Texas A&M University (TAMU) BIOL112 Introductory Biology II Exam 3 Practice

Mutations are indeed the primary source of new alleles in a population, contributing significantly to genetic diversity. A mutation refers to a change in the DNA sequence of an organism. These changes can occur due to various factors, such as errors during DNA replication, exposure to environmental factors, or even viral infections. When a mutation creates a new allele, it alters the genetic makeup of an organism, which can lead to variations in traits.

This genetic variation is crucial for evolution as it provides the raw material upon which natural selection can act. Without mutations, there would be no new alleles for the population to draw upon, and thus, genetic diversity would be severely limited. The presence of new alleles can affect an organism's ability to survive and reproduce in changing environments, leading to adaptive evolution.

While gene flow, sexual reproduction, and natural selection also play roles in shaping genetic diversity, they do not create new alleles. Gene flow involves the transfer of alleles between populations, sexual reproduction shuffles existing alleles to create new combinations, and natural selection favors certain alleles that enhance survival. However, the generation of entirely new alleles is fundamentally driven by mutations.