Gene Pool is an artificial life simulation in which populations of physics-based organisms evolve swimming capabilities over time. These organisms are called "swimbots". You can set mate preference criteria and thus influence what the swimbots consider as attractive qualities in potential mates. The most attractive swimbots get chosen most often and so their genetic building blocks propogate to future generations. Eventually, swimbots get better at pursuing each other, competing for food, and becoming babes to other swimbots. Local gene pools emerge which compete for sex and food (for energy to have more sex). Eventually a dominant sub-population takes over.