Which factor would most likely reduce genetic diversity in isolated patches?

Which factor would most likely reduce genetic diversity in isolated patches?

• A. High gene flow between patches
• B. Large, connected populations
• C. Frequent interbreeding between patches
• D. Prolonged isolation of patches with little gene flow

Answer: (D)

Genetic diversity within a population is shaped by how much mixing occurs between groups. When patches stay isolated for a long time with very little gene flow, each patch undergoes genetic drift and can suffer from inbreeding. Drift randomly loses alleles, especially rare ones, reducing the variety of genes (allelic diversity) in that patch. Inbreeding increases the chances of mating between related individuals, which lowers heterozygosity and overall genetic variation. Without new alleles coming in from other patches, the genetic diversity within each isolated patch tends to decline over time. In contrast, gene flow between patches introduces new alleles and helps maintain diversity, while large, connected populations also preserve it, and frequent interbreeding mixes gene pools. So prolonged isolation with little gene flow best explains the reduction in genetic diversity in isolated patches.

Genetic diversity within a population is shaped by how much mixing occurs between groups. When patches stay isolated for a long time with very little gene flow, each patch undergoes genetic drift and can suffer from inbreeding. Drift randomly loses alleles, especially rare ones, reducing the variety of genes (allelic diversity) in that patch. Inbreeding increases the chances of mating between related individuals, which lowers heterozygosity and overall genetic variation. Without new alleles coming in from other patches, the genetic diversity within each isolated patch tends to decline over time. In contrast, gene flow between patches introduces new alleles and helps maintain diversity, while large, connected populations also preserve it, and frequent interbreeding mixes gene pools. So prolonged isolation with little gene flow best explains the reduction in genetic diversity in isolated patches.