Klaus F. Steiner's scientific ventures

Why this website? Well, I'm passionate about science. Around 1990 I studied biology and a bit of mathematics and philosophy here in Graz, Austria. For my diploma thesis, I modeled and simulated the song interactions of bushcrickets. But then I ended up in software development and I am still employed today. For several years now, I have also been running a small puzzle company together with my spouse Karin.

My "inordinate" fondness for science has remained, even though my approach is playful rather than scientific. I keep insects, build formicariums, microscope, watch and photograph what crawls and flies. However, my most intense and serious approach to biology is of theoretical nature and with the help of my favorite tool to gain knowledge, the computer. I have created numerous computer models, mainly from evolutionary biology, and experimented with them. Now I came across a few things that seem remarkable to me and that I would like to report on. This page is the guide for that.

2024/2025

Altruism pays off in group-structured populations through probable reciprocity

Preprint: https://www.biorxiv.org/content/10.1101/2024.01.20.575560v2 (download PDF)

The evolution of altruistic traits is a Darwinian puzzle that has not yet been satisfactorily solved. Using multi-agent simulations for public goods games and a threshold model, I show here that there is a clear fitness advantage for the altruists in a mixed population of altruists and egoists if some conditions are met.

Simulation program

groupsim_CD_fitness_demo: run simulation in browser This multi-agent simuation shows the dynamics of altruistic cooperators and selfish defectors in a group-structured population. It demonstrates the basics of the processes and mechanisms described in the paper.

Demo video

Short clip to illustrate the key points of the simulation and the messages of the paper.
(It is edited a little too fast, please pause or slow down if necessary.)

2021

The Good, the Bad and the Stochastic: How Living in Groups Innately Supports Cooperation

Based on theoretical considerations and computer simulations, I show that living in groups brings advantages for cooperative traits through purely stochastic effects that result from the division of a population into groups. These advantages can be sufficient to compensate individual selection pressures that may be associated with the cooperative traits. In more complex agent-based simulation models, this effect combined with some migration between the groups leads to stable dynamic equilibria between cooperative and defective replicators in the population.

Supplementary simulation programs

	payoff_CD_deviation: download NetLogo simulation or open HTML simulation in browser Simulation of trait payoffs for different variances of the groups consisting of cooperators (C) and defectors (D). It was used for the data in figure 4. See "Model Info" (below the model) for details.
	groupingSimCD: download NetLogo simulation or open HTML simulation in browser Multi-agent simulation of trait evolution in groups of cooperators (C) and defectors (D) as used for figures 5-9. At the first time click "Setup" and then "Go", and a simulation starts. To stop click "Go" again. See "Model Info" (below the model) for details.

Last modified: March 14, 2025

Contact

I also maintain the website Vinckensteiner Rätsel und Denkspiele with puzzles and brain teasers (mainly in German, but with portions in English and Spanish) and the evolution page for kids Evolution in Aktion (in German).