多様性変動のコンピュータシミュレーション : 従来の研究と展望(<特集>生物多様性と古生物学)

抄録

During a past few decades, many computer simulations have been used to explore possible mechanisms controlling biodiversity in the geological time scale. Raup et al. (1973) conducted the stochastic simulation and generated some temporal diversity patterns that were similar to those seen in the fossil record. However, the stochastic model has been criticized because it could not generate several well-known diversity patterns such as living fossil, adaptive radiation, etc. Some improved models, in which inter-specific competition was incorporated, successfully generated mass extinction and rapid diversification pattern, but failed to generate living fossil lineages and high-diversity clades. In addition, these models have faced a relevant criticism: the dynamics of ecosystem cannot be fully understood in terms of models that simply describe competition among species. Differential equation models, based on various kinds of among-species interactions, generate most of the actual patterns of temporal diversity, even though it requires some unrealistic assumptions that oversimplify the nature. It is easy to understand the effect of each factor on the behavior of the system using a simple model based on a few significant factors. In addition, simple models are useful for simulations of ancient ecosystems in which complicated models are not available because of lacking detailed knowledge on the systems. Therefore, simple models are suitable for researches on biodiversity change over geological time.