refers to the variation at the level of individual genes (polymorphism), and provides a mechanism for populations to adapt to their ever-changing environment. The more variation, the better the chance that at least some of the individuals will have an allelic variant that is suited for the new environment, and will produce offspring with the variant that will in turn reproduce and continue the population into subsequent generations.
, or biodiversity, is the collection of species of plants, animals, bacteria, etc. - all the living organisms - that inhabit a particular ecosystem. An environment consists of the cycle of exchange between non-living organic material (minerals, nutrients, etc.) and the living biodiversity.
There is a delicate interdependence between biological and genetic diversity; changes in biodiversity result in changes in the environment, requiring subsequent adaptation of the remaining species. Changes in genetic diversity, particularly loss of diversity through loss of species, results in a loss of biological diversity.
is the aggregate of different environmental types in a region. For example, a country on the coast could have a diversity of ecosystems from sandy beaches with salt water-adapted biodiversity, to lush rain forests and dry deserts, each with a unique set of species.