There are a lot of the world's endangered species,this is not what we can all know.Climate change,environmental pollution,over the killing of man-made,such as excessive deforestation will lead to the extinction of animals.On the one hand,to adapt to the environment is a long-term changes in their own species because they can not continue to adapt to the new environment and the population decreased slowly become extinct,this ecological laws is normal; but more as a result of human activities,environmental change,human hunting,so that species,or to speed up the rate of species extinction.