Final answer:
The three primary mechanisms of evolution are natural selection, genetic drift, and gene flow, which together with mutation contribute to the evolutionary changes observed in populations.
Step-by-step explanation:
The three primary mechanisms of evolution are:
- Natural selection, which acts on phenotypic variations in populations, selecting for beneficial traits and against detrimental ones.
- Genetic drift, which involves random changes in allele frequencies due to chance events affecting certain individuals in a population.
- Gene flow, where allele frequencies change as a result of individuals moving into or out of a population, bringing new alleles with them or removing existing ones.
These mechanisms, along with mutation, drive the evolutionary changes we observe in populations over time.