Genetics plays a crucial role in natural selection by influencing the heritable traits that affect an organism's ability to survive and reproduce. Variations in genes can result in different phenotypes, leading some individuals to be more adapted to their environments. For example, advantageous traits may increase an organism's fitness, allowing it to reproduce more successfully. Over time, these traits become more prevalent in a population, shaping its evolution. Thus, genetics is fundamental in determining which traits are favored by environmental pressures, steering the course of evolution and species adaptation.