Effect of Ecological Imbalance on diversity of organisms:
Origin of new species and extinction of some of the existing species is a part of the natural process of organic evolution. However, human activities are causing extinction at an unnatural or greater rate. Destruction or alteration of natural habitats, pollution of environment, degradation of ecosystem, hunting and poaching, over exploitation of economically important plant and animal species, etc pose great threat to the organisms, both plants and animals. The organisms of such ecosystem should adjust with the changed environment, migrate to some other region or else die. Thus, the original composition of the ecosystem is changed and the number of organisms is reduced.
As a consequence of above mentioned and some other factors, over the last few centuries many animal and plant species have become extinct and many more are facing the danger of extinction (endangered species). Once a species becomes extinct, it is permanently lost from the world and cannot be retrieved e.g., Cheetah from India and Dodo bird from Mauritius has become extinct.
Whatever has happened in the past, now it is our responsibility to prevent the numerous endangered species from becoming extinct. Man alone can do this and help to preserve the diversity of life on earth.