Pobre Darwin: a evolução de traços fenotípicos adaptativos sem evolução darwiniana positiva

Review

Heredity , (2 November 2011) | doi:10.1038/hdy.2011.97

Evolution of adaptive phenotypic traits without positive Darwinian selection

A L Hughes

Abstract

Recent evidence suggests the frequent occurrence of a simple non-Darwinian (but non-Lamarckian) model for the evolution of adaptive phenotypic traits, here entitled the plasticity–relaxation–mutation (PRM) mechanism. This mechanism involves ancestral phenotypic plasticity followed by specialization in one alternative environment and thus the permanent expression of one alternative phenotype. Once this specialization occurs, purifying selection on the molecular basis of other phenotypes is relaxed. Finally, mutations that permanently eliminate the pathways leading to alternative phenotypes can be fixed by genetic drift. Although the generality of the PRM mechanism is at present unknown, I discuss evidence for its widespread occurrence, including the prevalence of exaptations in evolution, evidence that phenotypic plasticity has preceded adaptation in a number of taxa and evidence that adaptive traits have resulted from loss of alternative developmental pathways. The PRM mechanism can easily explain cases of explosive adaptive radiation, as well as recently reported cases of apparent adaptive evolution over ecological time.

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NOTA DESTE BLOGGER:

Se este processo evolucionário não é darwiniano e nem lamarckiano, é o que??? E se a generalidade do mecanismo PRM é desconhecida, o que isso implica??? Estamos tateando no escuro em busca do fato, Fato, FATO da evolução darwiniana???

Queria ver a cara de alguns na Galera dos meninos e meninas de Darwin...