An Unusual Antagonistic Pleiotropy in the Penna Model for Biological Ageing

We combine the Penna Model for biological aging, which is based on the mutation-accumulation theory, with a sort of antagonistic pleiotropy. We show that depending on how the pleiotropy is introduced, it is possible to reproduce both the humans mortality, which increases exponentially with age, and fruitfly mortality, which decelerates at old ages, allowing the appearance of arbitrarily old Methuselah's.Comment: 8 pages, 3 figures, to appear in Physica

The Penna Model of Biological Aging

This review deals with computer simulation of biological ageing, particularly with the Penna model of 1995.Comment: 16-page invited review submitted to Bioinformatics and Biology Insight

Positive mutations and mutation-dependent Verhulst factor in Penna ageing model

We twice modify the Penna model for biological ageing. First we introduce back (good) mutations and a memory for them into the model. It allows us to observe an improvement of the species fitness over long time scales as well as punctuated equilibrium. Second we adopt a food/space competition factor that depends on the number of accumulated mutations in the individuals genomes, and get rid of the fixed limiting number of allowed mutations. Besides reproducing the main results of the standard model, we also observe a mortality maximum for the oldest old.Comment: 9 pages, including 3 figures, to be submitted to Physica

Monte Carlo Simulation of Age-Dependent Host-Parasite Relations

The death of a biological population is an extreme event which we investigate here for a host-parasitoid system. Our simulations using the Penna ageing model show how biological evolution can ``teach'' the parasitoids to avoid extinction by waiting for the right age of the host. We also show the dependence of extinction time on the population size.Comment: 8 pages including 6 figure