In populations where two species compete, natural selection due to interspecific competition is most evident in which context?

• A. In allopatric populations only
• B. In both allopatric and sympatric populations
• C. In neither context
• D. In sympatric populations only

Answer: (D)

Natural selection due to interspecific competition occurs where species coexist and compete for the same resources. In allopatric populations, the species live in separate areas and do not interact, so there is no competition between them to drive changes. In sympatric populations, the two species share the same space and resources, creating direct competition and selecting for traits that reduce overlap or give one species an advantage. This leads to observable changes like character displacement, where differences between species become more pronounced in areas of contact. So the phenomenon is most evident in sympatric populations.