We discuss two different ways of evolution for chromosomes and genomes. Purifying selection dominates in large panmictic populations, where the Mendelian law of independent gene assortment is valid. If instead the populations are small, recombination processes are not effective enough to ensure...

No influence was seen when in two models with memory effects the populations were drastically decreased after equilibrium was established, and then allowed to increase again.

Microscopic models dealing with the decisions of traders on the market have tried to reproduce real market behaviour. Possibly the simplest of these models is the herding approach of Cont and Bouchaud. Variations include letting the concentration varying between zero and unity (or zero and...

An earlier study [24] concluded, based on computer simulations and some inferences from empirical data, that languages will change the more slowly the larger the population gets. We replicate this study using a more complete language model for simulations (the Schulze model combined with a...

Monte Carlo simulations of a Sznajd model show that if a near-consensus is formed out of four initially equally widespread opinions, the one which at intermediate times is second in the number of adherents usually loses out against the third-placed opinion.

The Chowdhury model for ecosystems is modified by assuming a birth rate increasing with temperature, and additional minor changes. Its computer simulation based on individual births and deaths gives a biodiversity increasing from cold to warm climates. Complexity of foodwebs increases with time...

The 1995 model of Bonabeau et al. is generalized by giving each individual a different ability to win or lose a fight. We also introduce different groups such that the losers of fights between different groups are eliminated. The overall phase diagram for the first-order transition between...

Our earlier language model is modified to allow for the survival of a minority language without higher status, just because of the pride of its speakers in their linguistic identity. An appendix studies the roughness of the interface for linguistic regions when one language conquers the whole...