Scaling Effects in the Penna Ageing Model

Abstract

We have analysed the possibility of scaling the sexual Penna ageing model. Assuming that the number of genes expressed before the reproduction age grows linearly with the genome size and that the mutation rate per genome and generation is constant, we have found that the fraction of defective genes expressed before the minimum reproduction age drops with the genome size, while the number of defective genes eliminated by the genetic death grows with genome size. Thus, the evolutionary costs decrease with enlarging the genome. After rescaling the time scale according to the mutational clock, age distributions of populations do not depend on the genome size. Nevertheless, enlarging the genome increases the reproduction potential of populations.

Gompertz mortality law and scaling behavior of the Penna model

“…Scaling effects in the sexual model were also investigated by Laszkiewicz et al [14] through simulation.…”

“…Brigatti et al [13] investigated scaling in a sexual Penna model through simulation and suggested that results from the continuum model of Almeida et al [12] were not readily mapped onto the discrete model employed in simulation. Scaling effects in the sexual model were also investigated by Laszkiewicz et al [14] through simulation.…”

The Accumulation Theory of Ageing

“…While the two models above are individual-based, ie when an individual dies is determined by its life history, there is finally the Penna model ( Laszkiewicz et al, 2005, Penna, 1995, Stauffer, 2007. This, too, can explain an exponentially increasing mortality rate, albeit on a population level.…”

Phase Transition in the Genome Evolution Favors Nonrandom Distribution of Genes on Chromosomes

“…Detailed descriptions of the standard diploid Penna model can be found in many original papers [11] or reviews [12], [13]. We have used the modified, diploid version of the Penna model with sexual reproduction.…”