The evolutionary trend of organisms, which often evolved from a simpler structure to a more complex structure, is a mystery. It seems that the later living things appeared on the earth, the more complex their structures were. This study pointed out that the evolutionary trend of organisms was the result of the organisms' asymmetric evolution-the phenomenon which the partition of the more complex structure was actually larger than that of the simpler structure on the same evolutionary platform of organisms, it explained the cause of the asymmetric evolution and listed much important evidence for organisms' asymmetric evolution.
There is another way for new species to invade former settlers' habitats and successfully settle there; it is demonstrated that the su- per-population, which plays a key role in changing the world-wide environment, can create many new microhabitats in the old habitat, it is these new microhabitats that make new species easily come into the old habitat and settle there without fierce competition with former settlers. In other words, the super-population lead to the differentiation of the worldwide environment, lead to the environmental diversity in the biosphere. Through the differentiation of the environment the super-population produces many new microhabitats for new species, the appearance of many new microhabitats make it possible for new species to coexist with former settlers in the biosphere. The cqexistence of new species with former settlers or with new species' "ancestors" results in the increaseing in the biodiversity of the biosphere. The super-population is the founder of many new environments on the earth, it bridges the habitat diversity and the biodiversity. Now It is easy to explain the phenomenon that new species sometimes coexist with former settlers and even depend on former settlers in the biosphere rather than fierce competition between them.
Evolution,adaptation and selection always exist in the evolutionary process of any species,which is the result of interrelation and interaction between living things and their environments,and the incarnation of natural laws in the evolutionary process of any species. Only if accurately understanding their connotation and interrelation among them,taking the evolution of living things as the line with centralizing the human sustainable development,dialectically unifying the active adaptation of the human being to their environments and oriented selection of nature and the society to species,we can acquire a better understanding of evolution of living things and a deeper understanding of the human sustainable development under biologically evolutionary background and uphold the true Darwinism,modern evolutionary point of view and the concept of current sustainable development in theory and in practice.