The Biodiversity And A Kind Of Ecological Models With Muti-species

Penna model was introduced by T. J. P. Penna in 1995. Recent years, there are many phenomena reproduced by the model. This model is based on the hypothesis of mutational accumulation. Hence, a bit-string is used to represent the individual's genome in the biological model. Furthermore, owing to simulate the dynamics of population, Penna introduced some strategies of survival, diseases and reproduce into the model. In this paper, the theory called 'Cellular Automata' is also applied. Cellular Automata is a model based on cellular evolution, with discrete time, pace and state, which can only serve in gaining values from a determinate set.We developed the Penna model to record the information of ancestor in the process of individual's evolution. Besides, both of the entropies of blood relationship and genetic diversity are defined. The tendency of the entropies demonstrates that each living individual within species has exactly the same set of ancestors which belongs to different times. All living individuals at any time have not only the most recent common ancestors but also the earlier ones. The result of genetic diversity shows that the complexity of biosystem is caused by mutation and there is no contribution of sexual reproduction to conserving genetic diversity in large time scale. In short, the basic condition of conserving genetic diversity is mutation.Secondly, the two species' biosystem is described by means of the Penna Model with intelligence. In addition, both species are prey and predator separately. The result of simulation reveals that predator has more knowledge quantity then prey, however the situation of intelligence's degree is opposite.Finally, this thesis discusses a four species' prey-predator biosystem based on the Cellular Automata with three layers. In some cases, it is found that the relative values of prey-predator probabilities are important to the size of species' population and the stability of coexistence.The thesis is organized as follows:Chapter 1: the Penna models based on asexual and sexual are represented separately.Chapter 2: the theory of Cellular Automata is introduced.Chapter 3: the common ancestor is discussed by the Penna model. Chapter 4: there are two parts in this chapter. In part one, we research evolution of two species' intelligence and knowledge with prey-predator biosystem. Moreover, the relation of four species' coexistence is analyzed by Penna model and Cellular Automata in part two.