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Universal adaptive strategy theory (UAST) is an evolutionary theory developed by J. Philip Grime (University of Sheffield, UK) in collaboration with Simon Pierce (University of Milan, Italy) describing the general limits to ecology and evolution based on the trade-off that organisms face when the resources they gain from the environment are allocated between either growth, maintenance or regeneration – known as the universal three-way trade-off. ==General Theory== A universal three-way trade-off produces adaptive strategies throughout the tree of life, with extreme strategies facilitating the survival of genes via: C (competitive), the survival of the individual using traits that maximize resource acquisition and resource control in consistently productive niches; S (stress-tolerant), individual survival via maintenance of metabolic performance in variable and unproductive niches; or R (ruderal), rapid gene propagation via rapid completion of the lifecycle and regeneration in niches where events are frequently lethal to the individual. It is impossible for an organism to evolve a survival strategy in which all resources are devoted exclusively to one of these investment paths, but relatively extreme strategies exist, with a range of intermediates. The system can be represented by a triangle, with the three extreme possibilities at its vertices. The different species may be located at some particular point inside this triangle, accommodating a certain percentage of each of the three strategies. It is possible to use multivariate statistics to determine the main trends in phenotypic variability in a range of organisms, which for various major animal groups (most prominently vertebrates), has been shown to have three main endpoints consistent with UAST. UAST is a key part of the twin-filter model describing how species with similar overall strategies but divergent sets of minor traits coexist in ecological communities. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Universal adaptive strategy theory (UAST)」の詳細全文を読む スポンサード リンク
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