anopheles stephensi is the main malaria vector in south of iran. it has been known to be resistant to ddt, malathion and dieldrin. after appearance of resistance the area was treated with propoxur, at the rate of 2 g/m2 twice a year for 14 successive years. this species is still susceptible to propoxur. in order to forecast the possibility of development of propoxur resistance in an.stephensi, ...

What engenders biodiversity? Natural selection certainly adapts species to their ecological niches, but does it really create all of the new niches and new species to ll them? Consider: the most successful, complex, and numerous species on earth are composed of sexually-reproducing animals and owering plants. Both groups typically undergo a form of sexual selection through mate choice: animals ...

Natural selection arising from resource competition and environmental heterogeneity can drive adaptive radiation. Ecological opportunity facilitates this process, resulting in rapid divergence of ecological traits in many celebrated radiations. In other cases, sexual selection is thought to fuel divergence in mating signals ahead of ecological divergence. Comparing divergence rates between natu...

The many documented examples of parallel and convergent evolution in similar environments are strong evidence for the role of natural selection in the evolution of trait variation. However, species may respond to selection in different ways; idiosyncrasies of their evolutionary history may affect how different species respond to the same selective pressure. To determine whether evolutionary his...

materials and methods in total, among 134 patients clinically suspected of having pityriasis versicolor, attending the department of mycology, boali sina hospital and referral laboratory of the mazandaran university of medical sciences, 116/134 (86.5%) positive patients for malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. all 116 ...

Most genes linked to male reproductive function have been known to evolve rapidly among species and to show signatures of positive selection. Different male species-specific reproductive strategies have been proposed to underlie positive selection, such as sperm competitive advantage and control over females postmating physiology. However, an underexplored aspect potentially affecting male repr...

Mutualisms are widespread, yet their evolution has received less theoretical attention than within-species social behaviors. Here, we extend previous models of unconditional pairwise interspecies social behavior, to consider selection for donation but also for donation-suppressing modifiers. We present conditions under which modifiers that suppress costly donation receive either positive or neg...