Biodiversity: Concept, Theories, and Significance in River Ecology

Biological diversity in nature is being viewed as a product of ongoing evolutionary events on existing biotic communities. Diversity found within and among keystone predator populations can have the potential to influence the future direction of diversity at three levels of eco-biological processes such as biological organization, from the lowest level of biomolecules (genes) to the highest hierarchical form as ecosystems, and through eco-evolutionary feedbacks. At present, species extinction has progressed rapidly, with an accelerating rate, due to human-mediated disturbances ranging from local human activities to global climate change. India as one of the 18 megadiversity countries having 4 out of 34 hot spots of the world not only boasts of accommodating a very rich biodiversity wealth in terms of species diversity but is naturally gifted with an innumerable variability of genes (genetic diversity) within species along with harboring an enormous numbers of endemic species in 3 major biological realms (Indo-Malayan, Eurasian and Afrotropical), 10 biogeographic zones and 26 biotic provinces.