In modern evolutionary theory (Neo-Darwinism), specific mechanisms alter allele frequencies and genetic variation within population gene pools. Match each evolutionary mechanism on the left with its corresponding impact on population genetics on the right.
- Genetic Drift (Bottleneck Effect)Random shift in allele frequencies following a drastic reduction in population size due to an environmental disaster
- Gene FlowExchange of alleles between neighboring populations due to migration, reducing genetic differences between them
- Stabilizing SelectionSelective pressure favoring intermediate phenotypes while eliminating extreme variations from the gene pool
- Directional SelectionShift in allele frequencies favoring one extreme phenotypic trait over others in response to environmental change
Answer
Genetic Drift (Bottleneck Effect) pairs with random allele shifts following severe population crashes; Gene Flow pairs with allele exchange between migrating populations; Stabilizing Selection pairs with favoring intermediate traits over extremes; Directional Selection pairs with shifting population traits toward one extreme.
Each microevolutionary mechanism has a distinct outcome: the bottleneck effect causes random loss of alleles during population crashes; gene flow introduces or homogenizes genetic variation between populations through migration; stabilizing selection preserves the average phenotype; and directional selection drives allele frequencies toward a specific phenotypic extreme.
Step-by-Step Solution
Key Concept
Mechanisms of Microevolution and Neo-Darwinian Genetics