The enormous diversity of life forms in the biosphere has evolved essentially through the process of trial and error during course of organic evolution. The changes in character of living organism which confer some advantage to the species are retained.
The changes in climatic conditions are reflected in the distribution of living organism and the pattern of biodiversity on our planet. The number of species present per unit area decreases as we move from mild tropics to the tundra's.
The Indian region (8° to 30° N and 60° to 97.5°) with total area of 329 million hectares is very rich in biodiversity. It is estimated that about 4500 species of plants occur in this country. The position of Indian sub-continent at the confluence of there biogeography reels is also an important contributing factor and explain the preserve of African, European, Sind, Japanese and Indo-Malayan elements in the flora and fauna in India. It is the sum total of such remarkable diversity that has made India a "gene bank" for a number of food crops, forest trees, medical and aromatic plants and domesticated animal.
Warm tropical regions between the tropic of cancer and Capricorn on either side of equator have provided the most suitable habitat living organism. In habitat which does not provide the optimum conditions, organisms have to adopt themselves to the prevailing adverse conditions.
Forests are important bioreserves; most of the 1700 million hectares of tropical forests are located in poor countries. The forests surrounding Reo de Aneroid are part of vegetation which is rich in species of plants and animals that are endemic. There are about 53.5% of trees species found only in these forests and studies of birds, reptiles, primates and butter flies have revealed equally high or higher endemics.
It is important to preserve the numerous varieties of plants and animals that belong to one species. Each variety within a species contains unique genes and the diversity of genes within a species increases its capacity to adopt to pollution disease and other changes in the environment.