Which process introduces new genetic variation into a population?

The introduction of new genetic variation into a population primarily occurs through mutations. Mutations are spontaneous changes in the DNA sequence that can result from various factors, such as errors during DNA replication, exposure to radiation, or certain chemicals. These changes can affect a single nucleotide or larger segments of DNA, leading to new alleles that may not have existed in the original gene pool.

Mutations are crucial because they are the raw material for evolution, providing the variation upon which natural selection, genetic drift, and other evolutionary processes can act. Without mutations, populations would have limited genetic diversity, reducing their ability to adapt to changing environments or survive challenges such as diseases or climate shifts.

In contrast, while gene flow involves the transfer of genetic material between populations, it does not create new mutations but rather mixes existing genetic variations from different populations. Genetic drift is the random change in allele frequencies within a population, often leading to the loss of variation without introducing new genetic material. Natural selection works on existing variations within populations rather than introducing new ones itself. Therefore, mutations are the primary mechanism by which new genetic variation is generated in a population.