Evolutionary Theory is the scientific explanation for how species change over time through a process called natural selection. This theory, first popularized by Charles Darwin, suggests that organisms with traits better suited to their environment are more likely to survive and reproduce. Over generations, these advantageous traits become more common in the population, leading to gradual changes in the species. Additionally, genetic variation plays a crucial role in evolution. Each individual has unique traits due to differences in their genes. When these variations are passed on to offspring, they can lead to new adaptations, helping species thrive in changing environments and contributing to the diversity of life we see today.