What is the primary source of genetic diversity in a population?

Mutations are the primary source of genetic diversity in a population because they introduce new genetic variations into the genome. These changes can occur in various ways, such as alterations in DNA sequences, which can result from errors during DNA replication, exposure to certain environmental factors, or the influence of various mutagens. As mutations create different alleles for a gene, they contribute to a larger pool of genetic differences within a population.

This genetic variability is crucial for evolution and natural selection, as it provides the raw material upon which these processes can act. When environmental pressures favor certain traits over others, the variation caused by mutations can determine which individuals are more likely to survive and reproduce, thus shaping the genetic structure of future generations.

While selective breeding can manipulate traits within a species, it does not create new genetic variation and relies on existing genetic diversity. Environmental change can affect populations and lead to selective pressures but does not itself generate genetic diversity. Hybrid vigor, or heterosis, refers to the improved or enhanced characteristics seen in hybrids compared to their parents, but it is a result of the combinations of existing genetic material rather than a source of new genetic variations.