The argument is put forward that genetic mutations are viable then only, when the changed pattern Of growth and/or metabolism is accommodated by the taxon-specific biochemistry of the organisms, i.e. by adaptive, somatic/physiological plasticity. The range of somatic plasticity under changing environmental conditions, therefore, has a certain predictive value for the kind of mutations that are likely to be viable.
Somatic or phenotypic plasticity
Somatic or phenotypic plasticity in relation to developmental physiology and evolution was a major subject of research up to the 1940-ties (lit refs see Walker, 1979), when it faded under the combined impact of probability theory, of theoretical physics, classical Mendelian genetics and "The Cold War". Consequently, evolutionary theory was driven by the "Modern Synthesis" (Huxley, 1942) and the central dognaa of natural selection and random mutations, implying competition and maximization of growth. With the inevitable historical delay, the obsession with growth and competition has gripped modem Economy as well as Academia.
Meanwhile, molecular biology largely unravelled the structure and the function of the gene. "The Gene", in fact, is no more. It disintegrated into subunits, subject to deterministic and probabilistic rearrangements (Jacob, 1983;Portin, 1993). Most important, the gene is no longer a simple, static code, instead, genetic loci revealed themselves as complex, dynamic machineries, monitored by environmental/physiological stimuli, and involving the precise interaction of several loci. Gene regulation, orchestrating the time order of ontogenesis and metabolism, and establishing the direct biomechanical connection between specific environmental stimuli and specific genetic loci via perception, hormones and regulator proteins (as one may find in any textbook on cell biology as from the early 1980-ties), resuscitated the interest in somatic plasticity as a relevant evolutionary factor.
By somatic plasticity we understand the range of morphological and physiological