Evolution is the process through which species change over generations due to variations in traits. The most famous theory of evolution, proposed by Charles Darwin, is natural selection, where organisms with traits better suited to their environment are more likely to survive and reproduce.
There are other theories, such as Lamarckism, which suggests that organisms can pass on traits they acquire during their lifetime. The study of fossils, genetic data, and anatomical comparisons provides crucial evidence supporting evolutionary theory and helps scientists understand how species have evolved over millions of years.