Which process has the greatest influence on genetic variation in a population?

Mutation is the process that introduces new genetic variations into a population's gene pool. It occurs when there are changes to the DNA sequence, which can lead to new traits that were not previously present in the population. These mutations can arise from various sources, including environmental factors or errors during DNA replication.

While inheritance passes genetic information from parents to offspring, it does not create new variation; it merely transmits existing variations. Gene flow, which involves the movement of genes between populations (through migration), can introduce variation from one population to another, but it necessitates that mutations have already occurred in those migrating individuals. Natural selection acts on existing variations, favoring certain traits over others based on their fitness in a given environment, but again, it does not create new genetic diversity.

Thus, mutation is fundamental in generating the genetic diversity that is necessary for evolution and adaptation, making it the process with the greatest influence on genetic variation in a population.