Why certain regions have been declared as biodiversity'hot spots' by environmentalists of the world?Name any two regions of India

Faced with the conflict between development and conservation, many nations find it unrealistic and economically not feasible to conserve all their biological wealth.Invariably, the number of species waiting to be saved from extinction far exceeds the conservation resources available.
Hence,conservationists have declared certain regions as ‘‘hot spots’’ for maximum protection of these regions which have levels of species richness and high degree of endemism.
Example, Western Ghats and Sri Lanka and Himalaya.