Love kills: Simulations in Penna Ageing Model

The standard Penna ageing model with sexual reproduction is enlarged by adding additional bit-strings for love: Marriage happens only if the male love strings are sufficiently different from the female ones. We simulate at what level of required difference the population dies out. Love may have been a female invention long ago, when the brain of genus homo became large and required more food [1]. Thus the father was needed to help feed mother and baby. We try to check here if the restriction in the number of suitable mates caused by love can drive the whole population to extinction. First we describe the biology, then our model, and finally our results. For sexual reproduction of diploid organisms, usually two individuals of different gender are necessary (hermaphrodites are the exception). In theoretical concepts, considering a random assortment of genes, any preferences in the selection of partners for reproduction usually are ignored. In fact, it is known that such a selection can be a very important factor for the evolution of the genetic pool of a species. However, the selection of potential mates is only the first step influencing the assortment of genes. Generally, the assortment of genes can be affected at the pre-zygotic stages, like mating preferences or gamete pre-selection, or at post-zygotic stages, like miscarriage, or any other differential selection of individuals before and during their reproduction period. Sometimes it is difficult to find out at which stage the random assortment is disturbed. The first step generating non-random distribution of genes is the mating preference. There are more and more informations suggesting that there are not only the obvious phenotypic traits like size or strength of the male (or his bank account) which are preferred by females but that there are some other genetic characters which influence the mating decisions or even tune the genetic relations between mating pairs. Odour of individuals is such a trait determined by its genetic configuration. In the generation and recognition of an individ-ual's odour at least two groups of genes are involved. One group is the Major 1