Theories of evolution represent systematic attempts to explain the origin, diversification, and development of life on Earth. The understanding of evolution has progressed from speculative philosophical ideas to scientifically verified explanations based on evidence from genetics, paleontology, comparative anatomy, embryology, and molecular biology. Evolutionary theories have also influenced the study of ancient societies by explaining the biological and cultural development of humans, making them significant in understanding social formations and cultural patterns of the ancient world. One of the earliest theories of evolution was proposed by Jean-Baptiste Lamarck in the early nineteenth century. Lamarck rejected the idea that species were fixed and argued that living organisms change over time in response to environmental conditions. His theory, known as Lamarckism or the Theory of Inheritance of Acquired Characteristics, rested on two major principles. First, the use and disuse of organs determined their development or degeneration. Organs that were frequently used became stronger and more developed, while those that were not used gradually disappeared. Second, the characteristics acquired during an organism's lifetime were transmitted to its offspring. Lamarck illustrated his theory with the example of giraffes, suggesting that their ancestors developed long necks by repeatedly stretching to reach leaves on tall trees, and this acquired characteristic was inherited by successive generations. Although Lamarck's theory was revolutionary in proposing that species evolve, modern genetics has disproved the inheritance of acquired characteristics. Nevertheless, Lamarck's emphasis on environmental influence and adaptation contributed significantly to evolutionary thought and prepared the way for later scientific developments. The most influential explanation of evolution was developed by Charles Darwin and Alfred Russel Wallace. Darwin presented his theory in *On the Origin of Species* (1859), introducing the concept of Natural Selection. Darwin observed that organisms produce more offspring than can survive, leading to a struggle for existence because of limited resources. Within every population, individuals exhibit variations, some of which are heritable. Those possessing advantageous variations are more likely to survive and reproduce, passing these favorable traits to future generations. Over many generations, this process results in adaptation and eventually the formation of new species. Darwin's theory rests on several principles. Variation exists naturally within populations. Overproduction creates competition for food, shelter, and mates. Natural selection favors individuals with beneficial traits. The accumulation of advantageous