Theory suggests that frequency-dependent resource competition will disproportionately impact the most common phenotypes in a population. The resulting disruptive selection forms the driving force behind evolutionary models of niche diversification, character release, ecological sexual dimorphism, resource polymorphism, and sympatric speciation. However, there is little empirical support for the...

The maintenance of floral-color variation within natural populations is enigmatic because directional selection through pollinator preferences combined with random genetic drift should lead to the rapid loss of such variation. Fluctuating, balancing, and negative frequency-dependent selection mediated through pollinators have been identified as factors that may contribute to the maintenance of ...

the present investigation was carried out to study the variability, heritability, correlations and path coefficient analysis in 14 kabuli type chickpea genotypes during three successive cropping seasons (2011-14), in a randomized complete block design with four replications. combined analysis suggested significant differences between genotypes for most of characteristics. the highest phenotypic...

Inflation targeting framework has become a predominant monetary approach across the globe. Williams (2015) believes that in a very real sense, almost all economies are inflation targeters -either explicit or implicit- now.(1) Due to the increasing spread of this policy, it is necessary to consider the way it affects macroeconomic variables. using prevalent economic models for evaluating the eff...

in this paper, financial services in the iranian as a sector with a leontief production function, this sector buys inputs from other sectors for its productions and provides services to expedite the cash fellows and risk transformation to other sectors, the first relations are called backward linkage and the later relations are called forward linkage, for quantification of the linkage , employm...