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Absolute vs. relative fitness

Evolutionary biology “fitness” can be defined either in relative terms, normalized to the competition, or against an external standard. Many binary distinctions have been made between different kinds of fitness: not only absolute vs. relative fitness, but also r- vs. K-selection, natural vs. sexual selection, low vs. high density-dependence, selection on individuals vs. groups, and hard vs. soft selection. We are working on a new formulation of the concept of biological fitness, with three rather than two incommensurable fitness dimensions, subsuming these prior distinctions and resolving past problems with them. The three dimensions are competitiveness (similar to the w of population genetics), growth (similar to r-selection) and efficiency (a reformed version of K-selection). Competitiveness is normalized and unitless, while growth and efficiency are both absolute, with time and resource units respectively. Adaptation in asexual populations can then be modeled as a travelling wave in up to three fitness dimensions. We are using this approach  to define the conditions for evolutionary rescue, i.e. escape from extinction in a deteriorating environment.

I also wrote a book, Bypass Wall Street: A Biologist's Guide to the Rat Race, applying ideas of relative vs. absolute competition to economics, in particular the difference between money as a relative points system and wealth as an absolute store of value.