Species evolution is the process by which populations of organisms change over time through variations in their genetic traits. These changes can occur due to factors such as natural selection, genetic drift, and mutations. Over many generations, these adaptations can lead to the emergence of new species, as organisms become better suited to their environments. The theory of evolution, first popularized by Charles Darwin, explains how species adapt and evolve through mechanisms like survival of the fittest. This process is supported by evidence from various fields, including paleontology, genetics, and comparative anatomy, demonstrating the interconnectedness of life on Earth.