Body size is recognized as a major factor in evolutionary processes mediating sympatric diversification and community structuring. Life-history types with distinct body sizes can result from two fundamental mechanisms, size-dependent competition and size-dependent mortality. While previous theoretical studies investigated these two processes in separation, the model analyzed here allows both se...

Identifying the factors that promote or preclude the evolution of resource polymorphism is essential for understanding the origins of diversity. Although such polymorphisms have long been viewed as an adaptive response to intraspecific competition, they are by no means ubiquitous, even in populations experiencing strong competition. In the present study, we examined a potentially important cost...

Intransitive competition has the potential to be a powerful contributor to species coexistence, but there are few proposed biological mechanisms that could create intransitivities in natural communities. Using a three-species model of competition for space, we demonstrate a mechanism for coexistence that combines a colonization–competition tradeoff between two species with the ability of a thir...

Colonization is the crucial process underlying range expansions, biological invasions, and metapopulation dynamics. Which individuals leave their natal population to colonize empty habitats is a crucial question and is presently unresolved. Dispersal is the first step in colonization. However, not all dispersing individuals are necessarily good colonizers. Indeed, in some species, the phenotype...

purpose the aim of this study was to compare the levels of serum immunoglobulin (iga, igm, igg), testosterone and cortisol in semi-endurance elite runners during general preparation and competition phase of training. methods thirteen semi-endurance elite male runners with an average age of 18.92±1.7 years volunteered to take part in this study. the runners participated in the selected training ...

the law of prohibition of unfair competition prohibits any deed or action which is against the normal competition in the market. before emergence of special laws for protection of intellectual property rights, including trademarks, such right could be protected either by tort law claims or law of unfair competition. however, the law of prohibition of unfair competition covers a wider area than ...

The fibers in a skeletal muscle are divided into groups called "muscle units" whereby each muscle unit is innervated by a single neuron. It was found that neurons with low activation thresholds have smaller muscle units than neurons with higher activation thresholds. This results in a fixed recruitment order of muscle units, from smallest to largest, called the "size principle." It is thought t...