of developmental Proteases inhibitor regulation could play crucial roles in the evolution of the body form in amphibians with a biphasic life cycle. “
“The Mediterranean Basin is an acknowledged
hotspot for biodiversity, yet historical processes that shaped this biodiversity in North Africa remain poorly understood. This study aimed to elucidate the phylogeographic pattern of an endemic species of Mediterranean areas of North Africa, the Greater Egyptian Jerboa, Jaculus orientalis. The extent of phylogeographic patterns and molecular genetic diversity (mitochondrial cytochrome 上海皓元医药股份有限公司 b gene) were addressed in a survey of 45 jerboas from 24 localities. Our phylogeographical analyses show a strong
genetic subdivision into three areas along a west-east axis, corresponding to (1) Morocco and western Algeria; (2) eastern Algeria, Tunisia and western Libya; (3) eastern Libya and Egypt. Demographic analyses revealed different modalities of population expansion since the last glacial age depending on geographic areas. The dating using relaxed molecular clock analyses revealed that most splits occurred during the Quaternary (<1 million of years ago). Finally, we discussed the relative roles of geological and climatic change in generating this pattern of genetic structure observed for the Greater Egyptian Jerboa and other vegetal and animal species in North Africa. "
“Despite basal metabolic rate (BMR) being one of the most commonly measured physiological traits and an important indicator of competitive ability, very little is known about its genetic basis and relation to other physiological traits.