iranian cave barb (iranocypris typhlops, bruun and kaiser, 1944)is one of thevery rareandendemicspeciesof iran. its distributionrangeislimitedina habitat that causes some problems for its conservation. thisuniquehabitatfaces somenatural and humanthreatsand the habitatdestructionmeansthe extinctionof the species. based on, habitat selection for translocation of the species is an important object...

raccoon is a native species to north and central america. at present, it is an invasive species in many countries such as japan, germany, russia and iran. raccoon was observed for the first time in gilan province in iran in 1991. this research was employed ecological niche factor analysis (enfa) method to model habitat selection of raccoon in lavandevil wildlife refuge. the results showed that ...

Classic sex role theory predicts that sexual selection should be stronger in males in taxa showing conventional sex roles and stronger in females in role reversed mating systems. To test this very central prediction and to assess the utility of different measures of sexual selection, we estimated sexual selection in both sexes in four seed beetle species with divergent sex roles using a novel e...

Interactions among traits that build a complex structure may be represented as genetic covariation and correlation. Genetic correlations may act as constraints, deflecting the evolutionary response from the direction of natural selection. We investigated the relative importance of drift, selection, and constraints in driving skull divergence in a group of related toad species. The distributiona...

carbon sequestration in soil, leaf and litter of three tree species, viz. eucalyptuscamaldulensis, prosopisjuliflora and ziziphus spina-christi, plantation was investigated in the dehloran city, iran. results showed that the amount of sequestered c in leaf, litter and soil was significantly different among these species. the highest amount of sequestrated c was in leaf and the lowest amount in ...

Many species of phytoplankton typically co-occur within a single lake, as do many zooplankton species (the "paradox of the plankton"). Long-term co-occurrence suggests stable coexistence. Coexistence requires that species be equally "fit" on average. Coexistence mechanisms can equalize species' long-term average fitnesses by reducing fitness differences to low levels at all times, and by causin...

Do we know anything about its regulation? A little. In animal cells, components of the class I phosphatidylinositol (PI) 3-kinase pathway including Akt and Tor act as inhibitors, whereas the lipid phosphatase PTEN, class III PI 3-kinase and p70 S6 kinase appear to be positive regulators. In yeast, Tor kinase and protein kinase A are inhibitory, while PI 3kinase is required for autophagy. Many q...

The selective pressure on a protein-coding gene can be measured by comparing silent (synonymous) and replacement (nonsynonymous) substitution rates. Higher replacement than silent rates provide unequivocal evidence for adaptive evolution driven by Darwinian selection. Previous employment of this criterion involved pairwise sequence comparison, averaging rates over time and sequences, resulting ...