Whereas the new, optimized matrix d reduces the error cost (increases the fitness) of the standard code, the mean of the random code cost distribution remains the same, so the distance from the standard code to this mean increases when measured in standard deviation units (Table 1).
4. When evolutionary trajectories start from random codes whose fitness is comparable to the fitness of the standard code, they typically reach much higher level of optimization than that achieved by optimization of the standard code as an initial condition, and the same holds true for the minimization percentage.
The variant code can spread if the invasion fitness is higher than the fitness of the established code.
It became an issue of her fitness--the code word for weight.
Several genes coding for proteins within these regions were found to contribute to the fitness of the bacterium (Cl_02679 coding for ABC-type Fe3+-siderophore transport system; Cl_03044 coding for permease component, chloramphenicol acetyltransferase (EC 2.3.1.28); coding94 coding for multidrug-efflux transporter).
Here I think he overlooks that a genome is a population of sites, so that the impact of codon mutation on both the fitness of a genetic code and the relative fitness of code alterations can easily become comparable to that of translational error (Sella and Ardell [ 27]).
These authors calculate the invasion fitness of a variant code, which is the fitness of an individual using the variant code to translate a message that has the expected equilibrium codon usage of the established code.
Here, we describe an analysis of the code fitness landscape using particular error cost functions for codes constructed from blocks that are inherent to the standard genetic code.
where fit is the fitness of the muscle, while fit min is the minimum fitness.
The proponents of the translation-error hypothesis reasonably counter the above objections by showing that the distribution of the code error scores (fitness values) has a Gaussian-like shape where the better, more robust codes form a long tail such that the process of adaptation is non-linear, so approaching the absolute minimum is highly improbable [ 14, 30, 40, 41].
Among them, mRNA size and the coefficient responsible for the fitness of coding systems based on their size (k in Figure 1) are of a particular interest.
