The variety of living organisms on Earth is known as biodiversity or biological diversity. Not only is it found in vertebrates, it also present in plants, invertebrates and microorganisms.
In addition, biodiversity exists at all levels of habitats and climates, such as forests, island, coral reefs, mountaintops and deserts.
Generally, there are three levels of biodiversity, and they are defined as below.
•The variation in genes within and between populations.
•The variation in the number and distribution of species within and between populations.
•The variation in habitats, communities and ecological processes within and between ecosystems.
Of the three levels, the common measure of biodiversity is species diversity.
Eg: The level of biodiversity in a forest is higher than that in a paddy field because a greater number of species can be found in a forest.
The number of known species on Earth is recorded at approximately 1.6 million, most of which are insects. However, the actual number of species on Earth may be up to 30 million.