Species diversity on earth is not uniformly distributed. It is generally highest in the tropics and decreases towards the poles. Earth’s fossil history reveals the incidence of mass extinctions in the past. Earth’s rich biodiversity is vital for the very survival of mankind. It is believed that communities with high diversity tend to be less variable and more productive. The reasons of conserving biodiversity are narrowly utilitarian, broadly utilitarian and ethical. Biodiversity conservation may be in situ as well as ex-situ.