نتایج جستجو برای: species selection

تعداد نتایج: 844002  

2002
ATTE MOILANEN MAR CABEZA

Methods for designing regional reserve networks mostly concentrate on providing maximal representation of species occurring in the region. Representation-based methods, however, typically consider a static snapshot of species incidences, and the spatial dynamics of the species are ignored. It has been empirically demonstrated that reserves designed using representation do not guarantee another ...

2016
Carl Simpson

The mere existence of speciation and extinction make macroevolutionary processes possible. Speciation and extinction introduce discontinuities in the microevolutionary change 16 within lineages by initiating, disrupting, and terminating the continuity of species lineages. Within a clade, speciation and extinction become potent means of macroevolution in and of 18 themselves. This process, terme...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی - دانشکده اقتصاد 1389

abstract: about 60% of total premium of insurance industry is pertained?to life policies in the world; while the life insurance total premium in iran is less than 6% of total premium in insurance industry in 2008 (sigma, no 3/2009). among the reasons that discourage the life insurance industry is the problem of adverse selection. adverse selection theory describes a situation where the inf...

Journal: :Science 2010
Emma E Goldberg Joshua R Kohn Russell Lande Kelly A Robertson Stephen A Smith Boris Igić

Identifying traits that affect rates of speciation and extinction and, hence, explain differences in species diversity among clades is a major goal of evolutionary biology. Detecting such traits is especially difficult when they undergo frequent transitions between states. Self-incompatibility, the ability of hermaphrodites to enforce outcrossing, is frequently lost in flowering plants, enablin...

2008
David Jablonski

Species selection in the broad sense—also termed species sorting—shapes evolutionary patterns through differences in speciation and extinction rates (and their net outcome, often termed the emergent fitness of clades) that arise by interaction of intrinsic biological traits with the environment. Effectmacroevolution occurs when those biotic traits, such as body size or fecundity, reside at the ...

ژورنال: علمی شیلات ایران 2020

The purpose of breeding is to improve the quantity and quality of the desired characteristics in cultured species in the next generations. Individual selection is a simple and practical way to provide a quick response in improving high heritability traits for breeding most species in aquaculture. At first step, in Yasouj cold water fishes breeding research Center, in order to conducting selecti...

اسدی, مصطفی, جانی قربان, مهین,

The genus Elaeagnus (Elaeagnaceae) has been introduced in Iran by one or two species, i. e. E. angustifolia and E. orientalis . The species are widely cultivated trees, but native in a few localities. They are extremely variable in shape of leaves and fruits. Fruits used to be eaten highly and as they have variable tastes, the preferred ones have been subject to selection in the course of time....

Journal: :Journal of theoretical biology 1995
S H Rice

Species selection, differential rates of speciation or extinction resulting from species level characters, is often invoked as the main mechanism of macroevolution that is not simply an extension of microevolutionary processes. So long as we are careful in defining "species", the logic of species selection is sound. This does not mean, however, that this process can influence evolutionary dynam...

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