Evolution, the process by which species change over time through the mechanisms of variation, selection, and inheritance, is primarily driven by two key factors: genetic variation and natural selection. Genetic variation arises from mutations, recombination, and genetic drift, leading to differences in traits and characteristics among individuals within a population. This genetic diversity provides the raw material for evolution. Natural selection is the process by which certain traits confer advantages to individuals in their environment, increasing their likelihood of survival and reproduction. These advantageous traits are passed on to offspring, gradually becoming more common in the population. The combination of genetic variation and natural selection leads to adaptation and the evolution of species over generations. Other factors that can influence evolution include genetic migration (gene flow) between populations, non-random mating patterns, and changes in environmental conditions. Additionally, sexual selection, driven by mate preferences and competition for mates, can lead to the evolution of traits that enhance reproductive success. Evolutionary processes have shaped the diversity of life on Earth and explain the complexity and adaptations observed in organisms. While genetic variation and natural selection are the primary drivers of evolution, the field of evolutionary biology continues to explore the interplay of these factors and their outcomes across different species and environments.