Humans share the planet with as many as 8.7 million different forms of life and out of these; about 1.2 million have been documented. However, even after centuries of effort, some 86 per cent of these life forms have yet to be fully described. A huge percentage of the planet's original life forms are extinct. The planet's life forms exist in a delicate balance, owing to the ever-changing climate and other natural forces and phenomena - with consequent challenges to this balance.