The redundancy of crop growth and development and eukaryyotic genome including highly repeated DNA sequences show that gene has functional redundancy.The function and role of repetitive DNA are discussed in this paper.Living organisms have redundancy at different levels:organ, individual, population, community, ecosystem,as well as at the molecular level. Redundancy is a strategy for living organisms to reduce the negative influence of external conditions.
Based on the investigation data and relevant statistical data recently, with the methods of principle components analysis and cluster analysis, the present situation of grassland agriculture development and its sustainable degree of 30 poor counties located in karst mountains of Guangxi, Yunnan and Guizhou Provinces was studied. In the light of universal situation of the 30 poor counties, the index system of population, resources, environment, social and economic development for evaluating the sustainability degree of the local grassland agriculture system were determined preliminarily. By analyzing and calculating, the comprehensive index of grassland agriculture system sustainability of every county among the 30 poor counties have been obtained, and the comprehensive classification, order and evaluation for the present sustainable development degree of the 30 poor ones have been carried out.
