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The formal framework set out in chapter 2 is intended, first of all, as an instrument for uniform treatment of adaptation. If it is to be useful a wide variety of adaptive processes must fit comfortably within its confines. To give us a better idea of how the framework serves this end, the present chapter applies the framework in several different fields. It will repay the reader to skim through all of the illustrations on first reading, but he should skip without hesitation over difficult points on unfamiliar ground, reserving concentration for illustrations from familiar fields. Although each of the illustrations adds something to the substantiation of the framework no one of them is essential in itself to later developments. The interpretations, limited usually to one commonly used model per field, are of necessity largely informal, but two points can be checked in each case: (1) the facility of the framework in picking out and organizing the facts relevant to adaptation, and (2) the fit of established mathematical models within the framework. |
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. . . genes act in many ways, affecting many physiological and morphological characteristics which are relevant to survival. All of these come together into the sufficient parameter "fitness" or selective value. . . . Similarly environmental fluctuation, patchiness, and productivity can be combined . . . in . . . [a] measure of environmental uncertainty. . . .
Levins in Changing Environments (pp. 6-7) |
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The phenotype is the product of the harmonious interaction of all genes. The genotype is a "physiological team" in which a gene can make a maximum contribution to fitness by elaborating its chemical "gene product" in the needed quantity and at the time when it is needed in development. There is extensive interaction not only among the alleles of a locus, but also between loci. The main locale of |
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