Changes

: [[Variation]] within a [[species]] is the result of both [[genetic]] and environmental factors.

: The greater the [[genetic]] [[variation]] within a [[species]] the more likely a [[species]] will survive changes in the environment. Individuals may die, but with enough [[variation]] some of them will be better [[Adaptation|adapted]] to the change in their environment.

===Genetic Variation===

: Most of the [[variation]] between different [[species]] can be accounted for by the [[DNA]] differences between those [[species]].

: The [[variation]] within a [[species]] is due to [[mutation]]s causing different [[phenotype]]s. These [[variation]]s caused by [[mutation|genetic mutations]] are the source of [[Evolution by Natural Selection|evolution]].