Contextual descriptions of these levels are given and this lesson is dedicated to explaining these definitions, how species diversity is an integral part of functioning ecological communities, and why biological diversity is important to human survival. Genetic diversity is all of the genetic variation found within and among individuals of any given species. More specifically it encompasses all the alleles of all the genes that constitute the genetic makeup of an individual organism. Recall that a gene is a segment of DNA that codes for the production of a particular protein product e.g., melanistic proteins that produce eye color. Theoretically, the amount of genetic diversity increases with the number of individuals considered.
Genetic diversity is important to species because it creates natural variation among individuals.
When the physical factors of an area change some individuals may be better adapted to the new conditions as a result of this variation. These individuals survive and reproduce thus, persisting despite variable physical conditions where they live. This process is referred to as natural selection and genetic diversity is a very important component of this process. When introducing species diversity it is easiest to start with an operational definition of a species. Species diversity is a quantifiable measure of all the individuals of all the species that exist in a given area.