STUDYING THE NUMBER OF LINEAGES THROUGH MONTE-CARLO SIMULATIONS OF BIOLOGICAL AGING

We studied different versions of the Penna bit-string model for biolog ical ageing and found that, after many generations, the number of line ages N (maternal family names) always decays to one as a power-law N p roportional to t(-x) with an exponent z roughly equal to one. Measurin g the mean correlation between the ancestor genome and those of the ac tual population we obtained the result that it goes to zero much earli er before the number of families goes to one, the population keeping t hus its biological diversity. Considering maternal and paternal family names (doubled names) we also finished with only one pair of common a ncestors. Computing the number of families of a given size as a functi on of the size (number of individuals the family has had during its wh ole existence) again a power-law decay is obtained.