Biodiversity

Biodiversity is the variation of life forms within a given ecosystem, biome, or for the entire Earth. Biodiversity is often used as a measure of the health of biological systems. The biodiversity found on Earth today consists of many millions of distinct biological species, which is the product of nearly 3.5 billion years of evolution.

This is an introduction to biodiversity, taken from Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Biodiversity).