Directionality and community‐level selection

Directionality Theory and the Entropic Principle of Natural Selection

Darwinian fitness describes the capacity of an organism to appropriate resources from the environment and to convert these resources into net-offspring production. Studies of competition between related types indicate that fitness is analytically described by evolutionary entropy, a statistical measure which is positively correlated with population stability, and describes the number of accessi...

Directionality, timing, and sample selection in epidemiologic research design.

The foregoing commentaries demonstrate wide differences between their authors’ choice of terms describing epidemiologic research designs, and in the relative importance they attach to directionality, timing, and sample selection. Nowhere is this more evident than in their discrepant definitions of “prospective” and “retrospective” studies. According to Drs Greenland and Morgenstern, “Prospectiv...

Directionality of contact networks suppresses selection pressure in evolutionary dynamics.

Individuals of different types, may it be genetic, cultural, or else, with different levels of fitness often compete for reproduction and survival. A fitter type generally has higher chances of disseminating their copies to other individuals. The fixation probability of a single mutant type introduced in a population of wild-type individuals quantifies how likely the mutant type spreads. How mu...

Conflicting Directionality

Mortality plateaus and directionality theory.

Recent large scale studies of senescence in animals and humans have revealed mortality rates that levelled off at advanced ages. These empirical findings are now known to be inconsistent with evolutionary theories of senescence based on the Malthusian parameter as a measure of fitness. This article analyses the incidence of mortality plateaus in terms of directionality theory, a new class of mo...