Sumiwake structure in a finite and heterogeneous ecosystem

As previously reported [1], we developed a general platform for simulation and visualization called SIVA. With SIVA, one can simulate life activities and their evolution in conditions that approximate an actual terrestrial ecosystem and living organisms. These simulations are based on the development and examination of SIVA-I, II, and III as prototypes of the simulator. SIVA is characterized by simulated environmental conditions that are finite and heterogeneous, and by simulated individuals that are able to self-decompose as well as selfreproduce. The Java language source program of SIVA version 1.1 is distributed by ATR. In the present study, we conducted simulations with SIVA to examine evolutionary adaptation, and tried to clarify through examination of the simulation results whether the development of a broad distribution of individuals was the result of divergent proliferation of the most prolific individuals or the result of a complication of habitat segregation. It was found through a comparative analysis of visualized habitable area and of the degree of correspondence of genetic information that the complications of habitat segregation led to a broad distribution of individuals. This finding will introduce a way method to investigate the constructive mechanism of habitat segregation in an actual terrestrial ecosystem, and also points to a survival strategy for human beings.