Population

Definition

A group of individuals of the same species that live in the same geographic area at the same time and have the potential to interbreed, sharing a common gene pool. In arthropod studies, populations are often delineated by habitat patches, host associations, or metapopulation dynamics rather than simple geographic boundaries.

Etymology

From Latin 'populatio' (a peopling, multitude), from 'populus' (people)

Example

A population of the butterfly Euphydryas editha in a serpentine grassland patch may be partially isolated from neighboring populations by unsuitable habitat, creating source-sink dynamics where local extinction and recolonization shape genetic structure.

Synonyms

• Deme
• local population

Related Terms

• metapopulation
• effective population size
• gene pool
• population genetics
• census population
• Founder effect
• population bottleneck
• subpopulation

Usage Notes

Distinguished from 'species' (which may comprise many populations) and 'community' (which includes multiple species). 'Population' is sometimes used loosely for any group of organisms, but in strict ecological and evolutionary usage requires conspecificity and potential gene flow. In conservation contexts, 'effective population size' (Ne) is often more relevant than census counts. Contrast with 'assemblage' (taxonomically mixed group) and 'aggregation' (spatial clumping without genetic implications).