Similar term(s): study population, population group.
A group or number of people living within a specified area or sharing similar
characteristics (such as occupation or age).
Can also apply to study groups of animals and other organisms. In that case,
population refers to a group of individuals of the same species, occupying a
defined area, and usually isolated to some degree from other similar groups.
Sub-populations are members of population sub-groups who exhibit similar
specific characteristics which differ from those in the whole study population.