Editing Unit of selection (section)

=== Organism ===
{{further|Hologenome theory of evolution}}

Selection at the level of the organism can be described as [[Darwinism]], and is well understood and considered common. If a relatively faster gazelle manages to survive and reproduce more, the causation of the higher fitness of this gazelle can be fully accounted for if one looks at how individual gazelles fare under predation.

The speed of the faster gazelle could be caused by a single gene, be polygenic, or be fully environmentally determined, but the unit of selection in this case is the individual since speed is a property of each individual gazelle.

When speaking about individual organism evolution an [[extended phenotype]] and [[superorganism]] must be also mentioned.